a350286c7c
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2339 42af7a65-404d-4744-a932-0658087f49c3
127 lines
4.8 KiB
C
127 lines
4.8 KiB
C
/********************************************************************************
|
|
* sched/pthread_once.c
|
|
*
|
|
* Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved.
|
|
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
* 3. Neither the name NuttX nor the names of its contributors may be
|
|
* used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
|
|
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
|
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
|
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
********************************************************************************/
|
|
|
|
/********************************************************************************
|
|
* Included Files
|
|
********************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <stdbool.h>
|
|
#include <pthread.h>
|
|
#include <sched.h>
|
|
#include <errno.h>
|
|
#include <debug.h>
|
|
|
|
/********************************************************************************
|
|
* Pre-processor Definitions
|
|
********************************************************************************/
|
|
|
|
/********************************************************************************
|
|
* Private Type Declarations
|
|
********************************************************************************/
|
|
|
|
/********************************************************************************
|
|
* Global Variables
|
|
********************************************************************************/
|
|
|
|
/********************************************************************************
|
|
* Private Variables
|
|
********************************************************************************/
|
|
|
|
/********************************************************************************
|
|
* Private Function Prototypes
|
|
********************************************************************************/
|
|
|
|
/********************************************************************************
|
|
* Public Functions
|
|
********************************************************************************/
|
|
|
|
/********************************************************************************
|
|
* Function: pthread_once
|
|
*
|
|
* Description:
|
|
* The first call to pthread_once() by any thread with a given once_control,
|
|
* will call the init_routine with no arguments. Subsequent calls to
|
|
* pthread_once() with the same once_control will have no effect. On return
|
|
* from pthread_once(), init_routine will have completed.
|
|
*
|
|
* Parameters:
|
|
* once_control - Determines if init_routine should be called. once_control
|
|
* should be declared and intialized as follows:
|
|
*
|
|
* pthread_once_t once_control = PTHREAD_ONCE_INIT;
|
|
*
|
|
* PTHREAD_ONCE_INIT is defined in pthread.h
|
|
* init_routine - The initialization routine that will be called once.
|
|
*
|
|
* Return Value:
|
|
* 0 (OK) on success or EINVAL if either once_control or init_routine are invalid
|
|
*
|
|
* Assumptions:
|
|
*
|
|
********************************************************************************/
|
|
|
|
int pthread_once(FAR pthread_once_t *once_control, CODE void (*init_routine)(void))
|
|
{
|
|
/* Sanity checks */
|
|
|
|
if (once_control && init_routine)
|
|
{
|
|
/* Prohibit pre-emption while we test and set the once_control */
|
|
|
|
sched_lock();
|
|
if (!*once_control)
|
|
{
|
|
*once_control = true;
|
|
|
|
/* Call the init_routine with pre-emption enabled. */
|
|
|
|
sched_unlock();
|
|
init_routine();
|
|
return OK;
|
|
}
|
|
|
|
/* The init_routine has already been called. Restore pre-emption and return */
|
|
|
|
sched_unlock();
|
|
return OK;
|
|
}
|
|
|
|
/* One of the two arguments is NULL */
|
|
|
|
return EINVAL;
|
|
}
|