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