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 Monitor* DirtyCardQ_CBL_mon = NULL;
83 Mutex* Shared_DirtyCardQ_lock = NULL;
84 Mutex* MarkStackFreeList_lock = NULL;
85 Mutex* MarkStackChunkList_lock = NULL;
86 Mutex* MonitoringSupport_lock = NULL;
87 Mutex* ParGCRareEvent_lock = NULL;
88 Mutex* DerivedPointerTableGC_lock = NULL;
89 Monitor* CGCPhaseManager_lock = NULL;
90 Mutex* Compile_lock = NULL;
91 Monitor* MethodCompileQueue_lock = NULL;
92 Monitor* CompileThread_lock = NULL;
93 Monitor* Compilation_lock = NULL;
94 Mutex* CompileTaskAlloc_lock = NULL;
95 Mutex* CompileStatistics_lock = NULL;
96 Mutex* DirectivesStack_lock = NULL;
97 Mutex* MultiArray_lock = NULL;
98 Monitor* Terminator_lock = NULL;
99 Monitor* BeforeExit_lock = NULL;
100 Monitor* Notify_lock = NULL;
101 Mutex* ProfilePrint_lock = NULL;
102 Mutex* ExceptionCache_lock = NULL;
103 Mutex* OsrList_lock = NULL;
104 Mutex* NMethodSweeperStats_lock = NULL;
105 #ifndef PRODUCT
106 Mutex* FullGCALot_lock = NULL;
107 #endif
108
109 Mutex* Debug1_lock = NULL;
110 Mutex* Debug2_lock = NULL;
111 Mutex* Debug3_lock = NULL;
112
113 Mutex* tty_lock = NULL;
114
115 Mutex* RawMonitor_lock = NULL;
116 Mutex* PerfDataMemAlloc_lock = NULL;
117 Mutex* PerfDataManager_lock = NULL;
118 Mutex* OopMapCacheAlloc_lock = NULL;
119
120 Mutex* FreeList_lock = NULL;
121 Mutex* OldSets_lock = NULL;
122 Monitor* RootRegionScan_lock = NULL;
123
124 Monitor* GCTaskManager_lock = NULL;
125
126 Mutex* Management_lock = NULL;
127 Monitor* Service_lock = NULL;
128 Monitor* PeriodicTask_lock = NULL;
129 Monitor* RedefineClasses_lock = NULL;
130
131 #if INCLUDE_JFR
132 Mutex* JfrStacktrace_lock = NULL;
133 Monitor* JfrMsg_lock = NULL;
134 Mutex* JfrBuffer_lock = NULL;
135 Mutex* JfrStream_lock = NULL;
136 Monitor* JfrThreadSampler_lock = NULL;
137 #endif
138
139 #ifndef SUPPORTS_NATIVE_CX8
140 Mutex* UnsafeJlong_lock = NULL;
141 #endif
142 Monitor* CodeHeapStateAnalytics_lock = NULL;
143
144 Mutex* MetaspaceExpand_lock = NULL;
145 Mutex* ClassLoaderDataGraph_lock = NULL;
146 Monitor* ThreadsSMRDelete_lock = NULL;
147 Mutex* SharedDecoder_lock = NULL;
148 Mutex* DCmdFactory_lock = NULL;
149 #if INCLUDE_NMT
150 Mutex* NMTQuery_lock = NULL;
151 #endif
152
153 #define MAX_NUM_MUTEX 128
154 static Monitor * _mutex_array[MAX_NUM_MUTEX];
155 static int _num_mutex;
156
157 #ifdef ASSERT
158 void assert_locked_or_safepoint(const Monitor * lock) {
159 // check if this thread owns the lock (common case)
160 if (IgnoreLockingAssertions) return;
161 assert(lock != NULL, "Need non-NULL lock");
162 if (lock->owned_by_self()) return;
163 if (SafepointSynchronize::is_at_safepoint()) return;
164 if (!Universe::is_fully_initialized()) return;
165 // see if invoker of VM operation owns it
166 VM_Operation* op = VMThread::vm_operation();
167 if (op != NULL && op->calling_thread() == lock->owner()) return;
168 fatal("must own lock %s", lock->name());
169 }
170
171 // a weaker assertion than the above
172 void assert_locked_or_safepoint_weak(const Monitor * lock) {
173 if (IgnoreLockingAssertions) return;
174 assert(lock != NULL, "Need non-NULL lock");
175 if (lock->is_locked()) return;
176 if (SafepointSynchronize::is_at_safepoint()) return;
177 if (!Universe::is_fully_initialized()) return;
178 fatal("must own lock %s", lock->name());
179 }
180
181 // a stronger assertion than the above
182 void assert_lock_strong(const Monitor * lock) {
183 if (IgnoreLockingAssertions) return;
184 assert(lock != NULL, "Need non-NULL lock");
185 if (lock->owned_by_self()) return;
186 fatal("must own lock %s", lock->name());
187 }
188 #endif
189
190 #define def(var, type, pri, vm_block, safepoint_check_allowed ) { \
191 var = new type(Mutex::pri, #var, vm_block, safepoint_check_allowed); \
192 assert(_num_mutex < MAX_NUM_MUTEX, "increase MAX_NUM_MUTEX"); \
193 _mutex_array[_num_mutex++] = var; \
194 }
195
196 // Using Padded subclasses to prevent false sharing of these global monitors and mutexes.
197 void mutex_init() {
198 def(tty_lock , PaddedMutex , tty, true, Monitor::_safepoint_check_never); // allow to lock in VM
199
200 def(CGC_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); // coordinate between fore- and background GC
201 def(STS_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
202
203 def(VMWeakAlloc_lock , PaddedMutex , vmweak, true, Monitor::_safepoint_check_never);
204 def(VMWeakActive_lock , PaddedMutex , vmweak-1, true, Monitor::_safepoint_check_never);
205
206 def(StringTableWeakAlloc_lock , PaddedMutex , vmweak, true, Monitor::_safepoint_check_never);
207 def(StringTableWeakActive_lock , PaddedMutex , vmweak-1, true, Monitor::_safepoint_check_never);
208
209 if (UseConcMarkSweepGC || UseG1GC) {
210 def(FullGCCount_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); // in support of ExplicitGCInvokesConcurrent
211 }
212 if (UseG1GC) {
213 def(SATB_Q_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never);
214
215 def(DirtyCardQ_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never);
216 def(Shared_DirtyCardQ_lock , PaddedMutex , access + 1, true, Monitor::_safepoint_check_never);
217
218 def(FreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
219 def(OldSets_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
220 def(RootRegionScan_lock , PaddedMonitor, leaf , true, Monitor::_safepoint_check_never);
221
222 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
223 def(StringDedupTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
224
225 def(MarkStackFreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
226 def(MarkStackChunkList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
227
228 def(MonitoringSupport_lock , PaddedMutex , native , true, Monitor::_safepoint_check_never); // used for serviceability monitoring support
229 }
230 if (UseShenandoahGC) {
231 def(SATB_Q_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never);
232
233 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
234 def(StringDedupTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
235 }
236 def(ParGCRareEvent_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_sometimes);
237 def(DerivedPointerTableGC_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
238 def(CGCPhaseManager_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_sometimes);
239 def(CodeCache_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
240 def(RawMonitor_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
241 def(OopMapCacheAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for oop_map_cache allocation.
242
243 def(MetaspaceExpand_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never);
244 def(ClassLoaderDataGraph_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always);
245
246 def(Patching_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); // used for safepointing and code patching.
247 def(Service_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); // used for service thread operations
248 def(JmethodIdCreation_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for creating jmethodIDs.
249
250 def(SystemDictionary_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always); // lookups done by VM thread
251 def(SharedDictionary_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // lookups done by VM thread
252 def(Module_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_always);
253 def(InlineCacheBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
254 def(VMStatistic_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always);
255 def(ExpandHeap_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // Used during compilation by VM thread
256 def(JNIHandleBlockFreeList_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never); // handles are used by VM thread
257 def(SignatureHandlerLibrary_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always);
258 def(SymbolArena_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_never);
259 def(ProfilePrint_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing
260 def(ExceptionCache_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing
261 def(OsrList_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
262 def(Debug1_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
263 #ifndef PRODUCT
264 def(FullGCALot_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // a lock to make FullGCALot MT safe
265 #endif
266 def(BeforeExit_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always);
267 def(PerfDataMemAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for allocating PerfData memory for performance data
268 def(PerfDataManager_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for synchronized access to PerfDataManager resources
269
270 // CMS_modUnionTable_lock leaf
271 // CMS_bitMap_lock leaf 1
272 // CMS_freeList_lock leaf 2
273
274 def(Threads_lock , PaddedMonitor, barrier, true, Monitor::_safepoint_check_sometimes);
275 def(NonJavaThreadsList_lock , PaddedMutex, leaf, true, Monitor::_safepoint_check_never);
276
277 def(VMOperationQueue_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_sometimes); // VM_thread allowed to block on these
278 def(VMOperationRequest_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_sometimes);
279 def(RetData_lock , PaddedMutex , nonleaf, false, Monitor::_safepoint_check_always);
280 def(Terminator_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_sometimes);
281 def(VtableStubs_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
282 def(Notify_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always);
283 def(JNIGlobalAlloc_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
284 def(JNIGlobalActive_lock , PaddedMutex , nonleaf-1, true, Monitor::_safepoint_check_never);
285 def(JNIWeakAlloc_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
286 def(JNIWeakActive_lock , PaddedMutex , nonleaf-1, true, Monitor::_safepoint_check_never);
287 def(JNICritical_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always); // used for JNI critical regions
288 def(AdapterHandlerLibrary_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always);
289
290 def(Heap_lock , PaddedMonitor, nonleaf+1, false, Monitor::_safepoint_check_sometimes);
291 def(JfieldIdCreation_lock , PaddedMutex , nonleaf+1, true, Monitor::_safepoint_check_always); // jfieldID, Used in VM_Operation
292 def(ResolvedMethodTable_lock , PaddedMutex , nonleaf+1, false, Monitor::_safepoint_check_always); // Used to protect ResolvedMethodTable
293
294 def(CompiledIC_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_never); // locks VtableStubs_lock, InlineCacheBuffer_lock
295 def(CompileTaskAlloc_lock , PaddedMutex , nonleaf+2, true, Monitor::_safepoint_check_always);
296 def(CompileStatistics_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always);
297 def(DirectivesStack_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
298 def(MultiArray_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always);
299
300 def(JvmtiThreadState_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // Used by JvmtiThreadState/JvmtiEventController
301 def(Management_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // used for JVM management
302
303 def(Compile_lock , PaddedMutex , nonleaf+3, true, Monitor::_safepoint_check_always);
304 def(MethodData_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always);
305 def(TouchedMethodLog_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always);
306
307 def(MethodCompileQueue_lock , PaddedMonitor, nonleaf+4, true, Monitor::_safepoint_check_always);
308 def(Debug2_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never);
309 def(Debug3_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never);
310 def(CompileThread_lock , PaddedMonitor, nonleaf+5, false, Monitor::_safepoint_check_always);
311 def(PeriodicTask_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_sometimes);
312 def(RedefineClasses_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_always);
313
314 if (WhiteBoxAPI) {
315 def(Compilation_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_never);
316 }
317
318 #if INCLUDE_JFR
319 def(JfrMsg_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always);
320 def(JfrBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
321 def(JfrStream_lock , PaddedMutex , leaf+1, true, Monitor::_safepoint_check_never); // ensure to rank lower than 'safepoint'
322 def(JfrStacktrace_lock , PaddedMutex , special, true, Monitor::_safepoint_check_sometimes);
323 def(JfrThreadSampler_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
324 #endif
325
326 #ifndef SUPPORTS_NATIVE_CX8
327 def(UnsafeJlong_lock , PaddedMutex , special, false, Monitor::_safepoint_check_never);
328 #endif
329
330 def(CodeHeapStateAnalytics_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
331
332 def(NMethodSweeperStats_lock , PaddedMutex , special, true, Monitor::_safepoint_check_sometimes);
333 def(ThreadsSMRDelete_lock , PaddedMonitor, special, false, Monitor::_safepoint_check_never);
334 def(SharedDecoder_lock , PaddedMutex , native, false, Monitor::_safepoint_check_never);
335 def(DCmdFactory_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
336 #if INCLUDE_NMT
337 def(NMTQuery_lock , PaddedMutex , max_nonleaf, false, Monitor::_safepoint_check_always);
338 #endif
339 }
340
341 GCMutexLocker::GCMutexLocker(Monitor * mutex) {
342 if (SafepointSynchronize::is_at_safepoint()) {
343 _locked = false;
344 } else {
345 _mutex = mutex;
346 _locked = true;
347 _mutex->lock();
348 }
349 }
350
351 // Print all mutexes/monitors that are currently owned by a thread; called
352 // by fatal error handler.
353 void print_owned_locks_on_error(outputStream* st) {
354 st->print("VM Mutex/Monitor currently owned by a thread: ");
355 bool none = true;
356 for (int i = 0; i < _num_mutex; i++) {
357 // see if it has an owner
358 if (_mutex_array[i]->owner() != NULL) {
359 if (none) {
360 // print format used by Mutex::print_on_error()
361 st->print_cr(" ([mutex/lock_event])");
362 none = false;
363 }
364 _mutex_array[i]->print_on_error(st);
365 st->cr();
366 }
367 }
368 if (none) st->print_cr("None");
369 }