Thread safety

With default configuration, library is not thread safe. This means whenever it is used with operating system, user must resolve it with care.

Library has locking mechanism support for thread safety, which needs to be enabled.

Tip

To enable thread-safety support, parameter OW_CFG_OS must be set to 1. Please check OW Configuration for more information about other options.

After thread-safety features has been enabled, it is necessary to implement 4 low-level system functions.

Tip

System function template example is available in onewire_uart/src/system/ folder.

Example code for CMSIS-OS V2

Note

Check System functions section for function description

System functions for CMSIS-OS based operating system
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/**
 * \file            ow_sys_cmsis_os.c
 * \brief           System functions for CMSIS-OS based operating system
 */

/*
 * Copyright (c) 2020 Tilen MAJERLE
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * This file is part of OneWire-UART library.
 *
 * Author:          Tilen MAJERLE <[email protected]>
 * Version:         v2.0.0
 */
#include "ow/ow.h"

#if OW_CFG_OS && !__DOXYGEN__

#include "cmsis_os.h"

uint8_t
ow_sys_mutex_create(OW_CFG_OS_MUTEX_HANDLE* mutex, void* arg) {
    const osMutexAttr_t attr = {
        .attr_bits = osMutexRecursive
    };

    *mutex = osMutexNew(&attr);                 /* Create new mutex */
    OW_UNUSED(arg);
    return 1;
}

uint8_t
ow_sys_mutex_delete(OW_CFG_OS_MUTEX_HANDLE* mutex, void* arg) {
    OW_UNUSED(arg);
    osMutexDelete(*mutex);                      /* Delete mutex */
    return 1;
}

uint8_t
ow_sys_mutex_wait(OW_CFG_OS_MUTEX_HANDLE* mutex, void* arg) {
    if (osMutexAcquire(*mutex, osWaitForever) != osOK) {
        return 0;
    }
    OW_UNUSED(arg);
    return 1;
}

uint8_t
ow_sys_mutex_release(OW_CFG_OS_MUTEX_HANDLE* mutex, void* arg) {
    if (osMutexRelease(*mutex) != osOK) {
        return 0;
    }
    OW_UNUSED(arg);
    return 1;
}

#endif /* OW_CFG_OS && !__DOXYGEN__ */