131 lines
6.0 KiB
C
131 lines
6.0 KiB
C
/**************************************************************************/
|
|
/* */
|
|
/* Copyright (c) Microsoft Corporation. All rights reserved. */
|
|
/* */
|
|
/* This software is licensed under the Microsoft Software License */
|
|
/* Terms for Microsoft Azure RTOS. Full text of the license can be */
|
|
/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
|
|
/* and in the root directory of this software. */
|
|
/* */
|
|
/**************************************************************************/
|
|
|
|
|
|
/**************************************************************************/
|
|
/**************************************************************************/
|
|
/** */
|
|
/** POSIX wrapper for THREADX */
|
|
/** */
|
|
/** */
|
|
/** */
|
|
/**************************************************************************/
|
|
/**************************************************************************/
|
|
|
|
/* Include necessary system files. */
|
|
|
|
#include "tx_api.h" /* Threadx API */
|
|
#include "pthread.h" /* Posix API */
|
|
#include "px_int.h" /* Posix helper functions */
|
|
|
|
|
|
/**************************************************************************/
|
|
/* */
|
|
/* FUNCTION RELEASE */
|
|
/* */
|
|
/* sem_trywait PORTABLE C */
|
|
/* 6.1.7 */
|
|
/* AUTHOR */
|
|
/* */
|
|
/* William E. Lamie, Microsoft Corporation */
|
|
/* */
|
|
/* DESCRIPTION */
|
|
/* */
|
|
/* This routine locks(takes) a semaphore if the semaphore is not */
|
|
/* currently locked. */
|
|
/* */
|
|
/* INPUT */
|
|
/* */
|
|
/* *sem Pointer to Semaphore */
|
|
/* */
|
|
/* OUTPUT */
|
|
/* */
|
|
/* OK If successful */
|
|
/* ERROR If error occurs */
|
|
/* */
|
|
/* CALLS */
|
|
/* */
|
|
/* posix_internal_error Returns generic error */
|
|
/* tx_semaphore_get ThreadX Semaphore get */
|
|
/* tx_thread_identify Returns currently running thread */
|
|
/* */
|
|
/* CALLED BY */
|
|
/* */
|
|
/* Application Code */
|
|
/* */
|
|
/* RELEASE HISTORY */
|
|
/* */
|
|
/* DATE NAME DESCRIPTION */
|
|
/* */
|
|
/* 06-02-2021 William E. Lamie Initial Version 6.1.7 */
|
|
/* */
|
|
/**************************************************************************/
|
|
INT sem_trywait(sem_t * sem)
|
|
{
|
|
|
|
TX_SEMAPHORE * TheSem;
|
|
INT retval;
|
|
INT pxerror;
|
|
|
|
/* Make sure we're calling this routine from a thread context. */
|
|
if (!tx_thread_identify() )
|
|
{
|
|
/* No error in POSIX. */
|
|
posix_internal_error(242);
|
|
|
|
/* Return error. */
|
|
return (ERROR);
|
|
}
|
|
|
|
/* Get ThreadX semaphore. */
|
|
TheSem = (TX_SEMAPHORE *)sem;
|
|
|
|
/* Check for an invalid semaphore pointer. */
|
|
if ((!TheSem) || (TheSem -> tx_semaphore_id != TX_SEMAPHORE_ID))
|
|
{
|
|
/* error in POSIX. */
|
|
posix_errno = EINVAL;
|
|
posix_set_pthread_errno(EINVAL);
|
|
return (EINVAL);
|
|
}
|
|
else
|
|
retval = tx_semaphore_get(TheSem,TX_NO_WAIT);
|
|
|
|
switch(retval)
|
|
{
|
|
|
|
case TX_SUCCESS :
|
|
|
|
sem->refCnt -= 1;
|
|
pxerror = OK;
|
|
break;
|
|
|
|
case TX_NO_INSTANCE:
|
|
|
|
posix_errno = EAGAIN;
|
|
posix_set_pthread_errno(EAGAIN);
|
|
pxerror = ERROR;
|
|
break;
|
|
|
|
case TX_DELETED :
|
|
case TX_WAIT_ABORTED :
|
|
case TX_SEMAPHORE_ERROR :
|
|
case TX_WAIT_ERROR :
|
|
|
|
/* No error in POSIX, give default. */
|
|
posix_errno = EINVAL;
|
|
posix_set_pthread_errno(EINVAL);
|
|
pxerror = ERROR;
|
|
break;
|
|
}
|
|
return(pxerror);
|
|
}
|