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

8184181: Use oopDesc::cas_set_mark() instead of raw CAS when accessing oop header

Browse Source 
Reviewed-by: dcubed, kbarrett
This commit is contained in:
Roman Kennke 2017-07-17 08:43:28 +02:00
parent 63ac8937a1
commit 1772da638b
2 changed files with 10 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
hotspot/src/share/vm/runtime/biasedLocking.cpp
View File

@ -1,5 +1,5 @@
/* /*
* Copyright (c) 2005, 2016, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
* *
* This code is free software; you can redistribute it and/or modify it * This code is free software; you can redistribute it and/or modify it
@ -579,7 +579,7 @@ BiasedLocking::Condition BiasedLocking::revoke_and_rebias(Handle obj, bool attem
// the bias of the object. // the bias of the object.
markOop biased_value = mark; markOop biased_value = mark;
markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age()); markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
markOop res_mark = (markOop) Atomic::cmpxchg_ptr(unbiased_prototype, obj->mark_addr(), mark); markOop res_mark = obj->cas_set_mark(unbiased_prototype, mark);
if (res_mark == biased_value) { if (res_mark == biased_value) {
return BIAS_REVOKED; return BIAS_REVOKED;
} }
@ -594,7 +594,7 @@ BiasedLocking::Condition BiasedLocking::revoke_and_rebias(Handle obj, bool attem
// by another thread so we simply return and let the caller deal // by another thread so we simply return and let the caller deal
// with it. // with it.
markOop biased_value = mark; markOop biased_value = mark;
markOop res_mark = (markOop) Atomic::cmpxchg_ptr(prototype_header, obj->mark_addr(), mark); markOop res_mark = obj->cas_set_mark(prototype_header, mark);
assert(!(*(obj->mark_addr()))->has_bias_pattern(), "even if we raced, should still be revoked"); assert(!(*(obj->mark_addr()))->has_bias_pattern(), "even if we raced, should still be revoked");
return BIAS_REVOKED; return BIAS_REVOKED;
} else if (prototype_header->bias_epoch() != mark->bias_epoch()) { } else if (prototype_header->bias_epoch() != mark->bias_epoch()) {
@ -609,14 +609,14 @@ BiasedLocking::Condition BiasedLocking::revoke_and_rebias(Handle obj, bool attem
assert(THREAD->is_Java_thread(), ""); assert(THREAD->is_Java_thread(), "");
markOop biased_value = mark; markOop biased_value = mark;
markOop rebiased_prototype = markOopDesc::encode((JavaThread*) THREAD, mark->age(), prototype_header->bias_epoch()); markOop rebiased_prototype = markOopDesc::encode((JavaThread*) THREAD, mark->age(), prototype_header->bias_epoch());
markOop res_mark = (markOop) Atomic::cmpxchg_ptr(rebiased_prototype, obj->mark_addr(), mark); markOop res_mark = obj->cas_set_mark(rebiased_prototype, mark);
if (res_mark == biased_value) { if (res_mark == biased_value) {
return BIAS_REVOKED_AND_REBIASED; return BIAS_REVOKED_AND_REBIASED;
} }
} else { } else {
markOop biased_value = mark; markOop biased_value = mark;
markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age()); markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
markOop res_mark = (markOop) Atomic::cmpxchg_ptr(unbiased_prototype, obj->mark_addr(), mark); markOop res_mark = obj->cas_set_mark(unbiased_prototype, mark);
if (res_mark == biased_value) { if (res_mark == biased_value) {
return BIAS_REVOKED; return BIAS_REVOKED;
} }

10
hotspot/src/share/vm/runtime/synchronizer.cpp
View File

@ -323,7 +323,7 @@ void ObjectSynchronizer::fast_exit(oop object, BasicLock* lock, TRAPS) {
// If the object is stack-locked by the current thread, try to // If the object is stack-locked by the current thread, try to
// swing the displaced header from the BasicLock back to the mark. // swing the displaced header from the BasicLock back to the mark.
assert(dhw->is_neutral(), "invariant"); assert(dhw->is_neutral(), "invariant");
if ((markOop) Atomic::cmpxchg_ptr(dhw, object->mark_addr(), mark) == mark) { if (object->cas_set_mark(dhw, mark) == mark) {
TEVENT(fast_exit: release stack-lock); TEVENT(fast_exit: release stack-lock);
return; return;
} }
@ -348,7 +348,7 @@ void ObjectSynchronizer::slow_enter(Handle obj, BasicLock* lock, TRAPS) {
// Anticipate successful CAS -- the ST of the displaced mark must // Anticipate successful CAS -- the ST of the displaced mark must
// be visible <= the ST performed by the CAS. // be visible <= the ST performed by the CAS.
lock->set_displaced_header(mark); lock->set_displaced_header(mark);
if (mark == (markOop) Atomic::cmpxchg_ptr(lock, obj()->mark_addr(), mark)) { if (mark == obj()->cas_set_mark((markOop) lock, mark)) {
TEVENT(slow_enter: release stacklock); TEVENT(slow_enter: release stacklock);
return; return;
} }
@ -758,7 +758,7 @@ intptr_t ObjectSynchronizer::FastHashCode(Thread * Self, oop obj) {
hash = get_next_hash(Self, obj); // allocate a new hash code hash = get_next_hash(Self, obj); // allocate a new hash code
temp = mark->copy_set_hash(hash); // merge the hash code into header temp = mark->copy_set_hash(hash); // merge the hash code into header
// use (machine word version) atomic operation to install the hash // use (machine word version) atomic operation to install the hash
test = (markOop) Atomic::cmpxchg_ptr(temp, obj->mark_addr(), mark); test = obj->cas_set_mark(temp, mark);
if (test == mark) { if (test == mark) {
return hash; return hash;
} }
@ -1452,7 +1452,7 @@ ObjectMonitor* ObjectSynchronizer::inflate(Thread * Self,
m->_recursions = 0; m->_recursions = 0;
m->_SpinDuration = ObjectMonitor::Knob_SpinLimit; // Consider: maintain by type/class m->_SpinDuration = ObjectMonitor::Knob_SpinLimit; // Consider: maintain by type/class
markOop cmp = (markOop) Atomic::cmpxchg_ptr(markOopDesc::INFLATING(), object->mark_addr(), mark); markOop cmp = object->cas_set_mark(markOopDesc::INFLATING(), mark);
if (cmp != mark) { if (cmp != mark) {
omRelease(Self, m, true); omRelease(Self, m, true);
continue; // Interference -- just retry continue; // Interference -- just retry
@ -1547,7 +1547,7 @@ ObjectMonitor* ObjectSynchronizer::inflate(Thread * Self,
m->_Responsible = NULL; m->_Responsible = NULL;
m->_SpinDuration = ObjectMonitor::Knob_SpinLimit; // consider: keep metastats by type/class m->_SpinDuration = ObjectMonitor::Knob_SpinLimit; // consider: keep metastats by type/class
if (Atomic::cmpxchg_ptr (markOopDesc::encode(m), object->mark_addr(), mark) != mark) { if (object->cas_set_mark(markOopDesc::encode(m), mark) != mark) {
m->set_object(NULL); m->set_object(NULL);
m->set_owner(NULL); m->set_owner(NULL);
m->Recycle(); m->Recycle();