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8067662: "java.lang.NullPointerException: Method name is null" from StackTraceElement.<init>

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Use method cpref and klass version to provide meaningful methods name in stacktraces

Reviewed-by: coleenp, dcubed
This commit is contained in:
Serguei Spitsyn 2015-03-20 02:44:51 -07:00
parent f2ecc46c20
commit cc2bb40bf3
4 changed files with 103 additions and 40 deletions
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90
hotspot/src/share/vm/classfile/javaClasses.cpp
View File

@ -1313,7 +1313,8 @@ static inline int version_at(unsigned int merged) {
}
static inline bool version_matches(Method* method, int version) {
return (method->constants()->version() == version && version < MAX_VERSION);
assert(version < MAX_VERSION, "version is too big");
return method != NULL && (method->constants()->version() == version);
}
static inline int get_line_number(Method* method, int bci) {
@ -1343,6 +1344,7 @@ class BacktraceBuilder: public StackObj {
typeArrayOop _methods;
typeArrayOop _bcis;
objArrayOop _mirrors;
typeArrayOop _cprefs; // needed to insulate method name against redefinition
int _index;
No_Safepoint_Verifier _nsv;
@ -1350,8 +1352,9 @@ class BacktraceBuilder: public StackObj {
enum {
trace_methods_offset = java_lang_Throwable::trace_methods_offset,
trace_bcis_offset = java_lang_Throwable::trace_bcis_offset,
trace_bcis_offset = java_lang_Throwable::trace_bcis_offset,
trace_mirrors_offset = java_lang_Throwable::trace_mirrors_offset,
trace_cprefs_offset = java_lang_Throwable::trace_cprefs_offset,
trace_next_offset = java_lang_Throwable::trace_next_offset,
trace_size = java_lang_Throwable::trace_size,
trace_chunk_size = java_lang_Throwable::trace_chunk_size
@ -1373,9 +1376,14 @@ class BacktraceBuilder: public StackObj {
assert(mirrors != NULL, "mirror array should be initialized in backtrace");
return mirrors;
}
static typeArrayOop get_cprefs(objArrayHandle chunk) {
typeArrayOop cprefs = typeArrayOop(chunk->obj_at(trace_cprefs_offset));
assert(cprefs != NULL, "cprefs array should be initialized in backtrace");
return cprefs;
}
// constructor for new backtrace
BacktraceBuilder(TRAPS): _methods(NULL), _bcis(NULL), _head(NULL), _mirrors(NULL) {
BacktraceBuilder(TRAPS): _methods(NULL), _bcis(NULL), _head(NULL), _mirrors(NULL), _cprefs(NULL) {
expand(CHECK);
_backtrace = _head;
_index = 0;
@ -1385,6 +1393,7 @@ class BacktraceBuilder: public StackObj {
_methods = get_methods(backtrace);
_bcis = get_bcis(backtrace);
_mirrors = get_mirrors(backtrace);
_cprefs = get_cprefs(backtrace);
assert(_methods->length() == _bcis->length() &&
_methods->length() == _mirrors->length(),
"method and source information arrays should match");
@ -1410,17 +1419,22 @@ class BacktraceBuilder: public StackObj {
objArrayOop mirrors = oopFactory::new_objectArray(trace_chunk_size, CHECK);
objArrayHandle new_mirrors(THREAD, mirrors);
typeArrayOop cprefs = oopFactory::new_shortArray(trace_chunk_size, CHECK);
typeArrayHandle new_cprefs(THREAD, cprefs);
if (!old_head.is_null()) {
old_head->obj_at_put(trace_next_offset, new_head());
}
new_head->obj_at_put(trace_methods_offset, new_methods());
new_head->obj_at_put(trace_bcis_offset, new_bcis());
new_head->obj_at_put(trace_mirrors_offset, new_mirrors());
new_head->obj_at_put(trace_cprefs_offset, new_cprefs());
_head = new_head();
_methods = new_methods();
_bcis = new_bcis();
_mirrors = new_mirrors();
_cprefs = new_cprefs();
_index = 0;
}
@ -1440,8 +1454,9 @@ class BacktraceBuilder: public StackObj {
method = mhandle();
}
_methods->short_at_put(_index, method->method_idnum());
_methods->short_at_put(_index, method->orig_method_idnum());
_bcis->int_at_put(_index, merge_bci_and_version(bci, method->constants()->version()));
_cprefs->short_at_put(_index, method->name_index());
// We need to save the mirrors in the backtrace to keep the class
// from being unloaded while we still have this stack trace.
@ -1454,27 +1469,26 @@ class BacktraceBuilder: public StackObj {
// Print stack trace element to resource allocated buffer
char* java_lang_Throwable::print_stack_element_to_buffer(Handle mirror,
int method_id, int version, int bci) {
int method_id, int version, int bci, int cpref) {
// Get strings and string lengths
InstanceKlass* holder = InstanceKlass::cast(java_lang_Class::as_Klass(mirror()));
const char* klass_name = holder->external_name();
int buf_len = (int)strlen(klass_name);
// The method id may point to an obsolete method, can't get more stack information
Method* method = holder->method_with_idnum(method_id);
if (method == NULL) {
char* buf = NEW_RESOURCE_ARRAY(char, buf_len + 64);
// This is what the java code prints in this case - added Redefined
sprintf(buf, "\tat %s.null (Redefined)", klass_name);
return buf;
}
Method* method = holder->method_with_orig_idnum(method_id, version);
char* method_name = method->name()->as_C_string();
// The method can be NULL if the requested class version is gone
Symbol* sym = (method != NULL) ? method->name() : holder->constants()->symbol_at(cpref);
char* method_name = sym->as_C_string();
buf_len += (int)strlen(method_name);
// Use specific ik version as a holder since the mirror might
// refer to version that is now obsolete and no longer accessible
// via the previous versions list.
holder = holder->get_klass_version(version);
char* source_file_name = NULL;
if (version_matches(method, version)) {
if (holder != NULL) {
Symbol* source = holder->source_file_name();
if (source != NULL) {
source_file_name = source->as_C_string();
@ -1516,17 +1530,18 @@ char* java_lang_Throwable::print_stack_element_to_buffer(Handle mirror,
}
void java_lang_Throwable::print_stack_element(outputStream *st, Handle mirror,
int method_id, int version, int bci) {
int method_id, int version, int bci, int cpref) {
ResourceMark rm;
char* buf = print_stack_element_to_buffer(mirror, method_id, version, bci);
char* buf = print_stack_element_to_buffer(mirror, method_id, version, bci, cpref);
st->print_cr("%s", buf);
}
void java_lang_Throwable::print_stack_element(outputStream *st, methodHandle method, int bci) {
Handle mirror = method->method_holder()->java_mirror();
int method_id = method->method_idnum();
int method_id = method->orig_method_idnum();
int version = method->constants()->version();
print_stack_element(st, mirror, method_id, version, bci);
int cpref = method->name_index();
print_stack_element(st, mirror, method_id, version, bci, cpref);
}
const char* java_lang_Throwable::no_stack_trace_message() {
@ -1551,6 +1566,7 @@ void java_lang_Throwable::print_stack_trace(oop throwable, outputStream* st) {
typeArrayHandle methods (THREAD, BacktraceBuilder::get_methods(result));
typeArrayHandle bcis (THREAD, BacktraceBuilder::get_bcis(result));
objArrayHandle mirrors (THREAD, BacktraceBuilder::get_mirrors(result));
typeArrayHandle cprefs (THREAD, BacktraceBuilder::get_cprefs(result));
int length = methods()->length();
for (int index = 0; index < length; index++) {
@ -1560,7 +1576,8 @@ void java_lang_Throwable::print_stack_trace(oop throwable, outputStream* st) {
int method = methods->short_at(index);
int version = version_at(bcis->int_at(index));
int bci = bci_at(bcis->int_at(index));
print_stack_element(st, mirror, method, version, bci);
int cpref = cprefs->short_at(index);
print_stack_element(st, mirror, method, version, bci, cpref);
}
result = objArrayHandle(THREAD, objArrayOop(result->obj_at(trace_next_offset)));
}
@ -1837,29 +1854,30 @@ oop java_lang_Throwable::get_stack_trace_element(oop throwable, int index, TRAPS
if (chunk == NULL) {
THROW_(vmSymbols::java_lang_IndexOutOfBoundsException(), NULL);
}
// Get method id, bci, version and mirror from chunk
// Get method id, bci, version, mirror and cpref from chunk
typeArrayOop methods = BacktraceBuilder::get_methods(chunk);
typeArrayOop bcis = BacktraceBuilder::get_bcis(chunk);
objArrayOop mirrors = BacktraceBuilder::get_mirrors(chunk);
typeArrayOop cprefs = BacktraceBuilder::get_cprefs(chunk);
assert(methods != NULL && bcis != NULL && mirrors != NULL, "sanity check");
int method = methods->short_at(chunk_index);
int version = version_at(bcis->int_at(chunk_index));
int bci = bci_at(bcis->int_at(chunk_index));
int cpref = cprefs->short_at(chunk_index);
Handle mirror(THREAD, mirrors->obj_at(chunk_index));
// Chunk can be partial full
if (mirror.is_null()) {
THROW_(vmSymbols::java_lang_IndexOutOfBoundsException(), NULL);
}
oop element = java_lang_StackTraceElement::create(mirror, method, version, bci, CHECK_0);
oop element = java_lang_StackTraceElement::create(mirror, method, version, bci, cpref, CHECK_0);
return element;
}
oop java_lang_StackTraceElement::create(Handle mirror, int method_id,
int version, int bci, TRAPS) {
int version, int bci, int cpref, TRAPS) {
// Allocate java.lang.StackTraceElement instance
Klass* k = SystemDictionary::StackTraceElement_klass();
assert(k != NULL, "must be loaded in 1.4+");
@ -1876,17 +1894,13 @@ oop java_lang_StackTraceElement::create(Handle mirror, int method_id,
oop classname = StringTable::intern((char*) str, CHECK_0);
java_lang_StackTraceElement::set_declaringClass(element(), classname);
Method* method = holder->method_with_idnum(method_id);
// Method on stack may be obsolete because it was redefined so cannot be
// found by idnum.
if (method == NULL) {
// leave name and fileName null
java_lang_StackTraceElement::set_lineNumber(element(), -1);
return element();
}
Method* method = holder->method_with_orig_idnum(method_id, version);
// The method can be NULL if the requested class version is gone
Symbol* sym = (method != NULL) ? method->name() : holder->constants()->symbol_at(cpref);
// Fill in method name
oop methodname = StringTable::intern(method->name(), CHECK_0);
oop methodname = StringTable::intern(sym, CHECK_0);
java_lang_StackTraceElement::set_methodName(element(), methodname);
if (!version_matches(method, version)) {
@ -1895,6 +1909,11 @@ oop java_lang_StackTraceElement::create(Handle mirror, int method_id,
java_lang_StackTraceElement::set_lineNumber(element(), -1);
} else {
// Fill in source file name and line number.
// Use specific ik version as a holder since the mirror might
// refer to version that is now obsolete and no longer accessible
// via the previous versions list.
holder = holder->get_klass_version(version);
assert(holder != NULL, "sanity check");
Symbol* source = holder->source_file_name();
if (ShowHiddenFrames && source == NULL)
source = vmSymbols::unknown_class_name();
@ -1909,8 +1928,9 @@ oop java_lang_StackTraceElement::create(Handle mirror, int method_id,
oop java_lang_StackTraceElement::create(methodHandle method, int bci, TRAPS) {
Handle mirror (THREAD, method->method_holder()->java_mirror());
int method_id = method->method_idnum();
return create(mirror, method_id, method->constants()->version(), bci, THREAD);
int method_id = method->orig_method_idnum();
int cpref = method->name_index();
return create(mirror, method_id, method->constants()->version(), bci, cpref, THREAD);
}
void java_lang_reflect_AccessibleObject::compute_offsets() {

11
hotspot/src/share/vm/classfile/javaClasses.hpp
View File

@ -485,8 +485,9 @@ class java_lang_Throwable: AllStatic {
trace_methods_offset = 0,
trace_bcis_offset = 1,
trace_mirrors_offset = 2,
trace_next_offset = 3,
trace_size = 4,
trace_cprefs_offset = 3,
trace_next_offset = 4,
trace_size = 5,
trace_chunk_size = 32
};
@ -497,7 +498,7 @@ class java_lang_Throwable: AllStatic {
static int static_unassigned_stacktrace_offset;
// Printing
static char* print_stack_element_to_buffer(Handle mirror, int method, int version, int bci);
static char* print_stack_element_to_buffer(Handle mirror, int method, int version, int bci, int cpref);
// StackTrace (programmatic access, new since 1.4)
static void clear_stacktrace(oop throwable);
// No stack trace available
@ -519,7 +520,7 @@ class java_lang_Throwable: AllStatic {
static void set_message(oop throwable, oop value);
static Symbol* detail_message(oop throwable);
static void print_stack_element(outputStream *st, Handle mirror, int method,
int version, int bci);
int version, int bci, int cpref);
static void print_stack_element(outputStream *st, methodHandle method, int bci);
static void print_stack_usage(Handle stream);
@ -1314,7 +1315,7 @@ class java_lang_StackTraceElement: AllStatic {
static void set_lineNumber(oop element, int value);
// Create an instance of StackTraceElement
static oop create(Handle mirror, int method, int version, int bci, TRAPS);
static oop create(Handle mirror, int method, int version, int bci, int cpref, TRAPS);
static oop create(methodHandle method, int bci, TRAPS);
// Debugging

31
hotspot/src/share/vm/oops/instanceKlass.cpp
View File

@ -3708,6 +3708,37 @@ Method* InstanceKlass::method_with_idnum(int idnum) {
return m;
}
Method* InstanceKlass::method_with_orig_idnum(int idnum) {
if (idnum >= methods()->length()) {
return NULL;
}
Method* m = methods()->at(idnum);
if (m != NULL && m->orig_method_idnum() == idnum) {
return m;
}
// Obsolete method idnum does not match the original idnum
for (int index = 0; index < methods()->length(); ++index) {
m = methods()->at(index);
if (m->orig_method_idnum() == idnum) {
return m;
}
}
// None found, return null for the caller to handle.
return NULL;
}
Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
InstanceKlass* holder = get_klass_version(version);
if (holder == NULL) {
return NULL; // The version of klass is gone, no method is found
}
Method* method = holder->method_with_orig_idnum(idnum);
return method;
}
jint InstanceKlass::get_cached_class_file_len() {
return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
}

11
hotspot/src/share/vm/oops/instanceKlass.hpp
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@ -329,6 +329,8 @@ class InstanceKlass: public Klass {
Array<Method*>* methods() const { return _methods; }
void set_methods(Array<Method*>* a) { _methods = a; }
Method* method_with_idnum(int idnum);
Method* method_with_orig_idnum(int idnum);
Method* method_with_orig_idnum(int idnum, int version);
// method ordering
Array<int>* method_ordering() const { return _method_ordering; }
@ -620,6 +622,15 @@ class InstanceKlass: public Klass {
InstanceKlass* previous_versions() const { return _previous_versions; }
InstanceKlass* get_klass_version(int version) {
for (InstanceKlass* ik = this; ik != NULL; ik = ik->previous_versions()) {
if (ik->constants()->version() == version) {
return ik;
}
}
return NULL;
}
bool has_been_redefined() const {
return (_misc_flags & _misc_has_been_redefined) != 0;
}