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
41Mutex* Patching_lock = NULL;
42Monitor* SystemDictionary_lock = NULL;
43Mutex* ProtectionDomainSet_lock = NULL;
44Mutex* SharedDictionary_lock = NULL;
45Mutex* Module_lock = NULL;
46Mutex* CompiledIC_lock = NULL;
47Mutex* InlineCacheBuffer_lock = NULL;
48Mutex* VMStatistic_lock = NULL;
49Mutex* JNIGlobalAlloc_lock = NULL;
50Mutex* JNIGlobalActive_lock = NULL;
51Mutex* JNIWeakAlloc_lock = NULL;
52Mutex* JNIWeakActive_lock = NULL;
53Mutex* StringTableWeakAlloc_lock = NULL;
54Mutex* StringTableWeakActive_lock = NULL;
55Mutex* JNIHandleBlockFreeList_lock = NULL;
56Mutex* VMWeakAlloc_lock = NULL;
57Mutex* VMWeakActive_lock = NULL;
58Mutex* ResolvedMethodTableWeakAlloc_lock = NULL;
59Mutex* ResolvedMethodTableWeakActive_lock = NULL;
60Mutex* JmethodIdCreation_lock = NULL;
61Mutex* JfieldIdCreation_lock = NULL;
62Monitor* JNICritical_lock = NULL;
63Mutex* JvmtiThreadState_lock = NULL;
64Monitor* Heap_lock = NULL;
65Mutex* ExpandHeap_lock = NULL;
66Mutex* AdapterHandlerLibrary_lock = NULL;
67Mutex* SignatureHandlerLibrary_lock = NULL;
68Mutex* VtableStubs_lock = NULL;
69Mutex* SymbolArena_lock = NULL;
70Monitor* StringDedupQueue_lock = NULL;
71Mutex* StringDedupTable_lock = NULL;
72Monitor* CodeCache_lock = NULL;
73Mutex* MethodData_lock = NULL;
74Mutex* TouchedMethodLog_lock = NULL;
75Mutex* RetData_lock = NULL;
76Monitor* VMOperationQueue_lock = NULL;
77Monitor* VMOperationRequest_lock = NULL;
78Monitor* SerializePage_lock = NULL;
79Monitor* Threads_lock = NULL;
80Mutex* NonJavaThreadsList_lock = NULL;
81Mutex* NonJavaThreadsListSync_lock = NULL;
82Monitor* CGC_lock = NULL;
83Monitor* STS_lock = NULL;
84Monitor* FullGCCount_lock = NULL;
85Monitor* SATB_Q_CBL_mon = NULL;
86Monitor* DirtyCardQ_CBL_mon = NULL;
87Mutex* Shared_DirtyCardQ_lock = NULL;
88Mutex* MarkStackFreeList_lock = NULL;
89Mutex* MarkStackChunkList_lock = NULL;
90Mutex* MonitoringSupport_lock = NULL;
91Mutex* ParGCRareEvent_lock = NULL;
92Monitor* CGCPhaseManager_lock = NULL;
93Mutex* Compile_lock = NULL;
94Monitor* MethodCompileQueue_lock = NULL;
95Monitor* CompileThread_lock = NULL;
96Monitor* Compilation_lock = NULL;
97Mutex* CompileTaskAlloc_lock = NULL;
98Mutex* CompileStatistics_lock = NULL;
99Mutex* DirectivesStack_lock = NULL;
100Mutex* MultiArray_lock = NULL;
101Monitor* Terminator_lock = NULL;
102Monitor* InitCompleted_lock = NULL;
103Monitor* BeforeExit_lock = NULL;
104Monitor* Notify_lock = NULL;
105Mutex* ProfilePrint_lock = NULL;
106Mutex* ExceptionCache_lock = NULL;
107Mutex* OsrList_lock = NULL;
108Mutex* NMethodSweeperStats_lock = NULL;
109#ifndef PRODUCT
110Mutex* FullGCALot_lock = NULL;
111#endif
112
113Mutex* Debug1_lock = NULL;
114Mutex* Debug2_lock = NULL;
115Mutex* Debug3_lock = NULL;
116
117Mutex* tty_lock = NULL;
118
119Mutex* RawMonitor_lock = NULL;
120Mutex* PerfDataMemAlloc_lock = NULL;
121Mutex* PerfDataManager_lock = NULL;
122Mutex* OopMapCacheAlloc_lock = NULL;
123
124Mutex* FreeList_lock = NULL;
125Mutex* OldSets_lock = NULL;
126Monitor* RootRegionScan_lock = NULL;
127
128Monitor* GCTaskManager_lock = NULL;
129
130Mutex* Management_lock = NULL;
131Monitor* Service_lock = NULL;
132Monitor* PeriodicTask_lock = NULL;
133Monitor* RedefineClasses_lock = NULL;
134
135#if INCLUDE_JFR
136Mutex* JfrStacktrace_lock = NULL;
137Monitor* JfrMsg_lock = NULL;
138Mutex* JfrBuffer_lock = NULL;
139Mutex* JfrStream_lock = NULL;
140Monitor* JfrThreadSampler_lock = NULL;
141#endif
142
143#ifndef SUPPORTS_NATIVE_CX8
144Mutex* UnsafeJlong_lock = NULL;
145#endif
146Monitor* CodeHeapStateAnalytics_lock = NULL;
147
148Mutex* MetaspaceExpand_lock = NULL;
149Mutex* ClassLoaderDataGraph_lock = NULL;
150Monitor* ThreadsSMRDelete_lock = NULL;
151Mutex* SharedDecoder_lock = NULL;
152Mutex* DCmdFactory_lock = NULL;
153#if INCLUDE_NMT
154Mutex* NMTQuery_lock = NULL;
155#endif
156#if INCLUDE_CDS
157#if INCLUDE_JVMTI
158Mutex* CDSClassFileStream_lock = NULL;
159#endif
160Mutex* DumpTimeTable_lock = NULL;
161#endif // INCLUDE_CDS
162
163#if INCLUDE_JVMCI
164Monitor* JVMCI_lock = NULL;
165Mutex* JVMCIGlobalAlloc_lock = NULL;
166Mutex* JVMCIGlobalActive_lock = NULL;
167#endif
168
169
170#define MAX_NUM_MUTEX 128
171static Monitor * _mutex_array[MAX_NUM_MUTEX];
172static int _num_mutex;
173
174#ifdef ASSERT
175void assert_locked_or_safepoint(const Monitor * lock) {
176 // check if this thread owns the lock (common case)
177 if (IgnoreLockingAssertions) return;
178 assert(lock != NULL, "Need non-NULL lock");
179 if (lock->owned_by_self()) return;
180 if (SafepointSynchronize::is_at_safepoint()) return;
181 if (!Universe::is_fully_initialized()) return;
182 // see if invoker of VM operation owns it
183 VM_Operation* op = VMThread::vm_operation();
184 if (op != NULL && op->calling_thread() == lock->owner()) return;
185 fatal("must own lock %s", lock->name());
186}
187
188// a weaker assertion than the above
189void assert_locked_or_safepoint_weak(const Monitor * lock) {
190 if (IgnoreLockingAssertions) return;
191 assert(lock != NULL, "Need non-NULL lock");
192 if (lock->is_locked()) return;
193 if (SafepointSynchronize::is_at_safepoint()) return;
194 if (!Universe::is_fully_initialized()) return;
195 fatal("must own lock %s", lock->name());
196}
197
198// a stronger assertion than the above
199void assert_lock_strong(const Monitor * lock) {
200 if (IgnoreLockingAssertions) return;
201 assert(lock != NULL, "Need non-NULL lock");
202 if (lock->owned_by_self()) return;
203 fatal("must own lock %s", lock->name());
204}
205#endif
206
207#define def(var, type, pri, vm_block, safepoint_check_allowed ) { \
208 var = new type(Mutex::pri, #var, vm_block, safepoint_check_allowed); \
209 assert(_num_mutex < MAX_NUM_MUTEX, "increase MAX_NUM_MUTEX"); \
210 _mutex_array[_num_mutex++] = var; \
211}
212
213// Using Padded subclasses to prevent false sharing of these global monitors and mutexes.
214void mutex_init() {
215 def(tty_lock , PaddedMutex , tty, true, Monitor::_safepoint_check_never); // allow to lock in VM
216
217 def(CGC_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); // coordinate between fore- and background GC
218 def(STS_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
219
220 def(VMWeakAlloc_lock , PaddedMutex , vmweak, true, Monitor::_safepoint_check_never);
221 def(VMWeakActive_lock , PaddedMutex , vmweak-1, true, Monitor::_safepoint_check_never);
222
223 def(StringTableWeakAlloc_lock , PaddedMutex , vmweak, true, Monitor::_safepoint_check_never);
224 def(StringTableWeakActive_lock , PaddedMutex , vmweak-1, true, Monitor::_safepoint_check_never);
225
226 def(ResolvedMethodTableWeakAlloc_lock , PaddedMutex , vmweak, true, Monitor::_safepoint_check_never);
227 def(ResolvedMethodTableWeakActive_lock , PaddedMutex , vmweak-1, true, Monitor::_safepoint_check_never);
228
229 def(FullGCCount_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); // in support of ExplicitGCInvokesConcurrent
230 if (UseG1GC) {
231 def(SATB_Q_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never);
232
233 def(DirtyCardQ_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never);
234 def(Shared_DirtyCardQ_lock , PaddedMutex , access + 1, true, Monitor::_safepoint_check_never);
235
236 def(FreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
237 def(OldSets_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
238 def(RootRegionScan_lock , PaddedMonitor, leaf , true, Monitor::_safepoint_check_never);
239
240 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
241 def(StringDedupTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
242
243 def(MarkStackFreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
244 def(MarkStackChunkList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
245
246 def(MonitoringSupport_lock , PaddedMutex , native , true, Monitor::_safepoint_check_never); // used for serviceability monitoring support
247 }
248 if (UseShenandoahGC) {
249 def(SATB_Q_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never);
250
251 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
252 def(StringDedupTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
253 }
254 def(ParGCRareEvent_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_always);
255 def(CGCPhaseManager_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_always);
256 def(CodeCache_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
257 def(RawMonitor_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
258 def(OopMapCacheAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for oop_map_cache allocation.
259
260 def(MetaspaceExpand_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never);
261 def(ClassLoaderDataGraph_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always);
262
263 def(Patching_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); // used for safepointing and code patching.
264 def(Service_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); // used for service thread operations
265 def(JmethodIdCreation_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for creating jmethodIDs.
266
267 def(SystemDictionary_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always);
268 def(ProtectionDomainSet_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never);
269 def(SharedDictionary_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always);
270 def(Module_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_always);
271 def(InlineCacheBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
272 def(VMStatistic_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always);
273 def(ExpandHeap_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // Used during compilation by VM thread
274 def(JNIHandleBlockFreeList_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never); // handles are used by VM thread
275 def(SignatureHandlerLibrary_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always);
276 def(SymbolArena_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_never);
277 def(ProfilePrint_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing
278 def(ExceptionCache_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing
279 def(OsrList_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
280 def(Debug1_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
281#ifndef PRODUCT
282 def(FullGCALot_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // a lock to make FullGCALot MT safe
283#endif
284 def(BeforeExit_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always);
285 def(PerfDataMemAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for allocating PerfData memory for performance data
286 def(PerfDataManager_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for synchronized access to PerfDataManager resources
287
288 // CMS_modUnionTable_lock leaf
289 // CMS_bitMap_lock leaf 1
290 // CMS_freeList_lock leaf 2
291
292 def(Threads_lock , PaddedMonitor, barrier, true, Monitor::_safepoint_check_sometimes); // Used for safepoint protocol.
293 def(NonJavaThreadsList_lock , PaddedMutex, leaf, true, Monitor::_safepoint_check_never);
294 def(NonJavaThreadsListSync_lock , PaddedMutex, leaf, true, Monitor::_safepoint_check_never);
295
296 def(VMOperationQueue_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_never); // VM_thread allowed to block on these
297 def(VMOperationRequest_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always);
298 def(RetData_lock , PaddedMutex , nonleaf, false, Monitor::_safepoint_check_always);
299 def(Terminator_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always);
300 def(InitCompleted_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
301 def(VtableStubs_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
302 def(Notify_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always);
303 def(JNIGlobalAlloc_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
304 def(JNIGlobalActive_lock , PaddedMutex , nonleaf-1, true, Monitor::_safepoint_check_never);
305 def(JNIWeakAlloc_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
306 def(JNIWeakActive_lock , PaddedMutex , nonleaf-1, true, Monitor::_safepoint_check_never);
307 def(JNICritical_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always); // used for JNI critical regions
308 def(AdapterHandlerLibrary_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always);
309
310 def(Heap_lock , PaddedMonitor, nonleaf+1, false, Monitor::_safepoint_check_sometimes); // Doesn't safepoint check during termination.
311 def(JfieldIdCreation_lock , PaddedMutex , nonleaf+1, true, Monitor::_safepoint_check_always); // jfieldID, Used in VM_Operation
312
313 def(CompiledIC_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_never); // locks VtableStubs_lock, InlineCacheBuffer_lock
314 def(CompileTaskAlloc_lock , PaddedMutex , nonleaf+2, true, Monitor::_safepoint_check_always);
315 def(CompileStatistics_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always);
316 def(DirectivesStack_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
317 def(MultiArray_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always);
318
319 def(JvmtiThreadState_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // Used by JvmtiThreadState/JvmtiEventController
320 def(Management_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // used for JVM management
321
322 def(Compile_lock , PaddedMutex , nonleaf+3, true, Monitor::_safepoint_check_always);
323 def(MethodData_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always);
324 def(TouchedMethodLog_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always);
325
326 def(MethodCompileQueue_lock , PaddedMonitor, nonleaf+4, true, Monitor::_safepoint_check_always);
327 def(Debug2_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never);
328 def(Debug3_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never);
329 def(CompileThread_lock , PaddedMonitor, nonleaf+5, false, Monitor::_safepoint_check_always);
330 def(PeriodicTask_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_always);
331 def(RedefineClasses_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_always);
332
333 if (WhiteBoxAPI) {
334 def(Compilation_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_never);
335 }
336
337#if INCLUDE_JFR
338 def(JfrMsg_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always);
339 def(JfrBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
340 def(JfrStream_lock , PaddedMutex , leaf+1, true, Monitor::_safepoint_check_never); // ensure to rank lower than 'safepoint'
341 def(JfrStacktrace_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
342 def(JfrThreadSampler_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
343#endif
344
345#ifndef SUPPORTS_NATIVE_CX8
346 def(UnsafeJlong_lock , PaddedMutex , special, false, Monitor::_safepoint_check_never);
347#endif
348
349 def(CodeHeapStateAnalytics_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
350 def(NMethodSweeperStats_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
351 def(ThreadsSMRDelete_lock , PaddedMonitor, special, false, Monitor::_safepoint_check_never);
352 def(SharedDecoder_lock , PaddedMutex , native, false, Monitor::_safepoint_check_never);
353 def(DCmdFactory_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
354#if INCLUDE_NMT
355 def(NMTQuery_lock , PaddedMutex , max_nonleaf, false, Monitor::_safepoint_check_always);
356#endif
357#if INCLUDE_CDS
358#if INCLUDE_JVMTI
359 def(CDSClassFileStream_lock , PaddedMutex , max_nonleaf, false, Monitor::_safepoint_check_always);
360#endif
361
362#if INCLUDE_JVMCI
363 def(JVMCI_lock , PaddedMonitor, nonleaf+2, true, Monitor::_safepoint_check_always);
364 def(JVMCIGlobalAlloc_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
365 def(JVMCIGlobalActive_lock , PaddedMutex , nonleaf-1, true, Monitor::_safepoint_check_never);
366#endif
367 def(DumpTimeTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
368#endif // INCLUDE_CDS
369}
370
371GCMutexLocker::GCMutexLocker(Monitor * mutex) {
372 if (SafepointSynchronize::is_at_safepoint()) {
373 _locked = false;
374 } else {
375 _mutex = mutex;
376 _locked = true;
377 _mutex->lock();
378 }
379}
380
381// Print all mutexes/monitors that are currently owned by a thread; called
382// by fatal error handler.
383void print_owned_locks_on_error(outputStream* st) {
384 st->print("VM Mutex/Monitor currently owned by a thread: ");
385 bool none = true;
386 for (int i = 0; i < _num_mutex; i++) {
387 // see if it has an owner
388 if (_mutex_array[i]->owner() != NULL) {
389 if (none) {
390 // print format used by Mutex::print_on_error()
391 st->print_cr(" ([mutex/lock_event])");
392 none = false;
393 }
394 _mutex_array[i]->print_on_error(st);
395 st->cr();
396 }
397 }
398 if (none) st->print_cr("None");
399}
400