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src/share/vm/services/classLoadingService.cpp@e018e6884bd8 (annotated)

src/share/vm/services/classLoadingService.cpp

Wed, 23 Dec 2009 09:23:54 -0800

author

ysr

date

Wed, 23 Dec 2009 09:23:54 -0800

changeset 1580

e018e6884bd8

parent 435

a61af66fc99e

child 1582

75bd253e25dd

permissions

-rw-r--r--

6631166: CMS: better heuristics when combatting fragmentation
Summary: Autonomic per-worker free block cache sizing, tunable coalition policies, fixes to per-size block statistics, retuned gain and bandwidth of some feedback loop filters to allow quicker reactivity to abrupt changes in ambient demand, and other heuristics to reduce fragmentation of the CMS old gen. Also tightened some assertions, including those related to locking.
Reviewed-by: jmasa

duke@435	1	/*
duke@435	2	* Copyright 2003-2005 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/_classLoadingService.cpp.incl"
duke@435	27
duke@435	28	#ifdef DTRACE_ENABLED
duke@435	29
duke@435	30	// Only bother with this argument setup if dtrace is available
duke@435	31
duke@435	32	HS_DTRACE_PROBE_DECL4(hotspot, class__loaded, char*, int, oop, bool);
duke@435	33	HS_DTRACE_PROBE_DECL4(hotspot, class__unloaded, char*, int, oop, bool);
duke@435	34
duke@435	35	#define DTRACE_CLASSLOAD_PROBE(type, clss, shared) \
duke@435	36	{ \
duke@435	37	char* data = NULL; \
duke@435	38	int len = 0; \
duke@435	39	symbolOop name = (clss)->name(); \
duke@435	40	if (name != NULL) { \
duke@435	41	data = (char*)name->bytes(); \
duke@435	42	len = name->utf8_length(); \
duke@435	43	} \
duke@435	44	HS_DTRACE_PROBE4(hotspot, class__##type, \
duke@435	45	data, len, (clss)->class_loader(), (shared)); \
duke@435	46	}
duke@435	47
duke@435	48	#else // ndef DTRACE_ENABLED
duke@435	49
duke@435	50	#define DTRACE_CLASSLOAD_PROBE(type, clss, shared)
duke@435	51
duke@435	52	#endif
duke@435	53
duke@435	54	// counters for classes loaded from class files
duke@435	55	PerfCounter* ClassLoadingService::_classes_loaded_count = NULL;
duke@435	56	PerfCounter* ClassLoadingService::_classes_unloaded_count = NULL;
duke@435	57	PerfCounter* ClassLoadingService::_classbytes_loaded = NULL;
duke@435	58	PerfCounter* ClassLoadingService::_classbytes_unloaded = NULL;
duke@435	59
duke@435	60	// counters for classes loaded from shared archive
duke@435	61	PerfCounter* ClassLoadingService::_shared_classes_loaded_count = NULL;
duke@435	62	PerfCounter* ClassLoadingService::_shared_classes_unloaded_count = NULL;
duke@435	63	PerfCounter* ClassLoadingService::_shared_classbytes_loaded = NULL;
duke@435	64	PerfCounter* ClassLoadingService::_shared_classbytes_unloaded = NULL;
duke@435	65	PerfVariable* ClassLoadingService::_class_methods_size = NULL;
duke@435	66
duke@435	67	void ClassLoadingService::init() {
duke@435	68	EXCEPTION_MARK;
duke@435	69
duke@435	70	// These counters are for java.lang.management API support.
duke@435	71	// They are created even if -XX:-UsePerfData is set and in
duke@435	72	// that case, they will be allocated on C heap.
duke@435	73	_classes_loaded_count =
duke@435	74	PerfDataManager::create_counter(JAVA_CLS, "loadedClasses",
duke@435	75	PerfData::U_Events, CHECK);
duke@435	76
duke@435	77	_classes_unloaded_count =
duke@435	78	PerfDataManager::create_counter(JAVA_CLS, "unloadedClasses",
duke@435	79	PerfData::U_Events, CHECK);
duke@435	80
duke@435	81	_shared_classes_loaded_count =
duke@435	82	PerfDataManager::create_counter(JAVA_CLS, "sharedLoadedClasses",
duke@435	83	PerfData::U_Events, CHECK);
duke@435	84
duke@435	85	_shared_classes_unloaded_count =
duke@435	86	PerfDataManager::create_counter(JAVA_CLS, "sharedUnloadedClasses",
duke@435	87	PerfData::U_Events, CHECK);
duke@435	88
duke@435	89	if (UsePerfData) {
duke@435	90	_classbytes_loaded =
duke@435	91	PerfDataManager::create_counter(SUN_CLS, "loadedBytes",
duke@435	92	PerfData::U_Bytes, CHECK);
duke@435	93
duke@435	94	_classbytes_unloaded =
duke@435	95	PerfDataManager::create_counter(SUN_CLS, "unloadedBytes",
duke@435	96	PerfData::U_Bytes, CHECK);
duke@435	97	_shared_classbytes_loaded =
duke@435	98	PerfDataManager::create_counter(SUN_CLS, "sharedLoadedBytes",
duke@435	99	PerfData::U_Bytes, CHECK);
duke@435	100
duke@435	101	_shared_classbytes_unloaded =
duke@435	102	PerfDataManager::create_counter(SUN_CLS, "sharedUnloadedBytes",
duke@435	103	PerfData::U_Bytes, CHECK);
duke@435	104	_class_methods_size =
duke@435	105	PerfDataManager::create_variable(SUN_CLS, "methodBytes",
duke@435	106	PerfData::U_Bytes, CHECK);
duke@435	107	}
duke@435	108	}
duke@435	109
duke@435	110	void ClassLoadingService::notify_class_unloaded(instanceKlass* k) {
duke@435	111	DTRACE_CLASSLOAD_PROBE(unloaded, k, false);
duke@435	112	// Classes that can be unloaded must be non-shared
duke@435	113	_classes_unloaded_count->inc();
duke@435	114
duke@435	115	if (UsePerfData) {
duke@435	116	// add the class size
duke@435	117	size_t size = compute_class_size(k);
duke@435	118	_classbytes_unloaded->inc(size);
duke@435	119
duke@435	120	// Compute method size & subtract from running total.
duke@435	121	// We are called during phase 1 of mark sweep, so it's
duke@435	122	// still ok to iterate through methodOops here.
duke@435	123	objArrayOop methods = k->methods();
duke@435	124	for (int i = 0; i < methods->length(); i++) {
duke@435	125	_class_methods_size->inc(-methods->obj_at(i)->size());
duke@435	126	}
duke@435	127	}
duke@435	128
duke@435	129	if (TraceClassUnloading) {
duke@435	130	ResourceMark rm;
ysr@1580	131	gclog_or_tty->print_cr("[Unloading class %s]", k->external_name());
duke@435	132	}
duke@435	133	}
duke@435	134
duke@435	135	void ClassLoadingService::notify_class_loaded(instanceKlass* k, bool shared_class) {
duke@435	136	DTRACE_CLASSLOAD_PROBE(loaded, k, shared_class);
duke@435	137	PerfCounter* classes_counter = (shared_class ? _shared_classes_loaded_count
duke@435	138	: _classes_loaded_count);
duke@435	139	// increment the count
duke@435	140	classes_counter->inc();
duke@435	141
duke@435	142	if (UsePerfData) {
duke@435	143	PerfCounter* classbytes_counter = (shared_class ? _shared_classbytes_loaded
duke@435	144	: _classbytes_loaded);
duke@435	145	// add the class size
duke@435	146	size_t size = compute_class_size(k);
duke@435	147	classbytes_counter->inc(size);
duke@435	148	}
duke@435	149	}
duke@435	150
duke@435	151	size_t ClassLoadingService::compute_class_size(instanceKlass* k) {
duke@435	152	// lifted from ClassStatistics.do_class(klassOop k)
duke@435	153
duke@435	154	size_t class_size = 0;
duke@435	155
duke@435	156	class_size += k->as_klassOop()->size();
duke@435	157
duke@435	158	if (k->oop_is_instance()) {
duke@435	159	class_size += k->methods()->size();
duke@435	160	class_size += k->constants()->size();
duke@435	161	class_size += k->local_interfaces()->size();
duke@435	162	class_size += k->transitive_interfaces()->size();
duke@435	163	// We do not have to count implementors, since we only store one!
duke@435	164	class_size += k->fields()->size();
duke@435	165	}
duke@435	166	return class_size * oopSize;
duke@435	167	}
duke@435	168
duke@435	169
duke@435	170	bool ClassLoadingService::set_verbose(bool verbose) {
duke@435	171	MutexLocker m(Management_lock);
duke@435	172
duke@435	173	// verbose will be set to the previous value
duke@435	174	bool succeed = CommandLineFlags::boolAtPut((char*)"TraceClassLoading", &verbose, MANAGEMENT);
duke@435	175	assert(succeed, "Setting TraceClassLoading flag fails");
duke@435	176	reset_trace_class_unloading();
duke@435	177
duke@435	178	return verbose;
duke@435	179	}
duke@435	180
duke@435	181	// Caller to this function must own Management_lock
duke@435	182	void ClassLoadingService::reset_trace_class_unloading() {
duke@435	183	assert(Management_lock->owned_by_self(), "Must own the Management_lock");
duke@435	184	bool value = MemoryService::get_verbose() || ClassLoadingService::get_verbose();
duke@435	185	bool succeed = CommandLineFlags::boolAtPut((char*)"TraceClassUnloading", &value, MANAGEMENT);
duke@435	186	assert(succeed, "Setting TraceClassUnLoading flag fails");
duke@435	187	}
duke@435	188
duke@435	189	GrowableArray<KlassHandle>* LoadedClassesEnumerator::_loaded_classes = NULL;
duke@435	190	Thread* LoadedClassesEnumerator::_current_thread = NULL;
duke@435	191
duke@435	192	LoadedClassesEnumerator::LoadedClassesEnumerator(Thread* cur_thread) {
duke@435	193	assert(cur_thread == Thread::current(), "Check current thread");
duke@435	194
duke@435	195	int init_size = ClassLoadingService::loaded_class_count();
duke@435	196	_klass_handle_array = new GrowableArray<KlassHandle>(init_size);
duke@435	197
duke@435	198	// For consistency of the loaded classes, grab the SystemDictionary lock
duke@435	199	MutexLocker sd_mutex(SystemDictionary_lock);
duke@435	200
duke@435	201	// Set _loaded_classes and _current_thread and begin enumerating all classes.
duke@435	202	// Only one thread will do the enumeration at a time.
duke@435	203	// These static variables are needed and they are used by the static method
duke@435	204	// add_loaded_class called from classes_do().
duke@435	205	_loaded_classes = _klass_handle_array;
duke@435	206	_current_thread = cur_thread;
duke@435	207
duke@435	208	SystemDictionary::classes_do(&add_loaded_class);
duke@435	209
duke@435	210	// FIXME: Exclude array klasses for now
duke@435	211	// Universe::basic_type_classes_do(&add_loaded_class);
duke@435	212	}