forked from Archive/PX4-Autopilot
133 lines
4.7 KiB
C
133 lines
4.7 KiB
C
/****************************************************************************
|
|
* include/semaphore.h
|
|
*
|
|
* Copyright (C) 2007-2009, 2012 Gregory Nutt. All rights reserved.
|
|
* Author: Gregory Nutt <gnutt@nuttx.org>
|
|
*
|
|
* 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.
|
|
*
|
|
****************************************************************************/
|
|
|
|
#ifndef __INCLUDE_SEMAPHORE_H
|
|
#define __INCLUDE_SEMAPHORE_H
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <stdint.h>
|
|
#include <limits.h>
|
|
|
|
#ifdef __cplusplus
|
|
#define EXTERN extern "C"
|
|
extern "C" {
|
|
#else
|
|
#define EXTERN extern
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Type Declarations
|
|
****************************************************************************/
|
|
|
|
/* This structure contains the holder of a semaphore */
|
|
|
|
#ifdef CONFIG_PRIORITY_INHERITANCE
|
|
struct semholder_s
|
|
{
|
|
#if CONFIG_SEM_PREALLOCHOLDERS > 0
|
|
struct semholder_s *flink; /* Implements singly linked list */
|
|
#endif
|
|
void *holder; /* Holder TCB (actual type is _TCB) */
|
|
int16_t counts; /* Number of counts owned by this holder */
|
|
};
|
|
|
|
#if CONFIG_SEM_PREALLOCHOLDERS > 0
|
|
# define SEMHOLDER_INITIALIZER {NULL, NULL, 0}
|
|
#else
|
|
# define SEMHOLDER_INITIALIZER {NULL, 0}
|
|
#endif
|
|
#endif /* CONFIG_PRIORITY_INHERITANCE */
|
|
|
|
/* This is the generic semaphore structure. */
|
|
|
|
struct sem_s
|
|
{
|
|
int16_t semcount; /* >0 -> Num counts available */
|
|
/* <0 -> Num tasks waiting for semaphore */
|
|
#ifdef CONFIG_PRIORITY_INHERITANCE
|
|
struct semholder_s hlist; /* List of holders of semaphore counts */
|
|
#endif
|
|
};
|
|
typedef struct sem_s sem_t;
|
|
|
|
/* Initializers */
|
|
|
|
#ifdef CONFIG_PRIORITY_INHERITANCE
|
|
# define SEM_INITIALIZER(c) {(c), SEMHOLDER_INITIALIZER}
|
|
#else
|
|
# define SEM_INITIALIZER(c) {(c)}
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Public Variables
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Function Prototypes
|
|
****************************************************************************/
|
|
/* Forward references needed by some prototypes */
|
|
|
|
struct timespec; /* Defined in time.h */
|
|
|
|
/* Counting Semaphore Interfaces (based on POSIX APIs) */
|
|
|
|
EXTERN int sem_init(FAR sem_t *sem, int pshared, unsigned int value);
|
|
EXTERN int sem_destroy(FAR sem_t *sem);
|
|
EXTERN FAR sem_t *sem_open(FAR const char *name, int oflag, ...);
|
|
EXTERN int sem_close(FAR sem_t *sem);
|
|
EXTERN int sem_unlink(FAR const char *name);
|
|
EXTERN int sem_wait(FAR sem_t *sem);
|
|
EXTERN int sem_timedwait(FAR sem_t *sem,
|
|
FAR const struct timespec *abstime);
|
|
EXTERN int sem_trywait(FAR sem_t *sem);
|
|
EXTERN int sem_post(FAR sem_t *sem);
|
|
EXTERN int sem_getvalue(FAR sem_t *sem, FAR int *sval);
|
|
|
|
#undef EXTERN
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* __INCLUDE_SEMAPHORE_H */
|