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