1.1 --- a/src/share/vm/runtime/objectMonitor.hpp Mon Oct 18 09:33:24 2010 -0700
1.2 +++ b/src/share/vm/runtime/objectMonitor.hpp Fri Oct 22 15:59:34 2010 -0400
1.3 @@ -22,6 +22,32 @@
1.4 *
1.5 */
1.6
1.7 +
1.8 +// ObjectWaiter serves as a "proxy" or surrogate thread.
1.9 +// TODO-FIXME: Eliminate ObjectWaiter and use the thread-specific
1.10 +// ParkEvent instead. Beware, however, that the JVMTI code
1.11 +// knows about ObjectWaiters, so we'll have to reconcile that code.
1.12 +// See next_waiter(), first_waiter(), etc.
1.13 +
1.14 +class ObjectWaiter : public StackObj {
1.15 + public:
1.16 + enum TStates { TS_UNDEF, TS_READY, TS_RUN, TS_WAIT, TS_ENTER, TS_CXQ } ;
1.17 + enum Sorted { PREPEND, APPEND, SORTED } ;
1.18 + ObjectWaiter * volatile _next;
1.19 + ObjectWaiter * volatile _prev;
1.20 + Thread* _thread;
1.21 + ParkEvent * _event;
1.22 + volatile int _notified ;
1.23 + volatile TStates TState ;
1.24 + Sorted _Sorted ; // List placement disposition
1.25 + bool _active ; // Contention monitoring is enabled
1.26 + public:
1.27 + ObjectWaiter(Thread* thread);
1.28 +
1.29 + void wait_reenter_begin(ObjectMonitor *mon);
1.30 + void wait_reenter_end(ObjectMonitor *mon);
1.31 +};
1.32 +
1.33 // WARNING:
1.34 // This is a very sensitive and fragile class. DO NOT make any
1.35 // change unless you are fully aware of the underlying semantics.
1.36 @@ -38,8 +64,6 @@
1.37 // It is also used as RawMonitor by the JVMTI
1.38
1.39
1.40 -class ObjectWaiter;
1.41 -
1.42 class ObjectMonitor {
1.43 public:
1.44 enum {
1.45 @@ -74,13 +98,16 @@
1.46
1.47
1.48 public:
1.49 - ObjectMonitor();
1.50 - ~ObjectMonitor();
1.51 -
1.52 markOop header() const;
1.53 void set_header(markOop hdr);
1.54
1.55 - intptr_t is_busy() const;
1.56 + intptr_t is_busy() const {
1.57 + // TODO-FIXME: merge _count and _waiters.
1.58 + // TODO-FIXME: assert _owner == null implies _recursions = 0
1.59 + // TODO-FIXME: assert _WaitSet != null implies _count > 0
1.60 + return _count|_waiters|intptr_t(_owner)|intptr_t(_cxq)|intptr_t(_EntryList ) ;
1.61 + }
1.62 +
1.63 intptr_t is_entered(Thread* current) const;
1.64
1.65 void* owner() const;
1.66 @@ -91,13 +118,58 @@
1.67 intptr_t count() const;
1.68 void set_count(intptr_t count);
1.69 intptr_t contentions() const ;
1.70 + intptr_t recursions() const { return _recursions; }
1.71
1.72 // JVM/DI GetMonitorInfo() needs this
1.73 - Thread * thread_of_waiter (ObjectWaiter *) ;
1.74 - ObjectWaiter * first_waiter () ;
1.75 - ObjectWaiter * next_waiter(ObjectWaiter* o);
1.76 + ObjectWaiter* first_waiter() { return _WaitSet; }
1.77 + ObjectWaiter* next_waiter(ObjectWaiter* o) { return o->_next; }
1.78 + Thread* thread_of_waiter(ObjectWaiter* o) { return o->_thread; }
1.79
1.80 - intptr_t recursions() const { return _recursions; }
1.81 + // initialize the monitor, exception the semaphore, all other fields
1.82 + // are simple integers or pointers
1.83 + ObjectMonitor() {
1.84 + _header = NULL;
1.85 + _count = 0;
1.86 + _waiters = 0,
1.87 + _recursions = 0;
1.88 + _object = NULL;
1.89 + _owner = NULL;
1.90 + _WaitSet = NULL;
1.91 + _WaitSetLock = 0 ;
1.92 + _Responsible = NULL ;
1.93 + _succ = NULL ;
1.94 + _cxq = NULL ;
1.95 + FreeNext = NULL ;
1.96 + _EntryList = NULL ;
1.97 + _SpinFreq = 0 ;
1.98 + _SpinClock = 0 ;
1.99 + OwnerIsThread = 0 ;
1.100 + }
1.101 +
1.102 + ~ObjectMonitor() {
1.103 + // TODO: Add asserts ...
1.104 + // _cxq == 0 _succ == NULL _owner == NULL _waiters == 0
1.105 + // _count == 0 _EntryList == NULL etc
1.106 + }
1.107 +
1.108 +private:
1.109 + void Recycle () {
1.110 + // TODO: add stronger asserts ...
1.111 + // _cxq == 0 _succ == NULL _owner == NULL _waiters == 0
1.112 + // _count == 0 EntryList == NULL
1.113 + // _recursions == 0 _WaitSet == NULL
1.114 + // TODO: assert (is_busy()|_recursions) == 0
1.115 + _succ = NULL ;
1.116 + _EntryList = NULL ;
1.117 + _cxq = NULL ;
1.118 + _WaitSet = NULL ;
1.119 + _recursions = 0 ;
1.120 + _SpinFreq = 0 ;
1.121 + _SpinClock = 0 ;
1.122 + OwnerIsThread = 0 ;
1.123 + }
1.124 +
1.125 +public:
1.126
1.127 void* object() const;
1.128 void* object_addr();
1.129 @@ -122,22 +194,9 @@
1.130 intptr_t complete_exit(TRAPS);
1.131 void reenter(intptr_t recursions, TRAPS);
1.132
1.133 - int raw_enter(TRAPS);
1.134 - int raw_exit(TRAPS);
1.135 - int raw_wait(jlong millis, bool interruptable, TRAPS);
1.136 - int raw_notify(TRAPS);
1.137 - int raw_notifyAll(TRAPS);
1.138 -
1.139 private:
1.140 - // JVMTI support -- remove ASAP
1.141 - int SimpleEnter (Thread * Self) ;
1.142 - int SimpleExit (Thread * Self) ;
1.143 - int SimpleWait (Thread * Self, jlong millis) ;
1.144 - int SimpleNotify (Thread * Self, bool All) ;
1.145 -
1.146 - private:
1.147 - void Recycle () ;
1.148 void AddWaiter (ObjectWaiter * waiter) ;
1.149 + static void DeferredInitialize();
1.150
1.151 ObjectWaiter * DequeueWaiter () ;
1.152 void DequeueSpecificWaiter (ObjectWaiter * waiter) ;
1.153 @@ -172,13 +231,17 @@
1.154 // The VM assumes write ordering wrt these fields, which can be
1.155 // read from other threads.
1.156
1.157 + protected: // protected for jvmtiRawMonitor
1.158 void * volatile _owner; // pointer to owning thread OR BasicLock
1.159 volatile intptr_t _recursions; // recursion count, 0 for first entry
1.160 + private:
1.161 int OwnerIsThread ; // _owner is (Thread *) vs SP/BasicLock
1.162 ObjectWaiter * volatile _cxq ; // LL of recently-arrived threads blocked on entry.
1.163 // The list is actually composed of WaitNodes, acting
1.164 // as proxies for Threads.
1.165 + protected:
1.166 ObjectWaiter * volatile _EntryList ; // Threads blocked on entry or reentry.
1.167 + private:
1.168 Thread * volatile _succ ; // Heir presumptive thread - used for futile wakeup throttling
1.169 Thread * volatile _Responsible ;
1.170 int _PromptDrain ; // rqst to drain cxq into EntryList ASAP
1.171 @@ -196,8 +259,12 @@
1.172 volatile intptr_t _count; // reference count to prevent reclaimation/deflation
1.173 // at stop-the-world time. See deflate_idle_monitors().
1.174 // _count is approximately |_WaitSet| + |_EntryList|
1.175 + protected:
1.176 volatile intptr_t _waiters; // number of waiting threads
1.177 + private:
1.178 + protected:
1.179 ObjectWaiter * volatile _WaitSet; // LL of threads wait()ing on the monitor
1.180 + private:
1.181 volatile int _WaitSetLock; // protects Wait Queue - simple spinlock
1.182
1.183 public:
1.184 @@ -205,4 +272,37 @@
1.185 ObjectMonitor * FreeNext ; // Free list linkage
1.186 intptr_t StatA, StatsB ;
1.187
1.188 + public:
1.189 + static void Initialize () ;
1.190 + static PerfCounter * _sync_ContendedLockAttempts ;
1.191 + static PerfCounter * _sync_FutileWakeups ;
1.192 + static PerfCounter * _sync_Parks ;
1.193 + static PerfCounter * _sync_EmptyNotifications ;
1.194 + static PerfCounter * _sync_Notifications ;
1.195 + static PerfCounter * _sync_SlowEnter ;
1.196 + static PerfCounter * _sync_SlowExit ;
1.197 + static PerfCounter * _sync_SlowNotify ;
1.198 + static PerfCounter * _sync_SlowNotifyAll ;
1.199 + static PerfCounter * _sync_FailedSpins ;
1.200 + static PerfCounter * _sync_SuccessfulSpins ;
1.201 + static PerfCounter * _sync_PrivateA ;
1.202 + static PerfCounter * _sync_PrivateB ;
1.203 + static PerfCounter * _sync_MonInCirculation ;
1.204 + static PerfCounter * _sync_MonScavenged ;
1.205 + static PerfCounter * _sync_Inflations ;
1.206 + static PerfCounter * _sync_Deflations ;
1.207 + static PerfLongVariable * _sync_MonExtant ;
1.208 +
1.209 + public:
1.210 + static int Knob_Verbose;
1.211 + static int Knob_SpinLimit;
1.212 };
1.213 +
1.214 +#undef TEVENT
1.215 +#define TEVENT(nom) {if (SyncVerbose) FEVENT(nom); }
1.216 +
1.217 +#define FEVENT(nom) { static volatile int ctr = 0 ; int v = ++ctr ; if ((v & (v-1)) == 0) { ::printf (#nom " : %d \n", v); ::fflush(stdout); }}
1.218 +
1.219 +#undef TEVENT
1.220 +#define TEVENT(nom) {;}
1.221 +
