kopia lustrzana https://github.com/espressif/esp-idf
74 wiersze
2.2 KiB
C
74 wiersze
2.2 KiB
C
![]() |
/*
|
||
|
* SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
|
||
|
*
|
||
|
* SPDX-License-Identifier: Apache-2.0
|
||
|
*/
|
||
|
|
||
|
#pragma once
|
||
|
|
||
|
#include <time.h>
|
||
|
|
||
|
#ifdef __cplusplus
|
||
|
extern "C" {
|
||
|
#endif
|
||
|
|
||
|
typedef unsigned int sem_t;
|
||
|
|
||
|
/**
|
||
|
* This is the maximum value to which any POSIX semaphore can count on ESP chips.
|
||
|
*/
|
||
|
#define SEM_VALUE_MAX 0x7FFF
|
||
|
|
||
|
/**
|
||
|
* This is a POSIX function, please refer to the POSIX specification for a detailed description.
|
||
|
*
|
||
|
* Must NOT be called if threads are still blocked on semaphore!
|
||
|
*/
|
||
|
int sem_destroy(sem_t *sem);
|
||
|
|
||
|
/**
|
||
|
* This is a POSIX function, please refer to the POSIX specification for a detailed description.
|
||
|
*
|
||
|
* Note that on ESP chips, pshared is ignored. Semaphores can always be shared between FreeRTOS tasks.
|
||
|
*/
|
||
|
int sem_init(sem_t *sem, int pshared, unsigned value);
|
||
|
|
||
|
/**
|
||
|
* This is a POSIX function, please refer to the POSIX specification for a detailed description.
|
||
|
*
|
||
|
* Note that, unlike specified in POSIX, this implementation returns -1 and sets errno to
|
||
|
* EAGAIN if the semaphore can not be unlocked (posted) due to its value being SEM_VALUE_MAX.
|
||
|
*/
|
||
|
int sem_post(sem_t *sem);
|
||
|
|
||
|
/**
|
||
|
* This is a POSIX function, please refer to the POSIX specification for a detailed description.
|
||
|
*
|
||
|
* Note the following three deviations/issues originating from the underlying FreeRTOS implementation:
|
||
|
* * The time value passed by abstime will be rounded up to the next FreeRTOS tick.
|
||
|
* * The actual timeout will happen after the tick the time was rounded to
|
||
|
* and before the following tick.
|
||
|
* * It is possible, though unlikely, that the task is preempted directly after the timeout calculation,
|
||
|
* delaying timeout of the following blocking operating system call by the duration of the preemption.
|
||
|
*/
|
||
|
int sem_timedwait(sem_t * restrict semaphore, const struct timespec *restrict abstime);
|
||
|
|
||
|
/**
|
||
|
* This is a POSIX function, please refer to the POSIX specification for a detailed description.
|
||
|
*/
|
||
|
int sem_trywait(sem_t *sem);
|
||
|
|
||
|
/**
|
||
|
* This is a POSIX function, please refer to the POSIX specification for a detailed description.
|
||
|
*/
|
||
|
int sem_wait(sem_t *sem);
|
||
|
|
||
|
/**
|
||
|
* This is a POSIX function, please refer to the POSIX specification for a detailed description.
|
||
|
*/
|
||
|
int sem_getvalue(sem_t *restrict sem, int *restrict sval);
|
||
|
|
||
|
#ifdef __cplusplus
|
||
|
}
|
||
|
#endif
|