1/*
2 * Copyright (c) 1997, 2016, 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_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
33extern Mutex*   Patching_lock;                   // a lock used to guard code patching of compiled code
34extern Monitor* SystemDictionary_lock;           // a lock on the system dictionary
35extern Mutex*   Module_lock;                     // a lock on module and package related data structures
36extern Mutex*   CompiledIC_lock;                 // a lock used to guard compiled IC patching and access
37extern Mutex*   InlineCacheBuffer_lock;          // a lock used to guard the InlineCacheBuffer
38extern Mutex*   VMStatistic_lock;                // a lock used to guard statistics count increment
39extern Mutex*   JNIGlobalHandle_lock;            // a lock on creating JNI global handles
40extern Mutex*   JNIHandleBlockFreeList_lock;     // a lock on the JNI handle block free list
41extern Mutex*   MemberNameTable_lock;            // a lock on the MemberNameTable updates
42extern Mutex*   JmethodIdCreation_lock;          // a lock on creating JNI method identifiers
43extern Mutex*   JfieldIdCreation_lock;           // a lock on creating JNI static field identifiers
44extern Monitor* JNICritical_lock;                // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
45extern Mutex*   JvmtiThreadState_lock;           // a lock on modification of JVMTI thread data
46extern Monitor* Heap_lock;                       // a lock on the heap
47extern Mutex*   ExpandHeap_lock;                 // a lock on expanding the heap
48extern Mutex*   AdapterHandlerLibrary_lock;      // a lock on the AdapterHandlerLibrary
49extern Mutex*   SignatureHandlerLibrary_lock;    // a lock on the SignatureHandlerLibrary
50extern Mutex*   VtableStubs_lock;                // a lock on the VtableStubs
51extern Mutex*   SymbolTable_lock;                // a lock on the symbol table
52extern Mutex*   StringTable_lock;                // a lock on the interned string table
53extern Monitor* StringDedupQueue_lock;           // a lock on the string deduplication queue
54extern Mutex*   StringDedupTable_lock;           // a lock on the string deduplication table
55extern Monitor* CodeCache_lock;                  // a lock on the CodeCache, rank is special, use MutexLockerEx
56extern Mutex*   MethodData_lock;                 // a lock on installation of method data
57extern Mutex*   TouchedMethodLog_lock;           // a lock on allocation of LogExecutedMethods info
58extern Mutex*   RetData_lock;                    // a lock on installation of RetData inside method data
59extern Mutex*   DerivedPointerTableGC_lock;      // a lock to protect the derived pointer table
60extern Monitor* VMOperationQueue_lock;           // a lock on queue of vm_operations waiting to execute
61extern Monitor* VMOperationRequest_lock;         // a lock on Threads waiting for a vm_operation to terminate
62extern Monitor* Safepoint_lock;                  // a lock used by the safepoint abstraction
63extern Monitor* Threads_lock;                    // a lock on the Threads table of active Java threads
64                                                 // (also used by Safepoints too to block threads creation/destruction)
65extern Monitor* CGC_lock;                        // used for coordination between
66                                                 // fore- & background GC threads.
67extern Monitor* STS_lock;                        // used for joining/leaving SuspendibleThreadSet.
68extern Monitor* FullGCCount_lock;                // in support of "concurrent" full gc
69extern Mutex*   SATB_Q_FL_lock;                  // Protects SATB Q
70                                                 // buffer free list.
71extern Monitor* SATB_Q_CBL_mon;                  // Protects SATB Q
72                                                 // completed buffer queue.
73extern Mutex*   Shared_SATB_Q_lock;              // Lock protecting SATB
74                                                 // queue shared by
75                                                 // non-Java threads.
76
77extern Mutex*   DirtyCardQ_FL_lock;              // Protects dirty card Q
78                                                 // buffer free list.
79extern Monitor* DirtyCardQ_CBL_mon;              // Protects dirty card Q
80                                                 // completed buffer queue.
81extern Mutex*   Shared_DirtyCardQ_lock;          // Lock protecting dirty card
82                                                 // queue shared by
83                                                 // non-Java threads.
84extern Mutex*   MarkStackFreeList_lock;          // Protects access to the global mark stack free list.
85extern Mutex*   MarkStackChunkList_lock;         // Protects access to the global mark stack chunk list.
86extern Mutex*   ParGCRareEvent_lock;             // Synchronizes various (rare) parallel GC ops.
87extern Mutex*   Compile_lock;                    // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
88extern Monitor* MethodCompileQueue_lock;         // a lock held when method compilations are enqueued, dequeued
89extern Monitor* CompileThread_lock;              // a lock held by compile threads during compilation system initialization
90extern Monitor* Compilation_lock;                // a lock used to pause compilation
91extern Mutex*   CompileTaskAlloc_lock;           // a lock held when CompileTasks are allocated
92extern Mutex*   CompileStatistics_lock;          // a lock held when updating compilation statistics
93extern Mutex*   DirectivesStack_lock;            // a lock held when mutating the dirstack and ref counting directives
94extern Mutex*   MultiArray_lock;                 // a lock used to guard allocation of multi-dim arrays
95extern Monitor* Terminator_lock;                 // a lock used to guard termination of the vm
96extern Monitor* BeforeExit_lock;                 // a lock used to guard cleanups and shutdown hooks
97extern Monitor* Notify_lock;                     // a lock used to synchronize the start-up of the vm
98extern Mutex*   ProfilePrint_lock;               // a lock used to serialize the printing of profiles
99extern Mutex*   ExceptionCache_lock;             // a lock used to synchronize exception cache updates
100extern Mutex*   OsrList_lock;                    // a lock used to serialize access to OSR queues
101
102#ifndef PRODUCT
103extern Mutex*   FullGCALot_lock;                 // a lock to make FullGCALot MT safe
104#endif // PRODUCT
105extern Mutex*   Debug1_lock;                     // A bunch of pre-allocated locks that can be used for tracing
106extern Mutex*   Debug2_lock;                     // down synchronization related bugs!
107extern Mutex*   Debug3_lock;
108
109extern Mutex*   RawMonitor_lock;
110extern Mutex*   PerfDataMemAlloc_lock;           // a lock on the allocator for PerfData memory for performance data
111extern Mutex*   PerfDataManager_lock;            // a long on access to PerfDataManager resources
112extern Mutex*   ParkerFreeList_lock;
113extern Mutex*   OopMapCacheAlloc_lock;           // protects allocation of oop_map caches
114
115extern Mutex*   FreeList_lock;                   // protects the free region list during safepoints
116extern Monitor* SecondaryFreeList_lock;          // protects the secondary free region list
117extern Mutex*   OldSets_lock;                    // protects the old region sets
118extern Monitor* RootRegionScan_lock;             // used to notify that the CM threads have finished scanning the IM snapshot regions
119extern Mutex*   MMUTracker_lock;                 // protects the MMU
120                                                 // tracker data structures
121
122extern Mutex*   Management_lock;                 // a lock used to serialize JVM management
123extern Monitor* Service_lock;                    // a lock used for service thread operation
124extern Monitor* PeriodicTask_lock;               // protects the periodic task structure
125extern Monitor* RedefineClasses_lock;            // locks classes from parallel redefinition
126
127#ifdef INCLUDE_TRACE
128extern Mutex*   JfrStacktrace_lock;              // used to guard access to the JFR stacktrace table
129extern Monitor* JfrMsg_lock;                     // protects JFR messaging
130extern Mutex*   JfrBuffer_lock;                  // protects JFR buffer operations
131extern Mutex*   JfrStream_lock;                  // protects JFR stream access
132extern Mutex*   JfrThreadGroups_lock;            // protects JFR access to Thread Groups
133#endif
134
135#ifndef SUPPORTS_NATIVE_CX8
136extern Mutex*   UnsafeJlong_lock;                // provides Unsafe atomic updates to jlongs on platforms that don't support cx8
137#endif
138
139// A MutexLocker provides mutual exclusion with respect to a given mutex
140// for the scope which contains the locker.  The lock is an OS lock, not
141// an object lock, and the two do not interoperate.  Do not use Mutex-based
142// locks to lock on Java objects, because they will not be respected if a
143// that object is locked using the Java locking mechanism.
144//
145//                NOTE WELL!!
146//
147// See orderAccess.hpp.  We assume throughout the VM that MutexLocker's
148// and friends constructors do a fence, a lock and an acquire *in that
149// order*.  And that their destructors do a release and unlock, in *that*
150// order.  If their implementations change such that these assumptions
151// are violated, a whole lot of code will break.
152
153// Print all mutexes/monitors that are currently owned by a thread; called
154// by fatal error handler.
155void print_owned_locks_on_error(outputStream* st);
156
157char *lock_name(Mutex *mutex);
158
159class MutexLocker: StackObj {
160 private:
161  Monitor * _mutex;
162 public:
163  MutexLocker(Monitor * mutex) {
164    assert(mutex->rank() != Mutex::special,
165      "Special ranked mutex should only use MutexLockerEx");
166    _mutex = mutex;
167    _mutex->lock();
168  }
169
170  // Overloaded constructor passing current thread
171  MutexLocker(Monitor * mutex, Thread *thread) {
172    assert(mutex->rank() != Mutex::special,
173      "Special ranked mutex should only use MutexLockerEx");
174    _mutex = mutex;
175    _mutex->lock(thread);
176  }
177
178  ~MutexLocker() {
179    _mutex->unlock();
180  }
181
182};
183
184// for debugging: check that we're already owning this lock (or are at a safepoint)
185#ifdef ASSERT
186void assert_locked_or_safepoint(const Monitor * lock);
187void assert_lock_strong(const Monitor * lock);
188#else
189#define assert_locked_or_safepoint(lock)
190#define assert_lock_strong(lock)
191#endif
192
193// A MutexLockerEx behaves like a MutexLocker when its constructor is
194// called with a Mutex.  Unlike a MutexLocker, its constructor can also be
195// called with NULL, in which case the MutexLockerEx is a no-op.  There
196// is also a corresponding MutexUnlockerEx.  We want to keep the
197// basic MutexLocker as fast as possible.  MutexLockerEx can also lock
198// without safepoint check.
199
200class MutexLockerEx: public StackObj {
201 private:
202  Monitor * _mutex;
203 public:
204  MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
205    _mutex = mutex;
206    if (_mutex != NULL) {
207      assert(mutex->rank() > Mutex::special || no_safepoint_check,
208        "Mutexes with rank special or lower should not do safepoint checks");
209      if (no_safepoint_check)
210        _mutex->lock_without_safepoint_check();
211      else
212        _mutex->lock();
213    }
214  }
215
216  ~MutexLockerEx() {
217    if (_mutex != NULL) {
218      _mutex->unlock();
219    }
220  }
221};
222
223// A MonitorLockerEx is like a MutexLockerEx above, except it takes
224// a possibly null Monitor, and allows wait/notify as well which are
225// delegated to the underlying Monitor.
226
227class MonitorLockerEx: public MutexLockerEx {
228 private:
229  Monitor * _monitor;
230 public:
231  MonitorLockerEx(Monitor* monitor,
232                  bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
233    MutexLockerEx(monitor, no_safepoint_check),
234    _monitor(monitor) {
235    // Superclass constructor did locking
236  }
237
238  ~MonitorLockerEx() {
239    #ifdef ASSERT
240      if (_monitor != NULL) {
241        assert_lock_strong(_monitor);
242      }
243    #endif  // ASSERT
244    // Superclass destructor will do unlocking
245  }
246
247  bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
248            long timeout = 0,
249            bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
250    if (_monitor != NULL) {
251      return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
252    }
253    return false;
254  }
255
256  bool notify_all() {
257    if (_monitor != NULL) {
258      return _monitor->notify_all();
259    }
260    return true;
261  }
262
263  bool notify() {
264    if (_monitor != NULL) {
265      return _monitor->notify();
266    }
267    return true;
268  }
269};
270
271
272
273// A GCMutexLocker is usually initialized with a mutex that is
274// automatically acquired in order to do GC.  The function that
275// synchronizes using a GCMutexLocker may be called both during and between
276// GC's.  Thus, it must acquire the mutex if GC is not in progress, but not
277// if GC is in progress (since the mutex is already held on its behalf.)
278
279class GCMutexLocker: public StackObj {
280private:
281  Monitor * _mutex;
282  bool _locked;
283public:
284  GCMutexLocker(Monitor * mutex);
285  ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
286};
287
288
289
290// A MutexUnlocker temporarily exits a previously
291// entered mutex for the scope which contains the unlocker.
292
293class MutexUnlocker: StackObj {
294 private:
295  Monitor * _mutex;
296
297 public:
298  MutexUnlocker(Monitor * mutex) {
299    _mutex = mutex;
300    _mutex->unlock();
301  }
302
303  ~MutexUnlocker() {
304    _mutex->lock();
305  }
306};
307
308// A MutexUnlockerEx temporarily exits a previously
309// entered mutex for the scope which contains the unlocker.
310
311class MutexUnlockerEx: StackObj {
312 private:
313  Monitor * _mutex;
314  bool _no_safepoint_check;
315
316 public:
317  MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
318    _mutex = mutex;
319    _no_safepoint_check = no_safepoint_check;
320    _mutex->unlock();
321  }
322
323  ~MutexUnlockerEx() {
324    if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
325      _mutex->lock_without_safepoint_check();
326    } else {
327      _mutex->lock();
328    }
329  }
330};
331
332#ifndef PRODUCT
333//
334// A special MutexLocker that allows:
335//   - reentrant locking
336//   - locking out of order
337//
338// Only to be used for verify code, where we can relax out dead-lock
339// detection code a bit (unsafe, but probably ok). This code is NEVER to
340// be included in a product version.
341//
342class VerifyMutexLocker: StackObj {
343 private:
344  Monitor * _mutex;
345  bool   _reentrant;
346 public:
347  VerifyMutexLocker(Monitor * mutex) {
348    _mutex     = mutex;
349    _reentrant = mutex->owned_by_self();
350    if (!_reentrant) {
351      // We temp. disable strict safepoint checking, while we require the lock
352      FlagSetting fs(StrictSafepointChecks, false);
353      _mutex->lock();
354    }
355  }
356
357  ~VerifyMutexLocker() {
358    if (!_reentrant) {
359      _mutex->unlock();
360    }
361  }
362};
363
364#endif
365
366#endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP
367