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