1 /*
2 * Copyright (c) 1997, 2020, 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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24
25 #ifndef SHARE_RUNTIME_MUTEXLOCKER_HPP
26 #define SHARE_RUNTIME_MUTEXLOCKER_HPP
27
28 #include "memory/allocation.hpp"
29 #include "runtime/flags/flagSetting.hpp"
30 #include "runtime/mutex.hpp"
31
32 // Mutexes used in the VM.
33
34 extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code
35 extern Mutex* CompiledMethod_lock; // a lock used to guard a compiled method and OSR queues
36 extern Monitor* SystemDictionary_lock; // a lock on the system dictionary
37 extern Mutex* ProtectionDomainSet_lock; // a lock on the pd_set list in the system dictionary
38 extern Mutex* SharedDictionary_lock; // a lock on the CDS shared dictionary
39 extern Mutex* Module_lock; // a lock on module and package related data structures
40 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access
41 extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer
42 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment
43 extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list
44 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers
45 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers
46 extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
47 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data
48 extern Monitor* Heap_lock; // a lock on the heap
49 extern Mutex* ExpandHeap_lock; // a lock on expanding the heap
50 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary
51 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary
52 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs
53 extern Mutex* SymbolArena_lock; // a lock on the symbol table arena
54 extern Monitor* StringDedupQueue_lock; // a lock on the string deduplication queue
55 extern Mutex* StringDedupTable_lock; // a lock on the string deduplication table
56 extern Monitor* CodeCache_lock; // a lock on the CodeCache, rank is special
57 extern Mutex* MethodData_lock; // a lock on installation of method data
58 extern Mutex* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info
59 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data
60 extern Monitor* CGCPhaseManager_lock; // a lock to protect a concurrent GC's phase management
61 extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute
62 extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate
63 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads
64 // (also used by Safepoints too to block threads creation/destruction)
65 extern Mutex* NonJavaThreadsList_lock; // a lock on the NonJavaThreads list
66 extern Mutex* NonJavaThreadsListSync_lock; // a lock for NonJavaThreads list synchronization
67 extern Monitor* CGC_lock; // used for coordination between
68 // fore- & background GC threads.
69 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet.
70 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc
71 extern Monitor* G1OldGCCount_lock; // in support of "concurrent" full gc
72 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card
73 // queue shared by
74 // non-Java threads.
75 extern Mutex* MarkStackFreeList_lock; // Protects access to the global mark stack free list.
76 extern Mutex* MarkStackChunkList_lock; // Protects access to the global mark stack chunk list.
77 extern Mutex* MonitoringSupport_lock; // Protects updates to the serviceability memory pools.
78 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops.
79 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
80 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued
81 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization
82 extern Monitor* Compilation_lock; // a lock used to pause compilation
83 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated
84 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics
85 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives
86 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays
87 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm
88 extern Monitor* InitCompleted_lock; // a lock used to signal threads waiting on init completed
89 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks
90 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm
91 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles
92 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates
93 extern Mutex* NMethodSweeperStats_lock; // a lock used to serialize access to sweeper statistics
94
95 #ifndef PRODUCT
96 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe
97 #endif // PRODUCT
98 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing
99 extern Mutex* Debug2_lock; // down synchronization related bugs!
100 extern Mutex* Debug3_lock;
101
102 extern Mutex* RawMonitor_lock;
103 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data
104 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources
105 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches
106
107 extern Mutex* FreeList_lock; // protects the free region list during safepoints
108 extern Mutex* OldSets_lock; // protects the old region sets
109 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions
110
111 extern Mutex* Management_lock; // a lock used to serialize JVM management
112 extern Monitor* Service_lock; // a lock used for service thread operation
113 extern Monitor* Notification_lock; // a lock used for notification thread operation
114 extern Monitor* PeriodicTask_lock; // protects the periodic task structure
115 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition
116 extern Mutex* Verify_lock; // synchronize initialization of verify library
117 extern Monitor* ThreadsSMRDelete_lock; // Used by ThreadsSMRSupport to take pressure off the Threads_lock
118 extern Mutex* ThreadIdTableCreate_lock; // Used by ThreadIdTable to lazily create the thread id table
119 extern Mutex* SharedDecoder_lock; // serializes access to the decoder during normal (not error reporting) use
120 extern Mutex* DCmdFactory_lock; // serialize access to DCmdFactory information
121 #if INCLUDE_NMT
122 extern Mutex* NMTQuery_lock; // serialize NMT Dcmd queries
123 #endif
124 #if INCLUDE_CDS
125 #if INCLUDE_JVMTI
126 extern Mutex* CDSClassFileStream_lock; // FileMapInfo::open_stream_for_jvmti
127 #endif
128 extern Mutex* DumpTimeTable_lock; // SystemDictionaryShared::find_or_allocate_info_for
129 #endif // INCLUDE_CDS
130 #if INCLUDE_JFR
131 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table
132 extern Monitor* JfrMsg_lock; // protects JFR messaging
133 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations
134 extern Mutex* JfrStream_lock; // protects JFR stream access
135 extern Monitor* JfrThreadSampler_lock; // used to suspend/resume JFR thread sampler
136 #endif
137
138 #ifndef SUPPORTS_NATIVE_CX8
139 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8
140 #endif
141
142 extern Mutex* MetaspaceExpand_lock; // protects Metaspace virtualspace and chunk expansions
143 extern Mutex* ClassLoaderDataGraph_lock; // protects CLDG list, needed for concurrent unloading
144
145
146 extern Mutex* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions.
147 // Only used locally in PrintCodeCacheLayout processing.
148
149 #if INCLUDE_JVMCI
150 extern Monitor* JVMCI_lock; // Monitor to control initialization of JVMCI
151 #endif
152
153 extern Mutex* tty_lock; // lock to synchronize output.
154
155 // A MutexLocker provides mutual exclusion with respect to a given mutex
156 // for the scope which contains the locker. The lock is an OS lock, not
157 // an object lock, and the two do not interoperate. Do not use Mutex-based
158 // locks to lock on Java objects, because they will not be respected if a
159 // that object is locked using the Java locking mechanism.
160 //
161 // NOTE WELL!!
162 //
163 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's
164 // and friends constructors do a fence, a lock and an acquire *in that
165 // order*. And that their destructors do a release and unlock, in *that*
166 // order. If their implementations change such that these assumptions
167 // are violated, a whole lot of code will break.
168
169 // Print all mutexes/monitors that are currently owned by a thread; called
170 // by fatal error handler.
171 void print_owned_locks_on_error(outputStream* st);
172
173 char *lock_name(Mutex *mutex);
174
175 // for debugging: check that we're already owning this lock (or are at a safepoint / handshake)
176 #ifdef ASSERT
177 void assert_locked_or_safepoint(const Mutex* lock);
178 void assert_locked_or_safepoint_weak(const Mutex* lock);
179 void assert_lock_strong(const Mutex* lock);
180 void assert_locked_or_safepoint_or_handshake(const Mutex* lock, const JavaThread* thread);
181 #else
182 #define assert_locked_or_safepoint(lock)
183 #define assert_locked_or_safepoint_weak(lock)
184 #define assert_lock_strong(lock)
185 #define assert_locked_or_safepoint_or_handshake(lock, thread)
186 #endif
187
188 class MutexLocker: public StackObj {
189 protected:
190 Mutex* _mutex;
191 private:
192 public:
193 MutexLocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
194 _mutex(mutex) {
195 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
196 if (_mutex != NULL) {
197 assert(_mutex->rank() > Mutex::special || no_safepoint_check,
198 "Mutexes with rank special or lower should not do safepoint checks");
199 if (no_safepoint_check) {
200 _mutex->lock_without_safepoint_check();
201 } else {
202 _mutex->lock();
203 }
204 }
205 }
206
207 MutexLocker(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
208 _mutex(mutex) {
209 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
210 if (_mutex != NULL) {
211 assert(_mutex->rank() > Mutex::special || no_safepoint_check,
212 "Mutexes with rank special or lower should not do safepoint checks");
213 if (no_safepoint_check) {
214 _mutex->lock_without_safepoint_check(thread);
215 } else {
216 _mutex->lock(thread);
217 }
218 }
219 }
220
221 ~MutexLocker() {
222 if (_mutex != NULL) {
223 assert_lock_strong(_mutex);
224 _mutex->unlock();
225 }
226 }
227 };
228
229 // A MonitorLocker is like a MutexLocker above, except it allows
230 // wait/notify as well which are delegated to the underlying Monitor.
231 // It also disallows NULL.
232
233 class MonitorLocker: public MutexLocker {
234 Mutex::SafepointCheckFlag _flag;
235 Monitor* _monitor;
236 public:
237 MonitorLocker(Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
238 MutexLocker(monitor, flag), _flag(flag), _monitor(monitor) {
239 // Superclass constructor did locking
240 assert(_monitor != NULL, "NULL monitor not allowed");
241 }
242
243 MonitorLocker(Thread* thread, Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
244 MutexLocker(thread, monitor, flag), _flag(flag), _monitor(monitor) {
245 // Superclass constructor did locking
246 assert(_monitor != NULL, "NULL monitor not allowed");
247 }
248
249 bool wait(long timeout = 0,
250 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
251 if (_flag == Mutex::_safepoint_check_flag) {
252 return _monitor->wait(timeout, as_suspend_equivalent);
253 } else {
254 return _monitor->wait_without_safepoint_check(timeout);
255 }
256 return false;
257 }
258
259 void notify_all() {
260 _monitor->notify_all();
261 }
262
263 void notify() {
264 _monitor->notify();
265 }
266 };
267
268
269 // A GCMutexLocker is usually initialized with a mutex that is
270 // automatically acquired in order to do GC. The function that
271 // synchronizes using a GCMutexLocker may be called both during and between
272 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not
273 // if GC is in progress (since the mutex is already held on its behalf.)
274
275 class GCMutexLocker: public StackObj {
276 private:
277 Mutex* _mutex;
278 bool _locked;
279 public:
280 GCMutexLocker(Mutex* mutex);
281 ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
282 };
283
284 // A MutexUnlocker temporarily exits a previously
285 // entered mutex for the scope which contains the unlocker.
286
287 class MutexUnlocker: StackObj {
288 private:
289 Mutex* _mutex;
290 bool _no_safepoint_check;
291
292 public:
293 MutexUnlocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
294 _mutex(mutex),
295 _no_safepoint_check(flag) {
296 _mutex->unlock();
297 }
298
299 ~MutexUnlocker() {
300 if (_no_safepoint_check) {
301 _mutex->lock_without_safepoint_check();
302 } else {
303 _mutex->lock();
304 }
305 }
306 };
307
308 #endif // SHARE_RUNTIME_MUTEXLOCKER_HPP