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104 lines
2.4 KiB
C
104 lines
2.4 KiB
C
/*
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* PROJECT: ReactOS Sound System "MME Buddy" Library
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* LICENSE: GPL - See COPYING in the top level directory
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* FILE: lib/sound/mmebuddy/reentrancy.c
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*
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* PURPOSE: Provides entry-point mutex guards.
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*
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* PROGRAMMERS: Andrew Greenwood (silverblade@reactos.org)
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*/
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#include "precomp.h"
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HANDLE EntrypointMutexes[SOUND_DEVICE_TYPES];
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/*
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Creates a set of mutexes which are used for the purpose of guarding the
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device-type specific module entry-points. If any of these fail creation,
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all of them will be destroyed and the failure reported.
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*/
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MMRESULT
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InitEntrypointMutexes()
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{
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UCHAR i;
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MMRESULT Result = MMSYSERR_NOERROR;
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/* Blank all entries ni the table first */
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for ( i = 0; i < SOUND_DEVICE_TYPES; ++ i )
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{
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EntrypointMutexes[i] = NULL;
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}
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/* Now create the mutexes */
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for ( i = 0; i < SOUND_DEVICE_TYPES; ++ i )
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{
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EntrypointMutexes[i] = CreateMutex(NULL, FALSE, NULL);
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if ( ! EntrypointMutexes[i] )
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{
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Result = Win32ErrorToMmResult(GetLastError());
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/* Clean up any mutexes we successfully created */
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CleanupEntrypointMutexes();
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break;
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}
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}
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return Result;
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}
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/*
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Cleans up any of the entry-point guard mutexes. This will only close the
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handles of mutexes which have been created, making it safe for use as a
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cleanup routine even within the InitEntrypointMutexes routine above.
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*/
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VOID
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CleanupEntrypointMutexes()
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{
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UCHAR i;
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/* Only clean up a mutex if it actually exists */
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for ( i = 0; i < SOUND_DEVICE_TYPES; ++ i )
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{
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if ( EntrypointMutexes[i] )
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{
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CloseHandle(EntrypointMutexes[i]);
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EntrypointMutexes[i] = NULL;
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}
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}
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}
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/*
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Grabs an entry-point mutex.
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*/
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VOID
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AcquireEntrypointMutex(
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IN MMDEVICE_TYPE DeviceType)
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{
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UCHAR i;
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SND_ASSERT( IS_VALID_SOUND_DEVICE_TYPE(DeviceType) );
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i = SOUND_DEVICE_TYPE_TO_INDEX(DeviceType);
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SND_ASSERT( EntrypointMutexes[i] );
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WaitForSingleObject(EntrypointMutexes[i], INFINITE);
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}
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/*
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Releases an entry-point mutex.
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*/
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VOID
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ReleaseEntrypointMutex(
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IN MMDEVICE_TYPE DeviceType)
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{
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UCHAR i;
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SND_ASSERT( IS_VALID_SOUND_DEVICE_TYPE(DeviceType) );
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i = SOUND_DEVICE_TYPE_TO_INDEX(DeviceType);
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SND_ASSERT( EntrypointMutexes[i] );
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ReleaseMutex(EntrypointMutexes[i]);
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}
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