zephyr/include/microkernel/mutex.h

110 lines
2.7 KiB
C

/*
* Copyright (c) 1997-2015 Wind River Systems, Inc.
*
* 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.
*/
/**
* @file
* @brief Microkernel mutex header file
*/
/**
* @brief Microkernel Mutexes
* @defgroup microkernel_mutex Microkernel Mutexes
* @ingroup microkernel_services
* @{
*/
#ifndef MUTEX_H
#define MUTEX_H
#ifdef __cplusplus
extern "C" {
#endif
#include <microkernel/base_api.h>
extern void _task_mutex_unlock(kmutex_t mutex);
/*
* Initializer for mutexes
*/
#define __MUTEX_DEFAULT \
{ \
.owner = ANYTASK, \
.current_owner_priority = 64, \
.original_owner_priority = 64, \
.level = 0, \
.waiters = NULL, \
.count = 0, \
.num_conflicts = 0, \
}
/**
* @brief Lock mutex.
*
* This routine locks mutex @a mutex. When the mutex is locked by another task,
* the routine will either wait until it becomes available, or until a specified
* time limit is reached.
*
* A task is permitted to lock a mutex it has already locked; in such a case,
* this routine immediately succeeds.
*
* @param mutex Mutex name.
* @param timeout Determine the action to take when the mutex is already locked.
* For TICKS_NONE, return immediately.
* For TICKS_UNLIMITED, wait as long as necessary.
* Otherwise, wait up to the specified number of ticks before timing out.
*
* @retval RC_OK Successfully locked mutex.
* @retval RC_TIME Timed out while waiting for mutex.
* @retval RC_FAIL Failed to immediately lock mutex when
* @a timeout = TICKS_NONE.
* @sa TICKS_NONE, TICKS_UNLIMITED
*/
extern int task_mutex_lock(kmutex_t mutex, int32_t timeout);
/**
* @brief Unlock mutex.
*
* This routine unlocks mutex @a m. The mutex must already be locked by the
* requesting task.
*
* The mutex cannot be claimed by another task until it has been unlocked by
* the requesting task as many times as it was locked by that task.
*
* @param m Mutex name.
*
* @return N/A
*/
#define task_mutex_unlock(m) _task_mutex_unlock(m)
/**
* @brief Define a private mutex.
*
* @param name Mutex name.
*/
#define DEFINE_MUTEX(name) \
struct _k_mutex_struct _k_mutex_obj_##name = __MUTEX_DEFAULT; \
const kmutex_t name = (kmutex_t)&_k_mutex_obj_##name;
/**
* @}
*/
#ifdef __cplusplus
}
#endif
#endif /* MUTEX_H */