mirror of https://github.com/PCSX2/pcsx2.git
145 lines
4.6 KiB
C
145 lines
4.6 KiB
C
/*
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* -------------------------------------------------------------
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*
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* Module: sem_destroy.c
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*
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* Purpose:
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* Semaphores aren't actually part of the PThreads standard.
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* They are defined by the POSIX Standard:
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*
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* POSIX 1003.1b-1993 (POSIX.1b)
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*
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* -------------------------------------------------------------
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*
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* --------------------------------------------------------------------------
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*
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* Pthreads-win32 - POSIX Threads Library for Win32
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* Copyright(C) 1998 John E. Bossom
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* Copyright(C) 1999,2005 Pthreads-win32 contributors
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*
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* Contact Email: rpj@callisto.canberra.edu.au
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*
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* The current list of contributors is contained
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* in the file CONTRIBUTORS included with the source
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* code distribution. The list can also be seen at the
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* following World Wide Web location:
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* http://sources.redhat.com/pthreads-win32/contributors.html
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library in the file COPYING.LIB;
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* if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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*/
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#include "pthread.h"
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#include "semaphore.h"
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#include "implement.h"
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int
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sem_destroy (sem_t * sem)
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/*
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* ------------------------------------------------------
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* DOCPUBLIC
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* This function destroys an unnamed semaphore.
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*
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* PARAMETERS
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* sem
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* pointer to an instance of sem_t
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*
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* DESCRIPTION
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* This function destroys an unnamed semaphore.
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*
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* RESULTS
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* 0 successfully destroyed semaphore,
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* -1 failed, error in errno
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* ERRNO
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* EINVAL 'sem' is not a valid semaphore,
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* ENOSYS semaphores are not supported,
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* EBUSY threads (or processes) are currently
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* blocked on 'sem'
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*
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* ------------------------------------------------------
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*/
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{
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int result = 0;
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sem_t s = NULL;
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if (sem == NULL || *sem == NULL)
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{
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result = EINVAL;
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}
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else
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{
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s = *sem;
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if ((result = pthread_mutex_lock (&s->lock)) == 0)
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{
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if (s->value < 0)
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{
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(void) pthread_mutex_unlock (&s->lock);
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result = EBUSY;
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}
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else
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{
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/* There are no threads currently blocked on this semaphore. */
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if (!CloseHandle (s->sem))
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{
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(void) pthread_mutex_unlock (&s->lock);
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result = EINVAL;
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}
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else
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{
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/*
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* Invalidate the semaphore handle when we have the lock.
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* Other sema operations should test this after acquiring the lock
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* to check that the sema is still valid, i.e. before performing any
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* operations. This may only be necessary before the sema op routine
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* returns so that the routine can return EINVAL - e.g. if setting
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* s->value to SEM_VALUE_MAX below does force a fall-through.
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*/
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*sem = NULL;
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/* Prevent anyone else actually waiting on or posting this sema.
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*/
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s->value = SEM_VALUE_MAX;
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(void) pthread_mutex_unlock (&s->lock);
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do
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{
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/* Give other threads a chance to run and exit any sema op
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* routines. Due to the SEM_VALUE_MAX value, if sem_post or
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* sem_wait were blocked by us they should fall through.
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*/
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Sleep(0);
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}
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while (pthread_mutex_destroy (&s->lock) == EBUSY);
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}
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}
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}
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}
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if (result != 0)
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{
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errno = result;
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return -1;
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}
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free (s);
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return 0;
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} /* sem_destroy */
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