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 #ifndef SHARE_VM_RUNTIME_MUTEXLOCKER_HPP
26 #define SHARE_VM_RUNTIME_MUTEXLOCKER_HPP
27
28 #include "memory/allocation.hpp"
29 #include "runtime/mutex.hpp"
30
31 // Mutexes used in the VM.
32
33 extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code
34 extern Monitor* SystemDictionary_lock; // a lock on the system dictionary
35 extern Mutex* Module_lock; // a lock on module and package related data structures
36 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access
37 extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer
38 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment
39 extern Mutex* JNIGlobalAlloc_lock; // JNI global storage allocate list lock
40 extern Mutex* JNIGlobalActive_lock; // JNI global storage active list lock
41 extern Mutex* JNIWeakAlloc_lock; // JNI weak storage allocate list lock
42 extern Mutex* JNIWeakActive_lock; // JNI weak storage active list lock
43 extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list
44 extern Mutex* VMWeakAlloc_lock; // VM Weak Handles storage allocate list lock
45 extern Mutex* VMWeakActive_lock; // VM Weak Handles storage active list lock
46 extern Mutex* ResolvedMethodTable_lock; // a lock on the ResolvedMethodTable updates
47 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers
48 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers
49 extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
50 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data
51 extern Monitor* Heap_lock; // a lock on the heap
52 extern Mutex* ExpandHeap_lock; // a lock on expanding the heap
53 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary
54 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary
55 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs
56 extern Mutex* SymbolTable_lock; // a lock on the symbol table
57 extern Mutex* StringTable_lock; // a lock on the interned string table
58 extern Monitor* StringDedupQueue_lock; // a lock on the string deduplication queue
59 extern Mutex* StringDedupTable_lock; // a lock on the string deduplication table
60 extern Monitor* CodeCache_lock; // a lock on the CodeCache, rank is special, use MutexLockerEx
61 extern Mutex* MethodData_lock; // a lock on installation of method data
62 extern Mutex* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info
63 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data
64 extern Mutex* DerivedPointerTableGC_lock; // a lock to protect the derived pointer table
65 extern Monitor* CGCPhaseManager_lock; // a lock to protect a concurrent GC's phase management
66 extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute
67 extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate
68 extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction
69 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads
70 // (also used by Safepoints too to block threads creation/destruction)
71 extern Monitor* CGC_lock; // used for coordination between
72 // fore- & background GC threads.
73 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet.
74 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc
75 extern Mutex* SATB_Q_FL_lock; // Protects SATB Q
76 // buffer free list.
77 extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q
78 // completed buffer queue.
79 extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB
80 // queue shared by
81 // non-Java threads.
82
83 extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q
84 // buffer free list.
85 extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q
86 // completed buffer queue.
87 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card
88 // queue shared by
89 // non-Java threads.
90 extern Mutex* MarkStackFreeList_lock; // Protects access to the global mark stack free list.
91 extern Mutex* MarkStackChunkList_lock; // Protects access to the global mark stack chunk list.
92 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops.
93 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
94 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued
95 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization
96 extern Monitor* Compilation_lock; // a lock used to pause compilation
97 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated
98 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics
99 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives
100 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays
101 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm
102 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks
103 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm
104 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles
105 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates
106 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues
107
108 #ifndef PRODUCT
109 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe
110 #endif // PRODUCT
111 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing
112 extern Mutex* Debug2_lock; // down synchronization related bugs!
113 extern Mutex* Debug3_lock;
114
115 extern Mutex* RawMonitor_lock;
116 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data
117 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources
118 extern Mutex* ParkerFreeList_lock;
119 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches
120
121 extern Mutex* FreeList_lock; // protects the free region list during safepoints
122 extern Monitor* SecondaryFreeList_lock; // protects the secondary free region list
123 extern Mutex* OldSets_lock; // protects the old region sets
124 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions
125
126 extern Mutex* Management_lock; // a lock used to serialize JVM management
127 extern Monitor* Service_lock; // a lock used for service thread operation
128 extern Monitor* PeriodicTask_lock; // protects the periodic task structure
129 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition
130
131 #if INCLUDE_TRACE
132 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table
133 extern Monitor* JfrMsg_lock; // protects JFR messaging
134 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations
135 extern Mutex* JfrStream_lock; // protects JFR stream access
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
144
145 // A MutexLocker provides mutual exclusion with respect to a given mutex
146 // for the scope which contains the locker. The lock is an OS lock, not
147 // an object lock, and the two do not interoperate. Do not use Mutex-based
148 // locks to lock on Java objects, because they will not be respected if a
149 // that object is locked using the Java locking mechanism.
150 //
151 // NOTE WELL!!
152 //
153 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's
154 // and friends constructors do a fence, a lock and an acquire *in that
155 // order*. And that their destructors do a release and unlock, in *that*
156 // order. If their implementations change such that these assumptions
157 // are violated, a whole lot of code will break.
158
159 // Print all mutexes/monitors that are currently owned by a thread; called
160 // by fatal error handler.
161 void print_owned_locks_on_error(outputStream* st);
162
163 char *lock_name(Mutex *mutex);
164
165 class MutexLocker: StackObj {
166 private:
167 Monitor * _mutex;
168 public:
169 MutexLocker(Monitor * mutex) {
170 assert(mutex->rank() != Mutex::special,
171 "Special ranked mutex should only use MutexLockerEx");
172 _mutex = mutex;
173 _mutex->lock();
174 }
175
176 // Overloaded constructor passing current thread
177 MutexLocker(Monitor * mutex, Thread *thread) {
178 assert(mutex->rank() != Mutex::special,
179 "Special ranked mutex should only use MutexLockerEx");
180 _mutex = mutex;
181 _mutex->lock(thread);
182 }
183
184 ~MutexLocker() {
185 _mutex->unlock();
186 }
187
188 };
189
190 // for debugging: check that we're already owning this lock (or are at a safepoint)
191 #ifdef ASSERT
192 void assert_locked_or_safepoint(const Monitor * lock);
193 void assert_lock_strong(const Monitor * lock);
194 #else
195 #define assert_locked_or_safepoint(lock)
196 #define assert_lock_strong(lock)
197 #endif
198
199 // A MutexLockerEx behaves like a MutexLocker when its constructor is
200 // called with a Mutex. Unlike a MutexLocker, its constructor can also be
201 // called with NULL, in which case the MutexLockerEx is a no-op. There
202 // is also a corresponding MutexUnlockerEx. We want to keep the
203 // basic MutexLocker as fast as possible. MutexLockerEx can also lock
204 // without safepoint check.
205
206 class MutexLockerEx: public StackObj {
207 private:
208 Monitor * _mutex;
209 public:
210 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
211 _mutex = mutex;
212 if (_mutex != NULL) {
213 assert(mutex->rank() > Mutex::special || no_safepoint_check,
214 "Mutexes with rank special or lower should not do safepoint checks");
215 if (no_safepoint_check)
216 _mutex->lock_without_safepoint_check();
217 else
218 _mutex->lock();
219 }
220 }
221
222 ~MutexLockerEx() {
223 if (_mutex != NULL) {
224 _mutex->unlock();
225 }
226 }
227 };
228
229 // A MonitorLockerEx is like a MutexLockerEx above, except it takes
230 // a possibly null Monitor, and allows wait/notify as well which are
231 // delegated to the underlying Monitor.
232
233 class MonitorLockerEx: public MutexLockerEx {
234 private:
235 Monitor * _monitor;
236 public:
237 MonitorLockerEx(Monitor* monitor,
238 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
239 MutexLockerEx(monitor, no_safepoint_check),
240 _monitor(monitor) {
241 // Superclass constructor did locking
242 }
243
244 ~MonitorLockerEx() {
245 #ifdef ASSERT
246 if (_monitor != NULL) {
247 assert_lock_strong(_monitor);
248 }
249 #endif // ASSERT
250 // Superclass destructor will do unlocking
251 }
252
253 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
254 long timeout = 0,
255 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
256 if (_monitor != NULL) {
257 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
258 }
259 return false;
260 }
261
262 bool notify_all() {
263 if (_monitor != NULL) {
264 return _monitor->notify_all();
265 }
266 return true;
267 }
268
269 bool notify() {
270 if (_monitor != NULL) {
271 return _monitor->notify();
272 }
273 return true;
274 }
275 };
276
277
278
279 // A GCMutexLocker is usually initialized with a mutex that is
280 // automatically acquired in order to do GC. The function that
281 // synchronizes using a GCMutexLocker may be called both during and between
282 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not
283 // if GC is in progress (since the mutex is already held on its behalf.)
284
285 class GCMutexLocker: public StackObj {
286 private:
287 Monitor * _mutex;
288 bool _locked;
289 public:
290 GCMutexLocker(Monitor * mutex);
291 ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
292 };
293
294
295
296 // A MutexUnlocker temporarily exits a previously
297 // entered mutex for the scope which contains the unlocker.
298
299 class MutexUnlocker: StackObj {
300 private:
301 Monitor * _mutex;
302
303 public:
304 MutexUnlocker(Monitor * mutex) {
305 _mutex = mutex;
306 _mutex->unlock();
307 }
308
309 ~MutexUnlocker() {
310 _mutex->lock();
311 }
312 };
313
314 // A MutexUnlockerEx temporarily exits a previously
315 // entered mutex for the scope which contains the unlocker.
316
317 class MutexUnlockerEx: StackObj {
318 private:
319 Monitor * _mutex;
320 bool _no_safepoint_check;
321
322 public:
323 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
324 _mutex = mutex;
325 _no_safepoint_check = no_safepoint_check;
326 _mutex->unlock();
327 }
328
329 ~MutexUnlockerEx() {
330 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
331 _mutex->lock_without_safepoint_check();
332 } else {
333 _mutex->lock();
334 }
335 }
336 };
337
338 #ifndef PRODUCT
339 //
340 // A special MutexLocker that allows:
341 // - reentrant locking
342 // - locking out of order
343 //
344 // Only to be used for verify code, where we can relax out dead-lock
345 // detection code a bit (unsafe, but probably ok). This code is NEVER to
346 // be included in a product version.
347 //
348 class VerifyMutexLocker: StackObj {
349 private:
350 Monitor * _mutex;
351 bool _reentrant;
352 public:
353 VerifyMutexLocker(Monitor * mutex) {
354 _mutex = mutex;
355 _reentrant = mutex->owned_by_self();
356 if (!_reentrant) {
357 // We temp. disable strict safepoint checking, while we require the lock
358 FlagSetting fs(StrictSafepointChecks, false);
359 _mutex->lock();
360 }
361 }
362
363 ~VerifyMutexLocker() {
364 if (!_reentrant) {
365 _mutex->unlock();
366 }
367 }
368 };
369
370 #endif
371
372 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP