vm_mutex_linux32.c

这是在PCA下的基于IPP库示例代码例子,在网上下了IPP的库之后,设置相关参数就可以编译该代码.

/*
//
//                  INTEL CORPORATION PROPRIETARY INFORMATION
//     This software is supplied under the terms of a license agreement or
//     nondisclosure agreement with Intel Corporation and may not be copied
//     or disclosed except in accordance with the terms of that agreement.
//       Copyright(c) 2003-2005 Intel Corporation. All Rights Reserved.
//
*/

#ifdef LINUX32

#include <pthread.h>
#include <sys/time.h>
#include <errno.h>
#include "vm_mutex.h"

/* Invalidate a mutex */
void vm_mutex_set_invalid(vm_mutex *mutex)
{
    /* check error(s) */
    if (NULL == mutex)
        return;

    mutex->is_valid = 0;

} /* void vm_mutex_set_invalid(vm_mutex *mutex) */

/* Verify if a mutex is valid */
int vm_mutex_is_valid(vm_mutex *mutex)
{
    /* check error(s) */
    if (NULL == mutex)
        return 0;

    return mutex->is_valid;

} /* int vm_mutex_is_valid(vm_mutex *mutex) */

/* Init a mutex, return 1 if success */
vm_status vm_mutex_init(vm_mutex *mutex)
{
    vm_status umc_res;
    pthread_mutexattr_t mutex_attr;

    /* check error(s) */
    if (NULL == mutex)
        return VM_NULL_PTR;

    vm_mutex_destroy(mutex);
    pthread_mutexattr_init(&mutex_attr);
    pthread_mutexattr_settype(&mutex_attr, PTHREAD_MUTEX_ERRORCHECK_NP);
    mutex->is_valid = !pthread_mutex_init(&mutex->handle, &mutex_attr);
    umc_res = mutex->is_valid ? VM_OK : VM_OPERATION_FAILED;
    pthread_mutexattr_destroy(&mutex_attr);
    return umc_res;

} /* vm_status vm_mutex_init(vm_mutex *mutex) */

/* Lock the mutex with blocking. */
vm_status vm_mutex_lock(vm_mutex *mutex)
{
    vm_status umc_res = VM_NOT_INITIALIZED;

    /* check error(s) */
    if (NULL == mutex)
        return VM_NULL_PTR;

    if (mutex->is_valid)
    {
        if (0 == pthread_mutex_lock(&mutex->handle))
            umc_res = VM_OK;
        else
            umc_res = VM_OPERATION_FAILED;
    }

    return umc_res;

} /* vm_status vm_mutex_lock(vm_mutex *mutex) */

/* Unlock the mutex. */
vm_status vm_mutex_unlock(vm_mutex *mutex)
{
    vm_status umc_res = VM_NOT_INITIALIZED;

    /* check error(s) */
    if (NULL == mutex)
        return VM_NULL_PTR;

    if (mutex->is_valid)
    {
        if (0 == pthread_mutex_unlock(&mutex->handle))
            umc_res = VM_OK;
        else
            umc_res = VM_OPERATION_FAILED;
    }

    return umc_res;

} /* vm_status vm_mutex_unlock(vm_mutex *mutex) */

/* Lock the mutex without blocking, return 1 if success */
vm_status vm_mutex_try_lock(vm_mutex *mutex)
{
    vm_status umc_res = VM_NOT_INITIALIZED;

    /* check error(s) */
    if (NULL == mutex)
        return VM_NULL_PTR;

    if (mutex->is_valid)
    {
        int i_res = pthread_mutex_trylock(&mutex->handle);
        switch (i_res)
        {
        case 0:
            umc_res = VM_OK;
            break;

        case EBUSY:
            umc_res = VM_TIMEOUT;
            break;

        default:
            umc_res = VM_OPERATION_FAILED;
            break;
        }
    }

    return umc_res;

} /* vm_status vm_mutex_try_lock(vm_mutex *mutex) */

/* Destroy the mutex */
void vm_mutex_destroy(vm_mutex *mutex)
{
    /* check error(s) */
    if (NULL == mutex)
        return;

    if (mutex->is_valid)
    {
        pthread_mutex_destroy(&mutex->handle);
        mutex->is_valid = 0;
    }

} /* void vm_mutex_destroy(vm_mutex *mutex) */

#endif /* LINUX32 */