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2018-06-08 14:10:49 +08:00

119 lines
3.3 KiB
C

// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef _ESPOS_SEMAPHORE_H_
#define _ESPOS_SEMAPHORE_H_
#include "espos_types.h"
#include "espos_errno.h"
#include "espos_time.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief create a semaphore
*
* @param sem semaphore handle point
* @param max_count semaphore maximum count
* @param init_count semaphore initialized count
*
* @return the result
* 0 : successful
* -ENOMEM : no enough memory
* -EINVAL : input parameter error
*
* @note if low-level module is YunOS, "max_count" does not work, and the reachable count is "0xFFFFFFFF"
*/
esp_err_t espos_sem_create(espos_sem_t *sem, espos_sem_count_t max_count, espos_sem_count_t init_count);
/**
* @brief set a semaphore name
*
* @param semaphore semaphore handle
* @param name semaphore's name
*
* @return the result
* 0 : successful
* -EINVAL : input parameter error
*/
esp_err_t espos_sem_set_name(espos_sem_t sem, const char *name);
/**
* @brief take semaphore
*
* @param sem semaphore handle
* @param wait_ticks sleep for system ticks if the semaphore is empty. Otherwise if semaphore is given,
* oldest blocked task will wake up.
* maximum time is "ESPOS_MAX_DELAY", no time is "ESPOS_NO_DELAY"
*
* @return the result
* 0 : successful
* -EINVAL : input parameter error
* -ETIMEDOUT : timeout and not take semaphore
*
* @note you can transform the millisecond to ticks by "espos_ms_to_ticks"
*/
esp_err_t espos_sem_take(espos_sem_t sem, espos_tick_t wait_ticks);
/**
* @brief try to take semaphore
*
* @param s semaphore handle
*
* @return the result
* 0 : successful
* -EINVAL : input parameter error
* -ETIMEDOUT : not take semaphore
*
* @note you can transform the millisecond to ticks by "espos_ms_to_ticks"
*/
#define espos_sem_trytake(s) espos_sem_take(s, ESPOS_NO_DELAY)
/**
* @brief give up semaphore
*
* @param sem semaphore handle
* @param wait_ticks no meaning
*
* @return the result
* 0 : successful
* -EINVAL : input parameter error
* -EAGAIN : the maximum count is reached
*
* @note you can transform the millisecond to ticks by "espos_ms_to_ticks"
*/
esp_err_t espos_sem_give(espos_sem_t sem);
/**
* @brief delete the semaphore
*
* @param sem semaphore handle
*
* @return the result
* 0 : successful
* -EINTR : you do this at interrupt state, and it is not supported
* -EINVAL : input parameter error
*
* @note if low-level module is YunOS, this function will awake all task blocked here
*/
esp_err_t espos_sem_del(espos_sem_t sem);
#ifdef __cplusplus
}
#endif
#endif /* _ESPOS_SEMAPHORE_H_ */