mbed-os/rtos/Mutex.cpp

/* mbed Microcontroller Library
 * Copyright (c) 2006-2012 ARM Limited
 *
 * 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.
 */
#include "rtos/Mutex.h"
#include "rtos/Kernel.h"

#include <string.h>
#include "mbed_error.h"
#include "mbed_assert.h"

namespace rtos {

Mutex::Mutex(): _count(0)
{
    constructor();
}

Mutex::Mutex(const char *name)
{
    constructor(name);
}

void Mutex::constructor(const char *name)
{
    memset(&_obj_mem, 0, sizeof(_obj_mem));
    osMutexAttr_t attr =
    { 0 };
    attr.name = name ? name : "aplication_unnamed_mutex";
    attr.cb_mem = &_obj_mem;
    attr.cb_size = sizeof(_obj_mem);
    attr.attr_bits = osMutexRecursive | osMutexPrioInherit | osMutexRobust;
    _id = osMutexNew(&attr);
    MBED_ASSERT(_id);
}

osStatus Mutex::lock(void)
{
    osStatus status = osMutexAcquire(_id, osWaitForever);
    if (osOK == status) {
        _count++;
    }

    if (status != osOK) {
        MBED_ERROR1(MBED_MAKE_ERROR(MBED_MODULE_KERNEL, MBED_ERROR_CODE_MUTEX_LOCK_FAILED), "Mutex lock failed", status);
    }

    return osOK;
}

osStatus Mutex::lock(uint32_t millisec)
{
    osStatus status = osMutexAcquire(_id, millisec);
    if (osOK == status) {
        _count++;
    }

    bool success = (status == osOK ||
                    (status == osErrorResource && millisec == 0) ||
                    (status == osErrorTimeout && millisec != osWaitForever));

    if (!success) {
        MBED_ERROR1(MBED_MAKE_ERROR(MBED_MODULE_KERNEL, MBED_ERROR_CODE_MUTEX_LOCK_FAILED), "Mutex lock failed", status);
    }

    return status;
}

bool Mutex::trylock()
{
    return trylock_for(0);
}

bool Mutex::trylock_for(uint32_t millisec)
{
    osStatus status = osMutexAcquire(_id, millisec);
    if (status == osOK) {
        return true;
    }

    bool success = (status == osOK ||
                    (status == osErrorResource && millisec == 0) ||
                    (status == osErrorTimeout && millisec != osWaitForever));

    if (!success) {
        MBED_ERROR1(MBED_MAKE_ERROR(MBED_MODULE_KERNEL, MBED_ERROR_CODE_MUTEX_LOCK_FAILED), "Mutex lock failed", status);
    }

    return false;
}

bool Mutex::trylock_until(uint64_t millisec)
{
    uint64_t now = Kernel::get_ms_count();

    if (now >= millisec) {
        return trylock();
    } else if (millisec - now >= osWaitForever) {
        // API permits early return
        return trylock_for(osWaitForever - 1);
    } else {
        return trylock_for(millisec - now);
    }
}

osStatus Mutex::unlock()
{
    _count--;

    osStatus status = osMutexRelease(_id);

    if (status != osOK) {
        MBED_ERROR1(MBED_MAKE_ERROR(MBED_MODULE_KERNEL, MBED_ERROR_CODE_MUTEX_UNLOCK_FAILED), "Mutex unlock failed", status);
    }

    return osOK;
}

osThreadId Mutex::get_owner()
{
    return osMutexGetOwner(_id);
}

Mutex::~Mutex()
{
    osMutexDelete(_id);
}

}