FreeRDP/winpr/libwinpr/utils/collections/CountdownEvent.c

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/**
* 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);
}
/**
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* 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;
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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);
}