/*
 $License:
    Copyright (C) 2012 InvenSense Corporation, All Rights Reserved.
 $
 */

/*******************************************************************************
 *
 * $Id: mlos_linux.c 5629 2011-06-11 03:13:08Z mcaramello $
 *
 ******************************************************************************/

/**
 *  @defgroup MLOS
 *  @brief OS Interface.
 *
 *  @{
 *      @file mlos.c
 *      @brief OS Interface.
 */

/* ------------- */
/* - Includes. - */
/* ------------- */

#include <sys/time.h>
#include <unistd.h>
#include <pthread.h>
#include <stdlib.h>
#include <errno.h>

#include "stdint_invensense.h"
#include "mlos.h"


/* -------------- */
/* - Functions. - */
/* -------------- */

/**
 *  @brief  Allocate space
 *  @param  num_bytes  number of bytes
 *  @return pointer to allocated space
 */
void *inv_malloc(unsigned int num_bytes)
{
    // Allocate space.
    void *alloc_ptr = malloc(num_bytes);
    return alloc_ptr;
}


/**
 *  @brief  Free allocated space
 *  @param  ptr pointer to space to deallocate
 *  @return error code.
 */
inv_error_t inv_free(void *ptr)
{
    if (ptr)
        free(ptr);
    return INV_SUCCESS;
}


/**
 *  @brief  Mutex create function
 *  @param  mutex   pointer to mutex handle
 *  @return error code.
 */
inv_error_t inv_create_mutex(HANDLE *mutex)
{
    int res;
    pthread_mutex_t *pm = malloc(sizeof(pthread_mutex_t));
    if(pm == NULL) 
        return INV_ERROR;

    res = pthread_mutex_init(pm, NULL);
    if(res == -1) {
        free(pm);
        return INV_ERROR_OS_CREATE_FAILED;
    }

    *mutex = (HANDLE)pm;

    return INV_SUCCESS;
}


/**
 *  @brief  Mutex lock function
 *  @param  mutex   Mutex handle
 *  @return error code.
 */
inv_error_t inv_lock_mutex(HANDLE mutex)
{
    int res;
    pthread_mutex_t *pm = (pthread_mutex_t *)mutex;

    res = pthread_mutex_lock(pm);
    if(res == -1)
        return INV_ERROR_OS_LOCK_FAILED;

    return INV_SUCCESS;
}


/**
 *  @brief  Mutex unlock function
 *  @param  mutex   mutex handle
 *  @return error code.
 */
inv_error_t inv_unlock_mutex(HANDLE mutex)
{
    int res;
    pthread_mutex_t *pm = (pthread_mutex_t *)mutex;

    res = pthread_mutex_unlock(pm);
    if(res == -1) 
        return INV_ERROR_OS_LOCK_FAILED;

    return INV_SUCCESS;
}


/**
 *  @brief  open file
 *  @param  filename    name of the file to open.
 *  @return error code.
 */
FILE *inv_fopen(char *filename)
{
    FILE *fp = fopen(filename, "r");
    return fp;
}


/**
 *  @brief  close the file.
 *  @param  fp  handle to file to close.
 *  @return error code.
 */
void inv_fclose(FILE *fp)
{
    fclose(fp);
}

/**
 *  @brief  Close Handle
 *  @param  handle  handle to the resource.
 *  @return Zero if success, an error code otherwise.
 */
inv_error_t inv_destroy_mutex(HANDLE handle)
{
    int error;
    pthread_mutex_t *pm = (pthread_mutex_t *)handle;
    error = pthread_mutex_destroy(pm);
    if (error)
        return errno;
    free((void*) handle);

    return INV_SUCCESS;}


/**
 *  @brief  Sleep function.
 */
void inv_sleep(int m_secs)
{
    usleep(m_secs * 1000);
}


/**
 *  @brief  get system's internal tick count.
 *          Used for time reference.
 *  @return current tick count.
 */
unsigned long inv_get_tick_count()
{
    struct timeval tv;

    if (gettimeofday(&tv, NULL) != 0)
        return 0;

    return (long)((tv.tv_sec * 1000000LL + tv.tv_usec) / 1000LL);
}

/** @} */