1/*
2 * Copyright (c) 2003, 2019, 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 "memory/allocation.inline.hpp"
29#include "oops/oop.inline.hpp"
30#include "runtime/handles.inline.hpp"
31#include "runtime/javaCalls.hpp"
32#include "runtime/orderAccess.hpp"
33#include "services/lowMemoryDetector.hpp"
34#include "services/management.hpp"
35#include "services/memoryManager.hpp"
36#include "services/memoryPool.hpp"
37#include "services/memoryService.hpp"
38#include "services/gcNotifier.hpp"
39#include "utilities/dtrace.hpp"
40
41MemoryManager::MemoryManager(const char* name) : _name(name) {
42 _num_pools = 0;
43 (void)const_cast<instanceOop&>(_memory_mgr_obj = instanceOop(NULL));
44}
45
46int MemoryManager::add_pool(MemoryPool* pool) {
47 int index = _num_pools;
48 assert(index < MemoryManager::max_num_pools, "_num_pools exceeds the max");
49 if (index < MemoryManager::max_num_pools) {
50 _pools[index] = pool;
51 _num_pools++;
52 }
53 pool->add_manager(this);
54 return index;
55}
56
57MemoryManager* MemoryManager::get_code_cache_memory_manager() {
58 return new MemoryManager("CodeCacheManager");
59}
60
61MemoryManager* MemoryManager::get_metaspace_memory_manager() {
62 return new MemoryManager("Metaspace Manager");
63}
64
65instanceOop MemoryManager::get_memory_manager_instance(TRAPS) {
66 // Must do an acquire so as to force ordering of subsequent
67 // loads from anything _memory_mgr_obj points to or implies.
68 instanceOop mgr_obj = OrderAccess::load_acquire(&_memory_mgr_obj);
69 if (mgr_obj == NULL) {
70 // It's ok for more than one thread to execute the code up to the locked region.
71 // Extra manager instances will just be gc'ed.
72 Klass* k = Management::sun_management_ManagementFactoryHelper_klass(CHECK_0);
73
74 Handle mgr_name = java_lang_String::create_from_str(name(), CHECK_0);
75
76 JavaValue result(T_OBJECT);
77 JavaCallArguments args;
78 args.push_oop(mgr_name); // Argument 1
79
80 Symbol* method_name = NULL;
81 Symbol* signature = NULL;
82 if (is_gc_memory_manager()) {
83 Klass* extKlass = Management::com_sun_management_internal_GarbageCollectorExtImpl_klass(CHECK_0);
84 // com.sun.management.GarbageCollectorMXBean is in jdk.management module which may not be present.
85 if (extKlass != NULL) {
86 k = extKlass;
87 }
88
89 method_name = vmSymbols::createGarbageCollector_name();
90
91 signature = vmSymbols::createGarbageCollector_signature();
92 args.push_oop(Handle()); // Argument 2 (for future extension)
93 } else {
94 method_name = vmSymbols::createMemoryManager_name();
95 signature = vmSymbols::createMemoryManager_signature();
96 }
97
98 InstanceKlass* ik = InstanceKlass::cast(k);
99
100 JavaCalls::call_static(&result,
101 ik,
102 method_name,
103 signature,
104 &args,
105 CHECK_0);
106
107 instanceOop m = (instanceOop) result.get_jobject();
108 instanceHandle mgr(THREAD, m);
109
110 {
111 // Get lock before setting _memory_mgr_obj
112 // since another thread may have created the instance
113 MutexLocker ml(Management_lock);
114
115 // Check if another thread has created the management object. We reload
116 // _memory_mgr_obj here because some other thread may have initialized
117 // it while we were executing the code before the lock.
118 //
119 // The lock has done an acquire, so the load can't float above it, but
120 // we need to do a load_acquire as above.
121 mgr_obj = OrderAccess::load_acquire(&_memory_mgr_obj);
122 if (mgr_obj != NULL) {
123 return mgr_obj;
124 }
125
126 // Get the address of the object we created via call_special.
127 mgr_obj = mgr();
128
129 // Use store barrier to make sure the memory accesses associated
130 // with creating the management object are visible before publishing
131 // its address. The unlock will publish the store to _memory_mgr_obj
132 // because it does a release first.
133 OrderAccess::release_store(&_memory_mgr_obj, mgr_obj);
134 }
135 }
136
137 return mgr_obj;
138}
139
140void MemoryManager::oops_do(OopClosure* f) {
141 f->do_oop((oop*) &_memory_mgr_obj);
142}
143
144GCStatInfo::GCStatInfo(int num_pools) {
145 // initialize the arrays for memory usage
146 _before_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools, mtInternal);
147 _after_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools, mtInternal);
148 _usage_array_size = num_pools;
149 clear();
150}
151
152GCStatInfo::~GCStatInfo() {
153 FREE_C_HEAP_ARRAY(MemoryUsage*, _before_gc_usage_array);
154 FREE_C_HEAP_ARRAY(MemoryUsage*, _after_gc_usage_array);
155}
156
157void GCStatInfo::set_gc_usage(int pool_index, MemoryUsage usage, bool before_gc) {
158 MemoryUsage* gc_usage_array;
159 if (before_gc) {
160 gc_usage_array = _before_gc_usage_array;
161 } else {
162 gc_usage_array = _after_gc_usage_array;
163 }
164 gc_usage_array[pool_index] = usage;
165}
166
167void GCStatInfo::clear() {
168 _index = 0;
169 _start_time = 0L;
170 _end_time = 0L;
171 for (int i = 0; i < _usage_array_size; i++) ::new (&_before_gc_usage_array[i]) MemoryUsage();
172 for (int i = 0; i < _usage_array_size; i++) ::new (&_after_gc_usage_array[i]) MemoryUsage();
173}
174
175
176GCMemoryManager::GCMemoryManager(const char* name, const char* gc_end_message) :
177 MemoryManager(name), _gc_end_message(gc_end_message) {
178 _num_collections = 0;
179 _last_gc_stat = NULL;
180 _last_gc_lock = new Mutex(Mutex::leaf, "_last_gc_lock", true,
181 Monitor::_safepoint_check_never);
182 _current_gc_stat = NULL;
183 _num_gc_threads = 1;
184 _notification_enabled = false;
185}
186
187GCMemoryManager::~GCMemoryManager() {
188 delete _last_gc_stat;
189 delete _last_gc_lock;
190 delete _current_gc_stat;
191}
192
193void GCMemoryManager::add_pool(MemoryPool* pool) {
194 add_pool(pool, true);
195}
196
197void GCMemoryManager::add_pool(MemoryPool* pool, bool always_affected_by_gc) {
198 int index = MemoryManager::add_pool(pool);
199 _pool_always_affected_by_gc[index] = always_affected_by_gc;
200}
201
202void GCMemoryManager::initialize_gc_stat_info() {
203 assert(MemoryService::num_memory_pools() > 0, "should have one or more memory pools");
204 _last_gc_stat = new(ResourceObj::C_HEAP, mtGC) GCStatInfo(MemoryService::num_memory_pools());
205 _current_gc_stat = new(ResourceObj::C_HEAP, mtGC) GCStatInfo(MemoryService::num_memory_pools());
206 // tracking concurrent collections we need two objects: one to update, and one to
207 // hold the publicly available "last (completed) gc" information.
208}
209
210void GCMemoryManager::gc_begin(bool recordGCBeginTime, bool recordPreGCUsage,
211 bool recordAccumulatedGCTime) {
212 assert(_last_gc_stat != NULL && _current_gc_stat != NULL, "Just checking");
213 if (recordAccumulatedGCTime) {
214 _accumulated_timer.start();
215 }
216 // _num_collections now increases in gc_end, to count completed collections
217 if (recordGCBeginTime) {
218 _current_gc_stat->set_index(_num_collections+1);
219 _current_gc_stat->set_start_time(Management::timestamp());
220 }
221
222 if (recordPreGCUsage) {
223 // Keep memory usage of all memory pools
224 for (int i = 0; i < MemoryService::num_memory_pools(); i++) {
225 MemoryPool* pool = MemoryService::get_memory_pool(i);
226 MemoryUsage usage = pool->get_memory_usage();
227 _current_gc_stat->set_before_gc_usage(i, usage);
228 HOTSPOT_MEM_POOL_GC_BEGIN(
229 (char *) name(), strlen(name()),
230 (char *) pool->name(), strlen(pool->name()),
231 usage.init_size(), usage.used(),
232 usage.committed(), usage.max_size());
233 }
234 }
235}
236
237// A collector MUST, even if it does not complete for some reason,
238// make a TraceMemoryManagerStats object where countCollection is true,
239// to ensure the current gc stat is placed in _last_gc_stat.
240void GCMemoryManager::gc_end(bool recordPostGCUsage,
241 bool recordAccumulatedGCTime,
242 bool recordGCEndTime, bool countCollection,
243 GCCause::Cause cause,
244 bool allMemoryPoolsAffected) {
245 if (recordAccumulatedGCTime) {
246 _accumulated_timer.stop();
247 }
248 if (recordGCEndTime) {
249 _current_gc_stat->set_end_time(Management::timestamp());
250 }
251
252 if (recordPostGCUsage) {
253 int i;
254 // keep the last gc statistics for all memory pools
255 for (i = 0; i < MemoryService::num_memory_pools(); i++) {
256 MemoryPool* pool = MemoryService::get_memory_pool(i);
257 MemoryUsage usage = pool->get_memory_usage();
258
259 HOTSPOT_MEM_POOL_GC_END(
260 (char *) name(), strlen(name()),
261 (char *) pool->name(), strlen(pool->name()),
262 usage.init_size(), usage.used(),
263 usage.committed(), usage.max_size());
264
265 _current_gc_stat->set_after_gc_usage(i, usage);
266 }
267
268 // Set last collection usage of the memory pools managed by this collector
269 for (i = 0; i < num_memory_pools(); i++) {
270 MemoryPool* pool = get_memory_pool(i);
271 MemoryUsage usage = pool->get_memory_usage();
272
273 if (allMemoryPoolsAffected || pool_always_affected_by_gc(i)) {
274 // Compare with GC usage threshold
275 pool->set_last_collection_usage(usage);
276 LowMemoryDetector::detect_after_gc_memory(pool);
277 }
278 }
279 }
280
281 if (countCollection) {
282 _num_collections++;
283 // alternately update two objects making one public when complete
284 {
285 MutexLocker ml(_last_gc_lock, Mutex::_no_safepoint_check_flag);
286 GCStatInfo *tmp = _last_gc_stat;
287 _last_gc_stat = _current_gc_stat;
288 _current_gc_stat = tmp;
289 // reset the current stat for diagnosability purposes
290 _current_gc_stat->clear();
291 }
292
293 if (is_notification_enabled()) {
294 GCNotifier::pushNotification(this, _gc_end_message, GCCause::to_string(cause));
295 }
296 }
297}
298
299size_t GCMemoryManager::get_last_gc_stat(GCStatInfo* dest) {
300 MutexLocker ml(_last_gc_lock, Mutex::_no_safepoint_check_flag);
301 if (_last_gc_stat->gc_index() != 0) {
302 dest->set_index(_last_gc_stat->gc_index());
303 dest->set_start_time(_last_gc_stat->start_time());
304 dest->set_end_time(_last_gc_stat->end_time());
305 assert(dest->usage_array_size() == _last_gc_stat->usage_array_size(),
306 "Must have same array size");
307 size_t len = dest->usage_array_size() * sizeof(MemoryUsage);
308 memcpy(dest->before_gc_usage_array(), _last_gc_stat->before_gc_usage_array(), len);
309 memcpy(dest->after_gc_usage_array(), _last_gc_stat->after_gc_usage_array(), len);
310 }
311 return _last_gc_stat->gc_index();
312}
313