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Diffstat (limited to 'nuttx/include/semaphore.h')
-rw-r--r-- | nuttx/include/semaphore.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/nuttx/include/semaphore.h b/nuttx/include/semaphore.h new file mode 100644 index 000000000..85214b9c2 --- /dev/null +++ b/nuttx/include/semaphore.h @@ -0,0 +1,132 @@ +/**************************************************************************** + * 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 */ |