1 /*
2 * Copyright (c) 1997, 2020, 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 Mutex* CompiledMethod_lock = NULL;
43 Monitor* SystemDictionary_lock = NULL;
44 Mutex* ProtectionDomainSet_lock = NULL;
45 Mutex* SharedDictionary_lock = NULL;
46 Mutex* Module_lock = NULL;
47 Mutex* CompiledIC_lock = NULL;
48 Mutex* InlineCacheBuffer_lock = NULL;
49 Mutex* VMStatistic_lock = NULL;
50 Mutex* JNIHandleBlockFreeList_lock = NULL;
51 Mutex* JmethodIdCreation_lock = NULL;
52 Mutex* JfieldIdCreation_lock = NULL;
53 Monitor* JNICritical_lock = NULL;
54 Mutex* JvmtiThreadState_lock = NULL;
55 Monitor* Heap_lock = NULL;
56 Mutex* ExpandHeap_lock = NULL;
57 Mutex* AdapterHandlerLibrary_lock = NULL;
58 Mutex* SignatureHandlerLibrary_lock = NULL;
59 Mutex* VtableStubs_lock = NULL;
60 Mutex* SymbolArena_lock = NULL;
61 Monitor* StringDedupQueue_lock = NULL;
62 Mutex* StringDedupTable_lock = NULL;
63 Monitor* CodeCache_lock = NULL;
64 Mutex* MethodData_lock = NULL;
65 Mutex* TouchedMethodLog_lock = NULL;
66 Mutex* RetData_lock = NULL;
67 Monitor* VMOperationQueue_lock = NULL;
68 Monitor* VMOperationRequest_lock = NULL;
69 Monitor* Threads_lock = NULL;
70 Mutex* NonJavaThreadsList_lock = NULL;
71 Mutex* NonJavaThreadsListSync_lock = NULL;
72 Monitor* CGC_lock = NULL;
73 Monitor* STS_lock = NULL;
74 Monitor* FullGCCount_lock = NULL;
75 Monitor* G1OldGCCount_lock = NULL;
76 Mutex* Shared_DirtyCardQ_lock = NULL;
77 Mutex* G1DetachedRefinementStats_lock = NULL;
78 Mutex* MarkStackFreeList_lock = NULL;
79 Mutex* MarkStackChunkList_lock = NULL;
80 Mutex* MonitoringSupport_lock = NULL;
81 Mutex* ParGCRareEvent_lock = NULL;
82 Monitor* ConcurrentGCBreakpoints_lock = NULL;
83 Mutex* Compile_lock = NULL;
84 Monitor* MethodCompileQueue_lock = NULL;
85 Monitor* CompileThread_lock = NULL;
86 Monitor* Compilation_lock = NULL;
87 Mutex* CompileTaskAlloc_lock = NULL;
88 Mutex* CompileStatistics_lock = NULL;
89 Mutex* DirectivesStack_lock = NULL;
90 Mutex* MultiArray_lock = NULL;
91 Monitor* Terminator_lock = NULL;
92 Monitor* InitCompleted_lock = NULL;
93 Monitor* BeforeExit_lock = NULL;
94 Monitor* Notify_lock = NULL;
95 Mutex* ProfilePrint_lock = NULL;
96 Mutex* ExceptionCache_lock = NULL;
97 Mutex* NMethodSweeperStats_lock = NULL;
98 #ifndef PRODUCT
99 Mutex* FullGCALot_lock = NULL;
100 #endif
101
102 Mutex* Debug1_lock = NULL;
103 Mutex* Debug2_lock = NULL;
104 Mutex* Debug3_lock = NULL;
105
106 Mutex* tty_lock = NULL;
107
108 Mutex* RawMonitor_lock = NULL;
109 Mutex* PerfDataMemAlloc_lock = NULL;
110 Mutex* PerfDataManager_lock = NULL;
111 Mutex* OopMapCacheAlloc_lock = NULL;
112
113 Mutex* FreeList_lock = NULL;
114 Mutex* OldSets_lock = NULL;
115 Monitor* RootRegionScan_lock = NULL;
116
117 Mutex* Management_lock = NULL;
118 Monitor* Service_lock = NULL;
119 Monitor* Notification_lock = NULL;
120 Monitor* PeriodicTask_lock = NULL;
121 Monitor* RedefineClasses_lock = NULL;
122 Mutex* Verify_lock = NULL;
123 Monitor* Zip_lock = NULL;
124
125 #if INCLUDE_JFR
126 Mutex* JfrStacktrace_lock = NULL;
127 Monitor* JfrMsg_lock = NULL;
128 Mutex* JfrBuffer_lock = NULL;
129 Mutex* JfrStream_lock = NULL;
130 Monitor* JfrThreadSampler_lock = NULL;
131 #endif
132
133 #ifndef SUPPORTS_NATIVE_CX8
134 Mutex* UnsafeJlong_lock = NULL;
135 #endif
136 Mutex* CodeHeapStateAnalytics_lock = NULL;
137
138 Mutex* MetaspaceExpand_lock = NULL;
139 Mutex* ClassLoaderDataGraph_lock = NULL;
140 Monitor* ThreadsSMRDelete_lock = NULL;
141 Mutex* ThreadIdTableCreate_lock = NULL;
142 Mutex* SharedDecoder_lock = NULL;
143 Mutex* DCmdFactory_lock = NULL;
144 #if INCLUDE_NMT
145 Mutex* NMTQuery_lock = NULL;
146 #endif
147 #if INCLUDE_CDS
148 #if INCLUDE_JVMTI
149 Mutex* CDSClassFileStream_lock = NULL;
150 #endif
151 Mutex* DumpTimeTable_lock = NULL;
152 Mutex* CDSLambda_lock = NULL;
153 #endif // INCLUDE_CDS
154
155 #if INCLUDE_JVMCI
156 Monitor* JVMCI_lock = NULL;
157 #endif
158
159
160 #define MAX_NUM_MUTEX 128
161 static Mutex* _mutex_array[MAX_NUM_MUTEX];
162 static int _num_mutex;
163
164 #ifdef ASSERT
165 void assert_locked_or_safepoint(const Mutex* lock) {
166 // check if this thread owns the lock (common case)
167 assert(lock != NULL, "Need non-NULL lock");
168 if (lock->owned_by_self()) return;
169 if (SafepointSynchronize::is_at_safepoint()) return;
170 if (!Universe::is_fully_initialized()) return;
171 // see if invoker of VM operation owns it
172 VM_Operation* op = VMThread::vm_operation();
173 if (op != NULL && op->calling_thread() == lock->owner()) return;
174 fatal("must own lock %s", lock->name());
175 }
176
177 // a weaker assertion than the above
178 void assert_locked_or_safepoint_weak(const Mutex* lock) {
179 assert(lock != NULL, "Need non-NULL lock");
180 if (lock->is_locked()) return;
181 if (SafepointSynchronize::is_at_safepoint()) return;
182 if (!Universe::is_fully_initialized()) return;
183 fatal("must own lock %s", lock->name());
184 }
185
186 // a stronger assertion than the above
187 void assert_lock_strong(const Mutex* lock) {
188 assert(lock != NULL, "Need non-NULL lock");
189 if (lock->owned_by_self()) return;
190 fatal("must own lock %s", lock->name());
191 }
192
193 void assert_locked_or_safepoint_or_handshake(const Mutex* lock, const JavaThread* thread) {
194 if (Thread::current() == thread->active_handshaker()) return;
195 assert_locked_or_safepoint(lock);
196 }
197 #endif
198
199 #define def(var, type, pri, vm_block, safepoint_check_allowed ) { \
200 var = new type(Mutex::pri, #var, vm_block, Mutex::safepoint_check_allowed); \
201 assert(_num_mutex < MAX_NUM_MUTEX, "increase MAX_NUM_MUTEX"); \
202 _mutex_array[_num_mutex++] = var; \
203 }
204
205 // Using Padded subclasses to prevent false sharing of these global monitors and mutexes.
206 void mutex_init() {
207 def(tty_lock , PaddedMutex , tty, true, _safepoint_check_never); // allow to lock in VM
208
209 def(CGC_lock , PaddedMonitor, special, true, _safepoint_check_never); // coordinate between fore- and background GC
210 def(STS_lock , PaddedMonitor, leaf, true, _safepoint_check_never);
211
212 def(FullGCCount_lock , PaddedMonitor, leaf, true, _safepoint_check_never); // in support of ExplicitGCInvokesConcurrent
213 if (UseG1GC) {
214 def(G1OldGCCount_lock , PaddedMonitor, leaf, true, _safepoint_check_always);
215
216 def(Shared_DirtyCardQ_lock , PaddedMutex , access + 1, true, _safepoint_check_never);
217
218 def(G1DetachedRefinementStats_lock, PaddedMutex, leaf , true, _safepoint_check_never);
219
220 def(FreeList_lock , PaddedMutex , leaf , true, _safepoint_check_never);
221 def(OldSets_lock , PaddedMutex , leaf , true, _safepoint_check_never);
222 def(RootRegionScan_lock , PaddedMonitor, leaf , true, _safepoint_check_never);
223
224 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, _safepoint_check_never);
225 def(StringDedupTable_lock , PaddedMutex , leaf, true, _safepoint_check_never);
226
227 def(MarkStackFreeList_lock , PaddedMutex , leaf , true, _safepoint_check_never);
228 def(MarkStackChunkList_lock , PaddedMutex , leaf , true, _safepoint_check_never);
229
230 def(MonitoringSupport_lock , PaddedMutex , native , true, _safepoint_check_never); // used for serviceability monitoring support
231 }
232 if (UseShenandoahGC) {
233 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, _safepoint_check_never);
234 def(StringDedupTable_lock , PaddedMutex , leaf + 1, true, _safepoint_check_never);
235 }
236 def(ParGCRareEvent_lock , PaddedMutex , leaf , true, _safepoint_check_always);
237 def(CodeCache_lock , PaddedMonitor, special, true, _safepoint_check_never);
238 def(RawMonitor_lock , PaddedMutex , special, true, _safepoint_check_never);
239 def(OopMapCacheAlloc_lock , PaddedMutex , leaf, true, _safepoint_check_always); // used for oop_map_cache allocation.
240
241 def(MetaspaceExpand_lock , PaddedMutex , leaf-1, true, _safepoint_check_never);
242 def(ClassLoaderDataGraph_lock , PaddedMutex , nonleaf, false, _safepoint_check_always);
243
244 def(Patching_lock , PaddedMutex , special, true, _safepoint_check_never); // used for safepointing and code patching.
245 def(CompiledMethod_lock , PaddedMutex , special-1, true, _safepoint_check_never);
246 def(Service_lock , PaddedMonitor, special, true, _safepoint_check_never); // used for service thread operations
247
248 if (UseNotificationThread) {
249 def(Notification_lock , PaddedMonitor, special, true, _safepoint_check_never); // used for notification thread operations
250 } else {
251 Notification_lock = Service_lock;
252 }
253
254 def(JmethodIdCreation_lock , PaddedMutex , leaf, true, _safepoint_check_never); // used for creating jmethodIDs.
255
256 def(SystemDictionary_lock , PaddedMonitor, leaf, true, _safepoint_check_always);
257 def(ProtectionDomainSet_lock , PaddedMutex , leaf-1, true, _safepoint_check_never);
258 def(SharedDictionary_lock , PaddedMutex , leaf, true, _safepoint_check_always);
259 def(Module_lock , PaddedMutex , leaf+2, false, _safepoint_check_always);
260 def(InlineCacheBuffer_lock , PaddedMutex , leaf, true, _safepoint_check_never);
261 def(VMStatistic_lock , PaddedMutex , leaf, false, _safepoint_check_always);
262 def(ExpandHeap_lock , PaddedMutex , leaf, true, _safepoint_check_always); // Used during compilation by VM thread
263 def(JNIHandleBlockFreeList_lock , PaddedMutex , leaf-1, true, _safepoint_check_never); // handles are used by VM thread
264 def(SignatureHandlerLibrary_lock , PaddedMutex , leaf, false, _safepoint_check_always);
265 def(SymbolArena_lock , PaddedMutex , leaf+2, true, _safepoint_check_never);
266 def(ProfilePrint_lock , PaddedMutex , leaf, false, _safepoint_check_always); // serial profile printing
267 def(ExceptionCache_lock , PaddedMutex , leaf, false, _safepoint_check_always); // serial profile printing
268 def(Debug1_lock , PaddedMutex , leaf, true, _safepoint_check_never);
269 #ifndef PRODUCT
270 def(FullGCALot_lock , PaddedMutex , leaf, false, _safepoint_check_always); // a lock to make FullGCALot MT safe
271 #endif
272 def(BeforeExit_lock , PaddedMonitor, leaf, true, _safepoint_check_always);
273 def(PerfDataMemAlloc_lock , PaddedMutex , leaf, true, _safepoint_check_always); // used for allocating PerfData memory for performance data
274 def(PerfDataManager_lock , PaddedMutex , leaf, true, _safepoint_check_always); // used for synchronized access to PerfDataManager resources
275
276 def(Threads_lock , PaddedMonitor, barrier, true, _safepoint_check_always); // Used for safepoint protocol.
277 def(NonJavaThreadsList_lock , PaddedMutex, barrier, true, _safepoint_check_never);
278 def(NonJavaThreadsListSync_lock , PaddedMutex, leaf, true, _safepoint_check_never);
279
280 def(VMOperationQueue_lock , PaddedMonitor, nonleaf, true, _safepoint_check_never); // VM_thread allowed to block on these
281 def(VMOperationRequest_lock , PaddedMonitor, nonleaf, true, _safepoint_check_always);
282 def(RetData_lock , PaddedMutex , nonleaf, false, _safepoint_check_always);
283 def(Terminator_lock , PaddedMonitor, nonleaf, true, _safepoint_check_always);
284 def(InitCompleted_lock , PaddedMonitor, leaf, true, _safepoint_check_never);
285 def(VtableStubs_lock , PaddedMutex , nonleaf, true, _safepoint_check_never);
286 def(Notify_lock , PaddedMonitor, nonleaf, true, _safepoint_check_always);
287 def(JNICritical_lock , PaddedMonitor, nonleaf, true, _safepoint_check_always); // used for JNI critical regions
288 def(AdapterHandlerLibrary_lock , PaddedMutex , nonleaf, true, _safepoint_check_always);
289
290 def(Heap_lock , PaddedMonitor, nonleaf+1, false, _safepoint_check_sometimes); // Doesn't safepoint check during termination.
291 def(JfieldIdCreation_lock , PaddedMutex , nonleaf+1, true, _safepoint_check_always); // jfieldID, Used in VM_Operation
292
293 def(CompiledIC_lock , PaddedMutex , nonleaf+2, false, _safepoint_check_never); // locks VtableStubs_lock, InlineCacheBuffer_lock
294 def(CompileTaskAlloc_lock , PaddedMutex , nonleaf+2, true, _safepoint_check_always);
295 def(CompileStatistics_lock , PaddedMutex , nonleaf+2, false, _safepoint_check_always);
296 def(DirectivesStack_lock , PaddedMutex , special, true, _safepoint_check_never);
297 def(MultiArray_lock , PaddedMutex , nonleaf+2, false, _safepoint_check_always);
298
299 def(JvmtiThreadState_lock , PaddedMutex , nonleaf+2, false, _safepoint_check_always); // Used by JvmtiThreadState/JvmtiEventController
300 def(Management_lock , PaddedMutex , nonleaf+2, false, _safepoint_check_always); // used for JVM management
301
302 def(ConcurrentGCBreakpoints_lock , PaddedMonitor, nonleaf, true, _safepoint_check_always);
303 def(Compile_lock , PaddedMutex , nonleaf+3, false, _safepoint_check_always);
304 def(MethodData_lock , PaddedMutex , nonleaf+3, false, _safepoint_check_always);
305 def(TouchedMethodLog_lock , PaddedMutex , nonleaf+3, false, _safepoint_check_always);
306
307 def(MethodCompileQueue_lock , PaddedMonitor, nonleaf+4, false, _safepoint_check_always);
308 def(Debug2_lock , PaddedMutex , nonleaf+4, true, _safepoint_check_never);
309 def(Debug3_lock , PaddedMutex , nonleaf+4, true, _safepoint_check_never);
310 def(CompileThread_lock , PaddedMonitor, nonleaf+5, false, _safepoint_check_always);
311 def(PeriodicTask_lock , PaddedMonitor, nonleaf+5, true, _safepoint_check_always);
312 def(RedefineClasses_lock , PaddedMonitor, nonleaf+5, true, _safepoint_check_always);
313 def(Verify_lock , PaddedMutex, nonleaf+5, true, _safepoint_check_always);
314 def(Zip_lock , PaddedMonitor, leaf, true, _safepoint_check_never);
315
316 if (WhiteBoxAPI) {
317 def(Compilation_lock , PaddedMonitor, leaf, false, _safepoint_check_never);
318 }
319
320 #if INCLUDE_JFR
321 def(JfrMsg_lock , PaddedMonitor, leaf, true, _safepoint_check_always);
322 def(JfrBuffer_lock , PaddedMutex , leaf, true, _safepoint_check_never);
323 def(JfrStream_lock , PaddedMutex , nonleaf + 1, false, _safepoint_check_never);
324 def(JfrStacktrace_lock , PaddedMutex , special, true, _safepoint_check_never);
325 def(JfrThreadSampler_lock , PaddedMonitor, leaf, true, _safepoint_check_never);
326 #endif
327
328 #ifndef SUPPORTS_NATIVE_CX8
329 def(UnsafeJlong_lock , PaddedMutex , special, false, _safepoint_check_never);
330 #endif
331
332 def(CodeHeapStateAnalytics_lock , PaddedMutex , leaf, true, _safepoint_check_never);
333 def(NMethodSweeperStats_lock , PaddedMutex , special, true, _safepoint_check_never);
334 def(ThreadsSMRDelete_lock , PaddedMonitor, special, true, _safepoint_check_never);
335 def(ThreadIdTableCreate_lock , PaddedMutex , leaf, false, _safepoint_check_always);
336 def(SharedDecoder_lock , PaddedMutex , native, true, _safepoint_check_never);
337 def(DCmdFactory_lock , PaddedMutex , leaf, true, _safepoint_check_never);
338 #if INCLUDE_NMT
339 def(NMTQuery_lock , PaddedMutex , max_nonleaf, false, _safepoint_check_always);
340 #endif
341 #if INCLUDE_CDS
342 #if INCLUDE_JVMTI
343 def(CDSClassFileStream_lock , PaddedMutex , max_nonleaf, false, _safepoint_check_always);
344 #endif
345 def(DumpTimeTable_lock , PaddedMutex , leaf - 1, true, _safepoint_check_never);
346 def(CDSLambda_lock , PaddedMutex , leaf, true, _safepoint_check_never);
347 #endif // INCLUDE_CDS
348
349 #if INCLUDE_JVMCI
350 def(JVMCI_lock , PaddedMonitor, nonleaf+2, true, _safepoint_check_always);
351 #endif
352 }
353
354 GCMutexLocker::GCMutexLocker(Mutex* mutex) {
355 if (SafepointSynchronize::is_at_safepoint()) {
356 _locked = false;
357 } else {
358 _mutex = mutex;
359 _locked = true;
360 _mutex->lock();
361 }
362 }
363
364 // Print all mutexes/monitors that are currently owned by a thread; called
365 // by fatal error handler.
366 void print_owned_locks_on_error(outputStream* st) {
367 st->print("VM Mutex/Monitor currently owned by a thread: ");
368 bool none = true;
369 for (int i = 0; i < _num_mutex; i++) {
370 // see if it has an owner
371 if (_mutex_array[i]->owner() != NULL) {
372 if (none) {
373 // print format used by Mutex::print_on_error()
374 st->print_cr(" ([mutex/lock_event])");
375 none = false;
376 }
377 _mutex_array[i]->print_on_error(st);
378 st->cr();
379 }
380 }
381 if (none) st->print_cr("None");
382 }