src/hotspot/share/runtime/objectMonitor.cpp

rev 51882 : imported patch 8211176-eager-object-monitor-init

*** 108,118 ****
  static int Knob_Penalty             = 200;     // spin failure penalty
  static int Knob_Poverty             = 1000;
  static int Knob_FixedSpin           = 0;
  static int Knob_PreSpin             = 10;      // 20-100 likely better
  
! static volatile int InitDone        = 0;
  
  // -----------------------------------------------------------------------------
  // Theory of operations -- Monitors lists, thread residency, etc:
  //
  // * A thread acquires ownership of a monitor by successfully
--- 108,118 ----
  static int Knob_Penalty             = 200;     // spin failure penalty
  static int Knob_Poverty             = 1000;
  static int Knob_FixedSpin           = 0;
  static int Knob_PreSpin             = 10;      // 20-100 likely better
  
! DEBUG_ONLY(static volatile bool InitDone = false;)
  
  // -----------------------------------------------------------------------------
  // Theory of operations -- Monitors lists, thread residency, etc:
  //
  // * A thread acquires ownership of a monitor by successfully
*** 426,436 ****
      assert(_owner == Self, "invariant");
      assert(_Responsible != Self, "invariant");
      return;
    }
  
!   DeferredInitialize();
  
    // We try one round of spinning *before* enqueueing Self.
    //
    // If the _owner is ready but OFFPROC we could use a YieldTo()
    // operation to donate the remainder of this thread's quantum
--- 426,436 ----
      assert(_owner == Self, "invariant");
      assert(_Responsible != Self, "invariant");
      return;
    }
  
!   assert(InitDone, "Unexpectedly not initialized");
  
    // We try one round of spinning *before* enqueueing Self.
    //
    // If the _owner is ready but OFFPROC we could use a YieldTo()
    // operation to donate the remainder of this thread's quantum
*** 1100,1110 ****
  intptr_t ObjectMonitor::complete_exit(TRAPS) {
    Thread * const Self = THREAD;
    assert(Self->is_Java_thread(), "Must be Java thread!");
    JavaThread *jt = (JavaThread *)THREAD;
  
!   DeferredInitialize();
  
    if (THREAD != _owner) {
      if (THREAD->is_lock_owned ((address)_owner)) {
        assert(_recursions == 0, "internal state error");
        _owner = THREAD;   // Convert from basiclock addr to Thread addr
--- 1100,1110 ----
  intptr_t ObjectMonitor::complete_exit(TRAPS) {
    Thread * const Self = THREAD;
    assert(Self->is_Java_thread(), "Must be Java thread!");
    JavaThread *jt = (JavaThread *)THREAD;
  
!   assert(InitDone, "Unexpectedly not initialized");
  
    if (THREAD != _owner) {
      if (THREAD->is_lock_owned ((address)_owner)) {
        assert(_recursions == 0, "internal state error");
        _owner = THREAD;   // Convert from basiclock addr to Thread addr
*** 1184,1194 ****
  void ObjectMonitor::wait(jlong millis, bool interruptible, TRAPS) {
    Thread * const Self = THREAD;
    assert(Self->is_Java_thread(), "Must be Java thread!");
    JavaThread *jt = (JavaThread *)THREAD;
  
!   DeferredInitialize();
  
    // Throw IMSX or IEX.
    CHECK_OWNER();
  
    EventJavaMonitorWait event;
--- 1184,1194 ----
  void ObjectMonitor::wait(jlong millis, bool interruptible, TRAPS) {
    Thread * const Self = THREAD;
    assert(Self->is_Java_thread(), "Must be Java thread!");
    JavaThread *jt = (JavaThread *)THREAD;
  
!   assert(InitDone, "Unexpectedly not initialized");
  
    // Throw IMSX or IEX.
    CHECK_OWNER();
  
    EventJavaMonitorWait event;
*** 1885,1895 ****
  // One-shot global initialization for the sync subsystem.
  // We could also defer initialization and initialize on-demand
  // the first time we call inflate().  Initialization would
  // be protected - like so many things - by the MonitorCache_lock.
  
! void ObjectMonitor::Initialize() {
    static int InitializationCompleted = 0;
    assert(InitializationCompleted == 0, "invariant");
    InitializationCompleted = 1;
    if (UsePerfData) {
      EXCEPTION_MARK;
--- 1885,1895 ----
  // One-shot global initialization for the sync subsystem.
  // We could also defer initialization and initialize on-demand
  // the first time we call inflate().  Initialization would
  // be protected - like so many things - by the MonitorCache_lock.
  
! void ObjectMonitor::init_2() {
    static int InitializationCompleted = 0;
    assert(InitializationCompleted == 0, "invariant");
    InitializationCompleted = 1;
    if (UsePerfData) {
      EXCEPTION_MARK;
*** 1913,1938 ****
  #undef NEWPERFCOUNTER
  #undef NEWPERFVARIABLE
    }
  }
  
! void ObjectMonitor::DeferredInitialize() {
!   if (InitDone > 0) return;
!   if (Atomic::cmpxchg (-1, &InitDone, 0) != 0) {
!     while (InitDone != 1) /* empty */;
!     return;
!   }
! 
    // One-shot global initialization ...
    // The initialization is idempotent, so we don't need locks.
    // In the future consider doing this via os::init_2().
  
    if (!os::is_MP()) {
      Knob_SpinLimit = 0;
      Knob_PreSpin   = 0;
      Knob_FixedSpin = -1;
    }
  
!   OrderAccess::fence();
!   InitDone = 1;
  }
  
--- 1913,1931 ----
  #undef NEWPERFCOUNTER
  #undef NEWPERFVARIABLE
    }
  }
  
! void ObjectMonitor::init() {
    // One-shot global initialization ...
    // The initialization is idempotent, so we don't need locks.
    // In the future consider doing this via os::init_2().
  
    if (!os::is_MP()) {
      Knob_SpinLimit = 0;
      Knob_PreSpin   = 0;
      Knob_FixedSpin = -1;
    }
  
!   DEBUG_ONLY(InitDone = true;)
  }