1 /*
2 * Copyright (c) 1997, 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 "memory/universe.hpp"
27 #include "runtime/mutexLocker.hpp"
28 #include "runtime/os.inline.hpp"
29 #include "runtime/safepoint.hpp"
30 #include "runtime/thread.inline.hpp"
31 #include "runtime/vmThread.hpp"
32
33 // Mutexes used in the VM (see comment in mutexLocker.hpp):
34 //
35 // Note that the following pointers are effectively final -- after having been
36 // set at JVM startup-time, they should never be subsequently mutated.
37 // Instead of using pointers to malloc()ed monitors and mutexes we should consider
38 // eliminating the indirection and using instances instead.
39 // Consider using GCC's __read_mostly.
40
41 Mutex* Patching_lock = NULL;
42 Monitor* SystemDictionary_lock = NULL;
43 Mutex* ProtectionDomainSet_lock = NULL;
44 Mutex* SharedDictionary_lock = NULL;
45 Mutex* Module_lock = NULL;
46 Mutex* CompiledIC_lock = NULL;
47 Mutex* InlineCacheBuffer_lock = NULL;
48 Mutex* VMStatistic_lock = NULL;
49 Mutex* JNIGlobalAlloc_lock = NULL;
50 Mutex* JNIGlobalActive_lock = NULL;
51 Mutex* JNIWeakAlloc_lock = NULL;
52 Mutex* JNIWeakActive_lock = NULL;
53 Mutex* StringTableWeakAlloc_lock = NULL;
54 Mutex* StringTableWeakActive_lock = NULL;
55 Mutex* JNIHandleBlockFreeList_lock = NULL;
56 Mutex* VMWeakAlloc_lock = NULL;
57 Mutex* VMWeakActive_lock = NULL;
58 Mutex* ResolvedMethodTableWeakAlloc_lock = NULL;
59 Mutex* ResolvedMethodTableWeakActive_lock = NULL;
60 Mutex* JmethodIdCreation_lock = NULL;
61 Mutex* JfieldIdCreation_lock = NULL;
62 Monitor* JNICritical_lock = NULL;
63 Mutex* JvmtiThreadState_lock = NULL;
64 Monitor* Heap_lock = NULL;
65 Mutex* ExpandHeap_lock = NULL;
66 Mutex* AdapterHandlerLibrary_lock = NULL;
67 Mutex* SignatureHandlerLibrary_lock = NULL;
68 Mutex* VtableStubs_lock = NULL;
69 Mutex* SymbolArena_lock = NULL;
70 Monitor* StringDedupQueue_lock = NULL;
71 Mutex* StringDedupTable_lock = NULL;
72 Monitor* CodeCache_lock = NULL;
73 Mutex* MethodData_lock = NULL;
74 Mutex* TouchedMethodLog_lock = NULL;
75 Mutex* RetData_lock = NULL;
76 Monitor* VMOperationQueue_lock = NULL;
77 Monitor* VMOperationRequest_lock = NULL;
78 Monitor* SerializePage_lock = NULL;
79 Monitor* Threads_lock = NULL;
80 Mutex* NonJavaThreadsList_lock = NULL;
81 Mutex* NonJavaThreadsListSync_lock = NULL;
82 Monitor* CGC_lock = NULL;
83 Monitor* STS_lock = NULL;
84 Monitor* FullGCCount_lock = NULL;
85 Monitor* SATB_Q_CBL_mon = NULL;
86 Monitor* DirtyCardQ_CBL_mon = NULL;
87 Mutex* Shared_DirtyCardQ_lock = NULL;
88 Mutex* MarkStackFreeList_lock = NULL;
89 Mutex* MarkStackChunkList_lock = NULL;
90 Mutex* MonitoringSupport_lock = NULL;
91 Mutex* ParGCRareEvent_lock = NULL;
92 Monitor* CGCPhaseManager_lock = NULL;
93 Mutex* Compile_lock = NULL;
94 Monitor* MethodCompileQueue_lock = NULL;
95 Monitor* CompileThread_lock = NULL;
96 Monitor* Compilation_lock = NULL;
97 Mutex* CompileTaskAlloc_lock = NULL;
98 Mutex* CompileStatistics_lock = NULL;
99 Mutex* DirectivesStack_lock = NULL;
100 Mutex* MultiArray_lock = NULL;
101 Monitor* Terminator_lock = NULL;
102 Monitor* InitCompleted_lock = NULL;
103 Monitor* BeforeExit_lock = NULL;
104 Monitor* Notify_lock = NULL;
105 Mutex* ProfilePrint_lock = NULL;
106 Mutex* ExceptionCache_lock = NULL;
107 Mutex* OsrList_lock = NULL;
108 Mutex* NMethodSweeperStats_lock = NULL;
109 #ifndef PRODUCT
110 Mutex* FullGCALot_lock = NULL;
111 #endif
112
113 Mutex* Debug1_lock = NULL;
114 Mutex* Debug2_lock = NULL;
115 Mutex* Debug3_lock = NULL;
116
117 Mutex* tty_lock = NULL;
118
119 Mutex* RawMonitor_lock = NULL;
120 Mutex* PerfDataMemAlloc_lock = NULL;
121 Mutex* PerfDataManager_lock = NULL;
122 Mutex* OopMapCacheAlloc_lock = NULL;
123
124 Mutex* FreeList_lock = NULL;
125 Mutex* OldSets_lock = NULL;
126 Monitor* RootRegionScan_lock = NULL;
127
128 Mutex* Management_lock = NULL;
129 Monitor* Service_lock = NULL;
130 Monitor* PeriodicTask_lock = NULL;
131 Monitor* RedefineClasses_lock = NULL;
132
133 #if INCLUDE_JFR
134 Mutex* JfrStacktrace_lock = NULL;
135 Monitor* JfrMsg_lock = NULL;
136 Mutex* JfrBuffer_lock = NULL;
137 Mutex* JfrStream_lock = NULL;
138 Monitor* JfrThreadSampler_lock = NULL;
139 #endif
140
141 #ifndef SUPPORTS_NATIVE_CX8
142 Mutex* UnsafeJlong_lock = NULL;
143 #endif
144 Monitor* CodeHeapStateAnalytics_lock = NULL;
145
146 Mutex* MetaspaceExpand_lock = NULL;
147 Mutex* ClassLoaderDataGraph_lock = NULL;
148 Monitor* ThreadsSMRDelete_lock = NULL;
149 Mutex* SharedDecoder_lock = NULL;
150 Mutex* DCmdFactory_lock = NULL;
151 #if INCLUDE_NMT
152 Mutex* NMTQuery_lock = NULL;
153 #endif
154 #if INCLUDE_CDS
155 #if INCLUDE_JVMTI
156 Mutex* CDSClassFileStream_lock = NULL;
157 #endif
158 Mutex* DumpTimeTable_lock = NULL;
159 #endif // INCLUDE_CDS
160
161 #if INCLUDE_JVMCI
162 Monitor* JVMCI_lock = NULL;
163 Mutex* JVMCIGlobalAlloc_lock = NULL;
164 Mutex* JVMCIGlobalActive_lock = NULL;
165 #endif
166
167
168 #define MAX_NUM_MUTEX 128
169 static Monitor * _mutex_array[MAX_NUM_MUTEX];
170 static int _num_mutex;
171
172 #ifdef ASSERT
173 void assert_locked_or_safepoint(const Monitor * lock) {
174 // check if this thread owns the lock (common case)
175 if (IgnoreLockingAssertions) return;
176 assert(lock != NULL, "Need non-NULL lock");
177 if (lock->owned_by_self()) return;
178 if (SafepointSynchronize::is_at_safepoint()) return;
179 if (!Universe::is_fully_initialized()) return;
180 // see if invoker of VM operation owns it
181 VM_Operation* op = VMThread::vm_operation();
182 if (op != NULL && op->calling_thread() == lock->owner()) return;
183 fatal("must own lock %s", lock->name());
184 }
185
186 // a weaker assertion than the above
187 void assert_locked_or_safepoint_weak(const Monitor * lock) {
188 if (IgnoreLockingAssertions) return;
189 assert(lock != NULL, "Need non-NULL lock");
190 if (lock->is_locked()) return;
191 if (SafepointSynchronize::is_at_safepoint()) return;
192 if (!Universe::is_fully_initialized()) return;
193 fatal("must own lock %s", lock->name());
194 }
195
196 // a stronger assertion than the above
197 void assert_lock_strong(const Monitor * lock) {
198 if (IgnoreLockingAssertions) return;
199 assert(lock != NULL, "Need non-NULL lock");
200 if (lock->owned_by_self()) return;
201 fatal("must own lock %s", lock->name());
202 }
203 #endif
204
205 #define def(var, type, pri, vm_block, safepoint_check_allowed ) { \
206 var = new type(Mutex::pri, #var, vm_block, safepoint_check_allowed); \
207 assert(_num_mutex < MAX_NUM_MUTEX, "increase MAX_NUM_MUTEX"); \
208 _mutex_array[_num_mutex++] = var; \
209 }
210
211 // Using Padded subclasses to prevent false sharing of these global monitors and mutexes.
212 void mutex_init() {
213 def(tty_lock , PaddedMutex , tty, true, Monitor::_safepoint_check_never); // allow to lock in VM
214
215 def(CGC_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); // coordinate between fore- and background GC
216 def(STS_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
217
218 def(VMWeakAlloc_lock , PaddedMutex , vmweak, true, Monitor::_safepoint_check_never);
219 def(VMWeakActive_lock , PaddedMutex , vmweak-1, true, Monitor::_safepoint_check_never);
220
221 def(StringTableWeakAlloc_lock , PaddedMutex , vmweak, true, Monitor::_safepoint_check_never);
222 def(StringTableWeakActive_lock , PaddedMutex , vmweak-1, true, Monitor::_safepoint_check_never);
223
224 def(ResolvedMethodTableWeakAlloc_lock , PaddedMutex , vmweak, true, Monitor::_safepoint_check_never);
225 def(ResolvedMethodTableWeakActive_lock , PaddedMutex , vmweak-1, true, Monitor::_safepoint_check_never);
226
227 def(FullGCCount_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); // in support of ExplicitGCInvokesConcurrent
228 if (UseG1GC) {
229 def(SATB_Q_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never);
230
231 def(DirtyCardQ_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never);
232 def(Shared_DirtyCardQ_lock , PaddedMutex , access + 1, true, Monitor::_safepoint_check_never);
233
234 def(FreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
235 def(OldSets_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
236 def(RootRegionScan_lock , PaddedMonitor, leaf , true, Monitor::_safepoint_check_never);
237
238 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
239 def(StringDedupTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
240
241 def(MarkStackFreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
242 def(MarkStackChunkList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
243
244 def(MonitoringSupport_lock , PaddedMutex , native , true, Monitor::_safepoint_check_never); // used for serviceability monitoring support
245 }
246 if (UseShenandoahGC) {
247 def(SATB_Q_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never);
248
249 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
250 def(StringDedupTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
251 }
252 def(ParGCRareEvent_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_always);
253 def(CGCPhaseManager_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_always);
254 def(CodeCache_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
255 def(RawMonitor_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
256 def(OopMapCacheAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for oop_map_cache allocation.
257
258 def(MetaspaceExpand_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never);
259 def(ClassLoaderDataGraph_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always);
260
261 def(Patching_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); // used for safepointing and code patching.
262 def(Service_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); // used for service thread operations
263 def(JmethodIdCreation_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for creating jmethodIDs.
264
265 def(SystemDictionary_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always);
266 def(ProtectionDomainSet_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never);
267 def(SharedDictionary_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always);
268 def(Module_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_always);
269 def(InlineCacheBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
270 def(VMStatistic_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always);
271 def(ExpandHeap_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // Used during compilation by VM thread
272 def(JNIHandleBlockFreeList_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never); // handles are used by VM thread
273 def(SignatureHandlerLibrary_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always);
274 def(SymbolArena_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_never);
275 def(ProfilePrint_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing
276 def(ExceptionCache_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing
277 def(OsrList_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
278 def(Debug1_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
279 #ifndef PRODUCT
280 def(FullGCALot_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // a lock to make FullGCALot MT safe
281 #endif
282 def(BeforeExit_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always);
283 def(PerfDataMemAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for allocating PerfData memory for performance data
284 def(PerfDataManager_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for synchronized access to PerfDataManager resources
285
286 // CMS_modUnionTable_lock leaf
287 // CMS_bitMap_lock leaf 1
288 // CMS_freeList_lock leaf 2
289
290 def(Threads_lock , PaddedMonitor, barrier, true, Monitor::_safepoint_check_sometimes); // Used for safepoint protocol.
291 def(NonJavaThreadsList_lock , PaddedMutex, leaf, true, Monitor::_safepoint_check_never);
292 def(NonJavaThreadsListSync_lock , PaddedMutex, leaf, true, Monitor::_safepoint_check_never);
293
294 def(VMOperationQueue_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_never); // VM_thread allowed to block on these
295 def(VMOperationRequest_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always);
296 def(RetData_lock , PaddedMutex , nonleaf, false, Monitor::_safepoint_check_always);
297 def(Terminator_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always);
298 def(InitCompleted_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
299 def(VtableStubs_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
300 def(Notify_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always);
301 def(JNIGlobalAlloc_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
302 def(JNIGlobalActive_lock , PaddedMutex , nonleaf-1, true, Monitor::_safepoint_check_never);
303 def(JNIWeakAlloc_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
304 def(JNIWeakActive_lock , PaddedMutex , nonleaf-1, true, Monitor::_safepoint_check_never);
305 def(JNICritical_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always); // used for JNI critical regions
306 def(AdapterHandlerLibrary_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always);
307
308 def(Heap_lock , PaddedMonitor, nonleaf+1, false, Monitor::_safepoint_check_sometimes); // Doesn't safepoint check during termination.
309 def(JfieldIdCreation_lock , PaddedMutex , nonleaf+1, true, Monitor::_safepoint_check_always); // jfieldID, Used in VM_Operation
310
311 def(CompiledIC_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_never); // locks VtableStubs_lock, InlineCacheBuffer_lock
312 def(CompileTaskAlloc_lock , PaddedMutex , nonleaf+2, true, Monitor::_safepoint_check_always);
313 def(CompileStatistics_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always);
314 def(DirectivesStack_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
315 def(MultiArray_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always);
316
317 def(JvmtiThreadState_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // Used by JvmtiThreadState/JvmtiEventController
318 def(Management_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // used for JVM management
319
320 def(Compile_lock , PaddedMutex , nonleaf+3, true, Monitor::_safepoint_check_always);
321 def(MethodData_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always);
322 def(TouchedMethodLog_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always);
323
324 def(MethodCompileQueue_lock , PaddedMonitor, nonleaf+4, true, Monitor::_safepoint_check_always);
325 def(Debug2_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never);
326 def(Debug3_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never);
327 def(CompileThread_lock , PaddedMonitor, nonleaf+5, false, Monitor::_safepoint_check_always);
328 def(PeriodicTask_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_always);
329 def(RedefineClasses_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_always);
330
331 if (WhiteBoxAPI) {
332 def(Compilation_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_never);
333 }
334
335 #if INCLUDE_JFR
336 def(JfrMsg_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always);
337 def(JfrBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
338 def(JfrStream_lock , PaddedMutex , leaf+1, true, Monitor::_safepoint_check_never); // ensure to rank lower than 'safepoint'
339 def(JfrStacktrace_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
340 def(JfrThreadSampler_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
341 #endif
342
343 #ifndef SUPPORTS_NATIVE_CX8
344 def(UnsafeJlong_lock , PaddedMutex , special, false, Monitor::_safepoint_check_never);
345 #endif
346
347 def(CodeHeapStateAnalytics_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
348 def(NMethodSweeperStats_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
349 def(ThreadsSMRDelete_lock , PaddedMonitor, special, false, Monitor::_safepoint_check_never);
350 def(SharedDecoder_lock , PaddedMutex , native, false, Monitor::_safepoint_check_never);
351 def(DCmdFactory_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
352 #if INCLUDE_NMT
353 def(NMTQuery_lock , PaddedMutex , max_nonleaf, false, Monitor::_safepoint_check_always);
354 #endif
355 #if INCLUDE_CDS
356 #if INCLUDE_JVMTI
357 def(CDSClassFileStream_lock , PaddedMutex , max_nonleaf, false, Monitor::_safepoint_check_always);
358 #endif
359
360 #if INCLUDE_JVMCI
361 def(JVMCI_lock , PaddedMonitor, nonleaf+2, true, Monitor::_safepoint_check_always);
362 def(JVMCIGlobalAlloc_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
363 def(JVMCIGlobalActive_lock , PaddedMutex , nonleaf-1, true, Monitor::_safepoint_check_never);
364 #endif
365 def(DumpTimeTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
366 #endif // INCLUDE_CDS
367 }
368
369 GCMutexLocker::GCMutexLocker(Monitor * mutex) {
370 if (SafepointSynchronize::is_at_safepoint()) {
371 _locked = false;
372 } else {
373 _mutex = mutex;
374 _locked = true;
375 _mutex->lock();
376 }
377 }
378
379 // Print all mutexes/monitors that are currently owned by a thread; called
380 // by fatal error handler.
381 void print_owned_locks_on_error(outputStream* st) {
382 st->print("VM Mutex/Monitor currently owned by a thread: ");
383 bool none = true;
384 for (int i = 0; i < _num_mutex; i++) {
385 // see if it has an owner
386 if (_mutex_array[i]->owner() != NULL) {
387 if (none) {
388 // print format used by Mutex::print_on_error()
389 st->print_cr(" ([mutex/lock_event])");
390 none = false;
391 }
392 _mutex_array[i]->print_on_error(st);
393 st->cr();
394 }
395 }
396 if (none) st->print_cr("None");
397 }