/**

 * WinPR: Windows Portable Runtime

 * Countdown Event

 *

 * Copyright 2012 Marc-Andre Moreau <marcandre.moreau@gmail.com>

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#ifdef HAVE_UNISTD_H

#include <unistd.h>

#endif

#include <winpr/crt.h>

#include <winpr/collections.h>

/**

 * C equivalent of the C# CountdownEvent Class

 * http://msdn.microsoft.com/en-us/library/dd235708/

 */

/**

 * Properties

 */

/**

 * Gets the number of remaining signals required to set the event.

 */

DWORD CountdownEvent_CurrentCount(wCountdownEvent* countdown)

{

	return countdown->count;

}

/**

 * Gets the numbers of signals initially required to set the event.

 */

DWORD CountdownEvent_InitialCount(wCountdownEvent* countdown)

{

	return countdown->initialCount;

}

/**

 * Determines whether the event is set.

 */

BOOL CountdownEvent_IsSet(wCountdownEvent* countdown)

{

	BOOL status = FALSE;

	if (WaitForSingleObject(countdown->event, 0) == WAIT_OBJECT_0)

		status = TRUE;

	return status;

}

/**

 * Gets a WaitHandle that is used to wait for the event to be set.

 */

HANDLE CountdownEvent_WaitHandle(wCountdownEvent* countdown)

{

	return countdown->event;

}

/**

 * Methods

 */

/**

 * Increments the CountdownEvent's current count by a specified value.

 */

void CountdownEvent_AddCount(wCountdownEvent* countdown, DWORD signalCount)

{

	EnterCriticalSection(&countdown->lock);

	countdown->count += signalCount;

	if (countdown->count > 0)

		ResetEvent(countdown->event);

	LeaveCriticalSection(&countdown->lock);

}

/**

 * Registers multiple signals with the CountdownEvent, decrementing the value of CurrentCount by the

 * specified amount.

 */

BOOL CountdownEvent_Signal(wCountdownEvent* countdown, DWORD signalCount)

{

	BOOL status;

	BOOL newStatus;

	BOOL oldStatus;

	status = newStatus = oldStatus = FALSE;

	EnterCriticalSection(&countdown->lock);

	if (WaitForSingleObject(countdown->event, 0) == WAIT_OBJECT_0)

		oldStatus = TRUE;

	if (signalCount <= countdown->count)

		countdown->count -= signalCount;

	else

		countdown->count = 0;

	if (countdown->count == 0)

		newStatus = TRUE;

	if (newStatus && (!oldStatus))

	{

		SetEvent(countdown->event);

		status = TRUE;

	}

	LeaveCriticalSection(&countdown->lock);

	return status;

}

/**

 * Resets the InitialCount property to a specified value.

 */

void CountdownEvent_Reset(wCountdownEvent* countdown, DWORD count)

{

	countdown->initialCount = count;

}

/**

 * Construction, Destruction

 */

wCountdownEvent* CountdownEvent_New(DWORD initialCount)

{

	wCountdownEvent* countdown = NULL;

	if (!(countdown = (wCountdownEvent*)calloc(1, sizeof(wCountdownEvent))))

		return NULL;

	countdown->count = initialCount;

	countdown->initialCount = initialCount;

	if (!InitializeCriticalSectionAndSpinCount(&countdown->lock, 4000))

		goto fail_critical_section;

	if (!(countdown->event = CreateEvent(NULL, TRUE, FALSE, NULL)))

		goto fail_create_event;

	if (countdown->count == 0)

		if (!SetEvent(countdown->event))

			goto fail_set_event;

	return countdown;

fail_set_event:

	CloseHandle(countdown->event);

fail_create_event:

	DeleteCriticalSection(&countdown->lock);

fail_critical_section:

	free(countdown);

	return NULL;

}

void CountdownEvent_Free(wCountdownEvent* countdown)

{

	if (!countdown)

		return;

	DeleteCriticalSection(&countdown->lock);

	CloseHandle(countdown->event);

	free(countdown);

}