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