Fri, 11 Feb 2011 14:15:16 +0100
7018257: jmm_DumpThreads allocates into permgen
Summary: Don't allocate in permgen
Reviewed-by: ysr, sla
1 /*
2 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
25 #include "precompiled.hpp"
26 #include "classfile/systemDictionary.hpp"
27 #include "classfile/vmSymbols.hpp"
28 #include "oops/oop.inline.hpp"
29 #include "runtime/handles.inline.hpp"
30 #include "runtime/javaCalls.hpp"
31 #include "services/lowMemoryDetector.hpp"
32 #include "services/management.hpp"
33 #include "services/memoryManager.hpp"
34 #include "services/memoryPool.hpp"
35 #include "services/memoryService.hpp"
36 #include "utilities/dtrace.hpp"
38 HS_DTRACE_PROBE_DECL8(hotspot, mem__pool__gc__begin, char*, int, char*, int,
39 size_t, size_t, size_t, size_t);
40 HS_DTRACE_PROBE_DECL8(hotspot, mem__pool__gc__end, char*, int, char*, int,
41 size_t, size_t, size_t, size_t);
43 MemoryManager::MemoryManager() {
44 _num_pools = 0;
45 _memory_mgr_obj = NULL;
46 }
48 void MemoryManager::add_pool(MemoryPool* pool) {
49 assert(_num_pools < MemoryManager::max_num_pools, "_num_pools exceeds the max");
50 if (_num_pools < MemoryManager::max_num_pools) {
51 _pools[_num_pools] = pool;
52 _num_pools++;
53 }
54 pool->add_manager(this);
55 }
57 MemoryManager* MemoryManager::get_code_cache_memory_manager() {
58 return (MemoryManager*) new CodeCacheMemoryManager();
59 }
61 GCMemoryManager* MemoryManager::get_copy_memory_manager() {
62 return (GCMemoryManager*) new CopyMemoryManager();
63 }
65 GCMemoryManager* MemoryManager::get_msc_memory_manager() {
66 return (GCMemoryManager*) new MSCMemoryManager();
67 }
69 GCMemoryManager* MemoryManager::get_parnew_memory_manager() {
70 return (GCMemoryManager*) new ParNewMemoryManager();
71 }
73 GCMemoryManager* MemoryManager::get_cms_memory_manager() {
74 return (GCMemoryManager*) new CMSMemoryManager();
75 }
77 GCMemoryManager* MemoryManager::get_psScavenge_memory_manager() {
78 return (GCMemoryManager*) new PSScavengeMemoryManager();
79 }
81 GCMemoryManager* MemoryManager::get_psMarkSweep_memory_manager() {
82 return (GCMemoryManager*) new PSMarkSweepMemoryManager();
83 }
85 GCMemoryManager* MemoryManager::get_g1YoungGen_memory_manager() {
86 return (GCMemoryManager*) new G1YoungGenMemoryManager();
87 }
89 GCMemoryManager* MemoryManager::get_g1OldGen_memory_manager() {
90 return (GCMemoryManager*) new G1OldGenMemoryManager();
91 }
93 instanceOop MemoryManager::get_memory_manager_instance(TRAPS) {
94 // Must do an acquire so as to force ordering of subsequent
95 // loads from anything _memory_mgr_obj points to or implies.
96 instanceOop mgr_obj = (instanceOop)OrderAccess::load_ptr_acquire(&_memory_mgr_obj);
97 if (mgr_obj == NULL) {
98 // It's ok for more than one thread to execute the code up to the locked region.
99 // Extra manager instances will just be gc'ed.
100 klassOop k = Management::sun_management_ManagementFactory_klass(CHECK_0);
101 instanceKlassHandle ik(THREAD, k);
103 Handle mgr_name = java_lang_String::create_from_str(name(), CHECK_0);
105 JavaValue result(T_OBJECT);
106 JavaCallArguments args;
107 args.push_oop(mgr_name); // Argument 1
109 Symbol* method_name = NULL;
110 Symbol* signature = NULL;
111 if (is_gc_memory_manager()) {
112 method_name = vmSymbols::createGarbageCollector_name();
113 signature = vmSymbols::createGarbageCollector_signature();
114 args.push_oop(Handle()); // Argument 2 (for future extension)
115 } else {
116 method_name = vmSymbols::createMemoryManager_name();
117 signature = vmSymbols::createMemoryManager_signature();
118 }
120 JavaCalls::call_static(&result,
121 ik,
122 method_name,
123 signature,
124 &args,
125 CHECK_0);
127 instanceOop m = (instanceOop) result.get_jobject();
128 instanceHandle mgr(THREAD, m);
130 {
131 // Get lock before setting _memory_mgr_obj
132 // since another thread may have created the instance
133 MutexLocker ml(Management_lock);
135 // Check if another thread has created the management object. We reload
136 // _memory_mgr_obj here because some other thread may have initialized
137 // it while we were executing the code before the lock.
138 //
139 // The lock has done an acquire, so the load can't float above it, but
140 // we need to do a load_acquire as above.
141 mgr_obj = (instanceOop)OrderAccess::load_ptr_acquire(&_memory_mgr_obj);
142 if (mgr_obj != NULL) {
143 return mgr_obj;
144 }
146 // Get the address of the object we created via call_special.
147 mgr_obj = mgr();
149 // Use store barrier to make sure the memory accesses associated
150 // with creating the management object are visible before publishing
151 // its address. The unlock will publish the store to _memory_mgr_obj
152 // because it does a release first.
153 OrderAccess::release_store_ptr(&_memory_mgr_obj, mgr_obj);
154 }
155 }
157 return mgr_obj;
158 }
160 void MemoryManager::oops_do(OopClosure* f) {
161 f->do_oop((oop*) &_memory_mgr_obj);
162 }
164 GCStatInfo::GCStatInfo(int num_pools) {
165 // initialize the arrays for memory usage
166 _before_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools);
167 _after_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools);
168 size_t len = num_pools * sizeof(MemoryUsage);
169 memset(_before_gc_usage_array, 0, len);
170 memset(_after_gc_usage_array, 0, len);
171 _usage_array_size = num_pools;
172 }
174 GCStatInfo::~GCStatInfo() {
175 FREE_C_HEAP_ARRAY(MemoryUsage*, _before_gc_usage_array);
176 FREE_C_HEAP_ARRAY(MemoryUsage*, _after_gc_usage_array);
177 }
179 void GCStatInfo::set_gc_usage(int pool_index, MemoryUsage usage, bool before_gc) {
180 MemoryUsage* gc_usage_array;
181 if (before_gc) {
182 gc_usage_array = _before_gc_usage_array;
183 } else {
184 gc_usage_array = _after_gc_usage_array;
185 }
186 gc_usage_array[pool_index] = usage;
187 }
189 void GCStatInfo::clear() {
190 _index = 0;
191 _start_time = 0L;
192 _end_time = 0L;
193 size_t len = _usage_array_size * sizeof(MemoryUsage);
194 memset(_before_gc_usage_array, 0, len);
195 memset(_after_gc_usage_array, 0, len);
196 }
199 GCMemoryManager::GCMemoryManager() : MemoryManager() {
200 _num_collections = 0;
201 _last_gc_stat = NULL;
202 _last_gc_lock = new Mutex(Mutex::leaf, "_last_gc_lock", true);
203 _current_gc_stat = NULL;
204 _num_gc_threads = 1;
205 }
207 GCMemoryManager::~GCMemoryManager() {
208 delete _last_gc_stat;
209 delete _last_gc_lock;
210 delete _current_gc_stat;
211 }
213 void GCMemoryManager::initialize_gc_stat_info() {
214 assert(MemoryService::num_memory_pools() > 0, "should have one or more memory pools");
215 _last_gc_stat = new GCStatInfo(MemoryService::num_memory_pools());
216 _current_gc_stat = new GCStatInfo(MemoryService::num_memory_pools());
217 // tracking concurrent collections we need two objects: one to update, and one to
218 // hold the publicly available "last (completed) gc" information.
219 }
221 void GCMemoryManager::gc_begin(bool recordGCBeginTime, bool recordPreGCUsage,
222 bool recordAccumulatedGCTime) {
223 assert(_last_gc_stat != NULL && _current_gc_stat != NULL, "Just checking");
224 if (recordAccumulatedGCTime) {
225 _accumulated_timer.start();
226 }
227 // _num_collections now increases in gc_end, to count completed collections
228 if (recordGCBeginTime) {
229 _current_gc_stat->set_index(_num_collections+1);
230 _current_gc_stat->set_start_time(Management::timestamp());
231 }
233 if (recordPreGCUsage) {
234 // Keep memory usage of all memory pools
235 for (int i = 0; i < MemoryService::num_memory_pools(); i++) {
236 MemoryPool* pool = MemoryService::get_memory_pool(i);
237 MemoryUsage usage = pool->get_memory_usage();
238 _current_gc_stat->set_before_gc_usage(i, usage);
239 HS_DTRACE_PROBE8(hotspot, mem__pool__gc__begin,
240 name(), strlen(name()),
241 pool->name(), strlen(pool->name()),
242 usage.init_size(), usage.used(),
243 usage.committed(), usage.max_size());
244 }
245 }
246 }
248 // A collector MUST, even if it does not complete for some reason,
249 // make a TraceMemoryManagerStats object where countCollection is true,
250 // to ensure the current gc stat is placed in _last_gc_stat.
251 void GCMemoryManager::gc_end(bool recordPostGCUsage,
252 bool recordAccumulatedGCTime,
253 bool recordGCEndTime, bool countCollection) {
254 if (recordAccumulatedGCTime) {
255 _accumulated_timer.stop();
256 }
257 if (recordGCEndTime) {
258 _current_gc_stat->set_end_time(Management::timestamp());
259 }
261 if (recordPostGCUsage) {
262 int i;
263 // keep the last gc statistics for all memory pools
264 for (i = 0; i < MemoryService::num_memory_pools(); i++) {
265 MemoryPool* pool = MemoryService::get_memory_pool(i);
266 MemoryUsage usage = pool->get_memory_usage();
268 HS_DTRACE_PROBE8(hotspot, mem__pool__gc__end,
269 name(), strlen(name()),
270 pool->name(), strlen(pool->name()),
271 usage.init_size(), usage.used(),
272 usage.committed(), usage.max_size());
274 _current_gc_stat->set_after_gc_usage(i, usage);
275 }
277 // Set last collection usage of the memory pools managed by this collector
278 for (i = 0; i < num_memory_pools(); i++) {
279 MemoryPool* pool = get_memory_pool(i);
280 MemoryUsage usage = pool->get_memory_usage();
282 // Compare with GC usage threshold
283 pool->set_last_collection_usage(usage);
284 LowMemoryDetector::detect_after_gc_memory(pool);
285 }
286 }
287 if (countCollection) {
288 _num_collections++;
289 // alternately update two objects making one public when complete
290 {
291 MutexLockerEx ml(_last_gc_lock, Mutex::_no_safepoint_check_flag);
292 GCStatInfo *tmp = _last_gc_stat;
293 _last_gc_stat = _current_gc_stat;
294 _current_gc_stat = tmp;
295 // reset the current stat for diagnosability purposes
296 _current_gc_stat->clear();
297 }
298 }
299 }
301 size_t GCMemoryManager::get_last_gc_stat(GCStatInfo* dest) {
302 MutexLockerEx ml(_last_gc_lock, Mutex::_no_safepoint_check_flag);
303 if (_last_gc_stat->gc_index() != 0) {
304 dest->set_index(_last_gc_stat->gc_index());
305 dest->set_start_time(_last_gc_stat->start_time());
306 dest->set_end_time(_last_gc_stat->end_time());
307 assert(dest->usage_array_size() == _last_gc_stat->usage_array_size(),
308 "Must have same array size");
309 size_t len = dest->usage_array_size() * sizeof(MemoryUsage);
310 memcpy(dest->before_gc_usage_array(), _last_gc_stat->before_gc_usage_array(), len);
311 memcpy(dest->after_gc_usage_array(), _last_gc_stat->after_gc_usage_array(), len);
312 }
313 return _last_gc_stat->gc_index();
314 }