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8049421: G1 Class Unloading after completing a concurrent mark cycle

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Co-authored-by: Mikael Gerdin <mikael.gerdin@oracle.com>
Reviewed-by: tschatzl, ehelin, brutisso, coleenp, roland, iveresov
This commit is contained in:
Stefan Karlsson 2014-07-07 10:12:40 +02:00
parent ef1e9b3c80
commit 1b001a2afd
75 changed files with 2169 additions and 874 deletions
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1
hotspot/src/share/vm/c1/c1_Runtime1.cpp
View File

@ -1050,6 +1050,7 @@ JRT_ENTRY(void, Runtime1::patch_code(JavaThread* thread, Runtime1::StubID stub_i
n_copy->set_data((intx) (load_klass()));
} else {
assert(mirror() != NULL, "klass not set");
// Don't need a G1 pre-barrier here since we assert above that data isn't an oop.
n_copy->set_data(cast_from_oop<intx>(mirror()));
}

4
hotspot/src/share/vm/ci/ciEnv.hpp
View File

@ -185,6 +185,10 @@ private:
}
}
void ensure_metadata_alive(ciMetadata* m) {
_factory->ensure_metadata_alive(m);
}
ciInstance* get_instance(oop o) {
if (o == NULL) return NULL;
return get_object(o)->as_instance();

1
hotspot/src/share/vm/ci/ciKlass.hpp
View File

@ -43,6 +43,7 @@ class ciKlass : public ciType {
friend class ciMethod;
friend class ciMethodData;
friend class ciObjArrayKlass;
friend class ciReceiverTypeData;
private:
ciSymbol* _name;

2
hotspot/src/share/vm/ci/ciMethodData.cpp
View File

@ -170,6 +170,7 @@ void ciReceiverTypeData::translate_receiver_data_from(const ProfileData* data) {
Klass* k = data->as_ReceiverTypeData()->receiver(row);
if (k != NULL) {
ciKlass* klass = CURRENT_ENV->get_klass(k);
CURRENT_ENV->ensure_metadata_alive(klass);
set_receiver(row, klass);
}
}
@ -191,6 +192,7 @@ void ciReturnTypeEntry::translate_type_data_from(const ReturnTypeEntry* ret) {
void ciSpeculativeTrapData::translate_from(const ProfileData* data) {
Method* m = data->as_SpeculativeTrapData()->method();
ciMethod* ci_m = CURRENT_ENV->get_method(m);
CURRENT_ENV->ensure_metadata_alive(ci_m);
set_method(ci_m);
}

1
hotspot/src/share/vm/ci/ciMethodData.hpp
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@ -70,6 +70,7 @@ protected:
Klass* v = TypeEntries::valid_klass(k);
if (v != NULL) {
ciKlass* klass = CURRENT_ENV->get_klass(v);
CURRENT_ENV->ensure_metadata_alive(klass);
return with_status(klass, k);
}
return with_status(NULL, k);

34
hotspot/src/share/vm/ci/ciObjectFactory.cpp
View File

@ -46,6 +46,9 @@
#include "oops/oop.inline.hpp"
#include "oops/oop.inline2.hpp"
#include "runtime/fieldType.hpp"
#if INCLUDE_ALL_GCS
# include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
#endif
// ciObjectFactory
//
@ -374,6 +377,37 @@ ciMetadata* ciObjectFactory::create_new_object(Metadata* o) {
return NULL;
}
// ------------------------------------------------------------------
// ciObjectFactory::ensure_metadata_alive
//
// Ensure that the metadata wrapped by the ciMetadata is kept alive by GC.
// This is primarily useful for metadata which is considered as weak roots
// by the GC but need to be strong roots if reachable from a current compilation.
//
void ciObjectFactory::ensure_metadata_alive(ciMetadata* m) {
ASSERT_IN_VM; // We're handling raw oops here.
#if INCLUDE_ALL_GCS
if (!UseG1GC) {
return;
}
Klass* metadata_owner_klass;
if (m->is_klass()) {
metadata_owner_klass = m->as_klass()->get_Klass();
} else if (m->is_method()) {
metadata_owner_klass = m->as_method()->get_Method()->constants()->pool_holder();
} else {
fatal("Not implemented for other types of metadata");
}
oop metadata_holder = metadata_owner_klass->klass_holder();
if (metadata_holder != NULL) {
G1SATBCardTableModRefBS::enqueue(metadata_holder);
}
#endif
}
//------------------------------------------------------------------
// ciObjectFactory::get_unloaded_method
//

2
hotspot/src/share/vm/ci/ciObjectFactory.hpp
View File

@ -75,6 +75,8 @@ private:
ciObject* create_new_object(oop o);
ciMetadata* create_new_object(Metadata* o);
void ensure_metadata_alive(ciMetadata* m);
static bool is_equal(NonPermObject* p, oop key) {
return p->object()->get_oop() == key;
}

120
hotspot/src/share/vm/classfile/classLoaderData.cpp
View File

@ -332,6 +332,27 @@ void ClassLoaderData::unload() {
}
}
#ifdef ASSERT
class AllAliveClosure : public OopClosure {
BoolObjectClosure* _is_alive_closure;
bool _found_dead;
public:
AllAliveClosure(BoolObjectClosure* is_alive_closure) : _is_alive_closure(is_alive_closure), _found_dead(false) {}
template <typename T> void do_oop_work(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
if (!_is_alive_closure->do_object_b(obj)) {
_found_dead = true;
}
}
}
void do_oop(oop* p) { do_oop_work<oop>(p); }
void do_oop(narrowOop* p) { do_oop_work<narrowOop>(p); }
bool found_dead() { return _found_dead; }
};
#endif
oop ClassLoaderData::keep_alive_object() const {
assert(!keep_alive(), "Don't use with CLDs that are artificially kept alive");
return is_anonymous() ? _klasses->java_mirror() : class_loader();
@ -341,7 +362,15 @@ bool ClassLoaderData::is_alive(BoolObjectClosure* is_alive_closure) const {
bool alive = keep_alive() // null class loader and incomplete anonymous klasses.
|| is_alive_closure->do_object_b(keep_alive_object());
assert(!alive || claimed(), "must be claimed");
#ifdef ASSERT
if (alive) {
AllAliveClosure all_alive_closure(is_alive_closure);
KlassToOopClosure klass_closure(&all_alive_closure);
const_cast<ClassLoaderData*>(this)->oops_do(&all_alive_closure, &klass_closure, false);
assert(!all_alive_closure.found_dead(), err_msg("Found dead oop in alive cld: " PTR_FORMAT, p2i(this)));
}
#endif
return alive;
}
@ -619,9 +648,9 @@ void ClassLoaderDataGraph::keep_alive_oops_do(OopClosure* f, KlassClosure* klass
void ClassLoaderDataGraph::always_strong_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
if (ClassUnloading) {
ClassLoaderDataGraph::keep_alive_oops_do(f, klass_closure, must_claim);
keep_alive_oops_do(f, klass_closure, must_claim);
} else {
ClassLoaderDataGraph::oops_do(f, klass_closure, must_claim);
oops_do(f, klass_closure, must_claim);
}
}
@ -631,6 +660,27 @@ void ClassLoaderDataGraph::cld_do(CLDClosure* cl) {
}
}
void ClassLoaderDataGraph::roots_cld_do(CLDClosure* strong, CLDClosure* weak) {
for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->_next) {
CLDClosure* closure = cld->keep_alive() ? strong : weak;
if (closure != NULL) {
closure->do_cld(cld);
}
}
}
void ClassLoaderDataGraph::keep_alive_cld_do(CLDClosure* cl) {
roots_cld_do(cl, NULL);
}
void ClassLoaderDataGraph::always_strong_cld_do(CLDClosure* cl) {
if (ClassUnloading) {
keep_alive_cld_do(cl);
} else {
cld_do(cl);
}
}
void ClassLoaderDataGraph::classes_do(KlassClosure* klass_closure) {
for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
cld->classes_do(klass_closure);
@ -686,6 +736,16 @@ GrowableArray<ClassLoaderData*>* ClassLoaderDataGraph::new_clds() {
return array;
}
bool ClassLoaderDataGraph::unload_list_contains(const void* x) {
assert(SafepointSynchronize::is_at_safepoint(), "only safe to call at safepoint");
for (ClassLoaderData* cld = _unloading; cld != NULL; cld = cld->next()) {
if (cld->metaspace_or_null() != NULL && cld->metaspace_or_null()->contains(x)) {
return true;
}
}
return false;
}
#ifndef PRODUCT
bool ClassLoaderDataGraph::contains_loader_data(ClassLoaderData* loader_data) {
for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
@ -801,6 +861,60 @@ Metaspace* ClassLoaderData::rw_metaspace() {
return _rw_metaspace;
}
ClassLoaderDataGraphKlassIteratorAtomic::ClassLoaderDataGraphKlassIteratorAtomic()
: _next_klass(NULL) {
ClassLoaderData* cld = ClassLoaderDataGraph::_head;
Klass* klass = NULL;
// Find the first klass in the CLDG.
while (cld != NULL) {
klass = cld->_klasses;
if (klass != NULL) {
_next_klass = klass;
return;
}
cld = cld->next();
}
}
Klass* ClassLoaderDataGraphKlassIteratorAtomic::next_klass_in_cldg(Klass* klass) {
Klass* next = klass->next_link();
if (next != NULL) {
return next;
}
// No more klasses in the current CLD. Time to find a new CLD.
ClassLoaderData* cld = klass->class_loader_data();
while (next == NULL) {
cld = cld->next();
if (cld == NULL) {
break;
}
next = cld->_klasses;
}
return next;
}
Klass* ClassLoaderDataGraphKlassIteratorAtomic::next_klass() {
Klass* head = (Klass*)_next_klass;
while (head != NULL) {
Klass* next = next_klass_in_cldg(head);
Klass* old_head = (Klass*)Atomic::cmpxchg_ptr(next, &_next_klass, head);
if (old_head == head) {
return head; // Won the CAS.
}
head = old_head;
}
// Nothing more for the iterator to hand out.
assert(head == NULL, err_msg("head is " PTR_FORMAT ", expected not null:", p2i(head)));
return NULL;
}
ClassLoaderDataGraphMetaspaceIterator::ClassLoaderDataGraphMetaspaceIterator() {
_data = ClassLoaderDataGraph::_head;

26
hotspot/src/share/vm/classfile/classLoaderData.hpp
View File

@ -31,7 +31,6 @@
#include "memory/metaspaceCounters.hpp"
#include "runtime/mutex.hpp"
#include "utilities/growableArray.hpp"
#if INCLUDE_TRACE
# include "utilities/ticks.hpp"
#endif
@ -59,6 +58,7 @@ class Metadebug;
class ClassLoaderDataGraph : public AllStatic {
friend class ClassLoaderData;
friend class ClassLoaderDataGraphMetaspaceIterator;
friend class ClassLoaderDataGraphKlassIteratorAtomic;
friend class VMStructs;
private:
// All CLDs (except the null CLD) can be reached by walking _head->_next->...
@ -74,10 +74,16 @@ class ClassLoaderDataGraph : public AllStatic {
static ClassLoaderData* find_or_create(Handle class_loader, TRAPS);
static void purge();
static void clear_claimed_marks();
// oops do
static void oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim);
static void always_strong_oops_do(OopClosure* blk, KlassClosure* klass_closure, bool must_claim);
static void keep_alive_oops_do(OopClosure* blk, KlassClosure* klass_closure, bool must_claim);
static void always_strong_oops_do(OopClosure* blk, KlassClosure* klass_closure, bool must_claim);
// cld do
static void cld_do(CLDClosure* cl);
static void roots_cld_do(CLDClosure* strong, CLDClosure* weak);
static void keep_alive_cld_do(CLDClosure* cl);
static void always_strong_cld_do(CLDClosure* cl);
// klass do
static void classes_do(KlassClosure* klass_closure);
static void classes_do(void f(Klass* const));
static void methods_do(void f(Method*));
@ -103,6 +109,7 @@ class ClassLoaderDataGraph : public AllStatic {
static void dump() { dump_on(tty); }
static void verify();
static bool unload_list_contains(const void* x);
#ifndef PRODUCT
static bool contains_loader_data(ClassLoaderData* loader_data);
#endif
@ -135,6 +142,7 @@ class ClassLoaderData : public CHeapObj<mtClass> {
};
friend class ClassLoaderDataGraph;
friend class ClassLoaderDataGraphKlassIteratorAtomic;
friend class ClassLoaderDataGraphMetaspaceIterator;
friend class MetaDataFactory;
friend class Method;
@ -194,7 +202,6 @@ class ClassLoaderData : public CHeapObj<mtClass> {
void unload();
bool keep_alive() const { return _keep_alive; }
bool is_alive(BoolObjectClosure* is_alive_closure) const;
void classes_do(void f(Klass*));
void loaded_classes_do(KlassClosure* klass_closure);
void classes_do(void f(InstanceKlass*));
@ -207,6 +214,9 @@ class ClassLoaderData : public CHeapObj<mtClass> {
MetaWord* allocate(size_t size);
public:
bool is_alive(BoolObjectClosure* is_alive_closure) const;
// Accessors
Metaspace* metaspace_or_null() const { return _metaspace; }
@ -292,6 +302,16 @@ class ClassLoaderData : public CHeapObj<mtClass> {
void initialize_shared_metaspaces();
};
// An iterator that distributes Klasses to parallel worker threads.
class ClassLoaderDataGraphKlassIteratorAtomic : public StackObj {
volatile Klass* _next_klass;
public:
ClassLoaderDataGraphKlassIteratorAtomic();
Klass* next_klass();
private:
static Klass* next_klass_in_cldg(Klass* klass);
};
class ClassLoaderDataGraphMetaspaceIterator : public StackObj {
ClassLoaderData* _data;
public:

37
hotspot/src/share/vm/classfile/dictionary.cpp
View File

@ -199,6 +199,26 @@ bool Dictionary::do_unloading() {
return class_was_unloaded;
}
void Dictionary::roots_oops_do(OopClosure* strong, OopClosure* weak) {
// Skip the strong roots probe marking if the closures are the same.
if (strong == weak) {
oops_do(strong);
return;
}
for (int index = 0; index < table_size(); index++) {
for (DictionaryEntry *probe = bucket(index);
probe != NULL;
probe = probe->next()) {
Klass* e = probe->klass();
ClassLoaderData* loader_data = probe->loader_data();
if (is_strongly_reachable(loader_data, e)) {
probe->set_strongly_reachable();
}
}
}
_pd_cache_table->roots_oops_do(strong, weak);
}
void Dictionary::always_strong_oops_do(OopClosure* blk) {
// Follow all system classes and temporary placeholders in dictionary; only
@ -490,6 +510,23 @@ void ProtectionDomainCacheTable::oops_do(OopClosure* f) {
}
}
void ProtectionDomainCacheTable::roots_oops_do(OopClosure* strong, OopClosure* weak) {
for (int index = 0; index < table_size(); index++) {
for (ProtectionDomainCacheEntry* probe = bucket(index);
probe != NULL;
probe = probe->next()) {
if (probe->is_strongly_reachable()) {
probe->reset_strongly_reachable();
probe->oops_do(strong);
} else {
if (weak != NULL) {
probe->oops_do(weak);
}
}
}
}
}
uint ProtectionDomainCacheTable::bucket_size() {
return sizeof(ProtectionDomainCacheEntry);
}

2
hotspot/src/share/vm/classfile/dictionary.hpp
View File

@ -89,6 +89,7 @@ public:
// GC support
void oops_do(OopClosure* f);
void always_strong_oops_do(OopClosure* blk);
void roots_oops_do(OopClosure* strong, OopClosure* weak);
void always_strong_classes_do(KlassClosure* closure);
@ -218,6 +219,7 @@ public:
// GC support
void oops_do(OopClosure* f);
void always_strong_oops_do(OopClosure* f);
void roots_oops_do(OopClosure* strong, OopClosure* weak);
static uint bucket_size();

5
hotspot/src/share/vm/classfile/metadataOnStackMark.cpp
View File

@ -47,8 +47,11 @@ MetadataOnStackMark::MetadataOnStackMark() {
if (_marked_objects == NULL) {
_marked_objects = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(1000, true);
}
Threads::metadata_do(Metadata::mark_on_stack);
CodeCache::alive_nmethods_do(nmethod::mark_on_stack);
if (JvmtiExport::has_redefined_a_class()) {
CodeCache::alive_nmethods_do(nmethod::mark_on_stack);
}
CompileBroker::mark_on_stack();
JvmtiCurrentBreakpoints::metadata_do(Metadata::mark_on_stack);
ThreadService::metadata_do(Metadata::mark_on_stack);

37
hotspot/src/share/vm/classfile/stringTable.cpp
View File

@ -37,6 +37,7 @@
#include "runtime/mutexLocker.hpp"
#include "utilities/hashtable.inline.hpp"
#if INCLUDE_ALL_GCS
#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
#include "gc_implementation/g1/g1StringDedup.hpp"
#endif
@ -157,11 +158,26 @@ oop StringTable::lookup(Symbol* symbol) {
return lookup(chars, length);
}
// Tell the GC that this string was looked up in the StringTable.
static void ensure_string_alive(oop string) {
// A lookup in the StringTable could return an object that was previously
// considered dead. The SATB part of G1 needs to get notified about this
// potential resurrection, otherwise the marking might not find the object.
#if INCLUDE_ALL_GCS
if (UseG1GC && string != NULL) {
G1SATBCardTableModRefBS::enqueue(string);
}
#endif
}
oop StringTable::lookup(jchar* name, int len) {
unsigned int hash = hash_string(name, len);
int index = the_table()->hash_to_index(hash);
return the_table()->lookup(index, name, len, hash);
oop string = the_table()->lookup(index, name, len, hash);
ensure_string_alive(string);
return string;
}
@ -172,7 +188,10 @@ oop StringTable::intern(Handle string_or_null, jchar* name,
oop found_string = the_table()->lookup(index, name, len, hashValue);
// Found
if (found_string != NULL) return found_string;
if (found_string != NULL) {
ensure_string_alive(found_string);
return found_string;
}
debug_only(StableMemoryChecker smc(name, len * sizeof(name[0])));
assert(!Universe::heap()->is_in_reserved(name),
@ -197,11 +216,17 @@ oop StringTable::intern(Handle string_or_null, jchar* name,
// Grab the StringTable_lock before getting the_table() because it could
// change at safepoint.
MutexLocker ml(StringTable_lock, THREAD);
oop added_or_found;
{
MutexLocker ml(StringTable_lock, THREAD);
// Otherwise, add to symbol to table
added_or_found = the_table()->basic_add(index, string, name, len,
hashValue, CHECK_NULL);
}
// Otherwise, add to symbol to table
return the_table()->basic_add(index, string, name, len,
hashValue, CHECK_NULL);
ensure_string_alive(added_or_found);
return added_or_found;
}
oop StringTable::intern(Symbol* symbol, TRAPS) {

19
hotspot/src/share/vm/classfile/systemDictionary.cpp
View File

@ -1612,13 +1612,7 @@ void SystemDictionary::add_to_hierarchy(instanceKlassHandle k, TRAPS) {
// system dictionary and follows the remaining classes' contents.
void SystemDictionary::always_strong_oops_do(OopClosure* blk) {
blk->do_oop(&_java_system_loader);
blk->do_oop(&_system_loader_lock_obj);
dictionary()->always_strong_oops_do(blk);
// Visit extra methods
invoke_method_table()->oops_do(blk);
roots_oops_do(blk, NULL);
}
void SystemDictionary::always_strong_classes_do(KlassClosure* closure) {
@ -1685,6 +1679,17 @@ bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive) {
return unloading_occurred;
}
void SystemDictionary::roots_oops_do(OopClosure* strong, OopClosure* weak) {
strong->do_oop(&_java_system_loader);
strong->do_oop(&_system_loader_lock_obj);
// Adjust dictionary
dictionary()->roots_oops_do(strong, weak);
// Visit extra methods
invoke_method_table()->oops_do(strong);
}
void SystemDictionary::oops_do(OopClosure* f) {
f->do_oop(&_java_system_loader);
f->do_oop(&_system_loader_lock_obj);

1
hotspot/src/share/vm/classfile/systemDictionary.hpp
View File

@ -330,6 +330,7 @@ public:
// Applies "f->do_oop" to all root oops in the system dictionary.
static void oops_do(OopClosure* f);
static void roots_oops_do(OopClosure* strong, OopClosure* weak);
// System loader lock
static oop system_loader_lock() { return _system_loader_lock_obj; }

83
hotspot/src/share/vm/code/codeCache.cpp
View File

@ -331,6 +331,11 @@ void CodeCache::blobs_do(CodeBlobClosure* f) {
// Walk the list of methods which might contain non-perm oops.
void CodeCache::scavenge_root_nmethods_do(CodeBlobClosure* f) {
assert_locked_or_safepoint(CodeCache_lock);
if (UseG1GC) {
return;
}
debug_only(mark_scavenge_root_nmethods());
for (nmethod* cur = scavenge_root_nmethods(); cur != NULL; cur = cur->scavenge_root_link()) {
@ -356,6 +361,11 @@ void CodeCache::scavenge_root_nmethods_do(CodeBlobClosure* f) {
void CodeCache::add_scavenge_root_nmethod(nmethod* nm) {
assert_locked_or_safepoint(CodeCache_lock);
if (UseG1GC) {
return;
}
nm->set_on_scavenge_root_list();
nm->set_scavenge_root_link(_scavenge_root_nmethods);
set_scavenge_root_nmethods(nm);
@ -364,6 +374,11 @@ void CodeCache::add_scavenge_root_nmethod(nmethod* nm) {
void CodeCache::drop_scavenge_root_nmethod(nmethod* nm) {
assert_locked_or_safepoint(CodeCache_lock);
if (UseG1GC) {
return;
}
print_trace("drop_scavenge_root", nm);
nmethod* last = NULL;
nmethod* cur = scavenge_root_nmethods();
@ -385,6 +400,11 @@ void CodeCache::drop_scavenge_root_nmethod(nmethod* nm) {
void CodeCache::prune_scavenge_root_nmethods() {
assert_locked_or_safepoint(CodeCache_lock);
if (UseG1GC) {
return;
}
debug_only(mark_scavenge_root_nmethods());
nmethod* last = NULL;
@ -417,6 +437,10 @@ void CodeCache::prune_scavenge_root_nmethods() {
#ifndef PRODUCT
void CodeCache::asserted_non_scavengable_nmethods_do(CodeBlobClosure* f) {
if (UseG1GC) {
return;
}
// While we are here, verify the integrity of the list.
mark_scavenge_root_nmethods();
for (nmethod* cur = scavenge_root_nmethods(); cur != NULL; cur = cur->scavenge_root_link()) {
@ -457,9 +481,36 @@ void CodeCache::verify_perm_nmethods(CodeBlobClosure* f_or_null) {
}
#endif //PRODUCT
void CodeCache::verify_clean_inline_caches() {
#ifdef ASSERT
FOR_ALL_ALIVE_BLOBS(cb) {
if (cb->is_nmethod()) {
nmethod* nm = (nmethod*)cb;
assert(!nm->is_unloaded(), "Tautology");
nm->verify_clean_inline_caches();
nm->verify();
}
}
#endif
}
void CodeCache::verify_icholder_relocations() {
#ifdef ASSERT
// make sure that we aren't leaking icholders
int count = 0;
FOR_ALL_BLOBS(cb) {
if (cb->is_nmethod()) {
nmethod* nm = (nmethod*)cb;
count += nm->verify_icholder_relocations();
}
}
assert(count + InlineCacheBuffer::pending_icholder_count() + CompiledICHolder::live_not_claimed_count() ==
CompiledICHolder::live_count(), "must agree");
#endif
}
void CodeCache::gc_prologue() {
assert(!nmethod::oops_do_marking_is_active(), "oops_do_marking_epilogue must be called");
}
void CodeCache::gc_epilogue() {
@ -472,41 +523,15 @@ void CodeCache::gc_epilogue() {
nm->cleanup_inline_caches();
}
DEBUG_ONLY(nm->verify());
nm->fix_oop_relocations();
DEBUG_ONLY(nm->verify_oop_relocations());
}
}
set_needs_cache_clean(false);
prune_scavenge_root_nmethods();
assert(!nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
#ifdef ASSERT
// make sure that we aren't leaking icholders
int count = 0;
FOR_ALL_BLOBS(cb) {
if (cb->is_nmethod()) {
RelocIterator iter((nmethod*)cb);
while(iter.next()) {
if (iter.type() == relocInfo::virtual_call_type) {
if (CompiledIC::is_icholder_call_site(iter.virtual_call_reloc())) {
CompiledIC *ic = CompiledIC_at(&iter);
if (TraceCompiledIC) {
tty->print("noticed icholder " INTPTR_FORMAT " ", p2i(ic->cached_icholder()));
ic->print();
}
assert(ic->cached_icholder() != NULL, "must be non-NULL");
count++;
}
}
}
}
}
assert(count + InlineCacheBuffer::pending_icholder_count() + CompiledICHolder::live_not_claimed_count() ==
CompiledICHolder::live_count(), "must agree");
#endif
verify_icholder_relocations();
}
void CodeCache::verify_oops() {
MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
VerifyOopClosure voc;

7
hotspot/src/share/vm/code/codeCache.hpp
View File

@ -134,10 +134,6 @@ class CodeCache : AllStatic {
// to) any unmarked codeBlobs in the cache. Sets "marked_for_unloading"
// to "true" iff some code got unloaded.
static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
static void oops_do(OopClosure* f) {
CodeBlobToOopClosure oopc(f, /*do_marking=*/ false);
blobs_do(&oopc);
}
static void asserted_non_scavengable_nmethods_do(CodeBlobClosure* f = NULL) PRODUCT_RETURN;
static void scavenge_root_nmethods_do(CodeBlobClosure* f);
@ -173,6 +169,9 @@ class CodeCache : AllStatic {
static void set_needs_cache_clean(bool v) { _needs_cache_clean = v; }
static void clear_inline_caches(); // clear all inline caches
static void verify_clean_inline_caches();
static void verify_icholder_relocations();
// Deoptimization
static int mark_for_deoptimization(DepChange& changes);
#ifdef HOTSWAP

12
hotspot/src/share/vm/code/compiledIC.cpp
View File

@ -99,13 +99,13 @@ void CompiledIC::internal_set_ic_destination(address entry_point, bool is_icstub
}
{
MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
MutexLockerEx pl(SafepointSynchronize::is_at_safepoint() ? NULL : Patching_lock, Mutex::_no_safepoint_check_flag);
#ifdef ASSERT
CodeBlob* cb = CodeCache::find_blob_unsafe(_ic_call);
assert(cb != NULL && cb->is_nmethod(), "must be nmethod");
CodeBlob* cb = CodeCache::find_blob_unsafe(_ic_call);
assert(cb != NULL && cb->is_nmethod(), "must be nmethod");
#endif
_ic_call->set_destination_mt_safe(entry_point);
}
_ic_call->set_destination_mt_safe(entry_point);
}
if (is_optimized() || is_icstub) {
// Optimized call sites don't have a cache value and ICStub call
@ -529,7 +529,7 @@ bool CompiledIC::is_icholder_entry(address entry) {
void CompiledStaticCall::set_to_clean() {
assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
// Reset call site
MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
MutexLockerEx pl(SafepointSynchronize::is_at_safepoint() ? NULL : Patching_lock, Mutex::_no_safepoint_check_flag);
#ifdef ASSERT
CodeBlob* cb = CodeCache::find_blob_unsafe(this);
assert(cb != NULL && cb->is_nmethod(), "must be nmethod");

331
hotspot/src/share/vm/code/nmethod.cpp
View File

@ -51,6 +51,8 @@
PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
unsigned char nmethod::_global_unloading_clock = 0;
#ifdef DTRACE_ENABLED
// Only bother with this argument setup if dtrace is available
@ -446,6 +448,7 @@ const char* nmethod::compile_kind() const {
// Fill in default values for various flag fields
void nmethod::init_defaults() {
_state = in_use;
_unloading_clock = 0;
_marked_for_reclamation = 0;
_has_flushed_dependencies = 0;
_has_unsafe_access = 0;
@ -464,7 +467,11 @@ void nmethod::init_defaults() {
_oops_do_mark_link = NULL;
_jmethod_id = NULL;
_osr_link = NULL;
_scavenge_root_link = NULL;
if (UseG1GC) {
_unloading_next = NULL;
} else {
_scavenge_root_link = NULL;
}
_scavenge_root_state = 0;
_compiler = NULL;
#if INCLUDE_RTM_OPT
@ -1170,6 +1177,77 @@ void nmethod::cleanup_inline_caches() {
}
}
void nmethod::verify_clean_inline_caches() {
assert_locked_or_safepoint(CompiledIC_lock);
// If the method is not entrant or zombie then a JMP is plastered over the
// first few bytes. If an oop in the old code was there, that oop
// should not get GC'd. Skip the first few bytes of oops on
// not-entrant methods.
address low_boundary = verified_entry_point();
if (!is_in_use()) {
low_boundary += NativeJump::instruction_size;
// %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
// This means that the low_boundary is going to be a little too high.
// This shouldn't matter, since oops of non-entrant methods are never used.
// In fact, why are we bothering to look at oops in a non-entrant method??
}
ResourceMark rm;
RelocIterator iter(this, low_boundary);
while(iter.next()) {
switch(iter.type()) {
case relocInfo::virtual_call_type:
case relocInfo::opt_virtual_call_type: {
CompiledIC *ic = CompiledIC_at(&iter);
// Ok, to lookup references to zombies here
CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
if( cb != NULL && cb->is_nmethod() ) {
nmethod* nm = (nmethod*)cb;
// Verify that inline caches pointing to both zombie and not_entrant methods are clean
if (!nm->is_in_use() || (nm->method()->code() != nm)) {
assert(ic->is_clean(), "IC should be clean");
}
}
break;
}
case relocInfo::static_call_type: {
CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
if( cb != NULL && cb->is_nmethod() ) {
nmethod* nm = (nmethod*)cb;
// Verify that inline caches pointing to both zombie and not_entrant methods are clean
if (!nm->is_in_use() || (nm->method()->code() != nm)) {
assert(csc->is_clean(), "IC should be clean");
}
}
break;
}
}
}
}
int nmethod::verify_icholder_relocations() {
int count = 0;
RelocIterator iter(this);
while(iter.next()) {
if (iter.type() == relocInfo::virtual_call_type) {
if (CompiledIC::is_icholder_call_site(iter.virtual_call_reloc())) {
CompiledIC *ic = CompiledIC_at(&iter);
if (TraceCompiledIC) {
tty->print("noticed icholder " INTPTR_FORMAT " ", p2i(ic->cached_icholder()));
ic->print();
}
assert(ic->cached_icholder() != NULL, "must be non-NULL");
count++;
}
}
}
return count;
}
// This is a private interface with the sweeper.
void nmethod::mark_as_seen_on_stack() {
assert(is_alive(), "Must be an alive method");
@ -1202,6 +1280,23 @@ void nmethod::inc_decompile_count() {
mdo->inc_decompile_count();
}
void nmethod::increase_unloading_clock() {
_global_unloading_clock++;
if (_global_unloading_clock == 0) {
// _nmethods are allocated with _unloading_clock == 0,
// so 0 is never used as a clock value.
_global_unloading_clock = 1;
}
}
void nmethod::set_unloading_clock(unsigned char unloading_clock) {
OrderAccess::release_store((volatile jubyte*)&_unloading_clock, unloading_clock);
}
unsigned char nmethod::unloading_clock() {
return (unsigned char)OrderAccess::load_acquire((volatile jubyte*)&_unloading_clock);
}
void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
post_compiled_method_unload();
@ -1247,6 +1342,10 @@ void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
// for later on.
CodeCache::set_needs_cache_clean(true);
}
// Unregister must be done before the state change
Universe::heap()->unregister_nmethod(this);
_state = unloaded;
// Log the unloading.
@ -1590,6 +1689,35 @@ void nmethod::post_compiled_method_unload() {
set_unload_reported();
}
void static clean_ic_if_metadata_is_dead(CompiledIC *ic, BoolObjectClosure *is_alive) {
if (ic->is_icholder_call()) {
// The only exception is compiledICHolder oops which may
// yet be marked below. (We check this further below).
CompiledICHolder* cichk_oop = ic->cached_icholder();
if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) &&
cichk_oop->holder_klass()->is_loader_alive(is_alive)) {
return;
}
} else {
Metadata* ic_oop = ic->cached_metadata();
if (ic_oop != NULL) {
if (ic_oop->is_klass()) {
if (((Klass*)ic_oop)->is_loader_alive(is_alive)) {
return;
}
} else if (ic_oop->is_method()) {
if (((Method*)ic_oop)->method_holder()->is_loader_alive(is_alive)) {
return;
}
} else {
ShouldNotReachHere();
}
}
}
ic->set_to_clean();
}
// This is called at the end of the strong tracing/marking phase of a
// GC to unload an nmethod if it contains otherwise unreachable
// oops.
@ -1633,31 +1761,7 @@ void nmethod::do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred)
while(iter.next()) {
if (iter.type() == relocInfo::virtual_call_type) {
CompiledIC *ic = CompiledIC_at(&iter);
if (ic->is_icholder_call()) {
// The only exception is compiledICHolder oops which may
// yet be marked below. (We check this further below).
CompiledICHolder* cichk_oop = ic->cached_icholder();
if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) &&
cichk_oop->holder_klass()->is_loader_alive(is_alive)) {
continue;
}
} else {
Metadata* ic_oop = ic->cached_metadata();
if (ic_oop != NULL) {
if (ic_oop->is_klass()) {
if (((Klass*)ic_oop)->is_loader_alive(is_alive)) {
continue;
}
} else if (ic_oop->is_method()) {
if (((Method*)ic_oop)->method_holder()->is_loader_alive(is_alive)) {
continue;
}
} else {
ShouldNotReachHere();
}
}
}
ic->set_to_clean();
clean_ic_if_metadata_is_dead(ic, is_alive);
}
}
}
@ -1695,6 +1799,175 @@ void nmethod::do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred)
verify_metadata_loaders(low_boundary, is_alive);
}
template <class CompiledICorStaticCall>
static bool clean_if_nmethod_is_unloaded(CompiledICorStaticCall *ic, address addr, BoolObjectClosure *is_alive, nmethod* from) {
// Ok, to lookup references to zombies here
CodeBlob *cb = CodeCache::find_blob_unsafe(addr);
if (cb != NULL && cb->is_nmethod()) {
nmethod* nm = (nmethod*)cb;
if (nm->unloading_clock() != nmethod::global_unloading_clock()) {
// The nmethod has not been processed yet.
return true;
}
// Clean inline caches pointing to both zombie and not_entrant methods
if (!nm->is_in_use() || (nm->method()->code() != nm)) {
ic->set_to_clean();
assert(ic->is_clean(), err_msg("nmethod " PTR_FORMAT "not clean %s", from, from->method()->name_and_sig_as_C_string()));
}
}
return false;
}
static bool clean_if_nmethod_is_unloaded(CompiledIC *ic, BoolObjectClosure *is_alive, nmethod* from) {
return clean_if_nmethod_is_unloaded(ic, ic->ic_destination(), is_alive, from);
}
static bool clean_if_nmethod_is_unloaded(CompiledStaticCall *csc, BoolObjectClosure *is_alive, nmethod* from) {
return clean_if_nmethod_is_unloaded(csc, csc->destination(), is_alive, from);
}
bool nmethod::do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred) {
ResourceMark rm;
// Make sure the oop's ready to receive visitors
assert(!is_zombie() && !is_unloaded(),
"should not call follow on zombie or unloaded nmethod");
// If the method is not entrant then a JMP is plastered over the
// first few bytes. If an oop in the old code was there, that oop
// should not get GC'd. Skip the first few bytes of oops on
// not-entrant methods.
address low_boundary = verified_entry_point();
if (is_not_entrant()) {
low_boundary += NativeJump::instruction_size;
// %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
// (See comment above.)
}
// The RedefineClasses() API can cause the class unloading invariant
// to no longer be true. See jvmtiExport.hpp for details.
// Also, leave a debugging breadcrumb in local flag.
bool a_class_was_redefined = JvmtiExport::has_redefined_a_class();
if (a_class_was_redefined) {
// This set of the unloading_occurred flag is done before the
// call to post_compiled_method_unload() so that the unloading
// of this nmethod is reported.
unloading_occurred = true;
}
// Exception cache
clean_exception_cache(is_alive);
bool is_unloaded = false;
bool postponed = false;
RelocIterator iter(this, low_boundary);
while(iter.next()) {
switch (iter.type()) {
case relocInfo::virtual_call_type:
if (unloading_occurred) {
// If class unloading occurred we first iterate over all inline caches and
// clear ICs where the cached oop is referring to an unloaded klass or method.
clean_ic_if_metadata_is_dead(CompiledIC_at(&iter), is_alive);
}
postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
break;
case relocInfo::opt_virtual_call_type:
postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
break;
case relocInfo::static_call_type:
postponed |= clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this);
break;
case relocInfo::oop_type:
if (!is_unloaded) {
// Unload check
oop_Relocation* r = iter.oop_reloc();
// Traverse those oops directly embedded in the code.
// Other oops (oop_index>0) are seen as part of scopes_oops.
assert(1 == (r->oop_is_immediate()) +
(r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
"oop must be found in exactly one place");
if (r->oop_is_immediate() && r->oop_value() != NULL) {
if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) {
is_unloaded = true;
}
}
}
break;
}
}
if (is_unloaded) {
return postponed;
}
// Scopes
for (oop* p = oops_begin(); p < oops_end(); p++) {
if (*p == Universe::non_oop_word()) continue; // skip non-oops
if (can_unload(is_alive, p, unloading_occurred)) {
is_unloaded = true;
break;
}
}
if (is_unloaded) {
return postponed;
}
// Ensure that all metadata is still alive
verify_metadata_loaders(low_boundary, is_alive);
return postponed;
}
void nmethod::do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred) {
ResourceMark rm;
// Make sure the oop's ready to receive visitors
assert(!is_zombie(),
"should not call follow on zombie nmethod");
// If the method is not entrant then a JMP is plastered over the
// first few bytes. If an oop in the old code was there, that oop
// should not get GC'd. Skip the first few bytes of oops on
// not-entrant methods.
address low_boundary = verified_entry_point();
if (is_not_entrant()) {
low_boundary += NativeJump::instruction_size;
// %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
// (See comment above.)
}
RelocIterator iter(this, low_boundary);
while(iter.next()) {
switch (iter.type()) {
case relocInfo::virtual_call_type:
clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
break;
case relocInfo::opt_virtual_call_type:
clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
break;
case relocInfo::static_call_type:
clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this);
break;
}
}
}
#ifdef ASSERT
class CheckClass : AllStatic {
@ -1911,7 +2184,7 @@ void nmethod::oops_do_marking_epilogue() {
assert(cur != NULL, "not NULL-terminated");
nmethod* next = cur->_oops_do_mark_link;
cur->_oops_do_mark_link = NULL;
cur->fix_oop_relocations();
cur->verify_oop_relocations();
NOT_PRODUCT(if (TraceScavenge) cur->print_on(tty, "oops_do, unmark"));
cur = next;
}
@ -2479,6 +2752,10 @@ public:
};
void nmethod::verify_scavenge_root_oops() {
if (UseG1GC) {
return;
}
if (!on_scavenge_root_list()) {
// Actually look inside, to verify the claim that it's clean.
DebugScavengeRoot debug_scavenge_root(this);

32
hotspot/src/share/vm/code/nmethod.hpp
View File

@ -111,6 +111,11 @@ class nmethod : public CodeBlob {
friend class NMethodSweeper;
friend class CodeCache; // scavengable oops
private:
// GC support to help figure out if an nmethod has been
// cleaned/unloaded by the current GC.
static unsigned char _global_unloading_clock;
// Shared fields for all nmethod's
Method* _method;
int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
@ -118,7 +123,13 @@ class nmethod : public CodeBlob {
// To support simple linked-list chaining of nmethods:
nmethod* _osr_link; // from InstanceKlass::osr_nmethods_head
nmethod* _scavenge_root_link; // from CodeCache::scavenge_root_nmethods
union {
// Used by G1 to chain nmethods.
nmethod* _unloading_next;
// Used by non-G1 GCs to chain nmethods.
nmethod* _scavenge_root_link; // from CodeCache::scavenge_root_nmethods
};
static nmethod* volatile _oops_do_mark_nmethods;
nmethod* volatile _oops_do_mark_link;
@ -180,6 +191,8 @@ class nmethod : public CodeBlob {
// Protected by Patching_lock
volatile unsigned char _state; // {alive, not_entrant, zombie, unloaded}
volatile unsigned char _unloading_clock; // Incremented after GC unloaded/cleaned the nmethod
#ifdef ASSERT
bool _oops_are_stale; // indicates that it's no longer safe to access oops section
#endif
@ -437,6 +450,15 @@ class nmethod : public CodeBlob {
bool unload_reported() { return _unload_reported; }
void set_unload_reported() { _unload_reported = true; }
void set_unloading_next(nmethod* next) { _unloading_next = next; }
nmethod* unloading_next() { return _unloading_next; }
static unsigned char global_unloading_clock() { return _global_unloading_clock; }
static void increase_unloading_clock();
void set_unloading_clock(unsigned char unloading_clock);
unsigned char unloading_clock();
bool is_marked_for_deoptimization() const { return _marked_for_deoptimization; }
void mark_for_deoptimization() { _marked_for_deoptimization = true; }
@ -552,6 +574,10 @@ public:
return (addr >= code_begin() && addr < verified_entry_point());
}
// Verify calls to dead methods have been cleaned.
void verify_clean_inline_caches();
// Verify and count cached icholder relocations.
int verify_icholder_relocations();
// Check that all metadata is still alive
void verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive);
@ -577,6 +603,10 @@ public:
// GC support
void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
// The parallel versions are used by G1.
bool do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred);
void do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred);
// Unload a nmethod if the *root object is dead.
bool can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred);
void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map,

138
hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp
View File

@ -1558,11 +1558,11 @@ bool CMSCollector::shouldConcurrentCollect() {
}
if (MetaspaceGC::should_concurrent_collect()) {
if (Verbose && PrintGCDetails) {
if (Verbose && PrintGCDetails) {
gclog_or_tty->print("CMSCollector: collect for metadata allocation ");
}
return true;
}
return true;
}
// CMSTriggerInterval starts a CMS cycle if enough time has passed.
if (CMSTriggerInterval >= 0) {
@ -2997,20 +2997,21 @@ void CMSCollector::verify_after_remark_work_1() {
HandleMark hm;
GenCollectedHeap* gch = GenCollectedHeap::heap();
// Get a clear set of claim bits for the strong roots processing to work with.
// Get a clear set of claim bits for the roots processing to work with.
ClassLoaderDataGraph::clear_claimed_marks();
// Mark from roots one level into CMS
MarkRefsIntoClosure notOlder(_span, verification_mark_bm());
gch->rem_set()->prepare_for_younger_refs_iterate(false); // Not parallel.
gch->gen_process_strong_roots(_cmsGen->level(),
true, // younger gens are roots
true, // activate StrongRootsScope
SharedHeap::ScanningOption(roots_scanning_options()),
&notOlder,
NULL,
NULL); // SSS: Provide correct closure
gch->gen_process_roots(_cmsGen->level(),
true, // younger gens are roots
true, // activate StrongRootsScope
SharedHeap::ScanningOption(roots_scanning_options()),
should_unload_classes(),
&notOlder,
NULL,
NULL); // SSS: Provide correct closure
// Now mark from the roots
MarkFromRootsClosure markFromRootsClosure(this, _span,
@ -3061,22 +3062,24 @@ void CMSCollector::verify_after_remark_work_2() {
HandleMark hm;
GenCollectedHeap* gch = GenCollectedHeap::heap();
// Get a clear set of claim bits for the strong roots processing to work with.
// Get a clear set of claim bits for the roots processing to work with.
ClassLoaderDataGraph::clear_claimed_marks();
// Mark from roots one level into CMS
MarkRefsIntoVerifyClosure notOlder(_span, verification_mark_bm(),
markBitMap());
KlassToOopClosure klass_closure(&notOlder);
CLDToOopClosure cld_closure(&notOlder, true);
gch->rem_set()->prepare_for_younger_refs_iterate(false); // Not parallel.
gch->gen_process_strong_roots(_cmsGen->level(),
true, // younger gens are roots
true, // activate StrongRootsScope
SharedHeap::ScanningOption(roots_scanning_options()),
&notOlder,
NULL,
&klass_closure);
gch->gen_process_roots(_cmsGen->level(),
true, // younger gens are roots
true, // activate StrongRootsScope
SharedHeap::ScanningOption(roots_scanning_options()),
should_unload_classes(),
&notOlder,
NULL,
&cld_closure);
// Now mark from the roots
MarkFromRootsVerifyClosure markFromRootsClosure(this, _span,
@ -3263,12 +3266,10 @@ bool ConcurrentMarkSweepGeneration::is_too_full() const {
void CMSCollector::setup_cms_unloading_and_verification_state() {
const bool should_verify = VerifyBeforeGC || VerifyAfterGC || VerifyDuringGC
|| VerifyBeforeExit;
const int rso = SharedHeap::SO_Strings | SharedHeap::SO_AllCodeCache;
const int rso = SharedHeap::SO_AllCodeCache;
// We set the proper root for this CMS cycle here.
if (should_unload_classes()) { // Should unload classes this cycle
remove_root_scanning_option(SharedHeap::SO_AllClasses);
add_root_scanning_option(SharedHeap::SO_SystemClasses);
remove_root_scanning_option(rso); // Shrink the root set appropriately
set_verifying(should_verify); // Set verification state for this cycle
return; // Nothing else needs to be done at this time
@ -3276,8 +3277,6 @@ void CMSCollector::setup_cms_unloading_and_verification_state() {
// Not unloading classes this cycle
assert(!should_unload_classes(), "Inconsistency!");
remove_root_scanning_option(SharedHeap::SO_SystemClasses);
add_root_scanning_option(SharedHeap::SO_AllClasses);
if ((!verifying() || unloaded_classes_last_cycle()) && should_verify) {
// Include symbols, strings and code cache elements to prevent their resurrection.
@ -3685,15 +3684,16 @@ void CMSCollector::checkpointRootsInitialWork(bool asynch) {
gch->set_par_threads(0);
} else {
// The serial version.
KlassToOopClosure klass_closure(&notOlder);
CLDToOopClosure cld_closure(&notOlder, true);
gch->rem_set()->prepare_for_younger_refs_iterate(false); // Not parallel.
gch->gen_process_strong_roots(_cmsGen->level(),
true, // younger gens are roots
true, // activate StrongRootsScope
SharedHeap::ScanningOption(roots_scanning_options()),
&notOlder,
NULL,
&klass_closure);
gch->gen_process_roots(_cmsGen->level(),
true, // younger gens are roots
true, // activate StrongRootsScope
SharedHeap::ScanningOption(roots_scanning_options()),
should_unload_classes(),
&notOlder,
NULL,
&cld_closure);
}
}
@ -5139,7 +5139,6 @@ void CMSParInitialMarkTask::work(uint worker_id) {
_timer.start();
GenCollectedHeap* gch = GenCollectedHeap::heap();
Par_MarkRefsIntoClosure par_mri_cl(_collector->_span, &(_collector->_markBitMap));
KlassToOopClosure klass_closure(&par_mri_cl);
// ---------- young gen roots --------------
{
@ -5155,13 +5154,17 @@ void CMSParInitialMarkTask::work(uint worker_id) {
// ---------- remaining roots --------------
_timer.reset();
_timer.start();
gch->gen_process_strong_roots(_collector->_cmsGen->level(),
false, // yg was scanned above
false, // this is parallel code
SharedHeap::ScanningOption(_collector->CMSCollector::roots_scanning_options()),
&par_mri_cl,
NULL,
&klass_closure);
CLDToOopClosure cld_closure(&par_mri_cl, true);
gch->gen_process_roots(_collector->_cmsGen->level(),
false, // yg was scanned above
false, // this is parallel code
SharedHeap::ScanningOption(_collector->CMSCollector::roots_scanning_options()),
_collector->should_unload_classes(),
&par_mri_cl,
NULL,
&cld_closure);
assert(_collector->should_unload_classes()
|| (_collector->CMSCollector::roots_scanning_options() & SharedHeap::SO_AllCodeCache),
"if we didn't scan the code cache, we have to be ready to drop nmethods with expired weak oops");
@ -5290,13 +5293,15 @@ void CMSParRemarkTask::work(uint worker_id) {
// ---------- remaining roots --------------
_timer.reset();
_timer.start();
gch->gen_process_strong_roots(_collector->_cmsGen->level(),
false, // yg was scanned above
false, // this is parallel code
SharedHeap::ScanningOption(_collector->CMSCollector::roots_scanning_options()),
&par_mrias_cl,
NULL,
NULL); // The dirty klasses will be handled below
gch->gen_process_roots(_collector->_cmsGen->level(),
false, // yg was scanned above
false, // this is parallel code
SharedHeap::ScanningOption(_collector->CMSCollector::roots_scanning_options()),
_collector->should_unload_classes(),
&par_mrias_cl,
NULL,
NULL); // The dirty klasses will be handled below
assert(_collector->should_unload_classes()
|| (_collector->CMSCollector::roots_scanning_options() & SharedHeap::SO_AllCodeCache),
"if we didn't scan the code cache, we have to be ready to drop nmethods with expired weak oops");
@ -5351,7 +5356,7 @@ void CMSParRemarkTask::work(uint worker_id) {
// We might have added oops to ClassLoaderData::_handles during the
// concurrent marking phase. These oops point to newly allocated objects
// that are guaranteed to be kept alive. Either by the direct allocation
// code, or when the young collector processes the strong roots. Hence,
// code, or when the young collector processes the roots. Hence,
// we don't have to revisit the _handles block during the remark phase.
// ---------- rescan dirty cards ------------
@ -5773,7 +5778,7 @@ void CMSCollector::do_remark_parallel() {
cms_space,
n_workers, workers, task_queues());
// Set up for parallel process_strong_roots work.
// Set up for parallel process_roots work.
gch->set_par_threads(n_workers);
// We won't be iterating over the cards in the card table updating
// the younger_gen cards, so we shouldn't call the following else
@ -5782,7 +5787,7 @@ void CMSCollector::do_remark_parallel() {
// gch->rem_set()->prepare_for_younger_refs_iterate(true); // parallel
// The young gen rescan work will not be done as part of
// process_strong_roots (which currently doesn't knw how to
// process_roots (which currently doesn't know how to
// parallelize such a scan), but rather will be broken up into
// a set of parallel tasks (via the sampling that the [abortable]
// preclean phase did of EdenSpace, plus the [two] tasks of
@ -5879,13 +5884,15 @@ void CMSCollector::do_remark_non_parallel() {
gch->rem_set()->prepare_for_younger_refs_iterate(false); // Not parallel.
GenCollectedHeap::StrongRootsScope srs(gch);
gch->gen_process_strong_roots(_cmsGen->level(),
true, // younger gens as roots
false, // use the local StrongRootsScope
SharedHeap::ScanningOption(roots_scanning_options()),
&mrias_cl,
NULL,
NULL); // The dirty klasses will be handled below
gch->gen_process_roots(_cmsGen->level(),
true, // younger gens as roots
false, // use the local StrongRootsScope
SharedHeap::ScanningOption(roots_scanning_options()),
should_unload_classes(),
&mrias_cl,
NULL,
NULL); // The dirty klasses will be handled below
assert(should_unload_classes()
|| (roots_scanning_options() & SharedHeap::SO_AllCodeCache),
@ -5925,7 +5932,7 @@ void CMSCollector::do_remark_non_parallel() {
// We might have added oops to ClassLoaderData::_handles during the
// concurrent marking phase. These oops point to newly allocated objects
// that are guaranteed to be kept alive. Either by the direct allocation
// code, or when the young collector processes the strong roots. Hence,
// code, or when the young collector processes the roots. Hence,
// we don't have to revisit the _handles block during the remark phase.
verify_work_stacks_empty();
@ -6175,15 +6182,14 @@ void CMSCollector::refProcessingWork(bool asynch, bool clear_all_soft_refs) {
// Clean up unreferenced symbols in symbol table.
SymbolTable::unlink();
}
{
GCTraceTime t("scrub string table", PrintGCDetails, false, _gc_timer_cm, _gc_tracer_cm->gc_id());
// Delete entries for dead interned strings.
StringTable::unlink(&_is_alive_closure);
}
}
// CMS doesn't use the StringTable as hard roots when class unloading is turned off.
// Need to check if we really scanned the StringTable.
if ((roots_scanning_options() & SharedHeap::SO_Strings) == 0) {
GCTraceTime t("scrub string table", PrintGCDetails, false, _gc_timer_cm, _gc_tracer_cm->gc_id());
// Delete entries for dead interned strings.
StringTable::unlink(&_is_alive_closure);
}
// Restore any preserved marks as a result of mark stack or
// work queue overflow

1
hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp
View File

@ -32,6 +32,7 @@
#include "gc_implementation/shared/generationCounters.hpp"
#include "memory/freeBlockDictionary.hpp"
#include "memory/generation.hpp"
#include "memory/iterator.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/virtualspace.hpp"
#include "services/memoryService.hpp"

166
hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp
View File

@ -24,6 +24,7 @@
#include "precompiled.hpp"
#include "classfile/symbolTable.hpp"
#include "code/codeCache.hpp"
#include "gc_implementation/g1/concurrentMark.inline.hpp"
#include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
@ -39,6 +40,7 @@
#include "gc_implementation/shared/gcTimer.hpp"
#include "gc_implementation/shared/gcTrace.hpp"
#include "gc_implementation/shared/gcTraceTime.hpp"
#include "memory/allocation.hpp"
#include "memory/genOopClosures.inline.hpp"
#include "memory/referencePolicy.hpp"
#include "memory/resourceArea.hpp"
@ -58,8 +60,8 @@ CMBitMapRO::CMBitMapRO(int shifter) :
_bmWordSize = 0;
}
HeapWord* CMBitMapRO::getNextMarkedWordAddress(HeapWord* addr,
HeapWord* limit) const {
HeapWord* CMBitMapRO::getNextMarkedWordAddress(const HeapWord* addr,
const HeapWord* limit) const {
// First we must round addr *up* to a possible object boundary.
addr = (HeapWord*)align_size_up((intptr_t)addr,
HeapWordSize << _shifter);
@ -76,8 +78,8 @@ HeapWord* CMBitMapRO::getNextMarkedWordAddress(HeapWord* addr,
return nextAddr;
}
HeapWord* CMBitMapRO::getNextUnmarkedWordAddress(HeapWord* addr,
HeapWord* limit) const {
HeapWord* CMBitMapRO::getNextUnmarkedWordAddress(const HeapWord* addr,
const HeapWord* limit) const {
size_t addrOffset = heapWordToOffset(addr);
if (limit == NULL) {
limit = _bmStartWord + _bmWordSize;
@ -1223,6 +1225,9 @@ public:
};
void ConcurrentMark::scanRootRegions() {
// Start of concurrent marking.
ClassLoaderDataGraph::clear_claimed_marks();
// scan_in_progress() will have been set to true only if there was
// at least one root region to scan. So, if it's false, we
// should not attempt to do any further work.
@ -1271,7 +1276,7 @@ void ConcurrentMark::markFromRoots() {
CMConcurrentMarkingTask markingTask(this, cmThread());
if (use_parallel_marking_threads()) {
_parallel_workers->set_active_workers((int)active_workers);
// Don't set _n_par_threads because it affects MT in process_strong_roots()
// Don't set _n_par_threads because it affects MT in process_roots()
// and the decisions on that MT processing is made elsewhere.
assert(_parallel_workers->active_workers() > 0, "Should have been set");
_parallel_workers->run_task(&markingTask);
@ -2142,23 +2147,29 @@ void ConcurrentMark::cleanup() {
// Update the soft reference policy with the new heap occupancy.
Universe::update_heap_info_at_gc();
// We need to make this be a "collection" so any collection pause that
// races with it goes around and waits for completeCleanup to finish.
g1h->increment_total_collections();
// We reclaimed old regions so we should calculate the sizes to make
// sure we update the old gen/space data.
g1h->g1mm()->update_sizes();
if (VerifyDuringGC) {
HandleMark hm; // handle scope
Universe::heap()->prepare_for_verify();
Universe::verify(VerifyOption_G1UsePrevMarking,
" VerifyDuringGC:(after)");
}
g1h->check_bitmaps("Cleanup End");
g1h->verify_region_sets_optional();
// We need to make this be a "collection" so any collection pause that
// races with it goes around and waits for completeCleanup to finish.
g1h->increment_total_collections();
// Clean out dead classes and update Metaspace sizes.
ClassLoaderDataGraph::purge();
MetaspaceGC::compute_new_size();
// We reclaimed old regions so we should calculate the sizes to make
// sure we update the old gen/space data.
g1h->g1mm()->update_sizes();
g1h->trace_heap_after_concurrent_cycle();
}
@ -2445,6 +2456,26 @@ void G1CMRefProcTaskExecutor::execute(EnqueueTask& enq_task) {
_g1h->set_par_threads(0);
}
void ConcurrentMark::weakRefsWorkParallelPart(BoolObjectClosure* is_alive, bool purged_classes) {
G1CollectedHeap::heap()->parallel_cleaning(is_alive, true, true, purged_classes);
}
// Helper class to get rid of some boilerplate code.
class G1RemarkGCTraceTime : public GCTraceTime {
static bool doit_and_prepend(bool doit) {
if (doit) {
gclog_or_tty->put(' ');
}
return doit;
}
public:
G1RemarkGCTraceTime(const char* title, bool doit)
: GCTraceTime(title, doit_and_prepend(doit), false, G1CollectedHeap::heap()->gc_timer_cm(),
G1CollectedHeap::heap()->concurrent_mark()->concurrent_gc_id()) {
}
};
void ConcurrentMark::weakRefsWork(bool clear_all_soft_refs) {
if (has_overflown()) {
// Skip processing the discovered references if we have
@ -2557,9 +2588,28 @@ void ConcurrentMark::weakRefsWork(bool clear_all_soft_refs) {
return;
}
g1h->unlink_string_and_symbol_table(&g1_is_alive,
/* process_strings */ false, // currently strings are always roots
/* process_symbols */ true);
assert(_markStack.isEmpty(), "Marking should have completed");
// Unload Klasses, String, Symbols, Code Cache, etc.
G1RemarkGCTraceTime trace("Unloading", G1Log::finer());
bool purged_classes;
{
G1RemarkGCTraceTime trace("System Dictionary Unloading", G1Log::finest());
purged_classes = SystemDictionary::do_unloading(&g1_is_alive);
}
{
G1RemarkGCTraceTime trace("Parallel Unloading", G1Log::finest());
weakRefsWorkParallelPart(&g1_is_alive, purged_classes);
}
if (G1StringDedup::is_enabled()) {
G1RemarkGCTraceTime trace("String Deduplication Unlink", G1Log::finest());
G1StringDedup::unlink(&g1_is_alive);
}
}
void ConcurrentMark::swapMarkBitMaps() {
@ -2568,6 +2618,57 @@ void ConcurrentMark::swapMarkBitMaps() {
_nextMarkBitMap = (CMBitMap*) temp;
}
class CMObjectClosure;
// Closure for iterating over objects, currently only used for
// processing SATB buffers.
class CMObjectClosure : public ObjectClosure {
private:
CMTask* _task;
public:
void do_object(oop obj) {
_task->deal_with_reference(obj);
}
CMObjectClosure(CMTask* task) : _task(task) { }
};
class G1RemarkThreadsClosure : public ThreadClosure {
CMObjectClosure _cm_obj;
G1CMOopClosure _cm_cl;
MarkingCodeBlobClosure _code_cl;
int _thread_parity;
bool _is_par;
public:
G1RemarkThreadsClosure(G1CollectedHeap* g1h, CMTask* task, bool is_par) :
_cm_obj(task), _cm_cl(g1h, g1h->concurrent_mark(), task), _code_cl(&_cm_cl, !CodeBlobToOopClosure::FixRelocations),
_thread_parity(SharedHeap::heap()->strong_roots_parity()), _is_par(is_par) {}
void do_thread(Thread* thread) {
if (thread->is_Java_thread()) {
if (thread->claim_oops_do(_is_par, _thread_parity)) {
JavaThread* jt = (JavaThread*)thread;
// In theory it should not be neccessary to explicitly walk the nmethods to find roots for concurrent marking
// however the liveness of oops reachable from nmethods have very complex lifecycles:
// * Alive if on the stack of an executing method
// * Weakly reachable otherwise
// Some objects reachable from nmethods, such as the class loader (or klass_holder) of the receiver should be
// live by the SATB invariant but other oops recorded in nmethods may behave differently.
jt->nmethods_do(&_code_cl);
jt->satb_mark_queue().apply_closure_and_empty(&_cm_obj);
}
} else if (thread->is_VM_thread()) {
if (thread->claim_oops_do(_is_par, _thread_parity)) {
JavaThread::satb_mark_queue_set().shared_satb_queue()->apply_closure_and_empty(&_cm_obj);
}
}
}
};
class CMRemarkTask: public AbstractGangTask {
private:
ConcurrentMark* _cm;
@ -2579,6 +2680,14 @@ public:
if (worker_id < _cm->active_tasks()) {
CMTask* task = _cm->task(worker_id);
task->record_start_time();
{
ResourceMark rm;
HandleMark hm;
G1RemarkThreadsClosure threads_f(G1CollectedHeap::heap(), task, !_is_serial);
Threads::threads_do(&threads_f);
}
do {
task->do_marking_step(1000000000.0 /* something very large */,
true /* do_termination */,
@ -2601,6 +2710,8 @@ void ConcurrentMark::checkpointRootsFinalWork() {
HandleMark hm;
G1CollectedHeap* g1h = G1CollectedHeap::heap();
G1RemarkGCTraceTime trace("Finalize Marking", G1Log::finer());
g1h->ensure_parsability(false);
if (G1CollectedHeap::use_parallel_gc_threads()) {
@ -3430,20 +3541,6 @@ public:
}
};
// Closure for iterating over objects, currently only used for
// processing SATB buffers.
class CMObjectClosure : public ObjectClosure {
private:
CMTask* _task;
public:
void do_object(oop obj) {
_task->deal_with_reference(obj);
}
CMObjectClosure(CMTask* task) : _task(task) { }
};
G1CMOopClosure::G1CMOopClosure(G1CollectedHeap* g1h,
ConcurrentMark* cm,
CMTask* task)
@ -3908,15 +4005,6 @@ void CMTask::drain_satb_buffers() {
}
}
if (!concurrent() && !has_aborted()) {
// We should only do this during remark.
if (G1CollectedHeap::use_parallel_gc_threads()) {
satb_mq_set.par_iterate_closure_all_threads(_worker_id);
} else {
satb_mq_set.iterate_closure_all_threads();
}
}
_draining_satb_buffers = false;
assert(has_aborted() ||

12
hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp
View File

@ -25,6 +25,7 @@
#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_HPP
#include "classfile/javaClasses.hpp"
#include "gc_implementation/g1/heapRegionSet.hpp"
#include "gc_implementation/shared/gcId.hpp"
#include "utilities/taskqueue.hpp"
@ -86,19 +87,19 @@ class CMBitMapRO VALUE_OBJ_CLASS_SPEC {
// Return the address corresponding to the next marked bit at or after
// "addr", and before "limit", if "limit" is non-NULL. If there is no
// such bit, returns "limit" if that is non-NULL, or else "endWord()".
HeapWord* getNextMarkedWordAddress(HeapWord* addr,
HeapWord* limit = NULL) const;
HeapWord* getNextMarkedWordAddress(const HeapWord* addr,
const HeapWord* limit = NULL) const;
// Return the address corresponding to the next unmarked bit at or after
// "addr", and before "limit", if "limit" is non-NULL. If there is no
// such bit, returns "limit" if that is non-NULL, or else "endWord()".
HeapWord* getNextUnmarkedWordAddress(HeapWord* addr,
HeapWord* limit = NULL) const;
HeapWord* getNextUnmarkedWordAddress(const HeapWord* addr,
const HeapWord* limit = NULL) const;
// conversion utilities
HeapWord* offsetToHeapWord(size_t offset) const {
return _bmStartWord + (offset << _shifter);
}
size_t heapWordToOffset(HeapWord* addr) const {
size_t heapWordToOffset(const HeapWord* addr) const {
return pointer_delta(addr, _bmStartWord) >> _shifter;
}
int heapWordDiffToOffsetDiff(size_t diff) const;
@ -476,6 +477,7 @@ protected:
ForceOverflowSettings _force_overflow_conc;
ForceOverflowSettings _force_overflow_stw;
void weakRefsWorkParallelPart(BoolObjectClosure* is_alive, bool purged_classes);
void weakRefsWork(bool clear_all_soft_refs);
void swapMarkBitMaps();

2
hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.cpp
View File

@ -426,7 +426,7 @@ G1BlockOffsetArray::forward_to_block_containing_addr_slow(HeapWord* q,
q = n;
oop obj = oop(q);
if (obj->klass_or_null() == NULL) return q;
n += obj->size();
n += block_size(q);
}
assert(q <= next_boundary && n > next_boundary, "Consequence of loop");
// [q, n) is the block that crosses the boundary.

2
hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.inline.hpp
View File

@ -113,7 +113,7 @@ forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n,
q = n;
oop obj = oop(q);
if (obj->klass_or_null() == NULL) return q;
n += obj->size();
n += block_size(q);
}
assert(q <= n, "wrong order for q and addr");
assert(addr < n, "wrong order for addr and n");

72
hotspot/src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp
View File

@ -30,23 +30,52 @@
PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
G1CodeRootChunk::G1CodeRootChunk() : _top(NULL), _next(NULL), _prev(NULL) {
G1CodeRootChunk::G1CodeRootChunk() : _top(NULL), _next(NULL), _prev(NULL), _free(NULL) {
_top = bottom();
}
void G1CodeRootChunk::reset() {
_next = _prev = NULL;
_free = NULL;
_top = bottom();
}
void G1CodeRootChunk::nmethods_do(CodeBlobClosure* cl) {
nmethod** cur = bottom();
NmethodOrLink* cur = bottom();
while (cur != _top) {
cl->do_code_blob(*cur);
if (is_nmethod(cur)) {
cl->do_code_blob(cur->_nmethod);
}
cur++;
}
}
bool G1CodeRootChunk::remove_lock_free(nmethod* method) {
NmethodOrLink* cur = bottom();
for (NmethodOrLink* cur = bottom(); cur != _top; cur++) {
if (cur->_nmethod == method) {
bool result = Atomic::cmpxchg_ptr(NULL, &cur->_nmethod, method) == method;
if (!result) {
// Someone else cleared out this entry.
return false;
}
// The method was cleared. Time to link it into the free list.
NmethodOrLink* prev_free;
do {
prev_free = (NmethodOrLink*)_free;
cur->_link = prev_free;
} while (Atomic::cmpxchg_ptr(cur, &_free, prev_free) != prev_free);
return true;
}
}
return false;
}
G1CodeRootChunkManager::G1CodeRootChunkManager() : _free_list(), _num_chunks_handed_out(0) {
_free_list.initialize();
_free_list.set_size(G1CodeRootChunk::word_size());
@ -140,34 +169,43 @@ G1CodeRootSet::~G1CodeRootSet() {
void G1CodeRootSet::add(nmethod* method) {
if (!contains(method)) {
// Try to add the nmethod. If there is not enough space, get a new chunk.
if (_list.head() == NULL || _list.head()->is_full()) {
G1CodeRootChunk* cur = new_chunk();
// Find the first chunk thatisn't full.
G1CodeRootChunk* cur = _list.head();
while (cur != NULL) {
if (!cur->is_full()) {
break;
}
cur = cur->next();
}
// All chunks are full, get a new chunk.
if (cur == NULL) {
cur = new_chunk();
_list.return_chunk_at_head(cur);
}
bool result = _list.head()->add(method);
// Add the nmethod.
bool result = cur->add(method);
guarantee(result, err_msg("Not able to add nmethod "PTR_FORMAT" to newly allocated chunk.", method));
_length++;
}
}
void G1CodeRootSet::remove(nmethod* method) {
void G1CodeRootSet::remove_lock_free(nmethod* method) {
G1CodeRootChunk* found = find(method);
if (found != NULL) {
bool result = found->remove(method);
guarantee(result, err_msg("could not find nmethod "PTR_FORMAT" during removal although we previously found it", method));
// eventually free completely emptied chunk
if (found->is_empty()) {
_list.remove_chunk(found);
free(found);
bool result = found->remove_lock_free(method);
if (result) {
Atomic::dec_ptr((volatile intptr_t*)&_length);
}
_length--;
}
assert(!contains(method), err_msg(PTR_FORMAT" still contains nmethod "PTR_FORMAT, this, method));
}
nmethod* G1CodeRootSet::pop() {
do {
while (true) {
G1CodeRootChunk* cur = _list.head();
if (cur == NULL) {
assert(_length == 0, "when there are no chunks, there should be no elements");
@ -180,7 +218,7 @@ nmethod* G1CodeRootSet::pop() {
} else {
free(_list.get_chunk_at_head());
}
} while (true);
}
}
G1CodeRootChunk* G1CodeRootSet::find(nmethod* method) {

87
hotspot/src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.hpp
View File

@ -31,6 +31,14 @@
class CodeBlobClosure;
// The elements of the G1CodeRootChunk is either:
// 1) nmethod pointers
// 2) nodes in an internally chained free list
typedef union {
nmethod* _nmethod;
void* _link;
} NmethodOrLink;
class G1CodeRootChunk : public CHeapObj<mtGC> {
private:
static const int NUM_ENTRIES = 32;
@ -38,16 +46,28 @@ class G1CodeRootChunk : public CHeapObj<mtGC> {
G1CodeRootChunk* _next;
G1CodeRootChunk* _prev;
nmethod** _top;
NmethodOrLink* _top;
// First free position within the chunk.
volatile NmethodOrLink* _free;
nmethod* _data[NUM_ENTRIES];
NmethodOrLink _data[NUM_ENTRIES];
nmethod** bottom() const {
return (nmethod**) &(_data[0]);
NmethodOrLink* bottom() const {
return (NmethodOrLink*) &(_data[0]);
}
nmethod** end() const {
return (nmethod**) &(_data[NUM_ENTRIES]);
NmethodOrLink* end() const {
return (NmethodOrLink*) &(_data[NUM_ENTRIES]);
}
bool is_link(NmethodOrLink* nmethod_or_link) {
return nmethod_or_link->_link == NULL ||
(bottom() <= nmethod_or_link->_link
&& nmethod_or_link->_link < end());
}
bool is_nmethod(NmethodOrLink* nmethod_or_link) {
return !is_link(nmethod_or_link);
}
public:
@ -85,46 +105,55 @@ class G1CodeRootChunk : public CHeapObj<mtGC> {
}
bool is_full() const {
return _top == (nmethod**)end();
return _top == end() && _free == NULL;
}
bool contains(nmethod* method) {
nmethod** cur = bottom();
NmethodOrLink* cur = bottom();
while (cur != _top) {
if (*cur == method) return true;
if (cur->_nmethod == method) return true;
cur++;
}
return false;
}
bool add(nmethod* method) {
if (is_full()) return false;
*_top = method;
_top++;
if (is_full()) {
return false;
}
if (_free != NULL) {
// Take from internally chained free list
NmethodOrLink* first_free = (NmethodOrLink*)_free;
_free = (NmethodOrLink*)_free->_link;
first_free->_nmethod = method;
} else {
// Take from top.
_top->_nmethod = method;
_top++;
}
return true;
}
bool remove(nmethod* method) {
nmethod** cur = bottom();
while (cur != _top) {
if (*cur == method) {
memmove(cur, cur + 1, (_top - (cur + 1)) * sizeof(nmethod**));
_top--;
return true;
}
cur++;
}
return false;
}
bool remove_lock_free(nmethod* method);
void nmethods_do(CodeBlobClosure* blk);
nmethod* pop() {
if (is_empty()) {
return NULL;
if (_free != NULL) {
// Kill the free list.
_free = NULL;
}
_top--;
return *_top;
while (!is_empty()) {
_top--;
if (is_nmethod(_top)) {
return _top->_nmethod;
}
}
return NULL;
}
};
@ -193,7 +222,7 @@ class G1CodeRootSet VALUE_OBJ_CLASS_SPEC {
// method is likely to be repeatedly called with the same nmethod.
void add(nmethod* method);
void remove(nmethod* method);
void remove_lock_free(nmethod* method);
nmethod* pop();
bool contains(nmethod* method);

650
hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
View File

@ -57,6 +57,7 @@
#include "gc_implementation/shared/gcTrace.hpp"
#include "gc_implementation/shared/gcTraceTime.hpp"
#include "gc_implementation/shared/isGCActiveMark.hpp"
#include "memory/allocation.hpp"
#include "memory/gcLocker.inline.hpp"
#include "memory/generationSpec.hpp"
#include "memory/iterator.hpp"
@ -91,10 +92,10 @@ size_t G1CollectedHeap::_humongous_object_threshold_in_words = 0;
// G1ParVerifyTask uses heap_region_par_iterate_chunked() for parallelism.
// The number of GC workers is passed to heap_region_par_iterate_chunked().
// It does use run_task() which sets _n_workers in the task.
// G1ParTask executes g1_process_strong_roots() ->
// SharedHeap::process_strong_roots() which calls eventually to
// G1ParTask executes g1_process_roots() ->
// SharedHeap::process_roots() which calls eventually to
// CardTableModRefBS::par_non_clean_card_iterate_work() which uses
// SequentialSubTasksDone. SharedHeap::process_strong_roots() also
// SequentialSubTasksDone. SharedHeap::process_roots() also
// directly uses SubTasksDone (_process_strong_tasks field in SharedHeap).
//
@ -3379,25 +3380,19 @@ void G1CollectedHeap::verify(bool silent, VerifyOption vo) {
if (!silent) { gclog_or_tty->print("Roots "); }
VerifyRootsClosure rootsCl(vo);
VerifyKlassClosure klassCl(this, &rootsCl);
CLDToKlassAndOopClosure cldCl(&klassCl, &rootsCl, false);
// We apply the relevant closures to all the oops in the
// system dictionary, class loader data graph and the string table.
// Don't verify the code cache here, since it's verified below.
const int so = SO_AllClasses | SO_Strings;
// Need cleared claim bits for the strong roots processing
ClassLoaderDataGraph::clear_claimed_marks();
process_strong_roots(true, // activate StrongRootsScope
ScanningOption(so), // roots scanning options
&rootsCl,
&klassCl
);
// Verify the nmethods in the code cache.
// system dictionary, class loader data graph, the string table
// and the nmethods in the code cache.
G1VerifyCodeRootOopClosure codeRootsCl(this, &rootsCl, vo);
G1VerifyCodeRootBlobClosure blobsCl(&codeRootsCl);
CodeCache::blobs_do(&blobsCl);
process_all_roots(true, // activate StrongRootsScope
SO_AllCodeCache, // roots scanning options
&rootsCl,
&cldCl,
&blobsCl);
bool failures = rootsCl.failures() || codeRootsCl.failures();
@ -3979,6 +3974,7 @@ G1CollectedHeap::do_collection_pause_at_safepoint(double target_pause_time_ms) {
increment_gc_time_stamp();
verify_before_gc();
check_bitmaps("GC Start");
COMPILER2_PRESENT(DerivedPointerTable::clear());
@ -4329,11 +4325,7 @@ void G1CollectedHeap::release_mutator_alloc_region() {
assert(_mutator_alloc_region.get() == NULL, "post-condition");
}
void G1CollectedHeap::init_gc_alloc_regions(EvacuationInfo& evacuation_info) {
assert_at_safepoint(true /* should_be_vm_thread */);
_survivor_gc_alloc_region.init();
_old_gc_alloc_region.init();
void G1CollectedHeap::use_retained_old_gc_alloc_region(EvacuationInfo& evacuation_info) {
HeapRegion* retained_region = _retained_old_gc_alloc_region;
_retained_old_gc_alloc_region = NULL;
@ -4365,6 +4357,15 @@ void G1CollectedHeap::init_gc_alloc_regions(EvacuationInfo& evacuation_info) {
}
}
void G1CollectedHeap::init_gc_alloc_regions(EvacuationInfo& evacuation_info) {
assert_at_safepoint(true /* should_be_vm_thread */);
_survivor_gc_alloc_region.init();
_old_gc_alloc_region.init();
use_retained_old_gc_alloc_region(evacuation_info);
}
void G1CollectedHeap::release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info) {
evacuation_info.set_allocation_regions(_survivor_gc_alloc_region.count() +
_old_gc_alloc_region.count());
@ -4587,7 +4588,7 @@ void G1ParCopyHelper::do_klass_barrier(T* p, oop new_obj) {
}
}
template <G1Barrier barrier, bool do_mark_object>
template <G1Barrier barrier, G1Mark do_mark_object>
template <class T>
void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
@ -4609,7 +4610,7 @@ void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
}
assert(forwardee != NULL, "forwardee should not be NULL");
oopDesc::encode_store_heap_oop(p, forwardee);
if (do_mark_object && forwardee != obj) {
if (do_mark_object != G1MarkNone && forwardee != obj) {
// If the object is self-forwarded we don't need to explicitly
// mark it, the evacuation failure protocol will do so.
mark_forwarded_object(obj, forwardee);
@ -4620,9 +4621,8 @@ void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
}
} else {
// The object is not in collection set. If we're a root scanning
// closure during an initial mark pause (i.e. do_mark_object will
// be true) then attempt to mark the object.
if (do_mark_object) {
// closure during an initial mark pause then attempt to mark the object.
if (do_mark_object == G1MarkFromRoot) {
mark_object(obj);
}
}
@ -4632,8 +4632,8 @@ void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
}
}
template void G1ParCopyClosure<G1BarrierEvac, false>::do_oop_work(oop* p);
template void G1ParCopyClosure<G1BarrierEvac, false>::do_oop_work(narrowOop* p);
template void G1ParCopyClosure<G1BarrierEvac, G1MarkNone>::do_oop_work(oop* p);
template void G1ParCopyClosure<G1BarrierEvac, G1MarkNone>::do_oop_work(narrowOop* p);
class G1ParEvacuateFollowersClosure : public VoidClosure {
protected:
@ -4746,6 +4746,51 @@ public:
_n_workers = active_workers;
}
// Helps out with CLD processing.
//
// During InitialMark we need to:
// 1) Scavenge all CLDs for the young GC.
// 2) Mark all objects directly reachable from strong CLDs.
template <G1Mark do_mark_object>
class G1CLDClosure : public CLDClosure {
G1ParCopyClosure<G1BarrierNone, do_mark_object>* _oop_closure;
G1ParCopyClosure<G1BarrierKlass, do_mark_object> _oop_in_klass_closure;
G1KlassScanClosure _klass_in_cld_closure;
bool _claim;
public:
G1CLDClosure(G1ParCopyClosure<G1BarrierNone, do_mark_object>* oop_closure,
bool only_young, bool claim)
: _oop_closure(oop_closure),
_oop_in_klass_closure(oop_closure->g1(),
oop_closure->pss(),
oop_closure->rp()),
_klass_in_cld_closure(&_oop_in_klass_closure, only_young),
_claim(claim) {
}
void do_cld(ClassLoaderData* cld) {
cld->oops_do(_oop_closure, &_klass_in_cld_closure, _claim);
}
};
class G1CodeBlobClosure: public CodeBlobClosure {
OopClosure* _f;
public:
G1CodeBlobClosure(OopClosure* f) : _f(f) {}
void do_code_blob(CodeBlob* blob) {
nmethod* that = blob->as_nmethod_or_null();
if (that != NULL) {
if (!that->test_set_oops_do_mark()) {
that->oops_do(_f);
that->fix_oop_relocations();
}
}
}
};
void work(uint worker_id) {
if (worker_id >= _n_workers) return; // no work needed this round
@ -4763,40 +4808,62 @@ public:
pss.set_evac_failure_closure(&evac_failure_cl);
G1ParScanExtRootClosure only_scan_root_cl(_g1h, &pss, rp);
G1ParScanMetadataClosure only_scan_metadata_cl(_g1h, &pss, rp);
bool only_young = _g1h->g1_policy()->gcs_are_young();
G1ParScanAndMarkExtRootClosure scan_mark_root_cl(_g1h, &pss, rp);
G1ParScanAndMarkMetadataClosure scan_mark_metadata_cl(_g1h, &pss, rp);
// Non-IM young GC.
G1ParCopyClosure<G1BarrierNone, G1MarkNone> scan_only_root_cl(_g1h, &pss, rp);
G1CLDClosure<G1MarkNone> scan_only_cld_cl(&scan_only_root_cl,
only_young, // Only process dirty klasses.
false); // No need to claim CLDs.
// IM young GC.
// Strong roots closures.
G1ParCopyClosure<G1BarrierNone, G1MarkFromRoot> scan_mark_root_cl(_g1h, &pss, rp);
G1CLDClosure<G1MarkFromRoot> scan_mark_cld_cl(&scan_mark_root_cl,
false, // Process all klasses.
true); // Need to claim CLDs.
// Weak roots closures.
G1ParCopyClosure<G1BarrierNone, G1MarkPromotedFromRoot> scan_mark_weak_root_cl(_g1h, &pss, rp);
G1CLDClosure<G1MarkPromotedFromRoot> scan_mark_weak_cld_cl(&scan_mark_weak_root_cl,
false, // Process all klasses.
true); // Need to claim CLDs.
bool only_young = _g1h->g1_policy()->gcs_are_young();
G1KlassScanClosure scan_mark_klasses_cl_s(&scan_mark_metadata_cl, false);
G1KlassScanClosure only_scan_klasses_cl_s(&only_scan_metadata_cl, only_young);
G1CodeBlobClosure scan_only_code_cl(&scan_only_root_cl);
G1CodeBlobClosure scan_mark_code_cl(&scan_mark_root_cl);
// IM Weak code roots are handled later.
OopClosure* scan_root_cl = &only_scan_root_cl;
G1KlassScanClosure* scan_klasses_cl = &only_scan_klasses_cl_s;
OopClosure* strong_root_cl;
OopClosure* weak_root_cl;
CLDClosure* strong_cld_cl;
CLDClosure* weak_cld_cl;
CodeBlobClosure* strong_code_cl;
if (_g1h->g1_policy()->during_initial_mark_pause()) {
// We also need to mark copied objects.
scan_root_cl = &scan_mark_root_cl;
scan_klasses_cl = &scan_mark_klasses_cl_s;
strong_root_cl = &scan_mark_root_cl;
weak_root_cl = &scan_mark_weak_root_cl;
strong_cld_cl = &scan_mark_cld_cl;
weak_cld_cl = &scan_mark_weak_cld_cl;
strong_code_cl = &scan_mark_code_cl;
} else {
strong_root_cl = &scan_only_root_cl;
weak_root_cl = &scan_only_root_cl;
strong_cld_cl = &scan_only_cld_cl;
weak_cld_cl = &scan_only_cld_cl;
strong_code_cl = &scan_only_code_cl;
}
G1ParPushHeapRSClosure push_heap_rs_cl(_g1h, &pss);
// Don't scan the scavengable methods in the code cache as part
// of strong root scanning. The code roots that point into a
// region in the collection set are scanned when we scan the
// region's RSet.
int so = SharedHeap::SO_AllClasses | SharedHeap::SO_Strings;
G1ParPushHeapRSClosure push_heap_rs_cl(_g1h, &pss);
pss.start_strong_roots();
_g1h->g1_process_strong_roots(/* is scavenging */ true,
SharedHeap::ScanningOption(so),
scan_root_cl,
&push_heap_rs_cl,
scan_klasses_cl,
worker_id);
_g1h->g1_process_roots(strong_root_cl,
weak_root_cl,
&push_heap_rs_cl,
strong_cld_cl,
weak_cld_cl,
strong_code_cl,
worker_id);
pss.end_strong_roots();
{
@ -4834,24 +4901,31 @@ public:
void
G1CollectedHeap::
g1_process_strong_roots(bool is_scavenging,
ScanningOption so,
OopClosure* scan_non_heap_roots,
OopsInHeapRegionClosure* scan_rs,
G1KlassScanClosure* scan_klasses,
uint worker_i) {
g1_process_roots(OopClosure* scan_non_heap_roots,
OopClosure* scan_non_heap_weak_roots,
OopsInHeapRegionClosure* scan_rs,
CLDClosure* scan_strong_clds,
CLDClosure* scan_weak_clds,
CodeBlobClosure* scan_strong_code,
uint worker_i) {
// First scan the strong roots
// First scan the shared roots.
double ext_roots_start = os::elapsedTime();
double closure_app_time_sec = 0.0;
BufferingOopClosure buf_scan_non_heap_roots(scan_non_heap_roots);
bool during_im = _g1h->g1_policy()->during_initial_mark_pause();
process_strong_roots(false, // no scoping; this is parallel code
so,
&buf_scan_non_heap_roots,
scan_klasses
);
BufferingOopClosure buf_scan_non_heap_roots(scan_non_heap_roots);
BufferingOopClosure buf_scan_non_heap_weak_roots(scan_non_heap_weak_roots);
process_roots(false, // no scoping; this is parallel code
SharedHeap::SO_None,
&buf_scan_non_heap_roots,
&buf_scan_non_heap_weak_roots,
scan_strong_clds,
// Initial Mark handles the weak CLDs separately.
(during_im ? NULL : scan_weak_clds),
scan_strong_code);
// Now the CM ref_processor roots.
if (!_process_strong_tasks->is_task_claimed(G1H_PS_refProcessor_oops_do)) {
@ -4862,10 +4936,21 @@ g1_process_strong_roots(bool is_scavenging,
ref_processor_cm()->weak_oops_do(&buf_scan_non_heap_roots);
}
if (during_im) {
// Barrier to make sure all workers passed
// the strong CLD and strong nmethods phases.
active_strong_roots_scope()->wait_until_all_workers_done_with_threads(n_par_threads());
// Now take the complement of the strong CLDs.
ClassLoaderDataGraph::roots_cld_do(NULL, scan_weak_clds);
}
// Finish up any enqueued closure apps (attributed as object copy time).
buf_scan_non_heap_roots.done();
buf_scan_non_heap_weak_roots.done();
double obj_copy_time_sec = buf_scan_non_heap_roots.closure_app_seconds();
double obj_copy_time_sec = buf_scan_non_heap_roots.closure_app_seconds()
+ buf_scan_non_heap_weak_roots.closure_app_seconds();
g1_policy()->phase_times()->record_obj_copy_time(worker_i, obj_copy_time_sec * 1000.0);
@ -4889,22 +4974,10 @@ g1_process_strong_roots(bool is_scavenging,
}
g1_policy()->phase_times()->record_satb_filtering_time(worker_i, satb_filtering_ms);
// If this is an initial mark pause, and we're not scanning
// the entire code cache, we need to mark the oops in the
// strong code root lists for the regions that are not in
// the collection set.
// Note all threads participate in this set of root tasks.
double mark_strong_code_roots_ms = 0.0;
if (g1_policy()->during_initial_mark_pause() && !(so & SO_AllCodeCache)) {
double mark_strong_roots_start = os::elapsedTime();
mark_strong_code_roots(worker_i);
mark_strong_code_roots_ms = (os::elapsedTime() - mark_strong_roots_start) * 1000.0;
}
g1_policy()->phase_times()->record_strong_code_root_mark_time(worker_i, mark_strong_code_roots_ms);
// Now scan the complement of the collection set.
CodeBlobToOopClosure eager_scan_code_roots(scan_non_heap_roots, true /* do_marking */);
g1_rem_set()->oops_into_collection_set_do(scan_rs, &eager_scan_code_roots, worker_i);
MarkingCodeBlobClosure scavenge_cs_nmethods(scan_non_heap_weak_roots, CodeBlobToOopClosure::FixRelocations);
g1_rem_set()->oops_into_collection_set_do(scan_rs, &scavenge_cs_nmethods, worker_i);
_process_strong_tasks->all_tasks_completed();
}
@ -4926,7 +4999,8 @@ private:
bool _do_in_parallel;
public:
G1StringSymbolTableUnlinkTask(BoolObjectClosure* is_alive, bool process_strings, bool process_symbols) :
AbstractGangTask("Par String/Symbol table unlink"), _is_alive(is_alive),
AbstractGangTask("String/Symbol Unlinking"),
_is_alive(is_alive),
_do_in_parallel(G1CollectedHeap::use_parallel_gc_threads()),
_process_strings(process_strings), _strings_processed(0), _strings_removed(0),
_process_symbols(process_symbols), _symbols_processed(0), _symbols_removed(0) {
@ -4948,6 +5022,14 @@ public:
guarantee(!_process_symbols || !_do_in_parallel || SymbolTable::parallel_claimed_index() >= _initial_symbol_table_size,
err_msg("claim value %d after unlink less than initial symbol table size %d",
SymbolTable::parallel_claimed_index(), _initial_symbol_table_size));
if (G1TraceStringSymbolTableScrubbing) {
gclog_or_tty->print_cr("Cleaned string and symbol table, "
"strings: "SIZE_FORMAT" processed, "SIZE_FORMAT" removed, "
"symbols: "SIZE_FORMAT" processed, "SIZE_FORMAT" removed",
strings_processed(), strings_removed(),
symbols_processed(), symbols_removed());
}
}
void work(uint worker_id) {
@ -4983,12 +5065,279 @@ public:
size_t symbols_removed() const { return (size_t)_symbols_removed; }
};
void G1CollectedHeap::unlink_string_and_symbol_table(BoolObjectClosure* is_alive,
bool process_strings, bool process_symbols) {
uint n_workers = (G1CollectedHeap::use_parallel_gc_threads() ?
_g1h->workers()->active_workers() : 1);
class G1CodeCacheUnloadingTask VALUE_OBJ_CLASS_SPEC {
private:
static Monitor* _lock;
G1StringSymbolTableUnlinkTask g1_unlink_task(is_alive, process_strings, process_symbols);
BoolObjectClosure* const _is_alive;
const bool _unloading_occurred;
const uint _num_workers;
// Variables used to claim nmethods.
nmethod* _first_nmethod;
volatile nmethod* _claimed_nmethod;
// The list of nmethods that need to be processed by the second pass.
volatile nmethod* _postponed_list;
volatile uint _num_entered_barrier;
public:
G1CodeCacheUnloadingTask(uint num_workers, BoolObjectClosure* is_alive, bool unloading_occurred) :
_is_alive(is_alive),
_unloading_occurred(unloading_occurred),
_num_workers(num_workers),
_first_nmethod(NULL),
_claimed_nmethod(NULL),
_postponed_list(NULL),
_num_entered_barrier(0)
{
nmethod::increase_unloading_clock();
_first_nmethod = CodeCache::alive_nmethod(CodeCache::first());
_claimed_nmethod = (volatile nmethod*)_first_nmethod;
}
~G1CodeCacheUnloadingTask() {
CodeCache::verify_clean_inline_caches();
CodeCache::set_needs_cache_clean(false);
guarantee(CodeCache::scavenge_root_nmethods() == NULL, "Must be");
CodeCache::verify_icholder_relocations();
}
private:
void add_to_postponed_list(nmethod* nm) {
nmethod* old;
do {
old = (nmethod*)_postponed_list;
nm->set_unloading_next(old);
} while ((nmethod*)Atomic::cmpxchg_ptr(nm, &_postponed_list, old) != old);
}
void clean_nmethod(nmethod* nm) {
bool postponed = nm->do_unloading_parallel(_is_alive, _unloading_occurred);
if (postponed) {
// This nmethod referred to an nmethod that has not been cleaned/unloaded yet.
add_to_postponed_list(nm);
}
// Mark that this thread has been cleaned/unloaded.
// After this call, it will be safe to ask if this nmethod was unloaded or not.
nm->set_unloading_clock(nmethod::global_unloading_clock());
}
void clean_nmethod_postponed(nmethod* nm) {
nm->do_unloading_parallel_postponed(_is_alive, _unloading_occurred);
}
static const int MaxClaimNmethods = 16;
void claim_nmethods(nmethod** claimed_nmethods, int *num_claimed_nmethods) {
nmethod* first;
nmethod* last;
do {
*num_claimed_nmethods = 0;
first = last = (nmethod*)_claimed_nmethod;
if (first != NULL) {
for (int i = 0; i < MaxClaimNmethods; i++) {
last = CodeCache::alive_nmethod(CodeCache::next(last));
if (last == NULL) {
break;
}
claimed_nmethods[i] = last;
(*num_claimed_nmethods)++;
}
}
} while ((nmethod*)Atomic::cmpxchg_ptr(last, &_claimed_nmethod, first) != first);
}
nmethod* claim_postponed_nmethod() {
nmethod* claim;
nmethod* next;
do {
claim = (nmethod*)_postponed_list;
if (claim == NULL) {
return NULL;
}
next = claim->unloading_next();
} while ((nmethod*)Atomic::cmpxchg_ptr(next, &_postponed_list, claim) != claim);
return claim;
}
public:
// Mark that we're done with the first pass of nmethod cleaning.
void barrier_mark(uint worker_id) {
MonitorLockerEx ml(_lock, Mutex::_no_safepoint_check_flag);
_num_entered_barrier++;
if (_num_entered_barrier == _num_workers) {
ml.notify_all();
}
}
// See if we have to wait for the other workers to
// finish their first-pass nmethod cleaning work.
void barrier_wait(uint worker_id) {
if (_num_entered_barrier < _num_workers) {
MonitorLockerEx ml(_lock, Mutex::_no_safepoint_check_flag);
while (_num_entered_barrier < _num_workers) {
ml.wait(Mutex::_no_safepoint_check_flag, 0, false);
}
}
}
// Cleaning and unloading of nmethods. Some work has to be postponed
// to the second pass, when we know which nmethods survive.
void work_first_pass(uint worker_id) {
// The first nmethods is claimed by the first worker.
if (worker_id == 0 && _first_nmethod != NULL) {
clean_nmethod(_first_nmethod);
_first_nmethod = NULL;
}
int num_claimed_nmethods;
nmethod* claimed_nmethods[MaxClaimNmethods];
while (true) {
claim_nmethods(claimed_nmethods, &num_claimed_nmethods);
if (num_claimed_nmethods == 0) {
break;
}
for (int i = 0; i < num_claimed_nmethods; i++) {
clean_nmethod(claimed_nmethods[i]);
}
}
}
void work_second_pass(uint worker_id) {
nmethod* nm;
// Take care of postponed nmethods.
while ((nm = claim_postponed_nmethod()) != NULL) {
clean_nmethod_postponed(nm);
}
}
};
Monitor* G1CodeCacheUnloadingTask::_lock = new Monitor(Mutex::leaf, "Code Cache Unload lock");
class G1KlassCleaningTask : public StackObj {
BoolObjectClosure* _is_alive;
volatile jint _clean_klass_tree_claimed;
ClassLoaderDataGraphKlassIteratorAtomic _klass_iterator;
public:
G1KlassCleaningTask(BoolObjectClosure* is_alive) :
_is_alive(is_alive),
_clean_klass_tree_claimed(0),
_klass_iterator() {
}
private:
bool claim_clean_klass_tree_task() {
if (_clean_klass_tree_claimed) {
return false;
}
return Atomic::cmpxchg(1, (jint*)&_clean_klass_tree_claimed, 0) == 0;
}
InstanceKlass* claim_next_klass() {
Klass* klass;
do {
klass =_klass_iterator.next_klass();
} while (klass != NULL && !klass->oop_is_instance());
return (InstanceKlass*)klass;
}
public:
void clean_klass(InstanceKlass* ik) {
ik->clean_implementors_list(_is_alive);
ik->clean_method_data(_is_alive);
// G1 specific cleanup work that has
// been moved here to be done in parallel.
ik->clean_dependent_nmethods();
}
void work() {
ResourceMark rm;
// One worker will clean the subklass/sibling klass tree.
if (claim_clean_klass_tree_task()) {
Klass::clean_subklass_tree(_is_alive);
}
// All workers will help cleaning the classes,
InstanceKlass* klass;
while ((klass = claim_next_klass()) != NULL) {
clean_klass(klass);
}
}
};
// To minimize the remark pause times, the tasks below are done in parallel.
class G1ParallelCleaningTask : public AbstractGangTask {
private:
G1StringSymbolTableUnlinkTask _string_symbol_task;
G1CodeCacheUnloadingTask _code_cache_task;
G1KlassCleaningTask _klass_cleaning_task;
public:
// The constructor is run in the VMThread.
G1ParallelCleaningTask(BoolObjectClosure* is_alive, bool process_strings, bool process_symbols, uint num_workers, bool unloading_occurred) :
AbstractGangTask("Parallel Cleaning"),
_string_symbol_task(is_alive, process_strings, process_symbols),
_code_cache_task(num_workers, is_alive, unloading_occurred),
_klass_cleaning_task(is_alive) {
}
// The parallel work done by all worker threads.
void work(uint worker_id) {
// Do first pass of code cache cleaning.
_code_cache_task.work_first_pass(worker_id);
// Let the threads, mark that the first pass is done.
_code_cache_task.barrier_mark(worker_id);
// Clean the Strings and Symbols.
_string_symbol_task.work(worker_id);
// Wait for all workers to finish the first code cache cleaning pass.
_code_cache_task.barrier_wait(worker_id);
// Do the second code cache cleaning work, which realize on
// the liveness information gathered during the first pass.
_code_cache_task.work_second_pass(worker_id);
// Clean all klasses that were not unloaded.
_klass_cleaning_task.work();
}
};
void G1CollectedHeap::parallel_cleaning(BoolObjectClosure* is_alive,
bool process_strings,
bool process_symbols,
bool class_unloading_occurred) {
uint n_workers = (G1CollectedHeap::use_parallel_gc_threads() ?
workers()->active_workers() : 1);
G1ParallelCleaningTask g1_unlink_task(is_alive, process_strings, process_symbols,
n_workers, class_unloading_occurred);
if (G1CollectedHeap::use_parallel_gc_threads()) {
set_par_threads(n_workers);
workers()->run_task(&g1_unlink_task);
@ -4996,12 +5345,21 @@ void G1CollectedHeap::unlink_string_and_symbol_table(BoolObjectClosure* is_alive
} else {
g1_unlink_task.work(0);
}
if (G1TraceStringSymbolTableScrubbing) {
gclog_or_tty->print_cr("Cleaned string and symbol table, "
"strings: "SIZE_FORMAT" processed, "SIZE_FORMAT" removed, "
"symbols: "SIZE_FORMAT" processed, "SIZE_FORMAT" removed",
g1_unlink_task.strings_processed(), g1_unlink_task.strings_removed(),
g1_unlink_task.symbols_processed(), g1_unlink_task.symbols_removed());
}
void G1CollectedHeap::unlink_string_and_symbol_table(BoolObjectClosure* is_alive,
bool process_strings, bool process_symbols) {
{
uint n_workers = (G1CollectedHeap::use_parallel_gc_threads() ?
_g1h->workers()->active_workers() : 1);
G1StringSymbolTableUnlinkTask g1_unlink_task(is_alive, process_strings, process_symbols);
if (G1CollectedHeap::use_parallel_gc_threads()) {
set_par_threads(n_workers);
workers()->run_task(&g1_unlink_task);
set_par_threads(0);
} else {
g1_unlink_task.work(0);
}
}
if (G1StringDedup::is_enabled()) {
@ -5594,6 +5952,10 @@ void G1CollectedHeap::evacuate_collection_set(EvacuationInfo& evacuation_info) {
{
StrongRootsScope srs(this);
// InitialMark needs claim bits to keep track of the marked-through CLDs.
if (g1_policy()->during_initial_mark_pause()) {
ClassLoaderDataGraph::clear_claimed_marks();
}
if (G1CollectedHeap::use_parallel_gc_threads()) {
// The individual threads will set their evac-failure closures.
@ -6629,106 +6991,6 @@ void G1CollectedHeap::purge_code_root_memory() {
g1_policy()->phase_times()->record_strong_code_root_purge_time(purge_time_ms);
}
// Mark all the code roots that point into regions *not* in the
// collection set.
//
// Note we do not want to use a "marking" CodeBlobToOopClosure while
// walking the the code roots lists of regions not in the collection
// set. Suppose we have an nmethod (M) that points to objects in two
// separate regions - one in the collection set (R1) and one not (R2).
// Using a "marking" CodeBlobToOopClosure here would result in "marking"
// nmethod M when walking the code roots for R1. When we come to scan
// the code roots for R2, we would see that M is already marked and it
// would be skipped and the objects in R2 that are referenced from M
// would not be evacuated.
class MarkStrongCodeRootCodeBlobClosure: public CodeBlobClosure {
class MarkStrongCodeRootOopClosure: public OopClosure {
ConcurrentMark* _cm;
HeapRegion* _hr;
uint _worker_id;
template <class T> void do_oop_work(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
// Only mark objects in the region (which is assumed
// to be not in the collection set).
if (_hr->is_in(obj)) {
_cm->grayRoot(obj, (size_t) obj->size(), _worker_id);
}
}
}
public:
MarkStrongCodeRootOopClosure(ConcurrentMark* cm, HeapRegion* hr, uint worker_id) :
_cm(cm), _hr(hr), _worker_id(worker_id) {
assert(!_hr->in_collection_set(), "sanity");
}
void do_oop(narrowOop* p) { do_oop_work(p); }
void do_oop(oop* p) { do_oop_work(p); }
};
MarkStrongCodeRootOopClosure _oop_cl;
public:
MarkStrongCodeRootCodeBlobClosure(ConcurrentMark* cm, HeapRegion* hr, uint worker_id):
_oop_cl(cm, hr, worker_id) {}
void do_code_blob(CodeBlob* cb) {
nmethod* nm = (cb == NULL) ? NULL : cb->as_nmethod_or_null();
if (nm != NULL) {
nm->oops_do(&_oop_cl);
}
}
};
class MarkStrongCodeRootsHRClosure: public HeapRegionClosure {
G1CollectedHeap* _g1h;
uint _worker_id;
public:
MarkStrongCodeRootsHRClosure(G1CollectedHeap* g1h, uint worker_id) :
_g1h(g1h), _worker_id(worker_id) {}
bool doHeapRegion(HeapRegion *hr) {
HeapRegionRemSet* hrrs = hr->rem_set();
if (hr->continuesHumongous()) {
// Code roots should never be attached to a continuation of a humongous region
assert(hrrs->strong_code_roots_list_length() == 0,
err_msg("code roots should never be attached to continuations of humongous region "HR_FORMAT
" starting at "HR_FORMAT", but has "SIZE_FORMAT,
HR_FORMAT_PARAMS(hr), HR_FORMAT_PARAMS(hr->humongous_start_region()),
hrrs->strong_code_roots_list_length()));
return false;
}
if (hr->in_collection_set()) {
// Don't mark code roots into regions in the collection set here.
// They will be marked when we scan them.
return false;
}
MarkStrongCodeRootCodeBlobClosure cb_cl(_g1h->concurrent_mark(), hr, _worker_id);
hr->strong_code_roots_do(&cb_cl);
return false;
}
};
void G1CollectedHeap::mark_strong_code_roots(uint worker_id) {
MarkStrongCodeRootsHRClosure cl(this, worker_id);
if (G1CollectedHeap::use_parallel_gc_threads()) {
heap_region_par_iterate_chunked(&cl,
worker_id,
workers()->active_workers(),
HeapRegion::ParMarkRootClaimValue);
} else {
heap_region_iterate(&cl);
}
}
class RebuildStrongCodeRootClosure: public CodeBlobClosure {
G1CollectedHeap* _g1h;

28
hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp
View File

@ -210,6 +210,7 @@ class G1FastCSetBiasedMappedArray : public G1BiasedMappedArray<bool> {
class RefineCardTableEntryClosure;
class G1CollectedHeap : public SharedHeap {
friend class VM_CollectForMetadataAllocation;
friend class VM_G1CollectForAllocation;
friend class VM_G1CollectFull;
friend class VM_G1IncCollectionPause;
@ -219,7 +220,7 @@ class G1CollectedHeap : public SharedHeap {
friend class OldGCAllocRegion;
// Closures used in implementation.
template <G1Barrier barrier, bool do_mark_object>
template <G1Barrier barrier, G1Mark do_mark_object>
friend class G1ParCopyClosure;
friend class G1IsAliveClosure;
friend class G1EvacuateFollowersClosure;
@ -346,6 +347,9 @@ private:
// It initializes the GC alloc regions at the start of a GC.
void init_gc_alloc_regions(EvacuationInfo& evacuation_info);
// Setup the retained old gc alloc region as the currrent old gc alloc region.
void use_retained_old_gc_alloc_region(EvacuationInfo& evacuation_info);
// It releases the GC alloc regions at the end of a GC.
void release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info);
@ -827,12 +831,13 @@ protected:
// param is for use with parallel roots processing, and should be
// the "i" of the calling parallel worker thread's work(i) function.
// In the sequential case this param will be ignored.
void g1_process_strong_roots(bool is_scavenging,
ScanningOption so,
OopClosure* scan_non_heap_roots,
OopsInHeapRegionClosure* scan_rs,
G1KlassScanClosure* scan_klasses,
uint worker_i);
void g1_process_roots(OopClosure* scan_non_heap_roots,
OopClosure* scan_non_heap_weak_roots,
OopsInHeapRegionClosure* scan_rs,
CLDClosure* scan_strong_clds,
CLDClosure* scan_weak_clds,
CodeBlobClosure* scan_strong_code,
uint worker_i);
// Notifies all the necessary spaces that the committed space has
// been updated (either expanded or shrunk). It should be called
@ -1025,7 +1030,7 @@ protected:
// of G1CollectedHeap::_gc_time_stamp.
unsigned int* _worker_cset_start_region_time_stamp;
enum G1H_process_strong_roots_tasks {
enum G1H_process_roots_tasks {
G1H_PS_filter_satb_buffers,
G1H_PS_refProcessor_oops_do,
// Leave this one last.
@ -1607,10 +1612,6 @@ public:
// Free up superfluous code root memory.
void purge_code_root_memory();
// During an initial mark pause, mark all the code roots that
// point into regions *not* in the collection set.
void mark_strong_code_roots(uint worker_id);
// Rebuild the strong code root lists for each region
// after a full GC.
void rebuild_strong_code_roots();
@ -1619,6 +1620,9 @@ public:
// in symbol table, possibly in parallel.
void unlink_string_and_symbol_table(BoolObjectClosure* is_alive, bool unlink_strings = true, bool unlink_symbols = true);
// Parallel phase of unloading/cleaning after G1 concurrent mark.
void parallel_cleaning(BoolObjectClosure* is_alive, bool process_strings, bool process_symbols, bool class_unloading_occurred);
// Redirty logged cards in the refinement queue.
void redirty_logged_cards();
// Verification

35
hotspot/src/share/vm/gc_implementation/g1/g1EvacFailure.hpp
View File

@ -71,6 +71,9 @@ private:
bool _during_initial_mark;
bool _during_conc_mark;
uint _worker_id;
HeapWord* _end_of_last_gap;
HeapWord* _last_gap_threshold;
HeapWord* _last_obj_threshold;
public:
RemoveSelfForwardPtrObjClosure(G1CollectedHeap* g1, ConcurrentMark* cm,
@ -83,7 +86,10 @@ public:
_update_rset_cl(update_rset_cl),
_during_initial_mark(during_initial_mark),
_during_conc_mark(during_conc_mark),
_worker_id(worker_id) { }
_worker_id(worker_id),
_end_of_last_gap(hr->bottom()),
_last_gap_threshold(hr->bottom()),
_last_obj_threshold(hr->bottom()) { }
size_t marked_bytes() { return _marked_bytes; }
@ -107,7 +113,12 @@ public:
HeapWord* obj_addr = (HeapWord*) obj;
assert(_hr->is_in(obj_addr), "sanity");
size_t obj_size = obj->size();
_hr->update_bot_for_object(obj_addr, obj_size);
HeapWord* obj_end = obj_addr + obj_size;
if (_end_of_last_gap != obj_addr) {
// there was a gap before obj_addr
_last_gap_threshold = _hr->cross_threshold(_end_of_last_gap, obj_addr);
}
if (obj->is_forwarded() && obj->forwardee() == obj) {
// The object failed to move.
@ -115,7 +126,9 @@ public:
// We consider all objects that we find self-forwarded to be
// live. What we'll do is that we'll update the prev marking
// info so that they are all under PTAMS and explicitly marked.
_cm->markPrev(obj);
if (!_cm->isPrevMarked(obj)) {
_cm->markPrev(obj);
}
if (_during_initial_mark) {
// For the next marking info we'll only mark the
// self-forwarded objects explicitly if we are during
@ -145,13 +158,18 @@ public:
// remembered set entries missing given that we skipped cards on
// the collection set. So, we'll recreate such entries now.
obj->oop_iterate(_update_rset_cl);
assert(_cm->isPrevMarked(obj), "Should be marked!");
} else {
// The object has been either evacuated or is dead. Fill it with a
// dummy object.
MemRegion mr((HeapWord*) obj, obj_size);
MemRegion mr(obj_addr, obj_size);
CollectedHeap::fill_with_object(mr);
// must nuke all dead objects which we skipped when iterating over the region
_cm->clearRangePrevBitmap(MemRegion(_end_of_last_gap, obj_end));
}
_end_of_last_gap = obj_end;
_last_obj_threshold = _hr->cross_threshold(obj_addr, obj_end);
}
};
@ -182,13 +200,6 @@ public:
during_conc_mark,
_worker_id);
MemRegion mr(hr->bottom(), hr->end());
// We'll recreate the prev marking info so we'll first clear
// the prev bitmap range for this region. We never mark any
// CSet objects explicitly so the next bitmap range should be
// cleared anyway.
_cm->clearRangePrevBitmap(mr);
hr->note_self_forwarding_removal_start(during_initial_mark,
during_conc_mark);
_g1h->check_bitmaps("Self-Forwarding Ptr Removal", hr);

10
hotspot/src/share/vm/gc_implementation/g1/g1GCPhaseTimes.cpp
View File

@ -167,7 +167,6 @@ G1GCPhaseTimes::G1GCPhaseTimes(uint max_gc_threads) :
_last_update_rs_processed_buffers(_max_gc_threads, "%d"),
_last_scan_rs_times_ms(_max_gc_threads, "%.1lf"),
_last_strong_code_root_scan_times_ms(_max_gc_threads, "%.1lf"),
_last_strong_code_root_mark_times_ms(_max_gc_threads, "%.1lf"),
_last_obj_copy_times_ms(_max_gc_threads, "%.1lf"),
_last_termination_times_ms(_max_gc_threads, "%.1lf"),
_last_termination_attempts(_max_gc_threads, SIZE_FORMAT),
@ -194,7 +193,6 @@ void G1GCPhaseTimes::note_gc_start(uint active_gc_threads) {
_last_update_rs_processed_buffers.reset();
_last_scan_rs_times_ms.reset();
_last_strong_code_root_scan_times_ms.reset();
_last_strong_code_root_mark_times_ms.reset();
_last_obj_copy_times_ms.reset();
_last_termination_times_ms.reset();
_last_termination_attempts.reset();
@ -215,7 +213,6 @@ void G1GCPhaseTimes::note_gc_end() {
_last_update_rs_processed_buffers.verify();
_last_scan_rs_times_ms.verify();
_last_strong_code_root_scan_times_ms.verify();
_last_strong_code_root_mark_times_ms.verify();
_last_obj_copy_times_ms.verify();
_last_termination_times_ms.verify();
_last_termination_attempts.verify();
@ -230,7 +227,6 @@ void G1GCPhaseTimes::note_gc_end() {
_last_update_rs_times_ms.get(i) +
_last_scan_rs_times_ms.get(i) +
_last_strong_code_root_scan_times_ms.get(i) +
_last_strong_code_root_mark_times_ms.get(i) +
_last_obj_copy_times_ms.get(i) +
_last_termination_times_ms.get(i);
@ -302,9 +298,6 @@ void G1GCPhaseTimes::print(double pause_time_sec) {
if (_last_satb_filtering_times_ms.sum() > 0.0) {
_last_satb_filtering_times_ms.print(2, "SATB Filtering (ms)");
}
if (_last_strong_code_root_mark_times_ms.sum() > 0.0) {
_last_strong_code_root_mark_times_ms.print(2, "Code Root Marking (ms)");
}
_last_update_rs_times_ms.print(2, "Update RS (ms)");
_last_update_rs_processed_buffers.print(3, "Processed Buffers");
_last_scan_rs_times_ms.print(2, "Scan RS (ms)");
@ -322,9 +315,6 @@ void G1GCPhaseTimes::print(double pause_time_sec) {
if (_last_satb_filtering_times_ms.sum() > 0.0) {
_last_satb_filtering_times_ms.print(1, "SATB Filtering (ms)");
}
if (_last_strong_code_root_mark_times_ms.sum() > 0.0) {
_last_strong_code_root_mark_times_ms.print(1, "Code Root Marking (ms)");
}
_last_update_rs_times_ms.print(1, "Update RS (ms)");
_last_update_rs_processed_buffers.print(2, "Processed Buffers");
_last_scan_rs_times_ms.print(1, "Scan RS (ms)");

9
hotspot/src/share/vm/gc_implementation/g1/g1GCPhaseTimes.hpp
View File

@ -120,7 +120,6 @@ class G1GCPhaseTimes : public CHeapObj<mtGC> {
WorkerDataArray<int> _last_update_rs_processed_buffers;
WorkerDataArray<double> _last_scan_rs_times_ms;
WorkerDataArray<double> _last_strong_code_root_scan_times_ms;
WorkerDataArray<double> _last_strong_code_root_mark_times_ms;
WorkerDataArray<double> _last_obj_copy_times_ms;
WorkerDataArray<double> _last_termination_times_ms;
WorkerDataArray<size_t> _last_termination_attempts;
@ -199,10 +198,6 @@ class G1GCPhaseTimes : public CHeapObj<mtGC> {
_last_strong_code_root_scan_times_ms.set(worker_i, ms);
}
void record_strong_code_root_mark_time(uint worker_i, double ms) {
_last_strong_code_root_mark_times_ms.set(worker_i, ms);
}
void record_obj_copy_time(uint worker_i, double ms) {
_last_obj_copy_times_ms.set(worker_i, ms);
}
@ -369,10 +364,6 @@ class G1GCPhaseTimes : public CHeapObj<mtGC> {
return _last_strong_code_root_scan_times_ms.average();
}
double average_last_strong_code_root_mark_time(){
return _last_strong_code_root_mark_times_ms.average();
}
double average_last_obj_copy_time() {
return _last_obj_copy_times_ms.average();
}

22
hotspot/src/share/vm/gc_implementation/g1/g1MarkSweep.cpp
View File

@ -129,13 +129,15 @@ void G1MarkSweep::mark_sweep_phase1(bool& marked_for_unloading,
SharedHeap* sh = SharedHeap::heap();
// Need cleared claim bits for the strong roots processing
// Need cleared claim bits for the roots processing
ClassLoaderDataGraph::clear_claimed_marks();
sh->process_strong_roots(true, // activate StrongRootsScope
SharedHeap::SO_SystemClasses,
MarkingCodeBlobClosure follow_code_closure(&GenMarkSweep::follow_root_closure, !CodeBlobToOopClosure::FixRelocations);
sh->process_strong_roots(true, // activate StrongRootsScope
SharedHeap::SO_None,
&GenMarkSweep::follow_root_closure,
&GenMarkSweep::follow_klass_closure);
&GenMarkSweep::follow_cld_closure,
&follow_code_closure);
// Process reference objects found during marking
ReferenceProcessor* rp = GenMarkSweep::ref_processor();
@ -304,13 +306,15 @@ void G1MarkSweep::mark_sweep_phase3() {
SharedHeap* sh = SharedHeap::heap();
// Need cleared claim bits for the strong roots processing
// Need cleared claim bits for the roots processing
ClassLoaderDataGraph::clear_claimed_marks();
sh->process_strong_roots(true, // activate StrongRootsScope
SharedHeap::SO_AllClasses | SharedHeap::SO_Strings | SharedHeap::SO_AllCodeCache,
&GenMarkSweep::adjust_pointer_closure,
&GenMarkSweep::adjust_klass_closure);
CodeBlobToOopClosure adjust_code_closure(&GenMarkSweep::adjust_pointer_closure, CodeBlobToOopClosure::FixRelocations);
sh->process_all_roots(true, // activate StrongRootsScope
SharedHeap::SO_AllCodeCache,
&GenMarkSweep::adjust_pointer_closure,
&GenMarkSweep::adjust_cld_closure,
&adjust_code_closure);
assert(GenMarkSweep::ref_processor() == g1h->ref_processor_stw(), "Sanity");
g1h->ref_processor_stw()->weak_oops_do(&GenMarkSweep::adjust_pointer_closure);

27
hotspot/src/share/vm/gc_implementation/g1/g1OopClosures.hpp
View File

@ -25,6 +25,8 @@
#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1OOPCLOSURES_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_G1OOPCLOSURES_HPP
#include "memory/iterator.hpp"
class HeapRegion;
class G1CollectedHeap;
class G1RemSet;
@ -106,7 +108,7 @@ protected:
template <class T> void do_klass_barrier(T* p, oop new_obj);
};
template <G1Barrier barrier, bool do_mark_object>
template <G1Barrier barrier, G1Mark do_mark_object>
class G1ParCopyClosure : public G1ParCopyHelper {
private:
template <class T> void do_oop_work(T* p);
@ -121,19 +123,19 @@ public:
template <class T> void do_oop_nv(T* p) { do_oop_work(p); }
virtual void do_oop(oop* p) { do_oop_nv(p); }
virtual void do_oop(narrowOop* p) { do_oop_nv(p); }
G1CollectedHeap* g1() { return _g1; };
G1ParScanThreadState* pss() { return _par_scan_state; }
ReferenceProcessor* rp() { return _ref_processor; };
};
typedef G1ParCopyClosure<G1BarrierNone, false> G1ParScanExtRootClosure;
typedef G1ParCopyClosure<G1BarrierKlass, false> G1ParScanMetadataClosure;
typedef G1ParCopyClosure<G1BarrierNone, true> G1ParScanAndMarkExtRootClosure;
typedef G1ParCopyClosure<G1BarrierKlass, true> G1ParScanAndMarkMetadataClosure;
typedef G1ParCopyClosure<G1BarrierNone, G1MarkNone> G1ParScanExtRootClosure;
typedef G1ParCopyClosure<G1BarrierNone, G1MarkFromRoot> G1ParScanAndMarkExtRootClosure;
typedef G1ParCopyClosure<G1BarrierNone, G1MarkPromotedFromRoot> G1ParScanAndMarkWeakExtRootClosure;
// We use a separate closure to handle references during evacuation
// failure processing.
typedef G1ParCopyClosure<G1BarrierEvac, false> G1ParScanHeapEvacFailureClosure;
typedef G1ParCopyClosure<G1BarrierEvac, G1MarkNone> G1ParScanHeapEvacFailureClosure;
class FilterIntoCSClosure: public ExtendedOopClosure {
G1CollectedHeap* _g1;
@ -164,10 +166,11 @@ public:
};
// Closure for iterating over object fields during concurrent marking
class G1CMOopClosure : public ExtendedOopClosure {
class G1CMOopClosure : public MetadataAwareOopClosure {
protected:
ConcurrentMark* _cm;
private:
G1CollectedHeap* _g1h;
ConcurrentMark* _cm;
CMTask* _task;
public:
G1CMOopClosure(G1CollectedHeap* g1h, ConcurrentMark* cm, CMTask* task);
@ -177,7 +180,7 @@ public:
};
// Closure to scan the root regions during concurrent marking
class G1RootRegionScanClosure : public ExtendedOopClosure {
class G1RootRegionScanClosure : public MetadataAwareOopClosure {
private:
G1CollectedHeap* _g1h;
ConcurrentMark* _cm;

5
hotspot/src/share/vm/gc_implementation/g1/g1OopClosures.inline.hpp
View File

@ -32,6 +32,7 @@
#include "gc_implementation/g1/g1RemSet.hpp"
#include "gc_implementation/g1/g1RemSet.inline.hpp"
#include "gc_implementation/g1/heapRegionRemSet.hpp"
#include "memory/iterator.inline.hpp"
#include "runtime/prefetch.inline.hpp"
/*
@ -108,10 +109,6 @@ inline void G1ParPushHeapRSClosure::do_oop_nv(T* p) {
template <class T>
inline void G1CMOopClosure::do_oop_nv(T* p) {
assert(_g1h->is_in_g1_reserved((HeapWord*) p), "invariant");
assert(!_g1h->is_on_master_free_list(
_g1h->heap_region_containing((HeapWord*) p)), "invariant");
oop obj = oopDesc::load_decode_heap_oop(p);
if (_cm->verbose_high()) {
gclog_or_tty->print_cr("[%u] we're looking at location "

11
hotspot/src/share/vm/gc_implementation/g1/g1_specialized_oop_closures.hpp
View File

@ -30,14 +30,21 @@
// non-virtually, using a mechanism defined in this file. Extend these
// macros in the obvious way to add specializations for new closures.
// Forward declarations.
enum G1Barrier {
G1BarrierNone,
G1BarrierEvac,
G1BarrierKlass
};
template<G1Barrier barrier, bool do_mark_object>
enum G1Mark {
G1MarkNone,
G1MarkFromRoot,
G1MarkPromotedFromRoot
};
// Forward declarations.
template<G1Barrier barrier, G1Mark do_mark_object>
class G1ParCopyClosure;
class G1ParScanClosure;

14
hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp
View File

@ -400,7 +400,6 @@ void HeapRegion::note_self_forwarding_removal_start(bool during_initial_mark,
// We always recreate the prev marking info and we'll explicitly
// mark all objects we find to be self-forwarded on the prev
// bitmap. So all objects need to be below PTAMS.
_prev_top_at_mark_start = top();
_prev_marked_bytes = 0;
if (during_initial_mark) {
@ -424,6 +423,7 @@ void HeapRegion::note_self_forwarding_removal_end(bool during_initial_mark,
assert(0 <= marked_bytes && marked_bytes <= used(),
err_msg("marked: "SIZE_FORMAT" used: "SIZE_FORMAT,
marked_bytes, used()));
_prev_top_at_mark_start = top();
_prev_marked_bytes = marked_bytes;
}
@ -905,7 +905,8 @@ void HeapRegion::verify(VerifyOption vo,
size_t obj_size = block_size(p);
object_num += 1;
if (is_humongous != g1->isHumongous(obj_size)) {
if (is_humongous != g1->isHumongous(obj_size) &&
!g1->is_obj_dead(obj, this)) { // Dead objects may have bigger block_size since they span several objects.
gclog_or_tty->print_cr("obj "PTR_FORMAT" is of %shumongous size ("
SIZE_FORMAT" words) in a %shumongous region",
p, g1->isHumongous(obj_size) ? "" : "non-",
@ -916,7 +917,9 @@ void HeapRegion::verify(VerifyOption vo,
// If it returns false, verify_for_object() will output the
// appropriate messasge.
if (do_bot_verify && !_offsets.verify_for_object(p, obj_size)) {
if (do_bot_verify &&
!g1->is_obj_dead(obj, this) &&
!_offsets.verify_for_object(p, obj_size)) {
*failures = true;
return;
}
@ -924,7 +927,10 @@ void HeapRegion::verify(VerifyOption vo,
if (!g1->is_obj_dead_cond(obj, this, vo)) {
if (obj->is_oop()) {
Klass* klass = obj->klass();
if (!klass->is_metaspace_object()) {
bool is_metaspace_object = Metaspace::contains(klass) ||
(vo == VerifyOption_G1UsePrevMarking &&
ClassLoaderDataGraph::unload_list_contains(klass));
if (!is_metaspace_object) {
gclog_or_tty->print_cr("klass "PTR_FORMAT" of object "PTR_FORMAT" "
"not metadata", klass, (void *)obj);
*failures = true;

6
hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp
View File

@ -247,11 +247,9 @@ class HeapRegion: public G1OffsetTableContigSpace {
bool _evacuation_failed;
// A heap region may be a member one of a number of special subsets, each
// represented as linked lists through the field below. Currently, these
// sets include:
// represented as linked lists through the field below. Currently, there
// is only one set:
// The collection set.
// The set of allocation regions used in a collection pause.
// Spaces that may contain gray objects.
HeapRegion* _next_in_special_set;
// next region in the young "generation" region set

21
hotspot/src/share/vm/gc_implementation/g1/heapRegion.inline.hpp
View File

@ -93,18 +93,27 @@ G1OffsetTableContigSpace::block_start_const(const void* p) const {
inline bool
HeapRegion::block_is_obj(const HeapWord* p) const {
return p < top();
G1CollectedHeap* g1h = G1CollectedHeap::heap();
return !g1h->is_obj_dead(oop(p), this);
}
inline size_t
HeapRegion::block_size(const HeapWord *addr) const {
const HeapWord* current_top = top();
if (addr < current_top) {
return oop(addr)->size();
} else {
assert(addr == current_top, "just checking");
// Old regions' dead objects may have dead classes
// We need to find the next live object in some other
// manner than getting the oop size
G1CollectedHeap* g1h = G1CollectedHeap::heap();
if (g1h->is_obj_dead(oop(addr), this)) {
HeapWord* next = g1h->concurrent_mark()->prevMarkBitMap()->
getNextMarkedWordAddress(addr, prev_top_at_mark_start());
assert(next > addr, "must get the next live object");
return pointer_delta(next, addr);
} else if (addr == top()) {
return pointer_delta(end(), addr);
}
return oop(addr)->size();
}
inline HeapWord* HeapRegion::par_allocate_no_bot_updates(size_t word_size) {

5
hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp
View File

@ -931,7 +931,10 @@ void HeapRegionRemSet::add_strong_code_root(nmethod* nm) {
void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) {
assert(nm != NULL, "sanity");
_code_roots.remove(nm);
assert_locked_or_safepoint(CodeCache_lock);
_code_roots.remove_lock_free(nm);
// Check that there were no duplicates
guarantee(!_code_roots.contains(nm), "duplicate entry found");
}

31
hotspot/src/share/vm/gc_implementation/g1/satbQueue.cpp
View File

@ -285,37 +285,6 @@ void SATBMarkQueueSet::set_par_closure(int i, ObjectClosure* par_closure) {
_par_closures[i] = par_closure;
}
void SATBMarkQueueSet::iterate_closure_all_threads() {
for(JavaThread* t = Threads::first(); t; t = t->next()) {
t->satb_mark_queue().apply_closure_and_empty(_closure);
}
shared_satb_queue()->apply_closure_and_empty(_closure);
}
void SATBMarkQueueSet::par_iterate_closure_all_threads(uint worker) {
SharedHeap* sh = SharedHeap::heap();
int parity = sh->strong_roots_parity();
for(JavaThread* t = Threads::first(); t; t = t->next()) {
if (t->claim_oops_do(true, parity)) {
t->satb_mark_queue().apply_closure_and_empty(_par_closures[worker]);
}
}
// We also need to claim the VMThread so that its parity is updated
// otherwise the next call to Thread::possibly_parallel_oops_do inside
// a StrongRootsScope might skip the VMThread because it has a stale
// parity that matches the parity set by the StrongRootsScope
//
// Whichever worker succeeds in claiming the VMThread gets to do
// the shared queue.
VMThread* vmt = VMThread::vm_thread();
if (vmt->claim_oops_do(true, parity)) {
shared_satb_queue()->apply_closure_and_empty(_par_closures[worker]);
}
}
bool SATBMarkQueueSet::apply_closure_to_completed_buffer_work(bool par,
uint worker) {
BufferNode* nd = NULL;

9
hotspot/src/share/vm/gc_implementation/g1/satbQueue.hpp
View File

@ -33,7 +33,9 @@ class SATBMarkQueueSet;
// A ptrQueue whose elements are "oops", pointers to object heads.
class ObjPtrQueue: public PtrQueue {
friend class Threads;
friend class SATBMarkQueueSet;
friend class G1RemarkThreadsClosure;
private:
// Filter out unwanted entries from the buffer.
@ -119,13 +121,6 @@ public:
// closures, one for each parallel GC thread.
void set_par_closure(int i, ObjectClosure* closure);
// Apply the registered closure to all entries on each
// currently-active buffer and then empty the buffer. It should only
// be called serially and at a safepoint.
void iterate_closure_all_threads();
// Parallel version of the above.
void par_iterate_closure_all_threads(uint worker);
// If there exists some completed buffer, pop it, then apply the
// registered closure to all its elements, and return true. If no
// completed buffers exist, return false.

23
hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp
View File

@ -614,18 +614,21 @@ void ParNewGenTask::work(uint worker_id) {
KlassScanClosure klass_scan_closure(&par_scan_state.to_space_root_closure(),
gch->rem_set()->klass_rem_set());
int so = SharedHeap::SO_AllClasses | SharedHeap::SO_Strings | SharedHeap::SO_ScavengeCodeCache;
CLDToKlassAndOopClosure cld_scan_closure(&klass_scan_closure,
&par_scan_state.to_space_root_closure(),
false);
par_scan_state.start_strong_roots();
gch->gen_process_strong_roots(_gen->level(),
true, // Process younger gens, if any,
// as strong roots.
false, // no scope; this is parallel code
SharedHeap::ScanningOption(so),
&par_scan_state.to_space_root_closure(),
&par_scan_state.older_gen_closure(),
&klass_scan_closure);
gch->gen_process_roots(_gen->level(),
true, // Process younger gens, if any,
// as strong roots.
false, // no scope; this is parallel code
SharedHeap::SO_ScavengeCodeCache,
GenCollectedHeap::StrongAndWeakRoots,
&par_scan_state.to_space_root_closure(),
&par_scan_state.older_gen_closure(),
&cld_scan_closure);
par_scan_state.end_strong_roots();
// "evacuate followers".

2
hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.hpp
View File

@ -69,7 +69,7 @@ class ParScanThreadState {
ParScanWithoutBarrierClosure _to_space_closure; // scan_without_gc_barrier
ParScanWithBarrierClosure _old_gen_closure; // scan_with_gc_barrier
ParRootScanWithoutBarrierClosure _to_space_root_closure; // scan_root_without_gc_barrier
// One of these two will be passed to process_strong_roots, which will
// One of these two will be passed to process_roots, which will
// set its generation. The first is for two-gen configs where the
// old gen collects the perm gen; the second is for arbitrary configs.
// The second isn't used right now (it used to be used for the train, an

4
hotspot/src/share/vm/gc_implementation/parallelScavenge/pcTasks.cpp
View File

@ -59,7 +59,7 @@ void ThreadRootsMarkingTask::do_it(GCTaskManager* manager, uint which) {
PSParallelCompact::MarkAndPushClosure mark_and_push_closure(cm);
CLDToOopClosure mark_and_push_from_clds(&mark_and_push_closure, true);
CodeBlobToOopClosure mark_and_push_in_blobs(&mark_and_push_closure, /*do_marking=*/ true);
MarkingCodeBlobClosure mark_and_push_in_blobs(&mark_and_push_closure, !CodeBlobToOopClosure::FixRelocations);
if (_java_thread != NULL)
_java_thread->oops_do(
@ -100,7 +100,7 @@ void MarkFromRootsTask::do_it(GCTaskManager* manager, uint which) {
case threads:
{
ResourceMark rm;
CodeBlobToOopClosure each_active_code_blob(&mark_and_push_closure, /*do_marking=*/ true);
MarkingCodeBlobClosure each_active_code_blob(&mark_and_push_closure, !CodeBlobToOopClosure::FixRelocations);
CLDToOopClosure mark_and_push_from_cld(&mark_and_push_closure);
Threads::oops_do(&mark_and_push_closure, &mark_and_push_from_cld, &each_active_code_blob);
}

10
hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp
View File

@ -536,14 +536,14 @@ void PSMarkSweep::mark_sweep_phase1(bool clear_all_softrefs) {
Universe::oops_do(mark_and_push_closure());
JNIHandles::oops_do(mark_and_push_closure()); // Global (strong) JNI handles
CLDToOopClosure mark_and_push_from_cld(mark_and_push_closure());
CodeBlobToOopClosure each_active_code_blob(mark_and_push_closure(), /*do_marking=*/ true);
MarkingCodeBlobClosure each_active_code_blob(mark_and_push_closure(), !CodeBlobToOopClosure::FixRelocations);
Threads::oops_do(mark_and_push_closure(), &mark_and_push_from_cld, &each_active_code_blob);
ObjectSynchronizer::oops_do(mark_and_push_closure());
FlatProfiler::oops_do(mark_and_push_closure());
Management::oops_do(mark_and_push_closure());
JvmtiExport::oops_do(mark_and_push_closure());
SystemDictionary::always_strong_oops_do(mark_and_push_closure());
ClassLoaderDataGraph::always_strong_oops_do(mark_and_push_closure(), follow_klass_closure(), true);
ClassLoaderDataGraph::always_strong_cld_do(follow_cld_closure());
// Do not treat nmethods as strong roots for mark/sweep, since we can unload them.
//CodeCache::scavenge_root_nmethods_do(CodeBlobToOopClosure(mark_and_push_closure()));
}
@ -633,16 +633,16 @@ void PSMarkSweep::mark_sweep_phase3() {
FlatProfiler::oops_do(adjust_pointer_closure());
Management::oops_do(adjust_pointer_closure());
JvmtiExport::oops_do(adjust_pointer_closure());
// SO_AllClasses
SystemDictionary::oops_do(adjust_pointer_closure());
ClassLoaderDataGraph::oops_do(adjust_pointer_closure(), adjust_klass_closure(), true);
ClassLoaderDataGraph::cld_do(adjust_cld_closure());
// Now adjust pointers in remaining weak roots. (All of which should
// have been cleared if they pointed to non-surviving objects.)
// Global (weak) JNI handles
JNIHandles::weak_oops_do(&always_true, adjust_pointer_closure());
CodeCache::oops_do(adjust_pointer_closure());
CodeBlobToOopClosure adjust_from_blobs(adjust_pointer_closure(), CodeBlobToOopClosure::FixRelocations);
CodeCache::blobs_do(&adjust_from_blobs);
StringTable::oops_do(adjust_pointer_closure());
ref_processor()->weak_oops_do(adjust_pointer_closure());
PSScavenge::reference_processor()->weak_oops_do(adjust_pointer_closure());

10
hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.hpp
View File

@ -40,11 +40,11 @@ class PSMarkSweep : public MarkSweep {
static CollectorCounters* _counters;
// Closure accessors
static OopClosure* mark_and_push_closure() { return &MarkSweep::mark_and_push_closure; }
static KlassClosure* follow_klass_closure() { return &MarkSweep::follow_klass_closure; }
static VoidClosure* follow_stack_closure() { return (VoidClosure*)&MarkSweep::follow_stack_closure; }
static OopClosure* adjust_pointer_closure() { return (OopClosure*)&MarkSweep::adjust_pointer_closure; }
static KlassClosure* adjust_klass_closure() { return &MarkSweep::adjust_klass_closure; }
static OopClosure* mark_and_push_closure() { return &MarkSweep::mark_and_push_closure; }
static VoidClosure* follow_stack_closure() { return (VoidClosure*)&MarkSweep::follow_stack_closure; }
static CLDClosure* follow_cld_closure() { return &MarkSweep::follow_cld_closure; }
static OopClosure* adjust_pointer_closure() { return (OopClosure*)&MarkSweep::adjust_pointer_closure; }
static CLDClosure* adjust_cld_closure() { return &MarkSweep::adjust_cld_closure; }
static BoolObjectClosure* is_alive_closure() { return (BoolObjectClosure*)&MarkSweep::is_alive; }
debug_only(public:) // Used for PSParallelCompact debugging

4
hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp
View File

@ -2474,7 +2474,6 @@ void PSParallelCompact::adjust_roots() {
FlatProfiler::oops_do(adjust_pointer_closure());
Management::oops_do(adjust_pointer_closure());
JvmtiExport::oops_do(adjust_pointer_closure());
// SO_AllClasses
SystemDictionary::oops_do(adjust_pointer_closure());
ClassLoaderDataGraph::oops_do(adjust_pointer_closure(), adjust_klass_closure(), true);
@ -2483,7 +2482,8 @@ void PSParallelCompact::adjust_roots() {
// Global (weak) JNI handles
JNIHandles::weak_oops_do(&always_true, adjust_pointer_closure());
CodeCache::oops_do(adjust_pointer_closure());
CodeBlobToOopClosure adjust_from_blobs(adjust_pointer_closure(), CodeBlobToOopClosure::FixRelocations);
CodeCache::blobs_do(&adjust_from_blobs);
StringTable::oops_do(adjust_pointer_closure());
ref_processor()->weak_oops_do(adjust_pointer_closure());
// Roots were visited so references into the young gen in roots

4
hotspot/src/share/vm/gc_implementation/parallelScavenge/psTasks.cpp
View File

@ -100,7 +100,7 @@ void ScavengeRootsTask::do_it(GCTaskManager* manager, uint which) {
case code_cache:
{
CodeBlobToOopClosure each_scavengable_code_blob(&roots_to_old_closure, /*do_marking=*/ true);
MarkingCodeBlobClosure each_scavengable_code_blob(&roots_to_old_closure, CodeBlobToOopClosure::FixRelocations);
CodeCache::scavenge_root_nmethods_do(&each_scavengable_code_blob);
}
break;
@ -123,7 +123,7 @@ void ThreadRootsTask::do_it(GCTaskManager* manager, uint which) {
PSPromotionManager* pm = PSPromotionManager::gc_thread_promotion_manager(which);
PSScavengeRootsClosure roots_closure(pm);
CLDClosure* roots_from_clds = NULL; // Not needed. All CLDs are already visited.
CodeBlobToOopClosure roots_in_blobs(&roots_closure, /*do_marking=*/ true);
MarkingCodeBlobClosure roots_in_blobs(&roots_closure, CodeBlobToOopClosure::FixRelocations);
if (_java_thread != NULL)
_java_thread->oops_do(&roots_closure, roots_from_clds, &roots_in_blobs);

13
hotspot/src/share/vm/gc_implementation/shared/markSweep.cpp
View File

@ -54,21 +54,14 @@ void MarkSweep::FollowRootClosure::do_oop(oop* p) { follow_root(p); }
void MarkSweep::FollowRootClosure::do_oop(narrowOop* p) { follow_root(p); }
MarkSweep::MarkAndPushClosure MarkSweep::mark_and_push_closure;
MarkSweep::FollowKlassClosure MarkSweep::follow_klass_closure;
MarkSweep::AdjustKlassClosure MarkSweep::adjust_klass_closure;
CLDToOopClosure MarkSweep::follow_cld_closure(&mark_and_push_closure);
CLDToOopClosure MarkSweep::adjust_cld_closure(&adjust_pointer_closure);
void MarkSweep::MarkAndPushClosure::do_oop(oop* p) { mark_and_push(p); }
void MarkSweep::MarkAndPushClosure::do_oop(narrowOop* p) { mark_and_push(p); }
void MarkSweep::FollowKlassClosure::do_klass(Klass* klass) {
klass->oops_do(&MarkSweep::mark_and_push_closure);
}
void MarkSweep::AdjustKlassClosure::do_klass(Klass* klass) {
klass->oops_do(&MarkSweep::adjust_pointer_closure);
}
void MarkSweep::follow_class_loader(ClassLoaderData* cld) {
cld->oops_do(&MarkSweep::mark_and_push_closure, &MarkSweep::follow_klass_closure, true);
MarkSweep::follow_cld_closure.do_cld(cld);
}
void MarkSweep::follow_stack() {

15
hotspot/src/share/vm/gc_implementation/shared/markSweep.hpp
View File

@ -65,17 +65,6 @@ class MarkSweep : AllStatic {
virtual void do_oop(narrowOop* p);
};
// The one and only place to start following the classes.
// Should only be applied to the ClassLoaderData klasses list.
class FollowKlassClosure : public KlassClosure {
public:
void do_klass(Klass* klass);
};
class AdjustKlassClosure : public KlassClosure {
public:
void do_klass(Klass* klass);
};
class FollowStackClosure: public VoidClosure {
public:
virtual void do_void();
@ -144,10 +133,10 @@ class MarkSweep : AllStatic {
static IsAliveClosure is_alive;
static FollowRootClosure follow_root_closure;
static MarkAndPushClosure mark_and_push_closure;
static FollowKlassClosure follow_klass_closure;
static FollowStackClosure follow_stack_closure;
static CLDToOopClosure follow_cld_closure;
static AdjustPointerClosure adjust_pointer_closure;
static AdjustKlassClosure adjust_klass_closure;
static CLDToOopClosure adjust_cld_closure;
// Accessors
static uint total_invocations() { return _total_invocations; }

130
hotspot/src/share/vm/gc_implementation/shared/vmGCOperations.cpp
View File

@ -195,6 +195,43 @@ void VM_GenCollectFull::doit() {
gch->do_full_collection(gch->must_clear_all_soft_refs(), _max_level);
}
bool VM_CollectForMetadataAllocation::initiate_concurrent_GC() {
#if INCLUDE_ALL_GCS
if (UseConcMarkSweepGC || UseG1GC) {
if (UseConcMarkSweepGC && CMSClassUnloadingEnabled) {
MetaspaceGC::set_should_concurrent_collect(true);
} else if (UseG1GC) {
G1CollectedHeap* g1h = G1CollectedHeap::heap();
g1h->g1_policy()->set_initiate_conc_mark_if_possible();
GCCauseSetter x(g1h, _gc_cause);
// At this point we are supposed to start a concurrent cycle. We
// will do so if one is not already in progress.
bool should_start = g1h->g1_policy()->force_initial_mark_if_outside_cycle(_gc_cause);
if (should_start) {
double pause_target = g1h->g1_policy()->max_pause_time_ms();
g1h->do_collection_pause_at_safepoint(pause_target);
}
}
return true;
}
#endif
return false;
}
static void log_metaspace_alloc_failure_for_concurrent_GC() {
if (Verbose && PrintGCDetails) {
if (UseConcMarkSweepGC) {
gclog_or_tty->print_cr("\nCMS full GC for Metaspace");
} else if (UseG1GC) {
gclog_or_tty->print_cr("\nG1 full GC for Metaspace");
}
}
}
void VM_CollectForMetadataAllocation::doit() {
SvcGCMarker sgcm(SvcGCMarker::FULL);
@ -206,54 +243,57 @@ void VM_CollectForMetadataAllocation::doit() {
// a GC that freed space for the allocation.
if (!MetadataAllocationFailALot) {
_result = _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
}
if (_result == NULL) {
if (UseConcMarkSweepGC) {
if (CMSClassUnloadingEnabled) {
MetaspaceGC::set_should_concurrent_collect(true);
}
// For CMS expand since the collection is going to be concurrent.
_result =
_loader_data->metaspace_non_null()->expand_and_allocate(_size, _mdtype);
}
if (_result == NULL) {
// Don't clear the soft refs yet.
if (Verbose && PrintGCDetails && UseConcMarkSweepGC) {
gclog_or_tty->print_cr("\nCMS full GC for Metaspace");
}
heap->collect_as_vm_thread(GCCause::_metadata_GC_threshold);
// After a GC try to allocate without expanding. Could fail
// and expansion will be tried below.
_result =
_loader_data->metaspace_non_null()->allocate(_size, _mdtype);
}
if (_result == NULL) {
// If still failing, allow the Metaspace to expand.
// See delta_capacity_until_GC() for explanation of the
// amount of the expansion.
// This should work unless there really is no more space
// or a MaxMetaspaceSize has been specified on the command line.
_result =
_loader_data->metaspace_non_null()->expand_and_allocate(_size, _mdtype);
if (_result == NULL) {
// If expansion failed, do a last-ditch collection and try allocating
// again. A last-ditch collection will clear softrefs. This
// behavior is similar to the last-ditch collection done for perm
// gen when it was full and a collection for failed allocation
// did not free perm gen space.
heap->collect_as_vm_thread(GCCause::_last_ditch_collection);
_result =
_loader_data->metaspace_non_null()->allocate(_size, _mdtype);
}
}
if (Verbose && PrintGCDetails && _result == NULL) {
gclog_or_tty->print_cr("\nAfter Metaspace GC failed to allocate size "
SIZE_FORMAT, _size);
if (_result != NULL) {
return;
}
}
if (_result == NULL && GC_locker::is_active_and_needs_gc()) {
if (initiate_concurrent_GC()) {
// For CMS and G1 expand since the collection is going to be concurrent.
_result = _loader_data->metaspace_non_null()->expand_and_allocate(_size, _mdtype);
if (_result != NULL) {
return;
}
log_metaspace_alloc_failure_for_concurrent_GC();
}
// Don't clear the soft refs yet.
heap->collect_as_vm_thread(GCCause::_metadata_GC_threshold);
// After a GC try to allocate without expanding. Could fail
// and expansion will be tried below.
_result = _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
if (_result != NULL) {
return;
}
// If still failing, allow the Metaspace to expand.
// See delta_capacity_until_GC() for explanation of the
// amount of the expansion.
// This should work unless there really is no more space
// or a MaxMetaspaceSize has been specified on the command line.
_result = _loader_data->metaspace_non_null()->expand_and_allocate(_size, _mdtype);
if (_result != NULL) {
return;
}
// If expansion failed, do a last-ditch collection and try allocating
// again. A last-ditch collection will clear softrefs. This
// behavior is similar to the last-ditch collection done for perm
// gen when it was full and a collection for failed allocation
// did not free perm gen space.
heap->collect_as_vm_thread(GCCause::_last_ditch_collection);
_result = _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
if (_result != NULL) {
return;
}
if (Verbose && PrintGCDetails) {
gclog_or_tty->print_cr("\nAfter Metaspace GC failed to allocate size "
SIZE_FORMAT, _size);
}
if (GC_locker::is_active_and_needs_gc()) {
set_gc_locked();
}
}

2
hotspot/src/share/vm/gc_implementation/shared/vmGCOperations.hpp
View File

@ -217,6 +217,8 @@ class VM_CollectForMetadataAllocation: public VM_GC_Operation {
virtual VMOp_Type type() const { return VMOp_CollectForMetadataAllocation; }
virtual void doit();
MetaWord* result() const { return _result; }
bool initiate_concurrent_GC();
};
class SvcGCMarker : public StackObj {

4
hotspot/src/share/vm/memory/cardTableModRefBS.cpp
View File

@ -429,7 +429,7 @@ void CardTableModRefBS::non_clean_card_iterate_possibly_parallel(Space* sp,
OopsInGenClosure* cl,
CardTableRS* ct) {
if (!mr.is_empty()) {
// Caller (process_strong_roots()) claims that all GC threads
// Caller (process_roots()) claims that all GC threads
// execute this call. With UseDynamicNumberOfGCThreads now all
// active GC threads execute this call. The number of active GC
// threads needs to be passed to par_non_clean_card_iterate_work()
@ -438,7 +438,7 @@ void CardTableModRefBS::non_clean_card_iterate_possibly_parallel(Space* sp,
// This is an example of where n_par_threads() is used instead
// of workers()->active_workers(). n_par_threads can be set to 0 to
// turn off parallelism. For example when this code is called as
// part of verification and SharedHeap::process_strong_roots() is being
// part of verification and SharedHeap::process_roots() is being
// used, then n_par_threads() may have been set to 0. active_workers
// is not overloaded with the meaning that it is a switch to disable
// parallelism and so keeps the meaning of the number of

22
hotspot/src/share/vm/memory/defNewGeneration.cpp
View File

@ -614,6 +614,9 @@ void DefNewGeneration::collect(bool full,
KlassScanClosure klass_scan_closure(&fsc_with_no_gc_barrier,
gch->rem_set()->klass_rem_set());
CLDToKlassAndOopClosure cld_scan_closure(&klass_scan_closure,
&fsc_with_no_gc_barrier,
false);
set_promo_failure_scan_stack_closure(&fsc_with_no_gc_barrier);
FastEvacuateFollowersClosure evacuate_followers(gch, _level, this,
@ -623,16 +626,15 @@ void DefNewGeneration::collect(bool full,
assert(gch->no_allocs_since_save_marks(0),
"save marks have not been newly set.");
int so = SharedHeap::SO_AllClasses | SharedHeap::SO_Strings | SharedHeap::SO_ScavengeCodeCache;
gch->gen_process_strong_roots(_level,
true, // Process younger gens, if any,
// as strong roots.
true, // activate StrongRootsScope
SharedHeap::ScanningOption(so),
&fsc_with_no_gc_barrier,
&fsc_with_gc_barrier,
&klass_scan_closure);
gch->gen_process_roots(_level,
true, // Process younger gens, if any,
// as strong roots.
true, // activate StrongRootsScope
SharedHeap::SO_ScavengeCodeCache,
GenCollectedHeap::StrongAndWeakRoots,
&fsc_with_no_gc_barrier,
&fsc_with_gc_barrier,
&cld_scan_closure);
// "evacuate followers".
evacuate_followers.do_void();

72
hotspot/src/share/vm/memory/genCollectedHeap.cpp
View File

@ -61,8 +61,8 @@
GenCollectedHeap* GenCollectedHeap::_gch;
NOT_PRODUCT(size_t GenCollectedHeap::_skip_header_HeapWords = 0;)
// The set of potentially parallel tasks in strong root scanning.
enum GCH_process_strong_roots_tasks {
// The set of potentially parallel tasks in root scanning.
enum GCH_strong_roots_tasks {
// We probably want to parallelize both of these internally, but for now...
GCH_PS_younger_gens,
// Leave this one last.
@ -72,11 +72,11 @@ enum GCH_process_strong_roots_tasks {
GenCollectedHeap::GenCollectedHeap(GenCollectorPolicy *policy) :
SharedHeap(policy),
_gen_policy(policy),
_gen_process_strong_tasks(new SubTasksDone(GCH_PS_NumElements)),
_gen_process_roots_tasks(new SubTasksDone(GCH_PS_NumElements)),
_full_collections_completed(0)
{
if (_gen_process_strong_tasks == NULL ||
!_gen_process_strong_tasks->valid()) {
if (_gen_process_roots_tasks == NULL ||
!_gen_process_roots_tasks->valid()) {
vm_exit_during_initialization("Failed necessary allocation.");
}
assert(policy != NULL, "Sanity check");
@ -584,24 +584,29 @@ HeapWord* GenCollectedHeap::satisfy_failed_allocation(size_t size, bool is_tlab)
void GenCollectedHeap::set_par_threads(uint t) {
SharedHeap::set_par_threads(t);
_gen_process_strong_tasks->set_n_threads(t);
_gen_process_roots_tasks->set_n_threads(t);
}
void GenCollectedHeap::
gen_process_strong_roots(int level,
bool younger_gens_as_roots,
bool activate_scope,
SharedHeap::ScanningOption so,
OopsInGenClosure* not_older_gens,
OopsInGenClosure* older_gens,
KlassClosure* klass_closure) {
// General strong roots.
gen_process_roots(int level,
bool younger_gens_as_roots,
bool activate_scope,
SharedHeap::ScanningOption so,
OopsInGenClosure* not_older_gens,
OopsInGenClosure* weak_roots,
OopsInGenClosure* older_gens,
CLDClosure* cld_closure,
CLDClosure* weak_cld_closure,
CodeBlobClosure* code_closure) {
SharedHeap::process_strong_roots(activate_scope, so,
not_older_gens, klass_closure);
// General roots.
SharedHeap::process_roots(activate_scope, so,
not_older_gens, weak_roots,
cld_closure, weak_cld_closure,
code_closure);
if (younger_gens_as_roots) {
if (!_gen_process_strong_tasks->is_task_claimed(GCH_PS_younger_gens)) {
if (!_gen_process_roots_tasks->is_task_claimed(GCH_PS_younger_gens)) {
for (int i = 0; i < level; i++) {
not_older_gens->set_generation(_gens[i]);
_gens[i]->oop_iterate(not_older_gens);
@ -617,7 +622,38 @@ gen_process_strong_roots(int level,
older_gens->reset_generation();
}
_gen_process_strong_tasks->all_tasks_completed();
_gen_process_roots_tasks->all_tasks_completed();
}
void GenCollectedHeap::
gen_process_roots(int level,
bool younger_gens_as_roots,
bool activate_scope,
SharedHeap::ScanningOption so,
bool only_strong_roots,
OopsInGenClosure* not_older_gens,
OopsInGenClosure* older_gens,
CLDClosure* cld_closure) {
const bool is_adjust_phase = !only_strong_roots && !younger_gens_as_roots;
bool is_moving_collection = false;
if (level == 0 || is_adjust_phase) {
// young collections are always moving
is_moving_collection = true;
}
MarkingCodeBlobClosure mark_code_closure(not_older_gens, is_moving_collection);
CodeBlobClosure* code_closure = &mark_code_closure;
gen_process_roots(level,
younger_gens_as_roots,
activate_scope, so,
not_older_gens, only_strong_roots ? NULL : not_older_gens,
older_gens,
cld_closure, only_strong_roots ? NULL : cld_closure,
code_closure);
}
void GenCollectedHeap::gen_process_weak_roots(OopClosure* root_closure) {

42
hotspot/src/share/vm/memory/genCollectedHeap.hpp
View File

@ -78,9 +78,9 @@ public:
unsigned int _full_collections_completed;
// Data structure for claiming the (potentially) parallel tasks in
// (gen-specific) strong roots processing.
SubTasksDone* _gen_process_strong_tasks;
SubTasksDone* gen_process_strong_tasks() { return _gen_process_strong_tasks; }
// (gen-specific) roots processing.
SubTasksDone* _gen_process_roots_tasks;
SubTasksDone* gen_process_roots_tasks() { return _gen_process_roots_tasks; }
// In block contents verification, the number of header words to skip
NOT_PRODUCT(static size_t _skip_header_HeapWords;)
@ -403,18 +403,30 @@ public:
// The "so" argument determines which of the roots
// the closure is applied to:
// "SO_None" does none;
// "SO_AllClasses" applies the closure to all entries in the SystemDictionary;
// "SO_SystemClasses" to all the "system" classes and loaders;
// "SO_Strings" applies the closure to all entries in the StringTable.
void gen_process_strong_roots(int level,
bool younger_gens_as_roots,
// The remaining arguments are in an order
// consistent with SharedHeap::process_strong_roots:
bool activate_scope,
SharedHeap::ScanningOption so,
OopsInGenClosure* not_older_gens,
OopsInGenClosure* older_gens,
KlassClosure* klass_closure);
private:
void gen_process_roots(int level,
bool younger_gens_as_roots,
bool activate_scope,
SharedHeap::ScanningOption so,
OopsInGenClosure* not_older_gens,
OopsInGenClosure* weak_roots,
OopsInGenClosure* older_gens,
CLDClosure* cld_closure,
CLDClosure* weak_cld_closure,
CodeBlobClosure* code_closure);
public:
static const bool StrongAndWeakRoots = false;
static const bool StrongRootsOnly = true;
void gen_process_roots(int level,
bool younger_gens_as_roots,
bool activate_scope,
SharedHeap::ScanningOption so,
bool only_strong_roots,
OopsInGenClosure* not_older_gens,
OopsInGenClosure* older_gens,
CLDClosure* cld_closure);
// Apply "root_closure" to all the weak roots of the system.
// These include JNI weak roots, string table,

30
hotspot/src/share/vm/memory/genMarkSweep.cpp
View File

@ -207,13 +207,14 @@ void GenMarkSweep::mark_sweep_phase1(int level,
// Need new claim bits before marking starts.
ClassLoaderDataGraph::clear_claimed_marks();
gch->gen_process_strong_roots(level,
false, // Younger gens are not roots.
true, // activate StrongRootsScope
SharedHeap::SO_SystemClasses,
&follow_root_closure,
&follow_root_closure,
&follow_klass_closure);
gch->gen_process_roots(level,
false, // Younger gens are not roots.
true, // activate StrongRootsScope
SharedHeap::SO_None,
GenCollectedHeap::StrongRootsOnly,
&follow_root_closure,
&follow_root_closure,
&follow_cld_closure);
// Process reference objects found during marking
{
@ -291,13 +292,14 @@ void GenMarkSweep::mark_sweep_phase3(int level) {
// are run.
adjust_pointer_closure.set_orig_generation(gch->get_gen(level));
gch->gen_process_strong_roots(level,
false, // Younger gens are not roots.
true, // activate StrongRootsScope
SharedHeap::SO_AllClasses | SharedHeap::SO_Strings | SharedHeap::SO_AllCodeCache,
&adjust_pointer_closure,
&adjust_pointer_closure,
&adjust_klass_closure);
gch->gen_process_roots(level,
false, // Younger gens are not roots.
true, // activate StrongRootsScope
SharedHeap::SO_AllCodeCache,
GenCollectedHeap::StrongAndWeakRoots,
&adjust_pointer_closure,
&adjust_pointer_closure,
&adjust_cld_closure);
gch->gen_process_weak_roots(&adjust_pointer_closure);

47
hotspot/src/share/vm/memory/iterator.cpp
View File

@ -35,6 +35,10 @@ void CLDToOopClosure::do_cld(ClassLoaderData* cld) {
cld->oops_do(_oop_closure, &_klass_closure, _must_claim_cld);
}
void CLDToKlassAndOopClosure::do_cld(ClassLoaderData* cld) {
cld->oops_do(_oop_closure, _klass_closure, _must_claim_cld);
}
void ObjectToOopClosure::do_object(oop obj) {
obj->oop_iterate(_cl);
}
@ -43,6 +47,20 @@ void VoidClosure::do_void() {
ShouldNotCallThis();
}
void CodeBlobToOopClosure::do_nmethod(nmethod* nm) {
nm->oops_do(_cl);
if (_fix_relocations) {
nm->fix_oop_relocations();
}
}
void CodeBlobToOopClosure::do_code_blob(CodeBlob* cb) {
nmethod* nm = cb->as_nmethod_or_null();
if (nm != NULL) {
do_nmethod(nm);
}
}
MarkingCodeBlobClosure::MarkScope::MarkScope(bool activate)
: _active(activate)
{
@ -55,32 +73,7 @@ MarkingCodeBlobClosure::MarkScope::~MarkScope() {
void MarkingCodeBlobClosure::do_code_blob(CodeBlob* cb) {
nmethod* nm = cb->as_nmethod_or_null();
if (nm == NULL) return;
if (!nm->test_set_oops_do_mark()) {
NOT_PRODUCT(if (TraceScavenge) nm->print_on(tty, "oops_do, 1st visit\n"));
do_newly_marked_nmethod(nm);
} else {
NOT_PRODUCT(if (TraceScavenge) nm->print_on(tty, "oops_do, skipped on 2nd visit\n"));
if (nm != NULL && !nm->test_set_oops_do_mark()) {
do_nmethod(nm);
}
}
void CodeBlobToOopClosure::do_newly_marked_nmethod(nmethod* nm) {
nm->oops_do(_cl, /*allow_zombie=*/ false);
}
void CodeBlobToOopClosure::do_code_blob(CodeBlob* cb) {
if (!_do_marking) {
nmethod* nm = cb->as_nmethod_or_null();
NOT_PRODUCT(if (TraceScavenge && Verbose && nm != NULL) nm->print_on(tty, "oops_do, unmarked visit\n"));
// This assert won't work, since there are lots of mini-passes
// (mostly in debug mode) that co-exist with marking phases.
//assert(!(cb->is_nmethod() && ((nmethod*)cb)->test_oops_do_mark()), "found marked nmethod during mark-free phase");
if (nm != NULL) {
nm->oops_do(_cl);
}
} else {
MarkingCodeBlobClosure::do_code_blob(cb);
}
}

65
hotspot/src/share/vm/memory/iterator.hpp
View File

@ -70,8 +70,8 @@ class ExtendedOopClosure : public OopClosure {
//
// Providing default implementations of the _nv functions unfortunately
// removes the compile-time safeness, but reduces the clutter for the
// ExtendedOopClosures that don't need to walk the metadata. Currently,
// only CMS needs these.
// ExtendedOopClosures that don't need to walk the metadata.
// Currently, only CMS and G1 need these.
virtual bool do_metadata() { return do_metadata_nv(); }
bool do_metadata_v() { return do_metadata(); }
@ -126,15 +126,16 @@ class KlassToOopClosure : public KlassClosure {
_oop_closure = oop_closure;
}
public:
public:
KlassToOopClosure(OopClosure* oop_closure = NULL) : _oop_closure(oop_closure) {}
virtual void do_klass(Klass* k);
};
class CLDToOopClosure : public CLDClosure {
OopClosure* _oop_closure;
OopClosure* _oop_closure;
KlassToOopClosure _klass_closure;
bool _must_claim_cld;
bool _must_claim_cld;
public:
CLDToOopClosure(OopClosure* oop_closure, bool must_claim_cld = true) :
@ -145,6 +146,23 @@ class CLDToOopClosure : public CLDClosure {
void do_cld(ClassLoaderData* cld);
};
class CLDToKlassAndOopClosure : public CLDClosure {
friend class SharedHeap;
friend class G1CollectedHeap;
protected:
OopClosure* _oop_closure;
KlassClosure* _klass_closure;
bool _must_claim_cld;
public:
CLDToKlassAndOopClosure(KlassClosure* klass_closure,
OopClosure* oop_closure,
bool must_claim_cld) :
_oop_closure(oop_closure),
_klass_closure(klass_closure),
_must_claim_cld(must_claim_cld) {}
void do_cld(ClassLoaderData* cld);
};
// The base class for all concurrent marking closures,
// that participates in class unloading.
// It's used to proxy through the metadata to the oops defined in them.
@ -246,14 +264,26 @@ class CodeBlobClosure : public Closure {
virtual void do_code_blob(CodeBlob* cb) = 0;
};
class MarkingCodeBlobClosure : public CodeBlobClosure {
// Applies an oop closure to all ref fields in code blobs
// iterated over in an object iteration.
class CodeBlobToOopClosure : public CodeBlobClosure {
OopClosure* _cl;
bool _fix_relocations;
protected:
void do_nmethod(nmethod* nm);
public:
CodeBlobToOopClosure(OopClosure* cl, bool fix_relocations) : _cl(cl), _fix_relocations(fix_relocations) {}
virtual void do_code_blob(CodeBlob* cb);
const static bool FixRelocations = true;
};
class MarkingCodeBlobClosure : public CodeBlobToOopClosure {
public:
MarkingCodeBlobClosure(OopClosure* cl, bool fix_relocations) : CodeBlobToOopClosure(cl, fix_relocations) {}
// Called for each code blob, but at most once per unique blob.
virtual void do_newly_marked_nmethod(nmethod* nm) = 0;
virtual void do_code_blob(CodeBlob* cb);
// = { if (!nmethod(cb)->test_set_oops_do_mark()) do_newly_marked_nmethod(cb); }
class MarkScope : public StackObj {
protected:
@ -266,23 +296,6 @@ class MarkingCodeBlobClosure : public CodeBlobClosure {
};
};
// Applies an oop closure to all ref fields in code blobs
// iterated over in an object iteration.
class CodeBlobToOopClosure: public MarkingCodeBlobClosure {
OopClosure* _cl;
bool _do_marking;
public:
virtual void do_newly_marked_nmethod(nmethod* cb);
// = { cb->oops_do(_cl); }
virtual void do_code_blob(CodeBlob* cb);
// = { if (_do_marking) super::do_code_blob(cb); else cb->oops_do(_cl); }
CodeBlobToOopClosure(OopClosure* cl, bool do_marking)
: _cl(cl), _do_marking(do_marking) {}
};
// MonitorClosure is used for iterating over monitors in the monitors cache
class ObjectMonitor;

1
hotspot/src/share/vm/memory/metadataFactory.hpp
View File

@ -25,6 +25,7 @@
#ifndef SHARE_VM_MEMORY_METADATAFACTORY_HPP
#define SHARE_VM_MEMORY_METADATAFACTORY_HPP
#include "classfile/classLoaderData.hpp"
#include "utilities/array.hpp"
#include "utilities/exceptions.hpp"
#include "utilities/globalDefinitions.hpp"

170
hotspot/src/share/vm/memory/sharedHeap.cpp
View File

@ -29,6 +29,7 @@
#include "gc_interface/collectedHeap.inline.hpp"
#include "memory/sharedHeap.hpp"
#include "oops/oop.inline.hpp"
#include "runtime/atomic.inline.hpp"
#include "runtime/fprofiler.hpp"
#include "runtime/java.hpp"
#include "services/management.hpp"
@ -39,8 +40,8 @@ PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
SharedHeap* SharedHeap::_sh;
// The set of potentially parallel tasks in strong root scanning.
enum SH_process_strong_roots_tasks {
// The set of potentially parallel tasks in root scanning.
enum SH_process_roots_tasks {
SH_PS_Universe_oops_do,
SH_PS_JNIHandles_oops_do,
SH_PS_ObjectSynchronizer_oops_do,
@ -58,6 +59,7 @@ SharedHeap::SharedHeap(CollectorPolicy* policy_) :
CollectedHeap(),
_collector_policy(policy_),
_rem_set(NULL),
_strong_roots_scope(NULL),
_strong_roots_parity(0),
_process_strong_tasks(new SubTasksDone(SH_PS_NumElements)),
_workers(NULL)
@ -114,6 +116,19 @@ public:
static AssertNonScavengableClosure assert_is_non_scavengable_closure;
#endif
SharedHeap::StrongRootsScope* SharedHeap::active_strong_roots_scope() const {
return _strong_roots_scope;
}
void SharedHeap::register_strong_roots_scope(SharedHeap::StrongRootsScope* scope) {
assert(_strong_roots_scope == NULL, "Should only have one StrongRootsScope active");
assert(scope != NULL, "Illegal argument");
_strong_roots_scope = scope;
}
void SharedHeap::unregister_strong_roots_scope(SharedHeap::StrongRootsScope* scope) {
assert(_strong_roots_scope == scope, "Wrong scope unregistered");
_strong_roots_scope = NULL;
}
void SharedHeap::change_strong_roots_parity() {
// Also set the new collection parity.
assert(_strong_roots_parity >= 0 && _strong_roots_parity <= 2,
@ -124,112 +139,161 @@ void SharedHeap::change_strong_roots_parity() {
"Not in range.");
}
SharedHeap::StrongRootsScope::StrongRootsScope(SharedHeap* outer, bool activate)
: MarkScope(activate)
SharedHeap::StrongRootsScope::StrongRootsScope(SharedHeap* heap, bool activate)
: MarkScope(activate), _sh(heap), _n_workers_done_with_threads(0)
{
if (_active) {
outer->change_strong_roots_parity();
_sh->register_strong_roots_scope(this);
_sh->change_strong_roots_parity();
// Zero the claimed high water mark in the StringTable
StringTable::clear_parallel_claimed_index();
}
}
SharedHeap::StrongRootsScope::~StrongRootsScope() {
// nothing particular
if (_active) {
_sh->unregister_strong_roots_scope(this);
}
}
void SharedHeap::process_strong_roots(bool activate_scope,
ScanningOption so,
OopClosure* roots,
KlassClosure* klass_closure) {
Monitor* SharedHeap::StrongRootsScope::_lock = new Monitor(Mutex::leaf, "StrongRootsScope lock", false);
void SharedHeap::StrongRootsScope::mark_worker_done_with_threads(uint n_workers) {
// The Thread work barrier is only needed by G1.
// No need to use the barrier if this is single-threaded code.
if (UseG1GC && n_workers > 0) {
uint new_value = (uint)Atomic::add(1, &_n_workers_done_with_threads);
if (new_value == n_workers) {
// This thread is last. Notify the others.
MonitorLockerEx ml(_lock, Mutex::_no_safepoint_check_flag);
_lock->notify_all();
}
}
}
void SharedHeap::StrongRootsScope::wait_until_all_workers_done_with_threads(uint n_workers) {
// No need to use the barrier if this is single-threaded code.
if (n_workers > 0 && (uint)_n_workers_done_with_threads != n_workers) {
MonitorLockerEx ml(_lock, Mutex::_no_safepoint_check_flag);
while ((uint)_n_workers_done_with_threads != n_workers) {
_lock->wait(Mutex::_no_safepoint_check_flag, 0, false);
}
}
}
void SharedHeap::process_roots(bool activate_scope,
ScanningOption so,
OopClosure* strong_roots,
OopClosure* weak_roots,
CLDClosure* strong_cld_closure,
CLDClosure* weak_cld_closure,
CodeBlobClosure* code_roots) {
StrongRootsScope srs(this, activate_scope);
// General strong roots.
// General roots.
assert(_strong_roots_parity != 0, "must have called prologue code");
assert(code_roots != NULL, "code root closure should always be set");
// _n_termination for _process_strong_tasks should be set up stream
// in a method not running in a GC worker. Otherwise the GC worker
// could be trying to change the termination condition while the task
// is executing in another GC worker.
// Iterating over the CLDG and the Threads are done early to allow G1 to
// first process the strong CLDs and nmethods and then, after a barrier,
// let the thread process the weak CLDs and nmethods.
if (!_process_strong_tasks->is_task_claimed(SH_PS_ClassLoaderDataGraph_oops_do)) {
ClassLoaderDataGraph::roots_cld_do(strong_cld_closure, weak_cld_closure);
}
// Some CLDs contained in the thread frames should be considered strong.
// Don't process them if they will be processed during the ClassLoaderDataGraph phase.
CLDClosure* roots_from_clds_p = (strong_cld_closure != weak_cld_closure) ? strong_cld_closure : NULL;
// Only process code roots from thread stacks if we aren't visiting the entire CodeCache anyway
CodeBlobClosure* roots_from_code_p = (so & SO_AllCodeCache) ? NULL : code_roots;
Threads::possibly_parallel_oops_do(strong_roots, roots_from_clds_p, roots_from_code_p);
// This is the point where this worker thread will not find more strong CLDs/nmethods.
// Report this so G1 can synchronize the strong and weak CLDs/nmethods processing.
active_strong_roots_scope()->mark_worker_done_with_threads(n_par_threads());
if (!_process_strong_tasks->is_task_claimed(SH_PS_Universe_oops_do)) {
Universe::oops_do(roots);
Universe::oops_do(strong_roots);
}
// Global (strong) JNI handles
if (!_process_strong_tasks->is_task_claimed(SH_PS_JNIHandles_oops_do))
JNIHandles::oops_do(roots);
CodeBlobToOopClosure code_roots(roots, true);
CLDToOopClosure roots_from_clds(roots);
// If we limit class scanning to SO_SystemClasses we need to apply a CLD closure to
// CLDs which are strongly reachable from the thread stacks.
CLDToOopClosure* roots_from_clds_p = ((so & SO_SystemClasses) ? &roots_from_clds : NULL);
// All threads execute this; the individual threads are task groups.
if (CollectedHeap::use_parallel_gc_threads()) {
Threads::possibly_parallel_oops_do(roots, roots_from_clds_p, &code_roots);
} else {
Threads::oops_do(roots, roots_from_clds_p, &code_roots);
}
JNIHandles::oops_do(strong_roots);
if (!_process_strong_tasks-> is_task_claimed(SH_PS_ObjectSynchronizer_oops_do))
ObjectSynchronizer::oops_do(roots);
ObjectSynchronizer::oops_do(strong_roots);
if (!_process_strong_tasks->is_task_claimed(SH_PS_FlatProfiler_oops_do))
FlatProfiler::oops_do(roots);
FlatProfiler::oops_do(strong_roots);
if (!_process_strong_tasks->is_task_claimed(SH_PS_Management_oops_do))
Management::oops_do(roots);
Management::oops_do(strong_roots);
if (!_process_strong_tasks->is_task_claimed(SH_PS_jvmti_oops_do))
JvmtiExport::oops_do(roots);
JvmtiExport::oops_do(strong_roots);
if (!_process_strong_tasks->is_task_claimed(SH_PS_SystemDictionary_oops_do)) {
if (so & SO_AllClasses) {
SystemDictionary::oops_do(roots);
} else if (so & SO_SystemClasses) {
SystemDictionary::always_strong_oops_do(roots);
} else {
fatal("We should always have selected either SO_AllClasses or SO_SystemClasses");
}
}
if (!_process_strong_tasks->is_task_claimed(SH_PS_ClassLoaderDataGraph_oops_do)) {
if (so & SO_AllClasses) {
ClassLoaderDataGraph::oops_do(roots, klass_closure, /* must_claim */ false);
} else if (so & SO_SystemClasses) {
ClassLoaderDataGraph::always_strong_oops_do(roots, klass_closure, /* must_claim */ true);
}
SystemDictionary::roots_oops_do(strong_roots, weak_roots);
}
// All threads execute the following. A specific chunk of buckets
// from the StringTable are the individual tasks.
if (so & SO_Strings) {
if (weak_roots != NULL) {
if (CollectedHeap::use_parallel_gc_threads()) {
StringTable::possibly_parallel_oops_do(roots);
StringTable::possibly_parallel_oops_do(weak_roots);
} else {
StringTable::oops_do(roots);
StringTable::oops_do(weak_roots);
}
}
if (!_process_strong_tasks->is_task_claimed(SH_PS_CodeCache_oops_do)) {
if (so & SO_ScavengeCodeCache) {
assert(&code_roots != NULL, "must supply closure for code cache");
assert(code_roots != NULL, "must supply closure for code cache");
// We only visit parts of the CodeCache when scavenging.
CodeCache::scavenge_root_nmethods_do(&code_roots);
CodeCache::scavenge_root_nmethods_do(code_roots);
}
if (so & SO_AllCodeCache) {
assert(&code_roots != NULL, "must supply closure for code cache");
assert(code_roots != NULL, "must supply closure for code cache");
// CMSCollector uses this to do intermediate-strength collections.
// We scan the entire code cache, since CodeCache::do_unloading is not called.
CodeCache::blobs_do(&code_roots);
CodeCache::blobs_do(code_roots);
}
// Verify that the code cache contents are not subject to
// movement by a scavenging collection.
DEBUG_ONLY(CodeBlobToOopClosure assert_code_is_non_scavengable(&assert_is_non_scavengable_closure, /*do_marking=*/ false));
DEBUG_ONLY(CodeBlobToOopClosure assert_code_is_non_scavengable(&assert_is_non_scavengable_closure, !CodeBlobToOopClosure::FixRelocations));
DEBUG_ONLY(CodeCache::asserted_non_scavengable_nmethods_do(&assert_code_is_non_scavengable));
}
_process_strong_tasks->all_tasks_completed();
}
void SharedHeap::process_all_roots(bool activate_scope,
ScanningOption so,
OopClosure* roots,
CLDClosure* cld_closure,
CodeBlobClosure* code_closure) {
process_roots(activate_scope, so,
roots, roots,
cld_closure, cld_closure,
code_closure);
}
void SharedHeap::process_strong_roots(bool activate_scope,
ScanningOption so,
OopClosure* roots,
CLDClosure* cld_closure,
CodeBlobClosure* code_closure) {
process_roots(activate_scope, so,
roots, NULL,
cld_closure, NULL,
code_closure);
}
class AlwaysTrueClosure: public BoolObjectClosure {
public:
bool do_object_b(oop p) { return true; }

72
hotspot/src/share/vm/memory/sharedHeap.hpp
View File

@ -69,14 +69,10 @@ class KlassClosure;
// number of active GC workers. CompactibleFreeListSpace and Space
// have SequentialSubTasksDone's.
// Example of using SubTasksDone and SequentialSubTasksDone
// G1CollectedHeap::g1_process_strong_roots() calls
// process_strong_roots(false, // no scoping; this is parallel code
// is_scavenging, so,
// &buf_scan_non_heap_roots,
// &eager_scan_code_roots);
// which delegates to SharedHeap::process_strong_roots() and uses
// G1CollectedHeap::g1_process_roots()
// to SharedHeap::process_roots() and uses
// SubTasksDone* _process_strong_tasks to claim tasks.
// process_strong_roots() calls
// process_roots() calls
// rem_set()->younger_refs_iterate()
// to scan the card table and which eventually calls down into
// CardTableModRefBS::par_non_clean_card_iterate_work(). This method
@ -182,12 +178,12 @@ public:
// task. (This also means that a parallel thread may only call
// process_strong_roots once.)
//
// For calls to process_strong_roots by sequential code, the parity is
// For calls to process_roots by sequential code, the parity is
// updated automatically.
//
// The idea is that objects representing fine-grained tasks, such as
// threads, will contain a "parity" field. A task will is claimed in the
// current "process_strong_roots" call only if its parity field is the
// current "process_roots" call only if its parity field is the
// same as the "strong_roots_parity"; task claiming is accomplished by
// updating the parity field to the strong_roots_parity with a CAS.
//
@ -198,27 +194,44 @@ public:
// c) to never return a distinguished value (zero) with which such
// task-claiming variables may be initialized, to indicate "never
// claimed".
private:
void change_strong_roots_parity();
public:
int strong_roots_parity() { return _strong_roots_parity; }
// Call these in sequential code around process_strong_roots.
// Call these in sequential code around process_roots.
// strong_roots_prologue calls change_strong_roots_parity, if
// parallel tasks are enabled.
class StrongRootsScope : public MarkingCodeBlobClosure::MarkScope {
public:
StrongRootsScope(SharedHeap* outer, bool activate = true);
// Used to implement the Thread work barrier.
static Monitor* _lock;
SharedHeap* _sh;
volatile jint _n_workers_done_with_threads;
public:
StrongRootsScope(SharedHeap* heap, bool activate = true);
~StrongRootsScope();
// Mark that this thread is done with the Threads work.
void mark_worker_done_with_threads(uint n_workers);
// Wait until all n_workers are done with the Threads work.
void wait_until_all_workers_done_with_threads(uint n_workers);
};
friend class StrongRootsScope;
// The current active StrongRootScope
StrongRootsScope* _strong_roots_scope;
StrongRootsScope* active_strong_roots_scope() const;
private:
void register_strong_roots_scope(StrongRootsScope* scope);
void unregister_strong_roots_scope(StrongRootsScope* scope);
void change_strong_roots_parity();
public:
enum ScanningOption {
SO_None = 0x0,
SO_AllClasses = 0x1,
SO_SystemClasses = 0x2,
SO_Strings = 0x4,
SO_AllCodeCache = 0x8,
SO_None = 0x0,
SO_AllCodeCache = 0x8,
SO_ScavengeCodeCache = 0x10
};
@ -227,15 +240,26 @@ public:
// Invoke the "do_oop" method the closure "roots" on all root locations.
// The "so" argument determines which roots the closure is applied to:
// "SO_None" does none;
// "SO_AllClasses" applies the closure to all entries in the SystemDictionary;
// "SO_SystemClasses" to all the "system" classes and loaders;
// "SO_Strings" applies the closure to all entries in StringTable;
// "SO_AllCodeCache" applies the closure to all elements of the CodeCache.
// "SO_ScavengeCodeCache" applies the closure to elements on the scavenge root list in the CodeCache.
void process_roots(bool activate_scope,
ScanningOption so,
OopClosure* strong_roots,
OopClosure* weak_roots,
CLDClosure* strong_cld_closure,
CLDClosure* weak_cld_closure,
CodeBlobClosure* code_roots);
void process_all_roots(bool activate_scope,
ScanningOption so,
OopClosure* roots,
CLDClosure* cld_closure,
CodeBlobClosure* code_roots);
void process_strong_roots(bool activate_scope,
ScanningOption so,
OopClosure* roots,
KlassClosure* klass_closure);
CLDClosure* cld_closure,
CodeBlobClosure* code_roots);
// Apply "root_closure" to the JNI weak roots..
void process_weak_roots(OopClosure* root_closure);
@ -251,7 +275,7 @@ public:
virtual void gc_epilogue(bool full) = 0;
// Sets the number of parallel threads that will be doing tasks
// (such as process strong roots) subsequently.
// (such as process roots) subsequently.
virtual void set_par_threads(uint t);
int n_termination();

61
hotspot/src/share/vm/oops/instanceKlass.cpp
View File

@ -245,6 +245,7 @@ InstanceKlass::InstanceKlass(int vtable_len,
set_static_oop_field_count(0);
set_nonstatic_field_size(0);
set_is_marked_dependent(false);
set_has_unloaded_dependent(false);
set_init_state(InstanceKlass::allocated);
set_init_thread(NULL);
set_reference_type(rt);
@ -1801,6 +1802,9 @@ jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
return id;
}
int nmethodBucket::decrement() {
return Atomic::add(-1, (volatile int *)&_count);
}
//
// Walk the list of dependent nmethods searching for nmethods which
@ -1815,7 +1819,7 @@ int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
nmethod* nm = b->get_nmethod();
// since dependencies aren't removed until an nmethod becomes a zombie,
// the dependency list may contain nmethods which aren't alive.
if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
if (b->count() > 0 && nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
if (TraceDependencies) {
ResourceMark rm;
tty->print_cr("Marked for deoptimization");
@ -1832,6 +1836,43 @@ int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
return found;
}
void InstanceKlass::clean_dependent_nmethods() {
assert_locked_or_safepoint(CodeCache_lock);
if (has_unloaded_dependent()) {
nmethodBucket* b = _dependencies;
nmethodBucket* last = NULL;
while (b != NULL) {
assert(b->count() >= 0, err_msg("bucket count: %d", b->count()));
nmethodBucket* next = b->next();
if (b->count() == 0) {
if (last == NULL) {
_dependencies = next;
} else {
last->set_next(next);
}
delete b;
// last stays the same.
} else {
last = b;
}
b = next;
}
set_has_unloaded_dependent(false);
}
#ifdef ASSERT
else {
// Verification
for (nmethodBucket* b = _dependencies; b != NULL; b = b->next()) {
assert(b->count() >= 0, err_msg("bucket count: %d", b->count()));
assert(b->count() != 0, "empty buckets need to be cleaned");
}
}
#endif
}
//
// Add an nmethodBucket to the list of dependencies for this nmethod.
@ -1866,13 +1907,10 @@ void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
nmethodBucket* last = NULL;
while (b != NULL) {
if (nm == b->get_nmethod()) {
if (b->decrement() == 0) {
if (last == NULL) {
_dependencies = b->next();
} else {
last->set_next(b->next());
}
delete b;
int val = b->decrement();
guarantee(val >= 0, err_msg("Underflow: %d", val));
if (val == 0) {
set_has_unloaded_dependent(true);
}
return;
}
@ -1911,6 +1949,11 @@ bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
nmethodBucket* b = _dependencies;
while (b != NULL) {
if (nm == b->get_nmethod()) {
#ifdef ASSERT
int count = b->count();
assert(count >= 0, "Just check if we ever get here 1");
assert(count > 0, "Just check if we ever get here 2");
#endif
return true;
}
b = b->next();
@ -2209,7 +2252,7 @@ int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
#endif // INCLUDE_ALL_GCS
void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
assert(is_loader_alive(is_alive), "this klass should be live");
assert(class_loader_data()->is_alive(is_alive), "this klass should be live");
if (is_interface()) {
if (ClassUnloading) {
Klass* impl = implementor();

7
hotspot/src/share/vm/oops/instanceKlass.hpp
View File

@ -197,6 +197,7 @@ class InstanceKlass: public Klass {
// _is_marked_dependent can be set concurrently, thus cannot be part of the
// _misc_flags.
bool _is_marked_dependent; // used for marking during flushing and deoptimization
bool _has_unloaded_dependent;
enum {
_misc_rewritten = 1 << 0, // methods rewritten.
@ -444,6 +445,9 @@ class InstanceKlass: public Klass {
bool is_marked_dependent() const { return _is_marked_dependent; }
void set_is_marked_dependent(bool value) { _is_marked_dependent = value; }
bool has_unloaded_dependent() const { return _has_unloaded_dependent; }
void set_has_unloaded_dependent(bool value) { _has_unloaded_dependent = value; }
// initialization (virtuals from Klass)
bool should_be_initialized() const; // means that initialize should be called
void initialize(TRAPS);
@ -922,6 +926,7 @@ class InstanceKlass: public Klass {
void clean_implementors_list(BoolObjectClosure* is_alive);
void clean_method_data(BoolObjectClosure* is_alive);
void clean_dependent_nmethods();
// Explicit metaspace deallocation of fields
// For RedefineClasses and class file parsing errors, we need to deallocate
@ -1210,7 +1215,7 @@ class nmethodBucket: public CHeapObj<mtClass> {
}
int count() { return _count; }
int increment() { _count += 1; return _count; }
int decrement() { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
int decrement();
nmethodBucket* next() { return _next; }
void set_next(nmethodBucket* b) { _next = b; }
nmethod* get_nmethod() { return _nmethod; }

34
hotspot/src/share/vm/oops/klass.cpp
View File

@ -42,6 +42,7 @@
#include "utilities/stack.hpp"
#include "utilities/macros.hpp"
#if INCLUDE_ALL_GCS
#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
#include "gc_implementation/parallelScavenge/psParallelCompact.hpp"
#include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
#include "gc_implementation/parallelScavenge/psScavenge.hpp"
@ -159,7 +160,12 @@ Klass::Klass() {
_primary_supers[0] = k;
set_super_check_offset(in_bytes(primary_supers_offset()));
set_java_mirror(NULL);
// The constructor is used from init_self_patching_vtbl_list,
// which doesn't zero out the memory before calling the constructor.
// Need to set the field explicitly to not hit an assert that the field
// should be NULL before setting it.
_java_mirror = NULL;
set_modifier_flags(0);
set_layout_helper(Klass::_lh_neutral_value);
set_name(NULL);
@ -383,7 +389,7 @@ bool Klass::is_loader_alive(BoolObjectClosure* is_alive) {
return mirror_alive;
}
void Klass::clean_weak_klass_links(BoolObjectClosure* is_alive) {
void Klass::clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses) {
if (!ClassUnloading) {
return;
}
@ -428,7 +434,7 @@ void Klass::clean_weak_klass_links(BoolObjectClosure* is_alive) {
}
// Clean the implementors list and method data.
if (current->oop_is_instance()) {
if (clean_alive_klasses && current->oop_is_instance()) {
InstanceKlass* ik = InstanceKlass::cast(current);
ik->clean_implementors_list(is_alive);
ik->clean_method_data(is_alive);
@ -440,12 +446,18 @@ void Klass::klass_update_barrier_set(oop v) {
record_modified_oops();
}
void Klass::klass_update_barrier_set_pre(void* p, oop v) {
// This barrier used by G1, where it's used remember the old oop values,
// so that we don't forget any objects that were live at the snapshot at
// the beginning. This function is only used when we write oops into
// Klasses. Since the Klasses are used as roots in G1, we don't have to
// do anything here.
// This barrier is used by G1 to remember the old oop values, so
// that we don't forget any objects that were live at the snapshot at
// the beginning. This function is only used when we write oops into Klasses.
void Klass::klass_update_barrier_set_pre(oop* p, oop v) {
#if INCLUDE_ALL_GCS
if (UseG1GC) {
oop obj = *p;
if (obj != NULL) {
G1SATBCardTableModRefBS::enqueue(obj);
}
}
#endif
}
void Klass::klass_oop_store(oop* p, oop v) {
@ -456,7 +468,7 @@ void Klass::klass_oop_store(oop* p, oop v) {
if (always_do_update_barrier) {
klass_oop_store((volatile oop*)p, v);
} else {
klass_update_barrier_set_pre((void*)p, v);
klass_update_barrier_set_pre(p, v);
*p = v;
klass_update_barrier_set(v);
}
@ -466,7 +478,7 @@ void Klass::klass_oop_store(volatile oop* p, oop v) {
assert(!Universe::heap()->is_in_reserved((void*)p), "Should store pointer into metadata");
assert(v == NULL || Universe::heap()->is_in_reserved((void*)v), "Should store pointer to an object");
klass_update_barrier_set_pre((void*)p, v);
klass_update_barrier_set_pre((oop*)p, v); // Cast away volatile.
OrderAccess::release_store_ptr(p, v);
klass_update_barrier_set(v);
}

7
hotspot/src/share/vm/oops/klass.hpp
View File

@ -553,7 +553,10 @@ class Klass : public Metadata {
// The is_alive closure passed in depends on the Garbage Collector used.
bool is_loader_alive(BoolObjectClosure* is_alive);
static void clean_weak_klass_links(BoolObjectClosure* is_alive);
static void clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive_klasses = true);
static void clean_subklass_tree(BoolObjectClosure* is_alive) {
clean_weak_klass_links(is_alive, false /* clean_alive_klasses */);
}
// iterators
virtual int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) = 0;
@ -660,7 +663,7 @@ class Klass : public Metadata {
private:
// barriers used by klass_oop_store
void klass_update_barrier_set(oop v);
void klass_update_barrier_set_pre(void* p, oop v);
void klass_update_barrier_set_pre(oop* p, oop v);
};
#endif // SHARE_VM_OOPS_KLASS_HPP

2
hotspot/src/share/vm/prims/jvmtiTagMap.cpp
View File

@ -3019,7 +3019,7 @@ inline bool VM_HeapWalkOperation::collect_simple_roots() {
// If there are any non-perm roots in the code cache, visit them.
blk.set_kind(JVMTI_HEAP_REFERENCE_OTHER);
CodeBlobToOopClosure look_in_blobs(&blk, false);
CodeBlobToOopClosure look_in_blobs(&blk, !CodeBlobToOopClosure::FixRelocations);
CodeCache::scavenge_root_nmethods_do(&look_in_blobs);
return true;

36
hotspot/src/share/vm/prims/whitebox.cpp
View File

@ -24,6 +24,7 @@
#include "precompiled.hpp"
#include "memory/metadataFactory.hpp"
#include "memory/universe.hpp"
#include "oops/oop.inline.hpp"
@ -38,6 +39,7 @@
#include "runtime/interfaceSupport.hpp"
#include "runtime/os.hpp"
#include "utilities/array.hpp"
#include "utilities/debug.hpp"
#include "utilities/macros.hpp"
#include "utilities/exceptions.hpp"
@ -726,7 +728,6 @@ WB_ENTRY(jobjectArray, WB_GetNMethod(JNIEnv* env, jobject o, jobject method, jbo
return result;
WB_END
WB_ENTRY(jlong, WB_GetThreadStackSize(JNIEnv* env, jobject o))
return (jlong) Thread::current()->stack_size();
WB_END
@ -736,6 +737,35 @@ WB_ENTRY(jlong, WB_GetThreadRemainingStackSize(JNIEnv* env, jobject o))
return (jlong) t->stack_available(os::current_stack_pointer()) - (jlong) StackShadowPages * os::vm_page_size();
WB_END
int WhiteBox::array_bytes_to_length(size_t bytes) {
return Array<u1>::bytes_to_length(bytes);
}
WB_ENTRY(jlong, WB_AllocateMetaspace(JNIEnv* env, jobject wb, jobject class_loader, jlong size))
if (size < 0) {
THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(),
err_msg("WB_AllocateMetaspace: size is negative: " JLONG_FORMAT, size));
}
oop class_loader_oop = JNIHandles::resolve(class_loader);
ClassLoaderData* cld = class_loader_oop != NULL
? java_lang_ClassLoader::loader_data(class_loader_oop)
: ClassLoaderData::the_null_class_loader_data();
void* metadata = MetadataFactory::new_writeable_array<u1>(cld, WhiteBox::array_bytes_to_length((size_t)size), thread);
return (jlong)(uintptr_t)metadata;
WB_END
WB_ENTRY(void, WB_FreeMetaspace(JNIEnv* env, jobject wb, jobject class_loader, jlong addr, jlong size))
oop class_loader_oop = JNIHandles::resolve(class_loader);
ClassLoaderData* cld = class_loader_oop != NULL
? java_lang_ClassLoader::loader_data(class_loader_oop)
: ClassLoaderData::the_null_class_loader_data();
MetadataFactory::free_array(cld, (Array<u1>*)(uintptr_t)addr);
WB_END
//Some convenience methods to deal with objects from java
int WhiteBox::offset_for_field(const char* field_name, oop object,
Symbol* signature_symbol) {
@ -866,6 +896,10 @@ static JNINativeMethod methods[] = {
{CC"isInStringTable", CC"(Ljava/lang/String;)Z", (void*)&WB_IsInStringTable },
{CC"fullGC", CC"()V", (void*)&WB_FullGC },
{CC"readReservedMemory", CC"()V", (void*)&WB_ReadReservedMemory },
{CC"allocateMetaspace",
CC"(Ljava/lang/ClassLoader;J)J", (void*)&WB_AllocateMetaspace },
{CC"freeMetaspace",
CC"(Ljava/lang/ClassLoader;JJ)V", (void*)&WB_FreeMetaspace },
{CC"getCPUFeatures", CC"()Ljava/lang/String;", (void*)&WB_GetCPUFeatures },
{CC"getNMethod", CC"(Ljava/lang/reflect/Executable;Z)[Ljava/lang/Object;",
(void*)&WB_GetNMethod },

2
hotspot/src/share/vm/prims/whitebox.hpp
View File

@ -62,6 +62,8 @@ class WhiteBox : public AllStatic {
Symbol* signature_symbol);
static const char* lookup_jstring(const char* field_name, oop object);
static bool lookup_bool(const char* field_name, oop object);
static int array_bytes_to_length(size_t bytes);
};

4
hotspot/src/share/vm/runtime/thread.cpp
View File

@ -4101,8 +4101,8 @@ void Threads::possibly_parallel_oops_do(OopClosure* f, CLDClosure* cld_f, CodeBl
SharedHeap* sh = SharedHeap::heap();
// Cannot yet substitute active_workers for n_par_threads
// because of G1CollectedHeap::verify() use of
// SharedHeap::process_strong_roots(). n_par_threads == 0 will
// turn off parallelism in process_strong_roots while active_workers
// SharedHeap::process_roots(). n_par_threads == 0 will
// turn off parallelism in process_roots while active_workers
// is being used for parallelism elsewhere.
bool is_par = sh->n_par_threads() > 0;
assert(!is_par ||

2
hotspot/src/share/vm/runtime/thread.hpp
View File

@ -452,7 +452,7 @@ class Thread: public ThreadShadow {
private:
bool claim_oops_do_par_case(int collection_parity);
public:
// Requires that "collection_parity" is that of the current strong roots
// Requires that "collection_parity" is that of the current roots
// iteration. If "is_par" is false, sets the parity of "this" to
// "collection_parity", and returns "true". If "is_par" is true,
// uses an atomic instruction to set the current threads parity to

24
hotspot/src/share/vm/utilities/array.hpp
View File

@ -305,6 +305,7 @@ class Array: public MetaspaceObj {
friend class MetadataFactory;
friend class VMStructs;
friend class MethodHandleCompiler; // special case
friend class WhiteBox;
protected:
int _length; // the number of array elements
T _data[1]; // the array memory
@ -326,6 +327,29 @@ protected:
static size_t byte_sizeof(int length) { return sizeof(Array<T>) + MAX2(length - 1, 0) * sizeof(T); }
// WhiteBox API helper.
static int bytes_to_length(size_t bytes) {
assert(is_size_aligned(bytes, BytesPerWord), "Must be, for now");
if (sizeof(Array<T>) >= bytes) {
return 0;
}
size_t left = bytes - sizeof(Array<T>);
assert(is_size_aligned(left, sizeof(T)), "Must be");
size_t elements = left / sizeof(T);
assert(elements <= (size_t)INT_MAX, err_msg("number of elements " SIZE_FORMAT "doesn't fit into an int.", elements));
int length = (int)elements;
assert((size_t)size(length) * BytesPerWord == bytes,
err_msg("Expected: " SIZE_FORMAT " got: " SIZE_FORMAT,
bytes, (size_t)size(length) * BytesPerWord));
return length;
}
explicit Array(int length) : _length(length) {
assert(length >= 0, "illegal length");
}

2
hotspot/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java
View File

@ -142,6 +142,8 @@ public class WhiteBox {
// Memory
public native void readReservedMemory();
public native long allocateMetaspace(ClassLoader classLoader, long size);
public native void freeMetaspace(ClassLoader classLoader, long addr, long size);
// force Full GC
public native void fullGC();