forked from Imagelibrary/rtems
51f823c932
Enable pthread_once() for all configurations. The pthread_once() function is one means to initialize POSIX keys. Another use case is the C++ support.
74 lines
1.7 KiB
C
74 lines
1.7 KiB
C
/**
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* @file
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*
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* @brief Call to function by Thread will call init_routine with no Arguments
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* @ingroup POSIXAPI
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*/
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/*
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* 16.1.8 Dynamic Package Initialization, P1003.1c/Draft 10, p. 154
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*
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* COPYRIGHT (c) 1989-1999.
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* On-Line Applications Research Corporation (OAR).
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*
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* The license and distribution terms for this file may be
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* found in the file LICENSE in this distribution or at
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* http://www.rtems.com/license/LICENSE.
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*/
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#if HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <pthread.h>
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#include <errno.h>
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#include <rtems/score/apimutex.h>
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#define PTHREAD_ONCE_INIT_NOT_RUN 0
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#define PTHREAD_ONCE_INIT_RUNNING 1
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#define PTHREAD_ONCE_INIT_COMPLETE 2
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int pthread_once(
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pthread_once_t *once_control,
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void (*init_routine)(void)
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)
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{
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int r = 0;
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if ( !once_control || !init_routine )
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return EINVAL;
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if ( once_control->is_initialized != 1 )
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return EINVAL;
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if ( once_control->init_executed != PTHREAD_ONCE_INIT_COMPLETE ) {
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_Once_Lock();
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/*
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* Getting to here means the once_control is locked so we have:
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* 1. The init has not run and the state is PTHREAD_ONCE_INIT_NOT_RUN.
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* 2. The init has finished and the state is PTHREAD_ONCE_INIT_RUN.
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* 3. The init is being run by this thread and the state
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* PTHREAD_ONCE_INIT_RUNNING so we are nesting. This is an error.
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*/
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switch ( once_control->init_executed ) {
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case PTHREAD_ONCE_INIT_NOT_RUN:
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once_control->init_executed = PTHREAD_ONCE_INIT_RUNNING;
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(*init_routine)();
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once_control->init_executed = PTHREAD_ONCE_INIT_COMPLETE;
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break;
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case PTHREAD_ONCE_INIT_RUNNING:
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r = EINVAL;
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break;
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default:
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break;
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}
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_Once_Unlock();
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}
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return r;
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}
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