168 lines
4.1 KiB
C
168 lines
4.1 KiB
C
/*
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* pthread_cond_init.c
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*
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* Description:
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* This translation unit implements condition variables and their primitives.
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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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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
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*/
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#include "pthread.h"
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#include "implement.h"
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int
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pthread_cond_init (pthread_cond_t * cond, const pthread_condattr_t * attr)
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/*
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* ------------------------------------------------------
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* DOCPUBLIC
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* This function initializes a condition variable.
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*
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* PARAMETERS
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* cond
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* pointer to an instance of pthread_cond_t
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*
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* attr
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* specifies optional creation attributes.
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*
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*
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* DESCRIPTION
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* This function initializes a condition variable.
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*
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* RESULTS
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* 0 successfully created condition variable,
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* EINVAL 'attr' is invalid,
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* EAGAIN insufficient resources (other than
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* memory,
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* ENOMEM insufficient memory,
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* EBUSY 'cond' is already initialized,
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*
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* ------------------------------------------------------
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*/
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{
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int result;
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pthread_cond_t cv = NULL;
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if (cond == NULL)
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{
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return EINVAL;
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}
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if ((attr != NULL && *attr != NULL) &&
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((*attr)->pshared == PTHREAD_PROCESS_SHARED))
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{
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/*
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* Creating condition variable that can be shared between
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* processes.
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*/
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result = ENOSYS;
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goto DONE;
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}
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cv = (pthread_cond_t) calloc (1, sizeof (*cv));
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if (cv == NULL)
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{
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result = ENOMEM;
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goto DONE;
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}
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cv->nWaitersBlocked = 0;
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cv->nWaitersToUnblock = 0;
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cv->nWaitersGone = 0;
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if (sem_init (&(cv->semBlockLock), 0, 1) != 0)
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{
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result = errno;
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goto FAIL0;
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}
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if (sem_init (&(cv->semBlockQueue), 0, 0) != 0)
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{
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result = errno;
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goto FAIL1;
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}
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if ((result = pthread_mutex_init (&(cv->mtxUnblockLock), 0)) != 0)
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{
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goto FAIL2;
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}
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result = 0;
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goto DONE;
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/*
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* -------------
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* Failed...
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* -------------
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*/
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FAIL2:
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(void) sem_destroy (&(cv->semBlockQueue));
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FAIL1:
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(void) sem_destroy (&(cv->semBlockLock));
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FAIL0:
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(void) free (cv);
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cv = NULL;
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DONE:
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if (0 == result)
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{
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ptw32_mcs_local_node_t node;
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ptw32_mcs_lock_acquire(&ptw32_cond_list_lock, &node);
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cv->next = NULL;
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cv->prev = ptw32_cond_list_tail;
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if (ptw32_cond_list_tail != NULL)
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{
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ptw32_cond_list_tail->next = cv;
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}
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ptw32_cond_list_tail = cv;
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if (ptw32_cond_list_head == NULL)
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{
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ptw32_cond_list_head = cv;
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}
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ptw32_mcs_lock_release(&node);
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}
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*cond = cv;
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return result;
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} /* pthread_cond_init */
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