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