1 /*
2 * Copyright (c) 1997, 2018, 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* SymbolTable_lock = NULL;
67 Mutex* StringTable_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* Safepoint_lock = NULL;
77 Monitor* SerializePage_lock = NULL;
78 Monitor* Threads_lock = NULL;
79 Mutex* NonJavaThreadsList_lock = NULL;
80 Monitor* CGC_lock = NULL;
81 Monitor* STS_lock = NULL;
82 Monitor* FullGCCount_lock = NULL;
83 Mutex* SATB_Q_FL_lock = NULL;
84 Monitor* SATB_Q_CBL_mon = NULL;
85 Mutex* Shared_SATB_Q_lock = NULL;
86 Mutex* DirtyCardQ_FL_lock = NULL;
87 Monitor* DirtyCardQ_CBL_mon = NULL;
88 Mutex* Shared_DirtyCardQ_lock = NULL;
89 Mutex* MarkStackFreeList_lock = NULL;
90 Mutex* MarkStackChunkList_lock = NULL;
91 Mutex* ParGCRareEvent_lock = NULL;
92 Mutex* DerivedPointerTableGC_lock = NULL;
93 Monitor* CGCPhaseManager_lock = NULL;
94 Mutex* Compile_lock = NULL;
95 Monitor* MethodCompileQueue_lock = NULL;
96 Monitor* CompileThread_lock = NULL;
97 Monitor* Compilation_lock = NULL;
98 Mutex* CompileTaskAlloc_lock = NULL;
99 Mutex* CompileStatistics_lock = NULL;
100 Mutex* DirectivesStack_lock = NULL;
101 Mutex* MultiArray_lock = NULL;
102 Monitor* Terminator_lock = NULL;
103 Monitor* BeforeExit_lock = NULL;
104 Monitor* Notify_lock = NULL;
105 Mutex* ProfilePrint_lock = NULL;
106 Mutex* ExceptionCache_lock = NULL;
107 Mutex* OsrList_lock = NULL;
108
109 #ifndef PRODUCT
110 Mutex* FullGCALot_lock = NULL;
111 #endif
112
113 Mutex* Debug1_lock = NULL;
114 Mutex* Debug2_lock = NULL;
115 Mutex* Debug3_lock = NULL;
116
117 Mutex* tty_lock = NULL;
118
119 Mutex* RawMonitor_lock = NULL;
120 Mutex* PerfDataMemAlloc_lock = NULL;
121 Mutex* PerfDataManager_lock = NULL;
122 Mutex* OopMapCacheAlloc_lock = NULL;
123
124 Mutex* FreeList_lock = NULL;
125 Mutex* OldSets_lock = NULL;
126 Monitor* RootRegionScan_lock = NULL;
127
128 Monitor* GCTaskManager_lock = NULL;
129
130 Mutex* Management_lock = NULL;
131 Monitor* Service_lock = NULL;
132 Monitor* PeriodicTask_lock = NULL;
133 Monitor* RedefineClasses_lock = NULL;
134
135 Mutex* ThreadHeapSampler_lock = NULL;
136
137 #if INCLUDE_JFR
138 Mutex* JfrStacktrace_lock = NULL;
139 Monitor* JfrMsg_lock = NULL;
140 Mutex* JfrBuffer_lock = NULL;
141 Mutex* JfrStream_lock = NULL;
142 #endif
143
144 #ifndef SUPPORTS_NATIVE_CX8
145 Mutex* UnsafeJlong_lock = NULL;
146 #endif
147 Monitor* CodeHeapStateAnalytics_lock = NULL;
148
149 Mutex* MetaspaceExpand_lock = NULL;
150 Mutex* ThreadIdTableCreate_lock = NULL;
151
152 #define MAX_NUM_MUTEX 128
153 static Monitor * _mutex_array[MAX_NUM_MUTEX];
154 static int _num_mutex;
155
156 #ifdef ASSERT
157 void assert_locked_or_safepoint(const Monitor * lock) {
158 // check if this thread owns the lock (common case)
159 if (IgnoreLockingAssertions) return;
160 assert(lock != NULL, "Need non-NULL lock");
161 if (lock->owned_by_self()) return;
162 if (SafepointSynchronize::is_at_safepoint()) return;
163 if (!Universe::is_fully_initialized()) return;
164 // see if invoker of VM operation owns it
165 VM_Operation* op = VMThread::vm_operation();
166 if (op != NULL && op->calling_thread() == lock->owner()) return;
167 fatal("must own lock %s", lock->name());
168 }
169
170 // a stronger assertion than the above
171 void assert_lock_strong(const Monitor * lock) {
172 if (IgnoreLockingAssertions) return;
173 assert(lock != NULL, "Need non-NULL lock");
174 if (lock->owned_by_self()) return;
175 fatal("must own lock %s", lock->name());
176 }
177 #endif
178
179 #define def(var, type, pri, vm_block, safepoint_check_allowed ) { \
180 var = new type(Mutex::pri, #var, vm_block, safepoint_check_allowed); \
181 assert(_num_mutex < MAX_NUM_MUTEX, "increase MAX_NUM_MUTEX"); \
182 _mutex_array[_num_mutex++] = var; \
183 }
184
185 // Using Padded subclasses to prevent false sharing of these global monitors and mutexes.
186 void mutex_init() {
187 def(tty_lock , PaddedMutex , tty, true, Monitor::_safepoint_check_never); // allow to lock in VM
188
189 def(CGC_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); // coordinate between fore- and background GC
190 def(STS_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
191
192 def(VMWeakAlloc_lock , PaddedMutex , vmweak, true, Monitor::_safepoint_check_never);
193 def(VMWeakActive_lock , PaddedMutex , vmweak-1, true, Monitor::_safepoint_check_never);
194
195 def(StringTableWeakAlloc_lock , PaddedMutex , vmweak, true, Monitor::_safepoint_check_never);
196 def(StringTableWeakActive_lock , PaddedMutex , vmweak-1, true, Monitor::_safepoint_check_never);
197
198 if (UseConcMarkSweepGC || UseG1GC) {
199 def(FullGCCount_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); // in support of ExplicitGCInvokesConcurrent
200 }
201 if (UseG1GC) {
202 def(SATB_Q_FL_lock , PaddedMutex , access, true, Monitor::_safepoint_check_never);
203 def(SATB_Q_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never);
204 def(Shared_SATB_Q_lock , PaddedMutex , access + 1, true, Monitor::_safepoint_check_never);
205
206 def(DirtyCardQ_FL_lock , PaddedMutex , access, true, Monitor::_safepoint_check_never);
207 def(DirtyCardQ_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never);
208 def(Shared_DirtyCardQ_lock , PaddedMutex , access + 1, true, Monitor::_safepoint_check_never);
209
210 def(FreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
211 def(OldSets_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
212 def(RootRegionScan_lock , PaddedMonitor, leaf , true, Monitor::_safepoint_check_never);
213
214 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never);
215 def(StringDedupTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
216
217 def(MarkStackFreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
218 def(MarkStackChunkList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never);
219 }
220 def(ParGCRareEvent_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_sometimes);
221 def(DerivedPointerTableGC_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
222 def(CGCPhaseManager_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_sometimes);
223 def(CodeCache_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
224 def(RawMonitor_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
225 def(OopMapCacheAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for oop_map_cache allocation.
226
227 def(MetaspaceExpand_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never);
228
229 def(Patching_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); // used for safepointing and code patching.
230 def(Service_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); // used for service thread operations
231 def(JmethodIdCreation_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for creating jmethodIDs.
232
233 def(SystemDictionary_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always); // lookups done by VM thread
234 def(SharedDictionary_lock , PaddedMutex, leaf, true, Monitor::_safepoint_check_always); // lookups done by VM thread
235 def(Module_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_always);
236 def(InlineCacheBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always);
237 def(VMStatistic_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always);
238 def(ExpandHeap_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // Used during compilation by VM thread
239 def(JNIHandleBlockFreeList_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); // handles are used by VM thread
240 def(SignatureHandlerLibrary_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always);
241 def(SymbolTable_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_always);
242 def(StringTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always);
243 def(ProfilePrint_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing
244 def(ExceptionCache_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing
245 def(OsrList_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
246 def(Debug1_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
247 #ifndef PRODUCT
248 def(FullGCALot_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // a lock to make FullGCALot MT safe
249 #endif
250 def(BeforeExit_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always);
251 def(PerfDataMemAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for allocating PerfData memory for performance data
252 def(PerfDataManager_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for synchronized access to PerfDataManager resources
253
254 // CMS_modUnionTable_lock leaf
255 // CMS_bitMap_lock leaf 1
256 // CMS_freeList_lock leaf 2
257
258 def(Safepoint_lock , PaddedMonitor, safepoint, true, Monitor::_safepoint_check_sometimes); // locks SnippetCache_lock/Threads_lock
259
260 def(Threads_lock , PaddedMonitor, barrier, true, Monitor::_safepoint_check_sometimes);
261 def(NonJavaThreadsList_lock , PaddedMutex, leaf, true, Monitor::_safepoint_check_never);
262
263 def(VMOperationQueue_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_sometimes); // VM_thread allowed to block on these
264 def(VMOperationRequest_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_sometimes);
265 def(RetData_lock , PaddedMutex , nonleaf, false, Monitor::_safepoint_check_always);
266 def(Terminator_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_sometimes);
267 def(VtableStubs_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always);
268 def(Notify_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always);
269 // OopStorage-based JNI may lock the alloc_locks while releasing a handle,
270 // while previous JNI didn't need a lock for handle release. This runs afoul
271 // of some places which hold other locks while releasing a handle, including
272 // the Patching_lock, which is of "special" rank. As a temporary workaround,
273 // lower the JNI oopstorage lock ranks to make them super-special.
274 def(JNIGlobalAlloc_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
275 def(JNIGlobalActive_lock , PaddedMutex , nonleaf-1, true, Monitor::_safepoint_check_never);
276 def(JNIWeakAlloc_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never);
277 def(JNIWeakActive_lock , PaddedMutex , nonleaf-1, true, Monitor::_safepoint_check_never);
278 def(JNICritical_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always); // used for JNI critical regions
279 def(AdapterHandlerLibrary_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always);
280
281 def(Heap_lock , PaddedMonitor, nonleaf+1, false, Monitor::_safepoint_check_sometimes);
282 def(JfieldIdCreation_lock , PaddedMutex , nonleaf+1, true, Monitor::_safepoint_check_always); // jfieldID, Used in VM_Operation
283 def(ResolvedMethodTable_lock , PaddedMutex , nonleaf+1, false, Monitor::_safepoint_check_always); // Used to protect ResolvedMethodTable
284
285 def(CompiledIC_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // locks VtableStubs_lock, InlineCacheBuffer_lock
286 def(CompileTaskAlloc_lock , PaddedMutex , nonleaf+2, true, Monitor::_safepoint_check_always);
287 def(CompileStatistics_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always);
288 def(DirectivesStack_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never);
289 def(MultiArray_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // locks SymbolTable_lock
290
291 def(JvmtiThreadState_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // Used by JvmtiThreadState/JvmtiEventController
292 def(Management_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // used for JVM management
293
294 def(Compile_lock , PaddedMutex , nonleaf+3, true, Monitor::_safepoint_check_sometimes);
295 def(MethodData_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always);
296 def(TouchedMethodLog_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always);
297
298 def(MethodCompileQueue_lock , PaddedMonitor, nonleaf+4, true, Monitor::_safepoint_check_always);
299 def(Debug2_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never);
300 def(Debug3_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never);
301 def(CompileThread_lock , PaddedMonitor, nonleaf+5, false, Monitor::_safepoint_check_always);
302 def(PeriodicTask_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_sometimes);
303 def(RedefineClasses_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_always);
304
305 def(ThreadHeapSampler_lock , PaddedMutex, nonleaf, false, Monitor::_safepoint_check_never);
306
307 if (WhiteBoxAPI) {
308 def(Compilation_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_never);
309 }
310
311 #if INCLUDE_JFR
312 def(JfrMsg_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always);
313 def(JfrBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
314 def(JfrStream_lock , PaddedMutex , leaf+1, true, Monitor::_safepoint_check_never); // ensure to rank lower than 'safepoint'
315 def(JfrStacktrace_lock , PaddedMutex , special, true, Monitor::_safepoint_check_sometimes);
316 #endif
317
318 #ifndef SUPPORTS_NATIVE_CX8
319 def(UnsafeJlong_lock , PaddedMutex , special, false, Monitor::_safepoint_check_never);
320 #endif
321
322 def(CodeHeapStateAnalytics_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never);
323 def(ThreadIdTableCreate_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always);
324 }
325
326 GCMutexLocker::GCMutexLocker(Monitor * mutex) {
327 if (SafepointSynchronize::is_at_safepoint()) {
328 _locked = false;
329 } else {
330 _mutex = mutex;
331 _locked = true;
332 _mutex->lock();
333 }
334 }
335
336 // Print all mutexes/monitors that are currently owned by a thread; called
337 // by fatal error handler.
338 void print_owned_locks_on_error(outputStream* st) {
339 st->print("VM Mutex/Monitor currently owned by a thread: ");
340 bool none = true;
341 for (int i = 0; i < _num_mutex; i++) {
342 // see if it has an owner
343 if (_mutex_array[i]->owner() != NULL) {
344 if (none) {
345 // print format used by Mutex::print_on_error()
346 st->print_cr(" ([mutex/lock_event])");
347 none = false;
348 }
349 _mutex_array[i]->print_on_error(st);
350 st->cr();
351 }
352 }
353 if (none) st->print_cr("None");
354 }