1 /*
2  * Copyright (c) 1997, 2015, 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
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23  */
24 
25 #include "precompiled.hpp"
26 #include "runtime/mutexLocker.hpp"
27 #include "runtime/safepoint.hpp"
28 #include "runtime/thread.inline.hpp"
29 #include "runtime/threadLocalStorage.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*   PackageTable_lock            = NULL;
43 Mutex*   CompiledIC_lock              = NULL;
44 Mutex*   InlineCacheBuffer_lock       = NULL;
45 Mutex*   VMStatistic_lock             = NULL;
46 Mutex*   JNIGlobalHandle_lock         = NULL;
47 Mutex*   JNIHandleBlockFreeList_lock  = NULL;
48 Mutex*   MemberNameTable_lock         = NULL;
49 Mutex*   JmethodIdCreation_lock       = NULL;
50 Mutex*   JfieldIdCreation_lock        = NULL;
51 Monitor* JNICritical_lock             = NULL;
52 Mutex*   JvmtiThreadState_lock        = NULL;
53 Monitor* JvmtiPendingEvent_lock       = NULL;
54 Monitor* Heap_lock                    = NULL;
55 Mutex*   ExpandHeap_lock              = NULL;
56 Mutex*   AdapterHandlerLibrary_lock   = NULL;
57 Mutex*   SignatureHandlerLibrary_lock = NULL;
58 Mutex*   VtableStubs_lock             = NULL;
59 Mutex*   SymbolTable_lock             = NULL;
60 Mutex*   StringTable_lock             = NULL;
61 Monitor* StringDedupQueue_lock        = NULL;
62 Mutex*   StringDedupTable_lock        = NULL;
63 Mutex*   CodeCache_lock               = NULL;
64 Mutex*   MethodData_lock              = NULL;
65 Mutex*   RetData_lock                 = NULL;
66 Monitor* VMOperationQueue_lock        = NULL;
67 Monitor* VMOperationRequest_lock      = NULL;
68 Monitor* Safepoint_lock               = NULL;
69 Monitor* SerializePage_lock           = NULL;
70 Monitor* Threads_lock                 = NULL;
71 Monitor* CGC_lock                     = NULL;
72 Monitor* STS_lock                     = NULL;
73 Monitor* SLT_lock                     = NULL;
74 Monitor* iCMS_lock                    = NULL;
75 Monitor* FullGCCount_lock             = NULL;
76 Monitor* CMark_lock                   = NULL;
77 Mutex*   CMRegionStack_lock           = NULL;
78 Mutex*   SATB_Q_FL_lock               = NULL;
79 Monitor* SATB_Q_CBL_mon               = NULL;
80 Mutex*   Shared_SATB_Q_lock           = NULL;
81 Mutex*   DirtyCardQ_FL_lock           = NULL;
82 Monitor* DirtyCardQ_CBL_mon           = NULL;
83 Mutex*   Shared_DirtyCardQ_lock       = NULL;
84 Mutex*   ParGCRareEvent_lock          = NULL;
85 Mutex*   EvacFailureStack_lock        = NULL;
86 Mutex*   DerivedPointerTableGC_lock   = NULL;
87 Mutex*   Compile_lock                 = NULL;
88 Monitor* MethodCompileQueue_lock      = NULL;
89 Monitor* CompileThread_lock           = NULL;
90 Mutex*   CompileTaskAlloc_lock        = NULL;
91 Mutex*   CompileStatistics_lock       = NULL;
92 Mutex*   MultiArray_lock              = NULL;
93 Monitor* Terminator_lock              = NULL;
94 Monitor* BeforeExit_lock              = NULL;
95 Monitor* Notify_lock                  = NULL;
96 Monitor* Interrupt_lock               = NULL;
97 Monitor* ProfileVM_lock               = NULL;
98 Mutex*   ProfilePrint_lock            = NULL;
99 Mutex*   ExceptionCache_lock          = NULL;
100 Monitor* ObjAllocPost_lock            = NULL;
101 Mutex*   OsrList_lock                 = NULL;
102 #ifndef PRODUCT
103 Mutex*   FullGCALot_lock              = NULL;
104 #endif
105 
106 Mutex*   Debug1_lock                  = NULL;
107 Mutex*   Debug2_lock                  = NULL;
108 Mutex*   Debug3_lock                  = NULL;
109 
110 Mutex*   tty_lock                     = NULL;
111 
112 Mutex*   RawMonitor_lock              = NULL;
113 Mutex*   PerfDataMemAlloc_lock        = NULL;
114 Mutex*   PerfDataManager_lock         = NULL;
115 Mutex*   OopMapCacheAlloc_lock        = NULL;
116 
117 Mutex*   FreeList_lock                = NULL;
118 Monitor* SecondaryFreeList_lock       = NULL;
119 Mutex*   OldSets_lock                 = NULL;
120 Monitor* RootRegionScan_lock          = NULL;
121 Mutex*   MMUTracker_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 #ifdef INCLUDE_JFR
131 Mutex*   JfrStacktrace_lock           = NULL;
132 Monitor* JfrMsg_lock                  = NULL;
133 Mutex*   JfrBuffer_lock               = NULL;
134 Mutex*   JfrStream_lock               = NULL;
135 Mutex*   JfrThreadGroups_lock         = NULL;
136 
137 #ifndef SUPPORTS_NATIVE_CX8
138 Mutex*   JfrCounters_lock             = NULL;
139 #endif
140 #endif
141 
142 #ifndef SUPPORTS_NATIVE_CX8
143 Mutex*   UnsafeJlong_lock             = NULL;
144 #endif
145 
146 #define MAX_NUM_MUTEX 128
147 static Monitor * _mutex_array[MAX_NUM_MUTEX];
148 static int _num_mutex;
149 
150 #ifdef ASSERT
assert_locked_or_safepoint(const Monitor * lock)151 void assert_locked_or_safepoint(const Monitor * lock) {
152   // check if this thread owns the lock (common case)
153   if (IgnoreLockingAssertions) return;
154   assert(lock != NULL, "Need non-NULL lock");
155   if (lock->owned_by_self()) return;
156   if (SafepointSynchronize::is_at_safepoint()) return;
157   if (!Universe::is_fully_initialized()) return;
158   // see if invoker of VM operation owns it
159   VM_Operation* op = VMThread::vm_operation();
160   if (op != NULL && op->calling_thread() == lock->owner()) return;
161   fatal(err_msg("must own lock %s", lock->name()));
162 }
163 
164 // a stronger assertion than the above
assert_lock_strong(const Monitor * lock)165 void assert_lock_strong(const Monitor * lock) {
166   if (IgnoreLockingAssertions) return;
167   assert(lock != NULL, "Need non-NULL lock");
168   if (lock->owned_by_self()) return;
169   fatal(err_msg("must own lock %s", lock->name()));
170 }
171 #endif
172 
173 #define def(var, type, pri, vm_block) {                           \
174   var = new type(Mutex::pri, #var, vm_block);                     \
175   assert(_num_mutex < MAX_NUM_MUTEX,                              \
176                     "increase MAX_NUM_MUTEX");                    \
177   _mutex_array[_num_mutex++] = var;                               \
178 }
179 
mutex_init()180 void mutex_init() {
181   def(tty_lock                     , Mutex  , event,       true ); // allow to lock in VM
182 
183   def(CGC_lock                   , Monitor, special,     true ); // coordinate between fore- and background GC
184   def(STS_lock                   , Monitor, leaf,        true );
185   if (UseConcMarkSweepGC) {
186     def(iCMS_lock                  , Monitor, special,     true ); // CMS incremental mode start/stop notification
187   }
188   if (UseConcMarkSweepGC || UseG1GC) {
189     def(FullGCCount_lock           , Monitor, leaf,        true ); // in support of ExplicitGCInvokesConcurrent
190   }
191   if (UseG1GC) {
192     def(CMark_lock                 , Monitor, nonleaf,     true ); // coordinate concurrent mark thread
193     def(CMRegionStack_lock         , Mutex,   leaf,        true );
194     def(SATB_Q_FL_lock             , Mutex  , special,     true );
195     def(SATB_Q_CBL_mon             , Monitor, nonleaf,     true );
196     def(Shared_SATB_Q_lock         , Mutex,   nonleaf,     true );
197 
198     def(DirtyCardQ_FL_lock         , Mutex  , special,     true );
199     def(DirtyCardQ_CBL_mon         , Monitor, nonleaf,     true );
200     def(Shared_DirtyCardQ_lock     , Mutex,   nonleaf,     true );
201 
202     def(FreeList_lock              , Mutex,   leaf     ,   true );
203     def(SecondaryFreeList_lock     , Monitor, leaf     ,   true );
204     def(OldSets_lock               , Mutex  , leaf     ,   true );
205     def(RootRegionScan_lock        , Monitor, leaf     ,   true );
206     def(MMUTracker_lock            , Mutex  , leaf     ,   true );
207     def(EvacFailureStack_lock      , Mutex  , nonleaf  ,   true );
208 
209     def(StringDedupQueue_lock      , Monitor, leaf,        true );
210     def(StringDedupTable_lock      , Mutex  , leaf,        true );
211   }
212   def(ParGCRareEvent_lock          , Mutex  , leaf     ,   true );
213   def(DerivedPointerTableGC_lock   , Mutex,   leaf,        true );
214   def(CodeCache_lock               , Mutex  , special,     true );
215   def(Interrupt_lock               , Monitor, special,     true ); // used for interrupt processing
216   def(RawMonitor_lock              , Mutex,   special,     true );
217   def(OopMapCacheAlloc_lock        , Mutex,   leaf,        true ); // used for oop_map_cache allocation.
218 
219   def(Patching_lock                , Mutex  , special,     true ); // used for safepointing and code patching.
220   def(ObjAllocPost_lock            , Monitor, special,     false);
221   def(Service_lock                 , Monitor, special,     true ); // used for service thread operations
222   def(JmethodIdCreation_lock       , Mutex  , leaf,        true ); // used for creating jmethodIDs.
223 
224   def(SystemDictionary_lock        , Monitor, leaf,        true ); // lookups done by VM thread
225   def(PackageTable_lock            , Mutex  , leaf,        false);
226   def(InlineCacheBuffer_lock       , Mutex  , leaf,        true );
227   def(VMStatistic_lock             , Mutex  , leaf,        false);
228   def(ExpandHeap_lock              , Mutex  , leaf,        true ); // Used during compilation by VM thread
229   def(JNIHandleBlockFreeList_lock  , Mutex  , leaf,        true ); // handles are used by VM thread
230   def(SignatureHandlerLibrary_lock , Mutex  , leaf,        false);
231   def(SymbolTable_lock             , Mutex  , leaf+2,      true );
232   def(StringTable_lock             , Mutex  , leaf,        true );
233   def(ProfilePrint_lock            , Mutex  , leaf,        false); // serial profile printing
234   def(ExceptionCache_lock          , Mutex  , leaf,        false); // serial profile printing
235   def(OsrList_lock                 , Mutex  , leaf,        true );
236   def(Debug1_lock                  , Mutex  , leaf,        true );
237 #ifndef PRODUCT
238   def(FullGCALot_lock              , Mutex  , leaf,        false); // a lock to make FullGCALot MT safe
239 #endif
240   def(BeforeExit_lock              , Monitor, leaf,        true );
241   def(PerfDataMemAlloc_lock        , Mutex  , leaf,        true ); // used for allocating PerfData memory for performance data
242   def(PerfDataManager_lock         , Mutex  , leaf,        true ); // used for synchronized access to PerfDataManager resources
243 
244   // CMS_modUnionTable_lock                   leaf
245   // CMS_bitMap_lock                          leaf + 1
246   // CMS_freeList_lock                        leaf + 2
247 
248   def(Safepoint_lock               , Monitor, safepoint,   true ); // locks SnippetCache_lock/Threads_lock
249 
250   def(Threads_lock                 , Monitor, barrier,     true );
251 
252   def(VMOperationQueue_lock        , Monitor, nonleaf,     true ); // VM_thread allowed to block on these
253   def(VMOperationRequest_lock      , Monitor, nonleaf,     true );
254   def(RetData_lock                 , Mutex  , nonleaf,     false);
255   def(Terminator_lock              , Monitor, nonleaf,     true );
256   def(VtableStubs_lock             , Mutex  , nonleaf,     true );
257   def(Notify_lock                  , Monitor, nonleaf,     true );
258   def(JNIGlobalHandle_lock         , Mutex  , nonleaf,     true ); // locks JNIHandleBlockFreeList_lock
259   def(JNICritical_lock             , Monitor, nonleaf,     true ); // used for JNI critical regions
260   def(AdapterHandlerLibrary_lock   , Mutex  , nonleaf,     true);
261   if (UseConcMarkSweepGC) {
262     def(SLT_lock                   , Monitor, nonleaf,     false );
263                     // used in CMS GC for locking PLL lock
264   }
265   def(Heap_lock                    , Monitor, nonleaf+1,   false);
266   def(JfieldIdCreation_lock        , Mutex  , nonleaf+1,   true ); // jfieldID, Used in VM_Operation
267   def(MemberNameTable_lock         , Mutex  , nonleaf+1,   false); // Used to protect MemberNameTable
268 
269   def(CompiledIC_lock              , Mutex  , nonleaf+2,   false); // locks VtableStubs_lock, InlineCacheBuffer_lock
270   def(CompileTaskAlloc_lock        , Mutex  , nonleaf+2,   true );
271   def(CompileStatistics_lock       , Mutex  , nonleaf+2,   false);
272   def(MultiArray_lock              , Mutex  , nonleaf+2,   false); // locks SymbolTable_lock
273 
274   def(JvmtiThreadState_lock        , Mutex  , nonleaf+2,   false); // Used by JvmtiThreadState/JvmtiEventController
275   def(JvmtiPendingEvent_lock       , Monitor, nonleaf,     false); // Used by JvmtiCodeBlobEvents
276   def(Management_lock              , Mutex  , nonleaf+2,   false); // used for JVM management
277 
278   def(Compile_lock                 , Mutex  , nonleaf+3,   true );
279   def(MethodData_lock              , Mutex  , nonleaf+3,   false);
280 
281   def(MethodCompileQueue_lock      , Monitor, nonleaf+4,   true );
282   def(Debug2_lock                  , Mutex  , nonleaf+4,   true );
283   def(Debug3_lock                  , Mutex  , nonleaf+4,   true );
284   def(ProfileVM_lock               , Monitor, special,   false); // used for profiling of the VMThread
285   def(CompileThread_lock           , Monitor, nonleaf+5,   false );
286   def(PeriodicTask_lock            , Monitor, nonleaf+5,   true);
287   def(RedefineClasses_lock         , Monitor, nonleaf+5,   true);
288 
289 #if INCLUDE_JFR
290   def(JfrMsg_lock                  , Monitor, leaf,        true);
291   def(JfrBuffer_lock               , Mutex,   leaf,        true);
292   def(JfrThreadGroups_lock         , Mutex,   leaf,        true);
293   def(JfrStream_lock               , Mutex,   nonleaf,     true);
294   def(JfrStacktrace_lock           , Mutex,   special,     true);
295 
296 #ifndef SUPPORTS_NATIVE_CX8
297   def(JfrCounters_lock             , Mutex,   special,     false);
298 #endif
299 #endif
300 
301 #ifndef SUPPORTS_NATIVE_CX8
302   def(UnsafeJlong_lock             , Mutex,   special,     false);
303 #endif
304 }
305 
GCMutexLocker(Monitor * mutex)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.
print_owned_locks_on_error(outputStream * st)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 }
335