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src/share/vm/memory/sharedHeap.cpp@981375ca07b7 (annotated)

src/share/vm/memory/sharedHeap.cpp

Fri, 17 Apr 2009 12:22:18 -0700

author

never

date

Fri, 17 Apr 2009 12:22:18 -0700

changeset 1149

981375ca07b7

parent 1014

0fbdb4381b99

child 1424

148e5441d916

permissions

-rw-r--r--

6831604: missing null check in guarantee
Reviewed-by: kvn

duke@435	1	/*
xdono@1014	2	* Copyright 2000-2009 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
duke@435	25	# include "incls/_precompiled.incl"
duke@435	26	# include "incls/_sharedHeap.cpp.incl"
duke@435	27
duke@435	28	SharedHeap* SharedHeap::_sh;
duke@435	29
duke@435	30	// The set of potentially parallel tasks in strong root scanning.
duke@435	31	enum SH_process_strong_roots_tasks {
duke@435	32	SH_PS_Universe_oops_do,
duke@435	33	SH_PS_JNIHandles_oops_do,
duke@435	34	SH_PS_ObjectSynchronizer_oops_do,
duke@435	35	SH_PS_FlatProfiler_oops_do,
duke@435	36	SH_PS_Management_oops_do,
duke@435	37	SH_PS_SystemDictionary_oops_do,
duke@435	38	SH_PS_jvmti_oops_do,
duke@435	39	SH_PS_vmSymbols_oops_do,
duke@435	40	SH_PS_SymbolTable_oops_do,
duke@435	41	SH_PS_StringTable_oops_do,
duke@435	42	SH_PS_CodeCache_oops_do,
duke@435	43	// Leave this one last.
duke@435	44	SH_PS_NumElements
duke@435	45	};
duke@435	46
duke@435	47	SharedHeap::SharedHeap(CollectorPolicy* policy_) :
duke@435	48	CollectedHeap(),
duke@435	49	_collector_policy(policy_),
duke@435	50	_perm_gen(NULL), _rem_set(NULL),
duke@435	51	_strong_roots_parity(0),
duke@435	52	_process_strong_tasks(new SubTasksDone(SH_PS_NumElements)),
duke@435	53	_workers(NULL), _n_par_threads(0)
duke@435	54	{
duke@435	55	if (_process_strong_tasks == NULL || !_process_strong_tasks->valid()) {
duke@435	56	vm_exit_during_initialization("Failed necessary allocation.");
duke@435	57	}
duke@435	58	_sh = this; // ch is static, should be set only once.
duke@435	59	if ((UseParNewGC ||
ysr@777	60	(UseConcMarkSweepGC && CMSParallelRemarkEnabled) ||
ysr@777	61	UseG1GC) &&
duke@435	62	ParallelGCThreads > 0) {
ysr@777	63	_workers = new WorkGang("Parallel GC Threads", ParallelGCThreads,
ysr@777	64	/* are_GC_task_threads */true,
ysr@777	65	/* are_ConcurrentGC_threads */false);
duke@435	66	if (_workers == NULL) {
duke@435	67	vm_exit_during_initialization("Failed necessary allocation.");
duke@435	68	}
duke@435	69	}
duke@435	70	}
duke@435	71
ysr@777	72	bool SharedHeap::heap_lock_held_for_gc() {
ysr@777	73	Thread* t = Thread::current();
ysr@777	74	return Heap_lock->owned_by_self()
ysr@777	75	|| ( (t->is_GC_task_thread() || t->is_VM_thread())
ysr@777	76	&& _thread_holds_heap_lock_for_gc);
ysr@777	77	}
duke@435	78
duke@435	79	void SharedHeap::set_par_threads(int t) {
duke@435	80	_n_par_threads = t;
duke@435	81	_process_strong_tasks->set_par_threads(t);
duke@435	82	}
duke@435	83
duke@435	84	class AssertIsPermClosure: public OopClosure {
duke@435	85	public:
coleenp@548	86	virtual void do_oop(oop* p) {
duke@435	87	assert((*p) == NULL || (*p)->is_perm(), "Referent should be perm.");
duke@435	88	}
coleenp@548	89	virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
duke@435	90	};
duke@435	91	static AssertIsPermClosure assert_is_perm_closure;
duke@435	92
duke@435	93	void SharedHeap::change_strong_roots_parity() {
duke@435	94	// Also set the new collection parity.
duke@435	95	assert(_strong_roots_parity >= 0 && _strong_roots_parity <= 2,
duke@435	96	"Not in range.");
duke@435	97	_strong_roots_parity++;
duke@435	98	if (_strong_roots_parity == 3) _strong_roots_parity = 1;
duke@435	99	assert(_strong_roots_parity >= 1 && _strong_roots_parity <= 2,
duke@435	100	"Not in range.");
duke@435	101	}
duke@435	102
duke@435	103	void SharedHeap::process_strong_roots(bool collecting_perm_gen,
duke@435	104	ScanningOption so,
duke@435	105	OopClosure* roots,
duke@435	106	OopsInGenClosure* perm_blk) {
duke@435	107	// General strong roots.
duke@435	108	if (n_par_threads() == 0) change_strong_roots_parity();
duke@435	109	if (!_process_strong_tasks->is_task_claimed(SH_PS_Universe_oops_do)) {
duke@435	110	Universe::oops_do(roots);
duke@435	111	ReferenceProcessor::oops_do(roots);
duke@435	112	// Consider perm-gen discovered lists to be strong.
duke@435	113	perm_gen()->ref_processor()->weak_oops_do(roots);
duke@435	114	}
duke@435	115	// Global (strong) JNI handles
duke@435	116	if (!_process_strong_tasks->is_task_claimed(SH_PS_JNIHandles_oops_do))
duke@435	117	JNIHandles::oops_do(roots);
duke@435	118	// All threads execute this; the individual threads are task groups.
duke@435	119	if (ParallelGCThreads > 0) {
duke@435	120	Threads::possibly_parallel_oops_do(roots);
duke@435	121	} else {
duke@435	122	Threads::oops_do(roots);
duke@435	123	}
duke@435	124	if (!_process_strong_tasks-> is_task_claimed(SH_PS_ObjectSynchronizer_oops_do))
duke@435	125	ObjectSynchronizer::oops_do(roots);
duke@435	126	if (!_process_strong_tasks->is_task_claimed(SH_PS_FlatProfiler_oops_do))
duke@435	127	FlatProfiler::oops_do(roots);
duke@435	128	if (!_process_strong_tasks->is_task_claimed(SH_PS_Management_oops_do))
duke@435	129	Management::oops_do(roots);
duke@435	130	if (!_process_strong_tasks->is_task_claimed(SH_PS_jvmti_oops_do))
duke@435	131	JvmtiExport::oops_do(roots);
duke@435	132
duke@435	133	if (!_process_strong_tasks->is_task_claimed(SH_PS_SystemDictionary_oops_do)) {
duke@435	134	if (so & SO_AllClasses) {
duke@435	135	SystemDictionary::oops_do(roots);
duke@435	136	} else
duke@435	137	if (so & SO_SystemClasses) {
duke@435	138	SystemDictionary::always_strong_oops_do(roots);
duke@435	139	}
duke@435	140	}
duke@435	141
duke@435	142	if (!_process_strong_tasks->is_task_claimed(SH_PS_SymbolTable_oops_do)) {
duke@435	143	if (so & SO_Symbols) {
duke@435	144	SymbolTable::oops_do(roots);
duke@435	145	}
duke@435	146	// Verify if the symbol table contents are in the perm gen
duke@435	147	NOT_PRODUCT(SymbolTable::oops_do(&assert_is_perm_closure));
duke@435	148	}
duke@435	149
duke@435	150	if (!_process_strong_tasks->is_task_claimed(SH_PS_StringTable_oops_do)) {
duke@435	151	if (so & SO_Strings) {
duke@435	152	StringTable::oops_do(roots);
duke@435	153	}
duke@435	154	// Verify if the string table contents are in the perm gen
duke@435	155	NOT_PRODUCT(StringTable::oops_do(&assert_is_perm_closure));
duke@435	156	}
duke@435	157
duke@435	158	if (!_process_strong_tasks->is_task_claimed(SH_PS_CodeCache_oops_do)) {
duke@435	159	if (so & SO_CodeCache) {
duke@435	160	CodeCache::oops_do(roots);
duke@435	161	}
duke@435	162	// Verify if the code cache contents are in the perm gen
duke@435	163	NOT_PRODUCT(CodeCache::oops_do(&assert_is_perm_closure));
duke@435	164	}
duke@435	165
duke@435	166	// Roots that should point only into permanent generation.
duke@435	167	{
duke@435	168	OopClosure* blk = NULL;
duke@435	169	if (collecting_perm_gen) {
duke@435	170	blk = roots;
duke@435	171	} else {
duke@435	172	debug_only(blk = &assert_is_perm_closure);
duke@435	173	}
duke@435	174	if (blk != NULL) {
duke@435	175	if (!_process_strong_tasks->is_task_claimed(SH_PS_vmSymbols_oops_do))
duke@435	176	vmSymbols::oops_do(blk);
duke@435	177	}
duke@435	178	}
duke@435	179
duke@435	180	if (!collecting_perm_gen) {
duke@435	181	// All threads perform this; coordination is handled internally.
duke@435	182
duke@435	183	rem_set()->younger_refs_iterate(perm_gen(), perm_blk);
duke@435	184	}
duke@435	185	_process_strong_tasks->all_tasks_completed();
duke@435	186	}
duke@435	187
duke@435	188	class AlwaysTrueClosure: public BoolObjectClosure {
duke@435	189	public:
duke@435	190	void do_object(oop p) { ShouldNotReachHere(); }
duke@435	191	bool do_object_b(oop p) { return true; }
duke@435	192	};
duke@435	193	static AlwaysTrueClosure always_true;
duke@435	194
duke@435	195	class SkipAdjustingSharedStrings: public OopClosure {
duke@435	196	OopClosure* _clo;
duke@435	197	public:
duke@435	198	SkipAdjustingSharedStrings(OopClosure* clo) : _clo(clo) {}
duke@435	199
coleenp@548	200	virtual void do_oop(oop* p) {
duke@435	201	oop o = (*p);
duke@435	202	if (!o->is_shared_readwrite()) {
duke@435	203	_clo->do_oop(p);
duke@435	204	}
duke@435	205	}
coleenp@548	206	virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
duke@435	207	};
duke@435	208
duke@435	209	// Unmarked shared Strings in the StringTable (which got there due to
duke@435	210	// being in the constant pools of as-yet unloaded shared classes) were
duke@435	211	// not marked and therefore did not have their mark words preserved.
duke@435	212	// These entries are also deliberately not purged from the string
duke@435	213	// table during unloading of unmarked strings. If an identity hash
duke@435	214	// code was computed for any of these objects, it will not have been
duke@435	215	// cleared to zero during the forwarding process or by the
duke@435	216	// RecursiveAdjustSharedObjectClosure, and will be confused by the
duke@435	217	// adjusting process as a forwarding pointer. We need to skip
duke@435	218	// forwarding StringTable entries which contain unmarked shared
duke@435	219	// Strings. Actually, since shared strings won't be moving, we can
duke@435	220	// just skip adjusting any shared entries in the string table.
duke@435	221
duke@435	222	void SharedHeap::process_weak_roots(OopClosure* root_closure,
duke@435	223	OopClosure* non_root_closure) {
duke@435	224	// Global (weak) JNI handles
duke@435	225	JNIHandles::weak_oops_do(&always_true, root_closure);
duke@435	226
duke@435	227	CodeCache::oops_do(non_root_closure);
duke@435	228	SymbolTable::oops_do(root_closure);
duke@435	229	if (UseSharedSpaces && !DumpSharedSpaces) {
duke@435	230	SkipAdjustingSharedStrings skip_closure(root_closure);
duke@435	231	StringTable::oops_do(&skip_closure);
duke@435	232	} else {
duke@435	233	StringTable::oops_do(root_closure);
duke@435	234	}
duke@435	235	}
duke@435	236
duke@435	237	void SharedHeap::set_barrier_set(BarrierSet* bs) {
duke@435	238	_barrier_set = bs;
duke@435	239	// Cached barrier set for fast access in oops
duke@435	240	oopDesc::set_bs(bs);
duke@435	241	}
duke@435	242
duke@435	243	void SharedHeap::post_initialize() {
duke@435	244	ref_processing_init();
duke@435	245	}
duke@435	246
duke@435	247	void SharedHeap::ref_processing_init() {
duke@435	248	perm_gen()->ref_processor_init();
duke@435	249	}
duke@435	250
duke@435	251	// Some utilities.
ysr@777	252	void SharedHeap::print_size_transition(outputStream* out,
ysr@777	253	size_t bytes_before,
duke@435	254	size_t bytes_after,
duke@435	255	size_t capacity) {
ysr@777	256	out->print(" %d%s->%d%s(%d%s)",
duke@435	257	byte_size_in_proper_unit(bytes_before),
duke@435	258	proper_unit_for_byte_size(bytes_before),
duke@435	259	byte_size_in_proper_unit(bytes_after),
duke@435	260	proper_unit_for_byte_size(bytes_after),
duke@435	261	byte_size_in_proper_unit(capacity),
duke@435	262	proper_unit_for_byte_size(capacity));
duke@435	263	}