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