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 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*   ClassLoaderDataGraph_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  , event,       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   def(ClassLoaderDataGraph_lock    , PaddedMutex  , nonleaf,     true,  Monitor::_safepoint_check_always);
229 
230   def(Patching_lock                , PaddedMutex  , special,     true,  Monitor::_safepoint_check_never);      // used for safepointing and code patching.
231   def(Service_lock                 , PaddedMonitor, special,     true,  Monitor::_safepoint_check_never);      // used for service thread operations
232   def(JmethodIdCreation_lock       , PaddedMutex  , leaf,        true,  Monitor::_safepoint_check_always);     // used for creating jmethodIDs.
233 
234   def(SystemDictionary_lock        , PaddedMonitor, leaf,        true,  Monitor::_safepoint_check_always);     // lookups done by VM thread
235   def(SharedDictionary_lock        , PaddedMutex,   leaf,        true,  Monitor::_safepoint_check_always);     // lookups done by VM thread
236   def(Module_lock                  , PaddedMutex  , leaf+2,      true,  Monitor::_safepoint_check_always);
237   def(InlineCacheBuffer_lock       , PaddedMutex  , leaf,        true,  Monitor::_safepoint_check_always);
238   def(VMStatistic_lock             , PaddedMutex  , leaf,        false, Monitor::_safepoint_check_always);
239   def(ExpandHeap_lock              , PaddedMutex  , leaf,        true,  Monitor::_safepoint_check_always);     // Used during compilation by VM thread
240   def(JNIHandleBlockFreeList_lock  , PaddedMutex  , leaf-1,      true,  Monitor::_safepoint_check_never);      // handles are used by VM thread
241   def(SignatureHandlerLibrary_lock , PaddedMutex  , leaf,        false, Monitor::_safepoint_check_always);
242   def(SymbolArena_lock             , PaddedMutex  , leaf+2,      true,  Monitor::_safepoint_check_never);
243   def(StringTable_lock             , PaddedMutex  , leaf,        true,  Monitor::_safepoint_check_always);
244   def(ProfilePrint_lock            , PaddedMutex  , leaf,        false, Monitor::_safepoint_check_always);     // serial profile printing
245   def(ExceptionCache_lock          , PaddedMutex  , leaf,        false, Monitor::_safepoint_check_always);     // serial profile printing
246   def(OsrList_lock                 , PaddedMutex  , leaf,        true,  Monitor::_safepoint_check_never);
247   def(Debug1_lock                  , PaddedMutex  , leaf,        true,  Monitor::_safepoint_check_never);
248 #ifndef PRODUCT
249   def(FullGCALot_lock              , PaddedMutex  , leaf,        false, Monitor::_safepoint_check_always);     // a lock to make FullGCALot MT safe
250 #endif
251   def(BeforeExit_lock              , PaddedMonitor, leaf,        true,  Monitor::_safepoint_check_always);
252   def(PerfDataMemAlloc_lock        , PaddedMutex  , leaf,        true,  Monitor::_safepoint_check_always);     // used for allocating PerfData memory for performance data
253   def(PerfDataManager_lock         , PaddedMutex  , leaf,        true,  Monitor::_safepoint_check_always);     // used for synchronized access to PerfDataManager resources
254 
255   // CMS_modUnionTable_lock                   leaf
256   // CMS_bitMap_lock                          leaf 1
257   // CMS_freeList_lock                        leaf 2
258 
259   def(Safepoint_lock               , PaddedMonitor, safepoint,   true,  Monitor::_safepoint_check_sometimes);  // locks SnippetCache_lock/Threads_lock
260 
261   def(Threads_lock                 , PaddedMonitor, barrier,     true,  Monitor::_safepoint_check_sometimes);
262   def(NonJavaThreadsList_lock      , PaddedMutex,   leaf,        true,  Monitor::_safepoint_check_never);
263 
264   def(VMOperationQueue_lock        , PaddedMonitor, nonleaf,     true,  Monitor::_safepoint_check_sometimes);  // VM_thread allowed to block on these
265   def(VMOperationRequest_lock      , PaddedMonitor, nonleaf,     true,  Monitor::_safepoint_check_sometimes);
266   def(RetData_lock                 , PaddedMutex  , nonleaf,     false, Monitor::_safepoint_check_always);
267   def(Terminator_lock              , PaddedMonitor, nonleaf,     true,  Monitor::_safepoint_check_sometimes);
268   def(VtableStubs_lock             , PaddedMutex  , nonleaf,     true,  Monitor::_safepoint_check_always);
269   def(Notify_lock                  , PaddedMonitor, nonleaf,     true,  Monitor::_safepoint_check_always);
270   def(JNIGlobalAlloc_lock          , PaddedMutex  , nonleaf,     true,  Monitor::_safepoint_check_never);
271   def(JNIGlobalActive_lock         , PaddedMutex  , nonleaf-1,   true,  Monitor::_safepoint_check_never);
272   def(JNIWeakAlloc_lock            , PaddedMutex  , nonleaf,     true,  Monitor::_safepoint_check_never);
273   def(JNIWeakActive_lock           , PaddedMutex  , nonleaf-1,   true,  Monitor::_safepoint_check_never);
274   def(JNICritical_lock             , PaddedMonitor, nonleaf,     true,  Monitor::_safepoint_check_always);     // used for JNI critical regions
275   def(AdapterHandlerLibrary_lock   , PaddedMutex  , nonleaf,     true,  Monitor::_safepoint_check_always);
276 
277   def(Heap_lock                    , PaddedMonitor, nonleaf+1,   false, Monitor::_safepoint_check_sometimes);
278   def(JfieldIdCreation_lock        , PaddedMutex  , nonleaf+1,   true,  Monitor::_safepoint_check_always);     // jfieldID, Used in VM_Operation
279   def(ResolvedMethodTable_lock     , PaddedMutex  , nonleaf+1,   false, Monitor::_safepoint_check_always);     // Used to protect ResolvedMethodTable
280 
281   def(CompiledIC_lock              , PaddedMutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);     // locks VtableStubs_lock, InlineCacheBuffer_lock
282   def(CompileTaskAlloc_lock        , PaddedMutex  , nonleaf+2,   true,  Monitor::_safepoint_check_always);
283   def(CompileStatistics_lock       , PaddedMutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);
284   def(DirectivesStack_lock         , PaddedMutex  , special,     true,  Monitor::_safepoint_check_never);
285   def(MultiArray_lock              , PaddedMutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);
286 
287   def(JvmtiThreadState_lock        , PaddedMutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);     // Used by JvmtiThreadState/JvmtiEventController
288   def(Management_lock              , PaddedMutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);     // used for JVM management
289 
290   def(Compile_lock                 , PaddedMutex  , nonleaf+3,   true,  Monitor::_safepoint_check_sometimes);
291   def(MethodData_lock              , PaddedMutex  , nonleaf+3,   false, Monitor::_safepoint_check_always);
292   def(TouchedMethodLog_lock        , PaddedMutex  , nonleaf+3,   false, Monitor::_safepoint_check_always);
293 
294   def(MethodCompileQueue_lock      , PaddedMonitor, nonleaf+4,   true,  Monitor::_safepoint_check_always);
295   def(Debug2_lock                  , PaddedMutex  , nonleaf+4,   true,  Monitor::_safepoint_check_never);
296   def(Debug3_lock                  , PaddedMutex  , nonleaf+4,   true,  Monitor::_safepoint_check_never);
297   def(CompileThread_lock           , PaddedMonitor, nonleaf+5,   false, Monitor::_safepoint_check_always);
298   def(PeriodicTask_lock            , PaddedMonitor, nonleaf+5,   true,  Monitor::_safepoint_check_sometimes);
299   def(RedefineClasses_lock         , PaddedMonitor, nonleaf+5,   true,  Monitor::_safepoint_check_always);
300 
301   def(ThreadHeapSampler_lock       , PaddedMutex,   nonleaf,     false, Monitor::_safepoint_check_never);
302 
303   if (WhiteBoxAPI) {
304     def(Compilation_lock           , PaddedMonitor, leaf,        false, Monitor::_safepoint_check_never);
305   }
306 
307 #if INCLUDE_JFR
308   def(JfrMsg_lock                  , PaddedMonitor, leaf,        true,  Monitor::_safepoint_check_always);
309   def(JfrBuffer_lock               , PaddedMutex  , leaf,        true,  Monitor::_safepoint_check_never);
310   def(JfrStream_lock               , PaddedMutex  , leaf+1,      true,  Monitor::_safepoint_check_never);      // ensure to rank lower than 'safepoint'
311   def(JfrStacktrace_lock           , PaddedMutex  , special,     true,  Monitor::_safepoint_check_sometimes);
312 #endif
313 
314 #ifndef SUPPORTS_NATIVE_CX8
315   def(UnsafeJlong_lock             , PaddedMutex  , special,     false, Monitor::_safepoint_check_never);
316 #endif
317 
318   def(CodeHeapStateAnalytics_lock  , PaddedMutex  , leaf,        true,  Monitor::_safepoint_check_never);
319 }
320 
321 GCMutexLocker::GCMutexLocker(Monitor * mutex) {
322   if (SafepointSynchronize::is_at_safepoint()) {
323     _locked = false;
324   } else {
325     _mutex = mutex;
326     _locked = true;
327     _mutex->lock();
328   }
329 }
330 
331 // Print all mutexes/monitors that are currently owned by a thread; called
332 // by fatal error handler.
333 void print_owned_locks_on_error(outputStream* st) {
334   st->print("VM Mutex/Monitor currently owned by a thread: ");
335   bool none = true;
336   for (int i = 0; i < _num_mutex; i++) {
337      // see if it has an owner
338      if (_mutex_array[i]->owner() != NULL) {
339        if (none) {
340           // print format used by Mutex::print_on_error()
341           st->print_cr(" ([mutex/lock_event])");
342           none = false;
343        }
344        _mutex_array[i]->print_on_error(st);
345        st->cr();
346      }
347   }
348   if (none) st->print_cr("None");
349 }