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* MarkStackFreeList_lock = NULL;
78 Mutex* MarkStackChunkList_lock = NULL;
79 Mutex* MonitoringSupport_lock = NULL;
80 Mutex* ParGCRareEvent_lock = NULL;
81 Monitor* CGCPhaseManager_lock = NULL;
82 Mutex* Compile_lock = NULL;
83 Monitor* MethodCompileQueue_lock = NULL;
84 Monitor* CompileThread_lock = NULL;
85 Monitor* Compilation_lock = NULL;
86 Mutex* CompileTaskAlloc_lock = NULL;
87 Mutex* CompileStatistics_lock = NULL;
88 Mutex* DirectivesStack_lock = NULL;
89 Mutex* MultiArray_lock = NULL;
90 Monitor* Terminator_lock = NULL;
91 Monitor* InitCompleted_lock = NULL;
92 Monitor* BeforeExit_lock = NULL;
93 Monitor* Notify_lock = NULL;
94 Mutex* ProfilePrint_lock = NULL;
95 Mutex* ExceptionCache_lock = NULL;
96 Mutex* NMethodSweeperStats_lock = NULL;
97 #ifndef PRODUCT
98 Mutex* FullGCALot_lock = NULL;
99 #endif
100
101 Mutex* Debug1_lock = NULL;
102 Mutex* Debug2_lock = NULL;
103 Mutex* Debug3_lock = NULL;
104
105 Mutex* tty_lock = NULL;
106
107 Mutex* RawMonitor_lock = NULL;
108 Mutex* PerfDataMemAlloc_lock = NULL;
109 Mutex* PerfDataManager_lock = NULL;
110 Mutex* OopMapCacheAlloc_lock = NULL;
111
112 Mutex* FreeList_lock = NULL;
113 Mutex* OldSets_lock = NULL;
114 Monitor* RootRegionScan_lock = NULL;
115
116 Mutex* Management_lock = NULL;
117 Monitor* Service_lock = NULL;
118 Monitor* Notification_lock = NULL;
119 Monitor* PeriodicTask_lock = NULL;
120 Monitor* RedefineClasses_lock = NULL;
121 Mutex* Verify_lock = NULL;
122
123 #if INCLUDE_JFR
124 Mutex* JfrStacktrace_lock = NULL;
125 Monitor* JfrMsg_lock = NULL;
126 Mutex* JfrBuffer_lock = NULL;
127 Mutex* JfrStream_lock = NULL;
128 Monitor* JfrThreadSampler_lock = NULL;
129 #endif
130
131 #if INCLUDE_TSAN
132 Mutex* TsanOopMap_lock = NULL;
133 #endif
134
135 #ifndef SUPPORTS_NATIVE_CX8
136 Mutex* UnsafeJlong_lock = NULL;
137 #endif
138 Mutex* CodeHeapStateAnalytics_lock = NULL;
139
140 Mutex* MetaspaceExpand_lock = NULL;
141 Mutex* ClassLoaderDataGraph_lock = NULL;
142 Monitor* ThreadsSMRDelete_lock = NULL;
143 Mutex* ThreadIdTableCreate_lock = NULL;
144 Mutex* SharedDecoder_lock = NULL;
145 Mutex* DCmdFactory_lock = NULL;
146 #if INCLUDE_NMT
147 Mutex* NMTQuery_lock = NULL;
148 #endif
149 #if INCLUDE_CDS
150 #if INCLUDE_JVMTI
151 Mutex* CDSClassFileStream_lock = NULL;
152 #endif
153 Mutex* DumpTimeTable_lock = NULL;
154 #endif // INCLUDE_CDS
155
156 #if INCLUDE_JVMCI
157 Monitor* JVMCI_lock = NULL;
158 #endif
159
160
161 #define MAX_NUM_MUTEX 128
162 static Mutex* _mutex_array[MAX_NUM_MUTEX];
163 static int _num_mutex;
164
165 #ifdef ASSERT
166 void assert_locked_or_safepoint(const Mutex* lock) {
167 // check if this thread owns the lock (common case)
168 assert(lock != NULL, "Need non-NULL lock");
169 if (lock->owned_by_self()) return;
170 if (SafepointSynchronize::is_at_safepoint()) return;
171 if (!Universe::is_fully_initialized()) return;
172 // see if invoker of VM operation owns it
173 VM_Operation* op = VMThread::vm_operation();
174 if (op != NULL && op->calling_thread() == lock->owner()) return;
175 fatal("must own lock %s", lock->name());
176 }
177
178 // a weaker assertion than the above
179 void assert_locked_or_safepoint_weak(const Mutex* lock) {
180 assert(lock != NULL, "Need non-NULL lock");
181 if (lock->is_locked()) return;
182 if (SafepointSynchronize::is_at_safepoint()) return;
183 if (!Universe::is_fully_initialized()) return;
184 fatal("must own lock %s", lock->name());
185 }
186
187 // a stronger assertion than the above
188 void assert_lock_strong(const Mutex* lock) {
189 assert(lock != NULL, "Need non-NULL lock");
190 if (lock->owned_by_self()) return;
191 fatal("must own lock %s", lock->name());
192 }
193
194 void assert_locked_or_safepoint_or_handshake(const Mutex* lock, const JavaThread* thread) {
195 if (Thread::current()->is_VM_thread() && thread->is_vmthread_processing_handshake()) return;
196 assert_locked_or_safepoint(lock);
197 }
198 #endif
199
200 #define def(var, type, pri, vm_block, safepoint_check_allowed ) { \
201 var = new type(Mutex::pri, #var, vm_block, Mutex::safepoint_check_allowed); \
202 assert(_num_mutex < MAX_NUM_MUTEX, "increase MAX_NUM_MUTEX"); \
203 _mutex_array[_num_mutex++] = var; \
204 }
205
206 // Using Padded subclasses to prevent false sharing of these global monitors and mutexes.
207 void mutex_init() {
208 def(tty_lock , PaddedMutex , tty, true, _safepoint_check_never); // allow to lock in VM
209
210 def(CGC_lock , PaddedMonitor, special, true, _safepoint_check_never); // coordinate between fore- and background GC
211 def(STS_lock , PaddedMonitor, leaf, true, _safepoint_check_never);
212
213 def(FullGCCount_lock , PaddedMonitor, leaf, true, _safepoint_check_never); // in support of ExplicitGCInvokesConcurrent
214 if (UseG1GC) {
215 def(G1OldGCCount_lock , PaddedMonitor, leaf, true, _safepoint_check_always);
216
217 def(Shared_DirtyCardQ_lock , PaddedMutex , access + 1, true, _safepoint_check_never);
218
219 def(FreeList_lock , PaddedMutex , leaf , true, _safepoint_check_never);
220 def(OldSets_lock , PaddedMutex , leaf , true, _safepoint_check_never);
221 def(RootRegionScan_lock , PaddedMonitor, leaf , true, _safepoint_check_never);
222
223 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, _safepoint_check_never);
224 def(StringDedupTable_lock , PaddedMutex , leaf, true, _safepoint_check_never);
225
226 def(MarkStackFreeList_lock , PaddedMutex , leaf , true, _safepoint_check_never);
227 def(MarkStackChunkList_lock , PaddedMutex , leaf , true, _safepoint_check_never);
228
229 def(MonitoringSupport_lock , PaddedMutex , native , true, _safepoint_check_never); // used for serviceability monitoring support
230 }
231 if (UseShenandoahGC) {
232 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, _safepoint_check_never);
233 def(StringDedupTable_lock , PaddedMutex , leaf + 1, true, _safepoint_check_never);
234 }
235 def(ParGCRareEvent_lock , PaddedMutex , leaf , true, _safepoint_check_always);
236 def(CGCPhaseManager_lock , PaddedMonitor, leaf, false, _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, leaf, 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(Compile_lock , PaddedMutex , nonleaf+3, false, _safepoint_check_always);
303 def(MethodData_lock , PaddedMutex , nonleaf+3, false, _safepoint_check_always);
304 def(TouchedMethodLog_lock , PaddedMutex , nonleaf+3, false, _safepoint_check_always);
305
306 def(MethodCompileQueue_lock , PaddedMonitor, nonleaf+4, false, _safepoint_check_always);
307 def(Debug2_lock , PaddedMutex , nonleaf+4, true, _safepoint_check_never);
308 def(Debug3_lock , PaddedMutex , nonleaf+4, true, _safepoint_check_never);
309 def(CompileThread_lock , PaddedMonitor, nonleaf+5, false, _safepoint_check_always);
310 def(PeriodicTask_lock , PaddedMonitor, nonleaf+5, true, _safepoint_check_always);
311 def(RedefineClasses_lock , PaddedMonitor, nonleaf+5, true, _safepoint_check_always);
312 def(Verify_lock , PaddedMutex, nonleaf+5, true, _safepoint_check_always);
313
314 if (WhiteBoxAPI) {
315 def(Compilation_lock , PaddedMonitor, leaf, false, _safepoint_check_never);
316 }
317
318 #if INCLUDE_JFR
319 def(JfrMsg_lock , PaddedMonitor, leaf, true, _safepoint_check_always);
320 def(JfrBuffer_lock , PaddedMutex , leaf, true, _safepoint_check_never);
321 def(JfrStream_lock , PaddedMutex , nonleaf + 1, false, _safepoint_check_never);
322 def(JfrStacktrace_lock , PaddedMutex , special, true, _safepoint_check_never);
323 def(JfrThreadSampler_lock , PaddedMonitor, leaf, true, _safepoint_check_never);
324 #endif
325
326 TSAN_RUNTIME_ONLY(
327 def(TsanOopMap_lock , PaddedMutex , special, true, _safepoint_check_never);
328 );
329
330 #ifndef SUPPORTS_NATIVE_CX8
331 def(UnsafeJlong_lock , PaddedMutex , special, false, _safepoint_check_never);
332 #endif
333
334 def(CodeHeapStateAnalytics_lock , PaddedMutex , leaf, true, _safepoint_check_never);
335 def(NMethodSweeperStats_lock , PaddedMutex , special, true, _safepoint_check_never);
336 def(ThreadsSMRDelete_lock , PaddedMonitor, special, true, _safepoint_check_never);
337 def(ThreadIdTableCreate_lock , PaddedMutex , leaf, false, _safepoint_check_always);
338 def(SharedDecoder_lock , PaddedMutex , native, true, _safepoint_check_never);
339 def(DCmdFactory_lock , PaddedMutex , leaf, true, _safepoint_check_never);
340 #if INCLUDE_NMT
341 def(NMTQuery_lock , PaddedMutex , max_nonleaf, false, _safepoint_check_always);
342 #endif
343 #if INCLUDE_CDS
344 #if INCLUDE_JVMTI
345 def(CDSClassFileStream_lock , PaddedMutex , max_nonleaf, false, _safepoint_check_always);
346 #endif
347 def(DumpTimeTable_lock , PaddedMutex , leaf, true, _safepoint_check_never);
348 #endif // INCLUDE_CDS
349
350 #if INCLUDE_JVMCI
351 def(JVMCI_lock , PaddedMonitor, nonleaf+2, true, _safepoint_check_always);
352 #endif
353 }
354
355 GCMutexLocker::GCMutexLocker(Mutex* mutex) {
356 if (SafepointSynchronize::is_at_safepoint()) {
357 _locked = false;
358 } else {
359 _mutex = mutex;
360 _locked = true;
361 _mutex->lock();
362 }
363 }
364
365 // Print all mutexes/monitors that are currently owned by a thread; called
366 // by fatal error handler.
367 void print_owned_locks_on_error(outputStream* st) {
368 st->print("VM Mutex/Monitor currently owned by a thread: ");
369 bool none = true;
370 for (int i = 0; i < _num_mutex; i++) {
371 // see if it has an owner
372 if (_mutex_array[i]->owner() != NULL) {
373 if (none) {
374 // print format used by Mutex::print_on_error()
375 st->print_cr(" ([mutex/lock_event])");
376 none = false;
377 }
378 _mutex_array[i]->print_on_error(st);
379 st->cr();
380 }
381 }
382 if (none) st->print_cr("None");
383 }