d0addb52bd
In #10527 performance was measured and ResetEvent did take a lot of time in these measurements. The reset is only required once though, so use a more fine grained trigger condition.
211 lines
4.2 KiB
C
211 lines
4.2 KiB
C
/**
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* WinPR: Windows Portable Runtime
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* Countdown Event
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*
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* Copyright 2012 Marc-Andre Moreau <marcandre.moreau@gmail.com>
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <winpr/config.h>
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#include <winpr/assert.h>
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#include <winpr/crt.h>
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#include <winpr/collections.h>
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struct CountdownEvent
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{
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size_t count;
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CRITICAL_SECTION lock;
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HANDLE event;
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size_t initialCount;
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};
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/**
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* C equivalent of the C# CountdownEvent Class
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* http://msdn.microsoft.com/en-us/library/dd235708/
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*/
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/**
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* Properties
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*/
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/**
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* Gets the number of remaining signals required to set the event.
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*/
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size_t CountdownEvent_CurrentCount(wCountdownEvent* countdown)
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{
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WINPR_ASSERT(countdown);
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EnterCriticalSection(&countdown->lock);
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const size_t rc = countdown->count;
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LeaveCriticalSection(&countdown->lock);
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return rc;
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}
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/**
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* Gets the numbers of signals initially required to set the event.
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*/
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size_t CountdownEvent_InitialCount(wCountdownEvent* countdown)
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{
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WINPR_ASSERT(countdown);
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EnterCriticalSection(&countdown->lock);
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const size_t rc = countdown->initialCount;
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LeaveCriticalSection(&countdown->lock);
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return rc;
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}
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/**
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* Determines whether the event is set.
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*/
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BOOL CountdownEvent_IsSet(wCountdownEvent* countdown)
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{
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BOOL status = FALSE;
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WINPR_ASSERT(countdown);
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if (WaitForSingleObject(countdown->event, 0) == WAIT_OBJECT_0)
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status = TRUE;
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return status;
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}
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/**
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* Gets a WaitHandle that is used to wait for the event to be set.
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*/
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HANDLE CountdownEvent_WaitHandle(wCountdownEvent* countdown)
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{
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WINPR_ASSERT(countdown);
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return countdown->event;
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}
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/**
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* Methods
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*/
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/**
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* Increments the CountdownEvent's current count by a specified value.
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*/
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void CountdownEvent_AddCount(wCountdownEvent* countdown, size_t signalCount)
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{
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WINPR_ASSERT(countdown);
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EnterCriticalSection(&countdown->lock);
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const BOOL signalSet = countdown->count == 0;
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countdown->count += signalCount;
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if (signalSet)
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ResetEvent(countdown->event);
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LeaveCriticalSection(&countdown->lock);
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}
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/**
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* Registers multiple signals with the CountdownEvent, decrementing the value of CurrentCount by the
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* specified amount.
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*/
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BOOL CountdownEvent_Signal(wCountdownEvent* countdown, size_t signalCount)
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{
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BOOL status = FALSE;
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BOOL newStatus = FALSE;
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BOOL oldStatus = FALSE;
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WINPR_ASSERT(countdown);
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EnterCriticalSection(&countdown->lock);
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if (WaitForSingleObject(countdown->event, 0) == WAIT_OBJECT_0)
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oldStatus = TRUE;
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if (signalCount <= countdown->count)
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countdown->count -= signalCount;
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else
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countdown->count = 0;
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if (countdown->count == 0)
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newStatus = TRUE;
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if (newStatus && (!oldStatus))
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{
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SetEvent(countdown->event);
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status = TRUE;
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}
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LeaveCriticalSection(&countdown->lock);
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return status;
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}
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/**
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* Resets the InitialCount property to a specified value.
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*/
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void CountdownEvent_Reset(wCountdownEvent* countdown, size_t count)
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{
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WINPR_ASSERT(countdown);
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countdown->initialCount = count;
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}
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/**
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* Construction, Destruction
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*/
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wCountdownEvent* CountdownEvent_New(size_t initialCount)
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{
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wCountdownEvent* countdown = (wCountdownEvent*)calloc(1, sizeof(wCountdownEvent));
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if (!countdown)
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return NULL;
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countdown->count = initialCount;
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countdown->initialCount = initialCount;
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if (!InitializeCriticalSectionAndSpinCount(&countdown->lock, 4000))
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goto fail;
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countdown->event = CreateEvent(NULL, TRUE, FALSE, NULL);
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if (!countdown->event)
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goto fail;
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if (countdown->count == 0)
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{
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if (!SetEvent(countdown->event))
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goto fail;
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}
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return countdown;
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fail:
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WINPR_PRAGMA_DIAG_PUSH
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WINPR_PRAGMA_DIAG_IGNORED_MISMATCHED_DEALLOC
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CountdownEvent_Free(countdown);
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WINPR_PRAGMA_DIAG_POP
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return NULL;
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}
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void CountdownEvent_Free(wCountdownEvent* countdown)
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{
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if (!countdown)
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return;
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DeleteCriticalSection(&countdown->lock);
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CloseHandle(countdown->event);
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free(countdown);
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}
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