FreeRTOS-RISCV/FreeRTOSv10.2.1/FreeRTOS-Plus/Source/Reliance-Edge/os/freertos/services/osmutex.c

135 lines
3.6 KiB
C

/* ----> DO NOT REMOVE THE FOLLOWING NOTICE <----
Copyright (c) 2014-2015 Datalight, Inc.
All Rights Reserved Worldwide.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; use version 2 of the License.
This program is distributed in the hope that it will be useful,
but "AS-IS," WITHOUT ANY WARRANTY; without even the implied warranty
of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/* Businesses and individuals that for commercial or other reasons cannot
comply with the terms of the GPLv2 license may obtain a commercial license
before incorporating Reliance Edge into proprietary software for
distribution in any form. Visit http://www.datalight.com/reliance-edge for
more information.
*/
/** @file
@brief Implements a synchronization object to provide mutual exclusion.
*/
#include <FreeRTOS.h>
#include <semphr.h>
#include <redfs.h>
#include <redosdeviations.h>
#if REDCONF_TASK_COUNT > 1U
static SemaphoreHandle_t xMutex;
#if defined(configSUPPORT_STATIC_ALLOCATION) && (configSUPPORT_STATIC_ALLOCATION == 1)
static StaticSemaphore_t xMutexBuffer;
#endif
/** @brief Initialize the mutex.
After initialization, the mutex is in the released state.
The behavior of calling this function when the mutex is still initialized
is undefined.
@return A negated ::REDSTATUS code indicating the operation result.
@retval 0 Operation was successful.
*/
REDSTATUS RedOsMutexInit(void)
{
REDSTATUS ret = 0;
#if defined(configSUPPORT_STATIC_ALLOCATION) && (configSUPPORT_STATIC_ALLOCATION == 1)
xMutex = xSemaphoreCreateMutexStatic(&xMutexBuffer);
if(xMutex == NULL)
{
/* The only error case for xSemaphoreCreateMutexStatic is that the mutex
buffer parameter is NULL, which is not the case.
*/
REDERROR();
ret = -RED_EINVAL;
}
#else
xMutex = xSemaphoreCreateMutex();
if(xMutex == NULL)
{
ret = -RED_ENOMEM;
}
#endif
return ret;
}
/** @brief Uninitialize the mutex.
The behavior of calling this function when the mutex is not initialized is
undefined; likewise, the behavior of uninitializing the mutex when it is
in the acquired state is undefined.
@return A negated ::REDSTATUS code indicating the operation result.
@retval 0 Operation was successful.
*/
REDSTATUS RedOsMutexUninit(void)
{
vSemaphoreDelete(xMutex);
xMutex = NULL;
return 0;
}
/** @brief Acquire the mutex.
The behavior of calling this function when the mutex is not initialized is
undefined; likewise, the behavior of recursively acquiring the mutex is
undefined.
*/
void RedOsMutexAcquire(void)
{
while(xSemaphoreTake(xMutex, portMAX_DELAY) != pdTRUE)
{
}
}
/** @brief Release the mutex.
The behavior is undefined in the following cases:
- Releasing the mutex when the mutex is not initialized.
- Releasing the mutex when it is not in the acquired state.
- Releasing the mutex from a task or thread other than the one which
acquired the mutex.
*/
void RedOsMutexRelease(void)
{
BaseType_t xSuccess;
xSuccess = xSemaphoreGive(xMutex);
REDASSERT(xSuccess == pdTRUE);
IGNORE_ERRORS(xSuccess);
}
#endif