1 /*
2 * Copyright (c) 2003, 2017, 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 */
24
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 "runtime/orderAccess.inline.hpp"
32 #include "services/lowMemoryDetector.hpp"
33 #include "services/management.hpp"
34 #include "services/memoryManager.hpp"
35 #include "services/memoryPool.hpp"
36 #include "services/memoryService.hpp"
37 #include "services/gcNotifier.hpp"
38 #include "utilities/dtrace.hpp"
39
40 MemoryManager::MemoryManager(const char* name) : _name(name) {
41 _num_pools = 0;
42 (void)const_cast<instanceOop&>(_memory_mgr_obj = instanceOop(NULL));
43 }
44
45 void MemoryManager::add_pool(MemoryPool* pool) {
46 assert(_num_pools < MemoryManager::max_num_pools, "_num_pools exceeds the max");
47 if (_num_pools < MemoryManager::max_num_pools) {
48 _pools[_num_pools] = pool;
49 _num_pools++;
50 }
51 pool->add_manager(this);
52 }
53
54 MemoryManager* MemoryManager::get_code_cache_memory_manager() {
55 return new MemoryManager("CodeCacheManager");
56 }
57
58 MemoryManager* MemoryManager::get_metaspace_memory_manager() {
59 return new MemoryManager("Metaspace Manager");
60 }
61
62 instanceOop MemoryManager::get_memory_manager_instance(TRAPS) {
63 // Must do an acquire so as to force ordering of subsequent
64 // loads from anything _memory_mgr_obj points to or implies.
65 instanceOop mgr_obj = OrderAccess::load_acquire(&_memory_mgr_obj);
66 if (mgr_obj == NULL) {
67 // It's ok for more than one thread to execute the code up to the locked region.
68 // Extra manager instances will just be gc'ed.
69 Klass* k = Management::sun_management_ManagementFactoryHelper_klass(CHECK_0);
70
71 Handle mgr_name = java_lang_String::create_from_str(name(), CHECK_0);
72
73 JavaValue result(T_OBJECT);
74 JavaCallArguments args;
75 args.push_oop(mgr_name); // Argument 1
76
77 Symbol* method_name = NULL;
78 Symbol* signature = NULL;
79 if (is_gc_memory_manager()) {
80 Klass* extKlass = Management::com_sun_management_internal_GarbageCollectorExtImpl_klass(CHECK_0);
81 // com.sun.management.GarbageCollectorMXBean is in jdk.management module which may not be present.
82 if (extKlass != NULL) {
83 k = extKlass;
84 }
85
86 method_name = vmSymbols::createGarbageCollector_name();
87
88 signature = vmSymbols::createGarbageCollector_signature();
89 args.push_oop(Handle()); // Argument 2 (for future extension)
90 } else {
91 method_name = vmSymbols::createMemoryManager_name();
92 signature = vmSymbols::createMemoryManager_signature();
93 }
94
95 InstanceKlass* ik = InstanceKlass::cast(k);
96
97 JavaCalls::call_static(&result,
98 ik,
99 method_name,
100 signature,
101 &args,
102 CHECK_0);
103
104 instanceOop m = (instanceOop) result.get_jobject();
105 instanceHandle mgr(THREAD, m);
106
107 {
108 // Get lock before setting _memory_mgr_obj
109 // since another thread may have created the instance
110 MutexLocker ml(Management_lock);
111
112 // Check if another thread has created the management object. We reload
113 // _memory_mgr_obj here because some other thread may have initialized
114 // it while we were executing the code before the lock.
115 //
116 // The lock has done an acquire, so the load can't float above it, but
117 // we need to do a load_acquire as above.
118 mgr_obj = OrderAccess::load_acquire(&_memory_mgr_obj);
119 if (mgr_obj != NULL) {
120 return mgr_obj;
121 }
122
123 // Get the address of the object we created via call_special.
124 mgr_obj = mgr();
125
126 // Use store barrier to make sure the memory accesses associated
127 // with creating the management object are visible before publishing
128 // its address. The unlock will publish the store to _memory_mgr_obj
129 // because it does a release first.
130 OrderAccess::release_store(&_memory_mgr_obj, mgr_obj);
131 }
132 }
133
134 return mgr_obj;
135 }
136
137 void MemoryManager::oops_do(OopClosure* f) {
138 f->do_oop((oop*) &_memory_mgr_obj);
139 }
140
141 GCStatInfo::GCStatInfo(int num_pools) {
142 // initialize the arrays for memory usage
143 _before_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools, mtInternal);
144 _after_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools, mtInternal);
145 _usage_array_size = num_pools;
146 clear();
147 }
148
149 GCStatInfo::~GCStatInfo() {
150 FREE_C_HEAP_ARRAY(MemoryUsage*, _before_gc_usage_array);
151 FREE_C_HEAP_ARRAY(MemoryUsage*, _after_gc_usage_array);
152 }
153
154 void GCStatInfo::set_gc_usage(int pool_index, MemoryUsage usage, bool before_gc) {
155 MemoryUsage* gc_usage_array;
156 if (before_gc) {
157 gc_usage_array = _before_gc_usage_array;
158 } else {
159 gc_usage_array = _after_gc_usage_array;
160 }
161 gc_usage_array[pool_index] = usage;
162 }
163
164 void GCStatInfo::clear() {
165 _index = 0;
166 _start_time = 0L;
167 _end_time = 0L;
168 size_t len = _usage_array_size * sizeof(MemoryUsage);
169 memset(_before_gc_usage_array, 0, len);
170 memset(_after_gc_usage_array, 0, len);
171 }
172
173
174 GCMemoryManager::GCMemoryManager(const char* name, const char* gc_end_message) :
175 MemoryManager(name), _gc_end_message(gc_end_message) {
176 _num_collections = 0;
177 _last_gc_stat = NULL;
178 _last_gc_lock = new Mutex(Mutex::leaf, "_last_gc_lock", true,
179 Monitor::_safepoint_check_never);
180 _current_gc_stat = NULL;
181 _num_gc_threads = 1;
182 _notification_enabled = false;
183 }
184
185 GCMemoryManager::~GCMemoryManager() {
186 delete _last_gc_stat;
187 delete _last_gc_lock;
188 delete _current_gc_stat;
189 }
190
191 void GCMemoryManager::initialize_gc_stat_info() {
192 assert(MemoryService::num_memory_pools() > 0, "should have one or more memory pools");
193 _last_gc_stat = new(ResourceObj::C_HEAP, mtGC) GCStatInfo(MemoryService::num_memory_pools());
194 _current_gc_stat = new(ResourceObj::C_HEAP, mtGC) GCStatInfo(MemoryService::num_memory_pools());
195 // tracking concurrent collections we need two objects: one to update, and one to
196 // hold the publicly available "last (completed) gc" information.
197 }
198
199 void GCMemoryManager::gc_begin(bool recordGCBeginTime, bool recordPreGCUsage,
200 bool recordAccumulatedGCTime) {
201 assert(_last_gc_stat != NULL && _current_gc_stat != NULL, "Just checking");
202 if (recordAccumulatedGCTime) {
203 _accumulated_timer.start();
204 }
205 // _num_collections now increases in gc_end, to count completed collections
206 if (recordGCBeginTime) {
207 _current_gc_stat->set_index(_num_collections+1);
208 _current_gc_stat->set_start_time(Management::timestamp());
209 }
210
211 if (recordPreGCUsage) {
212 // Keep memory usage of all memory pools
213 for (int i = 0; i < MemoryService::num_memory_pools(); i++) {
214 MemoryPool* pool = MemoryService::get_memory_pool(i);
215 MemoryUsage usage = pool->get_memory_usage();
216 _current_gc_stat->set_before_gc_usage(i, usage);
217 HOTSPOT_MEM_POOL_GC_BEGIN(
218 (char *) name(), strlen(name()),
219 (char *) pool->name(), strlen(pool->name()),
220 usage.init_size(), usage.used(),
221 usage.committed(), usage.max_size());
222 }
223 }
224 }
225
226 // A collector MUST, even if it does not complete for some reason,
227 // make a TraceMemoryManagerStats object where countCollection is true,
228 // to ensure the current gc stat is placed in _last_gc_stat.
229 void GCMemoryManager::gc_end(bool recordPostGCUsage,
230 bool recordAccumulatedGCTime,
231 bool recordGCEndTime, bool countCollection,
232 GCCause::Cause cause) {
233 if (recordAccumulatedGCTime) {
234 _accumulated_timer.stop();
235 }
236 if (recordGCEndTime) {
237 _current_gc_stat->set_end_time(Management::timestamp());
238 }
239
240 if (recordPostGCUsage) {
241 int i;
242 // keep the last gc statistics for all memory pools
243 for (i = 0; i < MemoryService::num_memory_pools(); i++) {
244 MemoryPool* pool = MemoryService::get_memory_pool(i);
245 MemoryUsage usage = pool->get_memory_usage();
246
247 HOTSPOT_MEM_POOL_GC_END(
248 (char *) name(), strlen(name()),
249 (char *) pool->name(), strlen(pool->name()),
250 usage.init_size(), usage.used(),
251 usage.committed(), usage.max_size());
252
253 _current_gc_stat->set_after_gc_usage(i, usage);
254 }
255
256 // Set last collection usage of the memory pools managed by this collector
257 for (i = 0; i < num_memory_pools(); i++) {
258 MemoryPool* pool = get_memory_pool(i);
259 MemoryUsage usage = pool->get_memory_usage();
260
261 // Compare with GC usage threshold
262 pool->set_last_collection_usage(usage);
263 LowMemoryDetector::detect_after_gc_memory(pool);
264 }
265 }
266
267 if (countCollection) {
268 _num_collections++;
269 // alternately update two objects making one public when complete
270 {
271 MutexLockerEx ml(_last_gc_lock, Mutex::_no_safepoint_check_flag);
272 GCStatInfo *tmp = _last_gc_stat;
273 _last_gc_stat = _current_gc_stat;
274 _current_gc_stat = tmp;
275 // reset the current stat for diagnosability purposes
276 _current_gc_stat->clear();
277 }
278
279 if (is_notification_enabled()) {
280 GCNotifier::pushNotification(this, _gc_end_message, GCCause::to_string(cause));
281 }
282 }
283 }
284
285 size_t GCMemoryManager::get_last_gc_stat(GCStatInfo* dest) {
286 MutexLockerEx ml(_last_gc_lock, Mutex::_no_safepoint_check_flag);
287 if (_last_gc_stat->gc_index() != 0) {
288 dest->set_index(_last_gc_stat->gc_index());
289 dest->set_start_time(_last_gc_stat->start_time());
290 dest->set_end_time(_last_gc_stat->end_time());
291 assert(dest->usage_array_size() == _last_gc_stat->usage_array_size(),
292 "Must have same array size");
293 size_t len = dest->usage_array_size() * sizeof(MemoryUsage);
294 memcpy(dest->before_gc_usage_array(), _last_gc_stat->before_gc_usage_array(), len);
295 memcpy(dest->after_gc_usage_array(), _last_gc_stat->after_gc_usage_array(), len);
296 }
297 return _last_gc_stat->gc_index();
298 }