open_toontown_panda3d/panda/src/pipeline/conditionVarFullWin32Impl.I

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// Filename: conditionVarFullWin32Impl.I
// Created by: drose (28Aug06)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) Carnegie Mellon University. All rights reserved.
//
// All use of this software is subject to the terms of the revised BSD
// license. You should have received a copy of this license along
// with this source code in a file named "LICENSE."
//
////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////
// Function: ConditionVarFullWin32Impl::Constructor
// Access: Public
// Description:
////////////////////////////////////////////////////////////////////
INLINE ConditionVarFullWin32Impl::
ConditionVarFullWin32Impl(MutexWin32Impl &mutex) {
_external_mutex = &mutex._lock;
// Create an auto-reset event and a manual-reset event.
_event_signal = CreateEvent(NULL, false, false, NULL);
_event_broadcast = CreateEvent(NULL, true, false, NULL);
_waiters_count = 0;
}
////////////////////////////////////////////////////////////////////
// Function: ConditionVarFullWin32Impl::Destructor
// Access: Public
// Description:
////////////////////////////////////////////////////////////////////
INLINE ConditionVarFullWin32Impl::
~ConditionVarFullWin32Impl() {
CloseHandle(_event_signal);
CloseHandle(_event_broadcast);
}
////////////////////////////////////////////////////////////////////
// Function: ConditionVarFullWin32Impl::wait
// Access: Public
// Description:
////////////////////////////////////////////////////////////////////
INLINE void ConditionVarFullWin32Impl::
wait() {
AtomicAdjust::inc(_waiters_count);
// It's ok to release the external_mutex here since Win32
// manual-reset events maintain state when used with SetEvent().
// This avoids the "lost wakeup" bug...
LeaveCriticalSection(_external_mutex);
// Wait for either event to become signaled due to notify() being
// called or notify_all() being called.
int result = WaitForMultipleObjects(2, &_event_signal, FALSE, INFINITE);
bool nonzero = AtomicAdjust::dec(_waiters_count);
bool last_waiter = (result == WAIT_OBJECT_0 + 1 && !nonzero);
// Some thread called notify_all().
if (last_waiter) {
// We're the last waiter to be notified or to stop waiting, so
// reset the manual event.
ResetEvent(_event_broadcast);
}
// Reacquire the <external_mutex>.
EnterCriticalSection(_external_mutex);
}
////////////////////////////////////////////////////////////////////
// Function: ConditionVarFullWin32Impl::wait
// Access: Public
// Description:
////////////////////////////////////////////////////////////////////
INLINE void ConditionVarFullWin32Impl::
wait(double timeout) {
AtomicAdjust::inc(_waiters_count);
// It's ok to release the external_mutex here since Win32
// manual-reset events maintain state when used with SetEvent().
// This avoids the "lost wakeup" bug...
LeaveCriticalSection(_external_mutex);
// Wait for either event to become signaled due to notify() being
// called or notify_all() being called.
int result = WaitForMultipleObjects(2, &_event_signal, FALSE, (DWORD)(timeout * 1000.0));
bool nonzero = AtomicAdjust::dec(_waiters_count);
bool last_waiter = (result == WAIT_OBJECT_0 + 1 && !nonzero);
// Some thread called notify_all().
if (last_waiter) {
// We're the last waiter to be notified or to stop waiting, so
// reset the manual event.
ResetEvent(_event_broadcast);
}
// Reacquire the <external_mutex>.
EnterCriticalSection(_external_mutex);
}
////////////////////////////////////////////////////////////////////
// Function: ConditionVarFullWin32Impl::notify
// Access: Public
// Description:
////////////////////////////////////////////////////////////////////
INLINE void ConditionVarFullWin32Impl::
notify() {
bool have_waiters = AtomicAdjust::get(_waiters_count) > 0;
if (have_waiters) {
SetEvent(_event_signal);
}
}
////////////////////////////////////////////////////////////////////
// Function: ConditionVarFullWin32Impl::notify_all
// Access: Public
// Description:
////////////////////////////////////////////////////////////////////
INLINE void ConditionVarFullWin32Impl::
notify_all() {
bool have_waiters = AtomicAdjust::get(_waiters_count) > 0;
if (have_waiters) {
SetEvent(_event_broadcast);
}
}