mirror of
https://github.com/eclipse-threadx/threadx.git
synced 2025-11-16 04:24:48 +00:00
257 lines
9.8 KiB
C
257 lines
9.8 KiB
C
/**************************************************************************/
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/* */
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/* Copyright (c) Microsoft Corporation. All rights reserved. */
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/* */
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/* This software is licensed under the Microsoft Software License */
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/* Terms for Microsoft Azure RTOS. Full text of the license can be */
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/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
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/* and in the root directory of this software. */
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/* */
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/**************************************************************************/
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/**************************************************************************/
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/**************************************************************************/
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/** */
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/** POSIX wrapper for THREADX */
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/** */
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/** */
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/** */
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/**************************************************************************/
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/**************************************************************************/
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/* Include necessary system files. */
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#include "tx_api.h" /* Threadx API */
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#include "pthread.h" /* Posix API */
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#include "px_int.h" /* Posix helper functions */
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/**************************************************************************/
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/* */
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/* FUNCTION RELEASE */
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/* */
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/* sem_open PORTABLE C */
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/* 6.1.7 */
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/* AUTHOR */
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/* */
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/* William E. Lamie, Microsoft Corporation */
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/* */
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/* DESCRIPTION */
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/* */
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/* This function creates/initialize a semaphore. */
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/* */
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/* INPUT */
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/* */
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/* name Semaphore name */
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/* oflags Flags */
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/* mode Optional parameter */
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/* value Optional parameter */
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/* */
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/* OUTPUT */
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/* */
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/* sem Semaphore descriptor */
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/* */
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/* CALLS */
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/* */
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/* posix_in_thread_context Make sure caller is thread */
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/* posix_find_sem Finds the required semaphore */
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/* posix_get_new_sem Get new semaphore block */
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/* posix_internal_error Internal posix error */
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/* tx_semaphore_create ThreadX semaphore create */
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/* posix_set_sem_name Sets name for semaphore */
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/* */
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/* CALLED BY */
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/* */
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/* Application Code */
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/* */
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/* RELEASE HISTORY */
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/* */
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/* DATE NAME DESCRIPTION */
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/* */
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/* 06-02-2021 William E. Lamie Initial Version 6.1.7 */
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/* */
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/**************************************************************************/
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sem_t * sem_open(const CHAR * name, ULONG oflag, ...)
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{
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TX_INTERRUPT_SAVE_AREA
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TX_SEMAPHORE *TheSem;
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sem_t *semid;
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ULONG retval;
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ULONG len;
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sem_t *posix_sem;
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va_list vl;
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UINT value;
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mode_t mode;
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/* Make sure we're calling this routine from a thread context. */
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if (!posix_in_thread_context())
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{
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/* return POSIX error. */
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posix_internal_error(444);
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/* return error. */
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return (( sem_t * )SEM_FAILED);
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}
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/* Find length of the name. The actual length is not known yet. */
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len = strlen(name);
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if(len > SEM_NAME_MAX)
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{
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/* Set appropriate errno. */
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posix_errno = ENAMETOOLONG;
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posix_set_pthread_errno(ENAMETOOLONG);
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/* Return ERROR. */
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return (( sem_t * ) SEM_FAILED);
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}
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/* Check if semaphore exists. */
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if(semid= posix_find_sem( name))
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{
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if(semid->unlink_flag ==TX_TRUE )
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{
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/* Return error. */
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posix_errno = EINVAL;
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posix_set_pthread_errno(EINVAL);
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return(( sem_t * )SEM_FAILED);
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}
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}
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/* Semaphore not found. */
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if(!(semid))
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{
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/* Check if flag set is O_EXCL. */
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if( oflag == O_EXCL )
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{
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/* Set error for sem does not exist and O_CREAT not set. */
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posix_errno = ENOENT;
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posix_set_pthread_errno(ENOENT);
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/* Return the SEM_FAILED error. */
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return(( sem_t * )SEM_FAILED);
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}
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if( (oflag == O_CREAT) || ( (oflag & (O_CREAT|O_EXCL )) == (O_CREAT|O_EXCL) ) )
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{
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/* Get the variable arguments pointers. */
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va_start( vl, oflag );
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mode = va_arg( vl, mode_t);
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mode = mode; /* just to keep compiler happy */
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value = va_arg( vl, ULONG);
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if(value > SEM_VALUE_MAX)
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{
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/* Semaphore value large. */
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posix_errno = EINVAL;
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posix_set_pthread_errno(EINVAL);
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/* Return ERROR */
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return (( sem_t * )SEM_FAILED);
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}
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/* Disable interrupts. */
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TX_DISABLE
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/* Get a new semaphore from the POSIX semaphore pool. */
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TheSem = posix_get_new_sem();
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/* Make sure we actually got a semaphore. */
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if (!TheSem)
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{
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/* Semaphore cannot be initialized due to resource constraint. */
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posix_errno = ENOSPC;
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posix_set_pthread_errno(ENOSPC);
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/* Restore interrupts. */
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TX_RESTORE
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/* return appropriate error code. */
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return(( sem_t * )SEM_FAILED);
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}
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/* Set the semaphore name. */
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posix_set_sem_name((sem_t *)TheSem, ( CHAR * ) name);
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/* Now actually create the ThreadX semaphore. */
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posix_sem = (struct POSIX_SEMAPHORE_STRUCT *)TheSem;
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retval = tx_semaphore_create(TheSem, ( CHAR * ) posix_sem->sem_name , value);
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/* Make sure it worked. */
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if (retval)
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{
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/* Return generic error. */
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posix_internal_error(100);
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/* Restore interrupts. */
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TX_RESTORE
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/* Return appropriate error code. */
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return(( sem_t * )SEM_FAILED);
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}
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/* Add the calling thread to the thread list. */
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posix_sem -> count += 1;
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/* Set initial count */
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posix_sem->refCnt = value;
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/* Give the caller the semaphore ID. */
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semid = (sem_t * )TheSem;
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/* Restore interrupts. */
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TX_RESTORE
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/* All done. */
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return(semid);
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}
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}
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/* Semaphore found. */
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if(semid)
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{
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/* Check if flags are O_CREAT|O_EXCL. */
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if( (oflag == O_EXCL) || (oflag & (O_CREAT|O_EXCL )) == (O_CREAT|O_EXCL) )
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{
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/* Set appropriate errno. */
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posix_errno = EEXIST;
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posix_set_pthread_errno(EEXIST);
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/* Return ERROR. */
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return (( sem_t * ) SEM_FAILED);
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}
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/* Check if flag is only O_CREAT. */
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if( (oflag == O_CREAT) || (oflag==0))
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{
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/* Disable interrupts. */
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TX_DISABLE
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/* Add the calling thread to the thread list. */
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semid -> count++;
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/* Restore interrupts. */
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TX_RESTORE
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/* Return semaphore. */
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return (( sem_t * ) semid);
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}
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}
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/* Semaphore value large. */
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posix_errno = EINVAL;
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posix_set_pthread_errno(EINVAL);
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/* Return ERROR. */
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return (( sem_t * ) SEM_FAILED);
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}
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