stan/jdk-24
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

8222518: Remove unnecessary caching of Parker object in java.lang.Thread

Browse Source 
Reviewed-by: dcubed, rehn
This commit is contained in:
David Holmes 2019-04-26 00:57:03 -04:00
parent f50047aa8e
commit ded4f6b5cf
4 changed files with 7 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
src/hotspot/share/classfile/javaClasses.cpp
View File

@ -1613,7 +1613,6 @@ int java_lang_Thread::_stackSize_offset = 0;
int java_lang_Thread::_tid_offset = 0;
int java_lang_Thread::_thread_status_offset = 0;
int java_lang_Thread::_park_blocker_offset = 0;
int java_lang_Thread::_park_event_offset = 0 ;
#define THREAD_FIELDS_DO(macro) \
macro(_name_offset, k, vmSymbols::name_name(), string_signature, false); \
@ -1627,8 +1626,7 @@ int java_lang_Thread::_park_event_offset = 0 ;
macro(_stackSize_offset, k, "stackSize", long_signature, false); \
macro(_tid_offset, k, "tid", long_signature, false); \
macro(_thread_status_offset, k, "threadStatus", int_signature, false); \
macro(_park_blocker_offset, k, "parkBlocker", object_signature, false); \
macro(_park_event_offset, k, "nativeParkEventPointer", long_signature, false)
macro(_park_blocker_offset, k, "parkBlocker", object_signature, false)
void java_lang_Thread::compute_offsets() {
assert(_group_offset == 0, "offsets should be initialized only once");
@ -1745,15 +1743,6 @@ oop java_lang_Thread::park_blocker(oop java_thread) {
return java_thread->obj_field(_park_blocker_offset);
}
jlong java_lang_Thread::park_event(oop java_thread) {
return java_thread->long_field(_park_event_offset);
}
bool java_lang_Thread::set_park_event(oop java_thread, jlong ptr) {
java_thread->long_field_put(_park_event_offset, ptr);
return true;
}
const char* java_lang_Thread::thread_status_name(oop java_thread) {
ThreadStatus status = (java_lang_Thread::ThreadStatus)java_thread->int_field(_thread_status_offset);
switch (status) {

7
src/hotspot/share/classfile/javaClasses.hpp
View File

@ -371,7 +371,6 @@ class java_lang_Thread : AllStatic {
static int _tid_offset;
static int _thread_status_offset;
static int _park_blocker_offset;
static int _park_event_offset ;
static void compute_offsets();
@ -413,12 +412,6 @@ class java_lang_Thread : AllStatic {
// Blocker object responsible for thread parking
static oop park_blocker(oop java_thread);
// Pointer to type-stable park handler, encoded as jlong.
// Should be set when apparently null
// For details, see unsafe.cpp Unsafe_Unpark
static jlong park_event(oop java_thread);
static bool set_park_event(oop java_thread, jlong ptr);
// Java Thread Status for JVMTI and M&M use.
// This thread status info is saved in threadStatus field of
// java.lang.Thread java class.

23
src/hotspot/share/prims/unsafe.cpp
View File

@ -949,27 +949,16 @@ UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread))
(void) tlh.cv_internal_thread_to_JavaThread(jthread, &thr, &java_thread);
if (java_thread != NULL) {
// This is a valid oop.
jlong lp = java_lang_Thread::park_event(java_thread);
if (lp != 0) {
// This cast is OK even though the jlong might have been read
// non-atomically on 32bit systems, since there, one word will
// always be zero anyway and the value set is always the same
p = (Parker*)addr_from_java(lp);
} else {
// Not cached in the java.lang.Thread oop yet (could be an
// older version of library).
if (thr != NULL) {
// The JavaThread is alive.
p = thr->parker();
if (p != NULL) {
// Cache the Parker in the java.lang.Thread oop for next time.
java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
}
}
if (thr != NULL) {
// The JavaThread is alive.
p = thr->parker();
}
}
} // ThreadsListHandle is destroyed here.
// 'p' points to type-stable-memory if non-NULL. If the target
// thread terminates before we get here the new user of this
// Parker will get a 'spurious' unpark - which is perfectly valid.
if (p != NULL) {
HOTSPOT_THREAD_UNPARK((uintptr_t) p);
p->unpark();

5
src/java.base/share/classes/java/lang/Thread.java
View File

@ -193,11 +193,6 @@ class Thread implements Runnable {
*/
private final long stackSize;
/*
* JVM-private state that persists after native thread termination.
*/
private long nativeParkEventPointer;
/*
* Thread ID
*/