jdk8-mips64-public/hotspot: src/share/vm/runtime/objectMonitor.hpp@b5cb079ecaa4 (annotated)

src/share/vm/runtime/objectMonitor.hpp@b5cb079ecaa4 (annotated)

src/share/vm/runtime/objectMonitor.hpp

Sun, 03 Feb 2013 22:43:57 +0100

author: ewendeli
date: Sun, 03 Feb 2013 22:43:57 +0100
changeset 4703: b5cb079ecaa4
parent 2325: c760f78e0a53
child 5103: f9be75d21404
permissions: -rw-r--r--

Merge

 /*
  * Copyright (c) 1998, 2010, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #ifndef SHARE_VM_RUNTIME_OBJECTMONITOR_HPP
 #define SHARE_VM_RUNTIME_OBJECTMONITOR_HPP
 #include "runtime/os.hpp"
 #include "runtime/park.hpp"
 #include "runtime/perfData.hpp"
 // ObjectWaiter serves as a "proxy" or surrogate thread.
 // TODO-FIXME: Eliminate ObjectWaiter and use the thread-specific
 // ParkEvent instead.  Beware, however, that the JVMTI code
 // knows about ObjectWaiters, so we'll have to reconcile that code.
 // See next_waiter(), first_waiter(), etc.
 class ObjectWaiter : public StackObj {
  public:
   enum TStates { TS_UNDEF, TS_READY, TS_RUN, TS_WAIT, TS_ENTER, TS_CXQ } ;
   enum Sorted  { PREPEND, APPEND, SORTED } ;
   ObjectWaiter * volatile _next;
   ObjectWaiter * volatile _prev;
   Thread*       _thread;
   ParkEvent *   _event;
   volatile int  _notified ;
   volatile TStates TState ;
   Sorted        _Sorted ;           // List placement disposition
   bool          _active ;           // Contention monitoring is enabled
  public:
   ObjectWaiter(Thread* thread);
   void wait_reenter_begin(ObjectMonitor *mon);
   void wait_reenter_end(ObjectMonitor *mon);
 };
 // WARNING:
 //   This is a very sensitive and fragile class. DO NOT make any
 // change unless you are fully aware of the underlying semantics.
 //   This class can not inherit from any other class, because I have
 // to let the displaced header be the very first word. Otherwise I
 // have to let markOop include this file, which would export the
 // monitor data structure to everywhere.
 //
 // The ObjectMonitor class is used to implement JavaMonitors which have
 // transformed from the lightweight structure of the thread stack to a
 // heavy weight lock due to contention
 // It is also used as RawMonitor by the JVMTI
 class ObjectMonitor {
  public:
   enum {
     OM_OK,                    // no error
     OM_SYSTEM_ERROR,          // operating system error
     OM_ILLEGAL_MONITOR_STATE, // IllegalMonitorStateException
     OM_INTERRUPTED,           // Thread.interrupt()
     OM_TIMED_OUT              // Object.wait() timed out
   };
  public:
   // TODO-FIXME: the "offset" routines should return a type of off_t instead of int ...
   // ByteSize would also be an appropriate type.
   static int header_offset_in_bytes()      { return offset_of(ObjectMonitor, _header);     }
   static int object_offset_in_bytes()      { return offset_of(ObjectMonitor, _object);     }
   static int owner_offset_in_bytes()       { return offset_of(ObjectMonitor, _owner);      }
   static int count_offset_in_bytes()       { return offset_of(ObjectMonitor, _count);      }
   static int recursions_offset_in_bytes()  { return offset_of(ObjectMonitor, _recursions); }
   static int cxq_offset_in_bytes()         { return offset_of(ObjectMonitor, _cxq) ;       }
   static int succ_offset_in_bytes()        { return offset_of(ObjectMonitor, _succ) ;      }
   static int EntryList_offset_in_bytes()   { return offset_of(ObjectMonitor, _EntryList);  }
   static int FreeNext_offset_in_bytes()    { return offset_of(ObjectMonitor, FreeNext);    }
   static int WaitSet_offset_in_bytes()     { return offset_of(ObjectMonitor, _WaitSet) ;   }
   static int Responsible_offset_in_bytes() { return offset_of(ObjectMonitor, _Responsible);}
   static int Spinner_offset_in_bytes()     { return offset_of(ObjectMonitor, _Spinner);    }
  public:
   // Eventaully we'll make provisions for multiple callbacks, but
   // now one will suffice.
   static int (*SpinCallbackFunction)(intptr_t, int) ;
   static intptr_t SpinCallbackArgument ;
  public:
   markOop   header() const;
   void      set_header(markOop hdr);
   intptr_t is_busy() const {
     // TODO-FIXME: merge _count and _waiters.
     // TODO-FIXME: assert _owner == null implies _recursions = 0
     // TODO-FIXME: assert _WaitSet != null implies _count > 0
     return _count|_waiters|intptr_t(_owner)|intptr_t(_cxq)|intptr_t(_EntryList ) ;
   }
   intptr_t  is_entered(Thread* current) const;
   void*     owner() const;
   void      set_owner(void* owner);
   intptr_t  waiters() const;
   intptr_t  count() const;
   void      set_count(intptr_t count);
   intptr_t  contentions() const ;
   intptr_t  recursions() const                                         { return _recursions; }
   // JVM/DI GetMonitorInfo() needs this
   ObjectWaiter* first_waiter()                                         { return _WaitSet; }
   ObjectWaiter* next_waiter(ObjectWaiter* o)                           { return o->_next; }
   Thread* thread_of_waiter(ObjectWaiter* o)                            { return o->_thread; }
   // initialize the monitor, exception the semaphore, all other fields
   // are simple integers or pointers
   ObjectMonitor() {
     _header       = NULL;
     _count        = 0;
     _waiters      = 0,
     _recursions   = 0;
     _object       = NULL;
     _owner        = NULL;
     _WaitSet      = NULL;
     _WaitSetLock  = 0 ;
     _Responsible  = NULL ;
     _succ         = NULL ;
     _cxq          = NULL ;
     FreeNext      = NULL ;
     _EntryList    = NULL ;
     _SpinFreq     = 0 ;
     _SpinClock    = 0 ;
     OwnerIsThread = 0 ;
   }
   ~ObjectMonitor() {
    // TODO: Add asserts ...
    // _cxq == 0 _succ == NULL _owner == NULL _waiters == 0
    // _count == 0 _EntryList  == NULL etc
   }
 private:
   void Recycle () {
     // TODO: add stronger asserts ...
     // _cxq == 0 _succ == NULL _owner == NULL _waiters == 0
     // _count == 0 EntryList  == NULL
     // _recursions == 0 _WaitSet == NULL
     // TODO: assert (is_busy()|_recursions) == 0
     _succ          = NULL ;
     _EntryList     = NULL ;
     _cxq           = NULL ;
     _WaitSet       = NULL ;
     _recursions    = 0 ;
     _SpinFreq      = 0 ;
     _SpinClock     = 0 ;
     OwnerIsThread  = 0 ;
   }
 public:
   void*     object() const;
   void*     object_addr();
   void      set_object(void* obj);
   bool      check(TRAPS);       // true if the thread owns the monitor.
   void      check_slow(TRAPS);
   void      clear();
 #ifndef PRODUCT
   void      verify();
   void      print();
 #endif
   bool      try_enter (TRAPS) ;
   void      enter(TRAPS);
   void      exit(TRAPS);
   void      wait(jlong millis, bool interruptable, TRAPS);
   void      notify(TRAPS);
   void      notifyAll(TRAPS);
 // Use the following at your own risk
   intptr_t  complete_exit(TRAPS);
   void      reenter(intptr_t recursions, TRAPS);
  private:
   void      AddWaiter (ObjectWaiter * waiter) ;
   static    void DeferredInitialize();
   ObjectWaiter * DequeueWaiter () ;
   void      DequeueSpecificWaiter (ObjectWaiter * waiter) ;
   void      EnterI (TRAPS) ;
   void      ReenterI (Thread * Self, ObjectWaiter * SelfNode) ;
   void      UnlinkAfterAcquire (Thread * Self, ObjectWaiter * SelfNode) ;
   int       TryLock (Thread * Self) ;
   int       NotRunnable (Thread * Self, Thread * Owner) ;
   int       TrySpin_Fixed (Thread * Self) ;
   int       TrySpin_VaryFrequency (Thread * Self) ;
   int       TrySpin_VaryDuration  (Thread * Self) ;
   void      ctAsserts () ;
   void      ExitEpilog (Thread * Self, ObjectWaiter * Wakee) ;
   bool      ExitSuspendEquivalent (JavaThread * Self) ;
  private:
   friend class ObjectSynchronizer;
   friend class ObjectWaiter;
   friend class VMStructs;
   // WARNING: this must be the very first word of ObjectMonitor
   // This means this class can't use any virtual member functions.
   // TODO-FIXME: assert that offsetof(_header) is 0 or get rid of the
   // implicit 0 offset in emitted code.
   volatile markOop   _header;       // displaced object header word - mark
   void*     volatile _object;       // backward object pointer - strong root
   double SharingPad [1] ;           // temp to reduce false sharing
   // All the following fields must be machine word aligned
   // The VM assumes write ordering wrt these fields, which can be
   // read from other threads.
  protected:                         // protected for jvmtiRawMonitor
   void *  volatile _owner;          // pointer to owning thread OR BasicLock
   volatile intptr_t  _recursions;   // recursion count, 0 for first entry
  private:
   int OwnerIsThread ;               // _owner is (Thread *) vs SP/BasicLock
   ObjectWaiter * volatile _cxq ;    // LL of recently-arrived threads blocked on entry.
                                     // The list is actually composed of WaitNodes, acting
                                     // as proxies for Threads.
  protected:
   ObjectWaiter * volatile _EntryList ;     // Threads blocked on entry or reentry.
  private:
   Thread * volatile _succ ;          // Heir presumptive thread - used for futile wakeup throttling
   Thread * volatile _Responsible ;
   int _PromptDrain ;                // rqst to drain cxq into EntryList ASAP
   volatile int _Spinner ;           // for exit->spinner handoff optimization
   volatile int _SpinFreq ;          // Spin 1-out-of-N attempts: success rate
   volatile int _SpinClock ;
   volatile int _SpinDuration ;
   volatile intptr_t _SpinState ;    // MCS/CLH list of spinners
   // TODO-FIXME: _count, _waiters and _recursions should be of
   // type int, or int32_t but not intptr_t.  There's no reason
   // to use 64-bit fields for these variables on a 64-bit JVM.
   volatile intptr_t  _count;        // reference count to prevent reclaimation/deflation
                                     // at stop-the-world time.  See deflate_idle_monitors().
                                     // _count is approximately |_WaitSet| + |_EntryList|
  protected:
   volatile intptr_t  _waiters;      // number of waiting threads
  private:
  protected:
   ObjectWaiter * volatile _WaitSet; // LL of threads wait()ing on the monitor
  private:
   volatile int _WaitSetLock;        // protects Wait Queue - simple spinlock
  public:
   int _QMix ;                       // Mixed prepend queue discipline
   ObjectMonitor * FreeNext ;        // Free list linkage
   intptr_t StatA, StatsB ;
  public:
   static void Initialize () ;
   static PerfCounter * _sync_ContendedLockAttempts ;
   static PerfCounter * _sync_FutileWakeups ;
   static PerfCounter * _sync_Parks ;
   static PerfCounter * _sync_EmptyNotifications ;
   static PerfCounter * _sync_Notifications ;
   static PerfCounter * _sync_SlowEnter ;
   static PerfCounter * _sync_SlowExit ;
   static PerfCounter * _sync_SlowNotify ;
   static PerfCounter * _sync_SlowNotifyAll ;
   static PerfCounter * _sync_FailedSpins ;
   static PerfCounter * _sync_SuccessfulSpins ;
   static PerfCounter * _sync_PrivateA ;
   static PerfCounter * _sync_PrivateB ;
   static PerfCounter * _sync_MonInCirculation ;
   static PerfCounter * _sync_MonScavenged ;
   static PerfCounter * _sync_Inflations ;
   static PerfCounter * _sync_Deflations ;
   static PerfLongVariable * _sync_MonExtant ;
  public:
   static int Knob_Verbose;
   static int Knob_SpinLimit;
 };
 #undef TEVENT
 #define TEVENT(nom) {if (SyncVerbose) FEVENT(nom); }
 #define FEVENT(nom) { static volatile int ctr = 0 ; int v = ++ctr ; if ((v & (v-1)) == 0) { ::printf (#nom " : %d \n", v); ::fflush(stdout); }}
 #undef  TEVENT
 #define TEVENT(nom) {;}
 #endif // SHARE_VM_RUNTIME_OBJECTMONITOR_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/runtime/objectMonitor.hpp@b5cb079ecaa4 (annotated)

src/share/vm/runtime/objectMonitor.hpp