• file
• revisions
• annotate
• diff
• comparison
• raw

src/share/vm/gc_implementation/shared/vmGCOperations.cpp@0bfd3fb24150 (annotated)

src/share/vm/gc_implementation/shared/vmGCOperations.cpp

Tue, 13 Apr 2010 13:52:10 -0700

author

jmasa

date

Tue, 13 Apr 2010 13:52:10 -0700

changeset 1822

0bfd3fb24150

parent 1050

c6c601a0f2d6

child 1827

bdb5361c461c

permissions

-rw-r--r--

6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
Summary: Ensure a full GC that clears SoftReferences before throwing an out-of-memory
Reviewed-by: ysr, jcoomes

duke@435	1	/*
xdono@631	2	* Copyright 2005-2008 Sun Microsystems, Inc. All Rights Reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
duke@435	19	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435	20	* CA 95054 USA or visit www.sun.com if you need additional information or
duke@435	21	* have any questions.
duke@435	22	*
duke@435	23	*/
duke@435	24	# include "incls/_precompiled.incl"
duke@435	25	# include "incls/_vmGCOperations.cpp.incl"
duke@435	26
duke@435	27	HS_DTRACE_PROBE_DECL1(hotspot, gc__begin, bool);
duke@435	28	HS_DTRACE_PROBE_DECL(hotspot, gc__end);
duke@435	29
duke@435	30	// The same dtrace probe can't be inserted in two different files, so we
duke@435	31	// have to call it here, so it's only in one file. Can't create new probes
duke@435	32	// for the other file anymore. The dtrace probes have to remain stable.
duke@435	33	void VM_GC_Operation::notify_gc_begin(bool full) {
duke@435	34	HS_DTRACE_PROBE1(hotspot, gc__begin, full);
duke@435	35	}
duke@435	36
duke@435	37	void VM_GC_Operation::notify_gc_end() {
duke@435	38	HS_DTRACE_PROBE(hotspot, gc__end);
duke@435	39	}
duke@435	40
duke@435	41	void VM_GC_Operation::acquire_pending_list_lock() {
duke@435	42	// we may enter this with pending exception set
duke@435	43	instanceRefKlass::acquire_pending_list_lock(&_pending_list_basic_lock);
duke@435	44	}
duke@435	45
duke@435	46
duke@435	47	void VM_GC_Operation::release_and_notify_pending_list_lock() {
duke@435	48
duke@435	49	instanceRefKlass::release_and_notify_pending_list_lock(&_pending_list_basic_lock);
duke@435	50	}
duke@435	51
duke@435	52	// Allocations may fail in several threads at about the same time,
duke@435	53	// resulting in multiple gc requests. We only want to do one of them.
duke@435	54	// In case a GC locker is active and the need for a GC is already signalled,
duke@435	55	// we want to skip this GC attempt altogether, without doing a futile
duke@435	56	// safepoint operation.
duke@435	57	bool VM_GC_Operation::skip_operation() const {
duke@435	58	bool skip = (_gc_count_before != Universe::heap()->total_collections());
duke@435	59	if (_full && skip) {
duke@435	60	skip = (_full_gc_count_before != Universe::heap()->total_full_collections());
duke@435	61	}
duke@435	62	if (!skip && GC_locker::is_active_and_needs_gc()) {
duke@435	63	skip = Universe::heap()->is_maximal_no_gc();
duke@435	64	assert(!(skip && (_gc_cause == GCCause::_gc_locker)),
duke@435	65	"GC_locker cannot be active when initiating GC");
duke@435	66	}
duke@435	67	return skip;
duke@435	68	}
duke@435	69
duke@435	70	bool VM_GC_Operation::doit_prologue() {
duke@435	71	assert(Thread::current()->is_Java_thread(), "just checking");
duke@435	72
duke@435	73	acquire_pending_list_lock();
duke@435	74	// If the GC count has changed someone beat us to the collection
duke@435	75	// Get the Heap_lock after the pending_list_lock.
duke@435	76	Heap_lock->lock();
ysr@777	77
duke@435	78	// Check invocations
duke@435	79	if (skip_operation()) {
duke@435	80	// skip collection
duke@435	81	Heap_lock->unlock();
duke@435	82	release_and_notify_pending_list_lock();
duke@435	83	_prologue_succeeded = false;
duke@435	84	} else {
duke@435	85	_prologue_succeeded = true;
ysr@777	86	SharedHeap* sh = SharedHeap::heap();
ysr@777	87	if (sh != NULL) sh->_thread_holds_heap_lock_for_gc = true;
duke@435	88	}
duke@435	89	return _prologue_succeeded;
duke@435	90	}
duke@435	91
duke@435	92
duke@435	93	void VM_GC_Operation::doit_epilogue() {
duke@435	94	assert(Thread::current()->is_Java_thread(), "just checking");
duke@435	95	// Release the Heap_lock first.
ysr@777	96	SharedHeap* sh = SharedHeap::heap();
ysr@777	97	if (sh != NULL) sh->_thread_holds_heap_lock_for_gc = false;
duke@435	98	Heap_lock->unlock();
duke@435	99	release_and_notify_pending_list_lock();
duke@435	100	}
duke@435	101
duke@435	102	bool VM_GC_HeapInspection::doit_prologue() {
duke@435	103	if (Universe::heap()->supports_heap_inspection()) {
duke@435	104	return VM_GC_Operation::doit_prologue();
duke@435	105	} else {
duke@435	106	return false;
duke@435	107	}
duke@435	108	}
duke@435	109
duke@435	110	bool VM_GC_HeapInspection::skip_operation() const {
duke@435	111	assert(Universe::heap()->supports_heap_inspection(), "huh?");
duke@435	112	return false;
duke@435	113	}
duke@435	114
duke@435	115	void VM_GC_HeapInspection::doit() {
duke@435	116	HandleMark hm;
duke@435	117	CollectedHeap* ch = Universe::heap();
duke@435	118	if (_full_gc) {
duke@435	119	ch->collect_as_vm_thread(GCCause::_heap_inspection);
duke@435	120	} else {
duke@435	121	// make the heap parsable (no need to retire TLABs)
duke@435	122	ch->ensure_parsability(false);
duke@435	123	}
ysr@1050	124	HeapInspection::heap_inspection(_out, _need_prologue /* need_prologue */);
duke@435	125	}
duke@435	126
duke@435	127
duke@435	128	void VM_GenCollectForAllocation::doit() {
duke@435	129	JvmtiGCForAllocationMarker jgcm;
duke@435	130	notify_gc_begin(false);
duke@435	131
duke@435	132	GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435	133	GCCauseSetter gccs(gch, _gc_cause);
duke@435	134	_res = gch->satisfy_failed_allocation(_size, _tlab);
duke@435	135	assert(gch->is_in_reserved_or_null(_res), "result not in heap");
duke@435	136
duke@435	137	if (_res == NULL && GC_locker::is_active_and_needs_gc()) {
duke@435	138	set_gc_locked();
duke@435	139	}
duke@435	140	notify_gc_end();
duke@435	141	}
duke@435	142
duke@435	143	void VM_GenCollectFull::doit() {
duke@435	144	JvmtiGCFullMarker jgcm;
duke@435	145	notify_gc_begin(true);
duke@435	146
duke@435	147	GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435	148	GCCauseSetter gccs(gch, _gc_cause);
duke@435	149	gch->do_full_collection(gch->must_clear_all_soft_refs(), _max_level);
duke@435	150	notify_gc_end();
duke@435	151	}
apetrusenko@574	152
apetrusenko@574	153	void VM_GenCollectForPermanentAllocation::doit() {
apetrusenko@574	154	JvmtiGCForAllocationMarker jgcm;
apetrusenko@574	155	notify_gc_begin(true);
ysr@777	156	SharedHeap* heap = (SharedHeap*)Universe::heap();
ysr@777	157	GCCauseSetter gccs(heap, _gc_cause);
ysr@777	158	switch (heap->kind()) {
ysr@777	159	case (CollectedHeap::GenCollectedHeap): {
ysr@777	160	GenCollectedHeap* gch = (GenCollectedHeap*)heap;
ysr@777	161	gch->do_full_collection(gch->must_clear_all_soft_refs(),
ysr@777	162	gch->n_gens() - 1);
ysr@777	163	break;
ysr@777	164	}
ysr@777	165	#ifndef SERIALGC
ysr@777	166	case (CollectedHeap::G1CollectedHeap): {
ysr@777	167	G1CollectedHeap* g1h = (G1CollectedHeap*)heap;
ysr@777	168	g1h->do_full_collection(_gc_cause == GCCause::_last_ditch_collection);
ysr@777	169	break;
ysr@777	170	}
ysr@777	171	#endif // SERIALGC
ysr@777	172	default:
ysr@777	173	ShouldNotReachHere();
ysr@777	174	}
ysr@777	175	_res = heap->perm_gen()->allocate(_size, false);
ysr@777	176	assert(heap->is_in_reserved_or_null(_res), "result not in heap");
apetrusenko@574	177	if (_res == NULL && GC_locker::is_active_and_needs_gc()) {
apetrusenko@574	178	set_gc_locked();
apetrusenko@574	179	}
apetrusenko@574	180	notify_gc_end();
apetrusenko@574	181	}