/* Copyright (c) 2009 The Khronos Group Inc.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and/or associated documentation files (the

 * "Materials"), to deal in the Materials without restriction, including

 * without limitation the rights to use, copy, modify, merge, publish,

 * distribute, sublicense, and/or sell copies of the Materials, and to

 * permit persons to whom the Materials are 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 Materials.

 *

 * THE MATERIALS ARE 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

 * MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.

 */

#ifdef __cplusplus

extern "C" {

#endif

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <sys/select.h>

#include <sys/time.h>

#include <sys/types.h>

#include <unistd.h>

#include "owfmessagequeue.h"

#include "owfmutex.h"

#include "owfsemaphore.h"

#include "owftypes.h"

#include "owfmemory.h"

#include "owfdebug.h"

#define LOCK_QUEUE(x)       OWF_Mutex_Lock(&(x->mutex))

#define UNLOCK_QUEUE(x)     OWF_Mutex_Unlock(&(x->mutex))

#define WAIT_TIL_THE_END_OF_TIME    -1

OWF_API_CALL void

OWF_MessageQueue_Destroy(OWF_MESSAGE_QUEUE* queue)

{

    if (!queue) {

        return;

    }

    close(queue->read);

    close(queue->write);

}

OWF_API_CALL OWFint

OWF_MessageQueue_Init(OWF_MESSAGE_QUEUE* queue)

{

    OWFint                     err; 

    int                        handles[2];

    OWF_ASSERT(queue);

    queue->read = queue->write = -1;

    err = pipe(handles);

    if (err) {

        return err;

    }

    queue->read     = handles[0];

    queue->write    = handles[1];

    return 0;

}

OWF_API_CALL void

OWF_Message_Send(OWF_MESSAGE_QUEUE* queue,

                 OWFuint msg,

                 void* data)

{

    OWF_MESSAGE             m;

    OWF_ASSERT(queue);

    m.id = msg;

    m.data = data;

    write(queue->write, &m, sizeof(OWF_MESSAGE));

}

static OWFint

OWF_Message_DoFetch(OWF_MESSAGE_QUEUE* queue,

                    OWF_MESSAGE* msg,

                    OWFint timeout)

{

    /*

    MUST BE CALLED FROM MUTEX

    */

    OWF_ASSERT(queue);

    OWF_ASSERT(msg);

    if (timeout > -1)

    {

        OWFint                  r = 0;

        fd_set                  s;

        struct timeval          to;

        to.tv_sec = 0;

        to.tv_usec = (suseconds_t) timeout;

        FD_ZERO(&s);

        FD_SET(queue->read, &s);

        r = select(FD_SETSIZE, &s, NULL, NULL, &to);

        if (r <  1)

        {

            return -1;

        }

    }

    read(queue->read, msg, sizeof(OWF_MESSAGE));

    return 0;

}

OWF_API_CALL OWFint

OWF_Message_Wait(OWF_MESSAGE_QUEUE* queue,

                 OWF_MESSAGE* msg,

                 OWFint timeout)

{

    OWF_ASSERT(queue);

    OWF_ASSERT(msg);

    return OWF_Message_DoFetch(queue, msg, timeout);

}

#ifdef __cplusplus

}

#endif