mirror of
https://github.com/azure-rtos/threadx
synced 2025-02-06 08:08:27 +08:00
114 lines
5.6 KiB
C
114 lines
5.6 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_wait 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 locks (takes) a semaphore. */
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/* */
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/* INPUT */
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/* */
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/* *sem Pointer to Semaphore */
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/* */
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/* OUTPUT */
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/* */
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/* OK If successful */
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/* ERROR If error occurs */
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/* */
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/* CALLS */
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/* */
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/* tx_thread_identify To check whether calling from a thread */
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/* tx_semaphore_get ThreadX Semaphore get */
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/* posix_internal_error Returns a generic error */
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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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INT sem_wait( sem_t * sem )
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{
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TX_SEMAPHORE * TheSem;
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/* Make sure we're calling this routine from a thread context. */
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if (! tx_thread_identify())
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{
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/* No wait when called from ISR. */
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posix_internal_error(242);
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/* Return Error. */
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return (ERROR);
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}
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/* get ThreadX semaphore. */
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TheSem = (TX_SEMAPHORE *)sem;
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/* Check for an invalid semaphore pointer. */
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if ((!TheSem) || (TheSem -> tx_semaphore_id != TX_SEMAPHORE_ID))
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{
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/* error in POSIX. */
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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 (EINVAL);
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}
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else
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{
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/* Takes the semaphore. */
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if(tx_semaphore_get(TheSem,TX_WAIT_FOREVER))
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{
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/* Return general error. */
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posix_internal_error(246);
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/* Return error. */
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return(ERROR);
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}
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return (OK);
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}
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}
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