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* ProtectionDomainSet_lock = NULL;
43 Mutex* SharedDictionary_lock = NULL;
44 Mutex* Module_lock = NULL;
45 Mutex* CompiledIC_lock = NULL;
46 Mutex* InlineCacheBuffer_lock = NULL;
47 Mutex* VMStatistic_lock = NULL;
48 Mutex* JNIGlobalAlloc_lock = NULL;
49 Mutex* JNIGlobalActive_lock = NULL;
50 Mutex* JNIWeakAlloc_lock = NULL;
51 Mutex* JNIWeakActive_lock = NULL;
52 Mutex* StringTableWeakAlloc_lock = NULL;
53 Mutex* StringTableWeakActive_lock = NULL;
54 Mutex* JNIHandleBlockFreeList_lock = NULL;
55 Mutex* VMWeakAlloc_lock = NULL;
56 Mutex* VMWeakActive_lock = NULL;
57 Mutex* ResolvedMethodTable_lock = NULL;
58 Mutex* JmethodIdCreation_lock = NULL;
59 Mutex* JfieldIdCreation_lock = NULL;
60 Monitor* JNICritical_lock = NULL;
61 Mutex* JvmtiThreadState_lock = NULL;
62 Monitor* Heap_lock = NULL;
63 Mutex* ExpandHeap_lock = NULL;
64 Mutex* AdapterHandlerLibrary_lock = NULL;
65 Mutex* SignatureHandlerLibrary_lock = NULL;
66 Mutex* VtableStubs_lock = NULL;
67 Mutex* SymbolArena_lock = NULL;
68 Monitor* StringDedupQueue_lock = NULL;
69 Mutex* StringDedupTable_lock = NULL;
70 Monitor* CodeCache_lock = NULL;
71 Mutex* MethodData_lock = NULL;
72 Mutex* TouchedMethodLog_lock = NULL;
73 Mutex* RetData_lock = NULL;
74 Monitor* VMOperationQueue_lock = NULL;
75 Monitor* VMOperationRequest_lock = NULL;
76 Monitor* SerializePage_lock = NULL;
77 Monitor* Threads_lock = NULL;
78 Mutex* NonJavaThreadsList_lock = NULL;
79 Monitor* CGC_lock = NULL;
80 Monitor* STS_lock = NULL;
81 Monitor* FullGCCount_lock = NULL;
82 Monitor* SATB_Q_CBL_mon = 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
219 def(DirtyCardQ_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never);
220 def(Shared_DirtyCardQ_lock , PaddedMutex , access + 1, true, Monitor::_safepoint_check_never);
221
222 def(FreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
223 def(OldSets_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
224 def(RootRegionScan_lock , PaddedMonitor, leaf , true, Monitor::_safepoint_check_never);
225
226 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
227 def(StringDedupTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
228
229 def(MarkStackFreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
230 def(MarkStackChunkList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
231
232 def(MonitoringSupport_lock , PaddedMutex , native , true, Monitor::_safepoint_check_never); // used for serviceability monitoring support
233 }
234 if (UseShenandoahGC) {
235 def(SATB_Q_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never);
236
237 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
238 def(StringDedupTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
239 }
240 def(ParGCRareEvent_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_sometimes);
241 def(DerivedPointerTableGC_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
242 def(CGCPhaseManager_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_sometimes);
243 def(CodeCache_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
244 def(RawMonitor_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
245 def(OopMapCacheAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for oop_map_cache allocation.
246
247 def(MetaspaceExpand_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never);
248 def(ClassLoaderDataGraph_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always);
249
250 def(Patching_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); // used for safepointing and code patching.
251 def(Service_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); // used for service thread operations
252 def(JmethodIdCreation_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for creating jmethodIDs.
253
254 def(SystemDictionary_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always); // lookups done by VM thread
255 def(ProtectionDomainSet_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never);
256 def(SharedDictionary_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // lookups done by VM thread
257 def(Module_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_always);
258 def(InlineCacheBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
259 def(VMStatistic_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always);
260 def(ExpandHeap_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // Used during compilation by VM thread
261 def(JNIHandleBlockFreeList_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never); // handles are used by VM thread
262 def(SignatureHandlerLibrary_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always);
263 def(SymbolArena_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_never);
264 def(ProfilePrint_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing
265 def(ExceptionCache_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing
266 def(OsrList_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
267 def(Debug1_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
268 #ifndef PRODUCT
269 def(FullGCALot_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // a lock to make FullGCALot MT safe
270 #endif
271 def(BeforeExit_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always);
272 def(PerfDataMemAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for allocating PerfData memory for performance data
273 def(PerfDataManager_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for synchronized access to PerfDataManager resources
274
275 // CMS_modUnionTable_lock leaf
276 // CMS_bitMap_lock leaf 1
277 // CMS_freeList_lock leaf 2
278
279 def(Threads_lock , PaddedMonitor, barrier, true, Monitor::_safepoint_check_sometimes);
280 def(NonJavaThreadsList_lock , PaddedMutex, leaf, true, Monitor::_safepoint_check_never);
281
282 def(VMOperationQueue_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_sometimes); // VM_thread allowed to block on these
283 def(VMOperationRequest_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_sometimes);
284 def(RetData_lock , PaddedMutex , nonleaf, false, Monitor::_safepoint_check_always);
285 def(Terminator_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_sometimes);
286 def(VtableStubs_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
287 def(Notify_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always);
288 def(JNIGlobalAlloc_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
289 def(JNIGlobalActive_lock , PaddedMutex , nonleaf-1, true, Monitor::_safepoint_check_never);
290 def(JNIWeakAlloc_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
291 def(JNIWeakActive_lock , PaddedMutex , nonleaf-1, true, Monitor::_safepoint_check_never);
292 def(JNICritical_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always); // used for JNI critical regions
293 def(AdapterHandlerLibrary_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always);
294
295 def(Heap_lock , PaddedMonitor, nonleaf+1, false, Monitor::_safepoint_check_sometimes);
296 def(JfieldIdCreation_lock , PaddedMutex , nonleaf+1, true, Monitor::_safepoint_check_always); // jfieldID, Used in VM_Operation
297 def(ResolvedMethodTable_lock , PaddedMutex , nonleaf+1, false, Monitor::_safepoint_check_always); // Used to protect ResolvedMethodTable
298
299 def(CompiledIC_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_never); // locks VtableStubs_lock, InlineCacheBuffer_lock
300 def(CompileTaskAlloc_lock , PaddedMutex , nonleaf+2, true, Monitor::_safepoint_check_always);
301 def(CompileStatistics_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always);
302 def(DirectivesStack_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
303 def(MultiArray_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always);
304
305 def(JvmtiThreadState_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // Used by JvmtiThreadState/JvmtiEventController
306 def(Management_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // used for JVM management
307
308 def(Compile_lock , PaddedMutex , nonleaf+3, true, Monitor::_safepoint_check_always);
309 def(MethodData_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always);
310 def(TouchedMethodLog_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always);
311
312 def(MethodCompileQueue_lock , PaddedMonitor, nonleaf+4, true, Monitor::_safepoint_check_always);
313 def(Debug2_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never);
314 def(Debug3_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never);
315 def(CompileThread_lock , PaddedMonitor, nonleaf+5, false, Monitor::_safepoint_check_always);
316 def(PeriodicTask_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_sometimes);
317 def(RedefineClasses_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_always);
318
319 if (WhiteBoxAPI) {
320 def(Compilation_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_never);
321 }
322
323 #if INCLUDE_JFR
324 def(JfrMsg_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always);
325 def(JfrBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
326 def(JfrStream_lock , PaddedMutex , leaf+1, true, Monitor::_safepoint_check_never); // ensure to rank lower than 'safepoint'
327 def(JfrStacktrace_lock , PaddedMutex , special, true, Monitor::_safepoint_check_sometimes);
328 def(JfrThreadSampler_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
329 #endif
330
331 #ifndef SUPPORTS_NATIVE_CX8
332 def(UnsafeJlong_lock , PaddedMutex , special, false, Monitor::_safepoint_check_never);
333 #endif
334
335 def(CodeHeapStateAnalytics_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
336
337 def(NMethodSweeperStats_lock , PaddedMutex , special, true, Monitor::_safepoint_check_sometimes);
338 def(ThreadsSMRDelete_lock , PaddedMonitor, special, false, Monitor::_safepoint_check_never);
339 def(SharedDecoder_lock , PaddedMutex , native, false, Monitor::_safepoint_check_never);
340 def(DCmdFactory_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
341 #if INCLUDE_NMT
342 def(NMTQuery_lock , PaddedMutex , max_nonleaf, false, Monitor::_safepoint_check_always);
343 #endif
344 #if INCLUDE_CDS && INCLUDE_JVMTI
345 def(CDSClassFileStream_lock , PaddedMutex , max_nonleaf, false, Monitor::_safepoint_check_always);
346 #endif
347 }
348
349 GCMutexLocker::GCMutexLocker(Monitor * 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 }