IPC messaging latency for OMAPL138 board

/*
 * Copyright (c) 2012-2013, Texas Instruments Incorporated
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/* =============================================================================
 *  @file   MessageQApp.c
 *
 *  @brief  Sample application for MessageQ module between MPU and Remote Proc
 *
 *  ============================================================================
 */

/* Standard headers */
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

/* IPC Headers */
#include <ti/ipc/Std.h>
#include <ti/ipc/Ipc.h>
#include <ti/ipc/MessageQ.h>

/* App defines:  Must match on remote proc side: */
#define HEAPID              0u
#define SLAVE_MESSAGEQNAME  "SLAVE"
#define MPU_MESSAGEQNAME    "HOST"

#define PROC_ID_DFLT        1     /* Host is zero, remote cores start at 1 */
#define NUM_LOOPS_DFLT   100

typedef struct SyncMsg {
    MessageQ_MsgHeader header;
    unsigned long numLoops;
    unsigned long print;
} SyncMsg ;

long diff(struct timespec start, struct timespec end)
{
    struct timespec temp;

    if ((end.tv_nsec - start.tv_nsec) < 0) {
        temp.tv_sec = end.tv_sec - start.tv_sec-1;
        temp.tv_nsec = 1000000000UL + end.tv_nsec - start.tv_nsec;
    } else {
        temp.tv_sec = end.tv_sec - start.tv_sec;
        temp.tv_nsec = end.tv_nsec - start.tv_nsec;
    }

    return (temp.tv_sec * 1000000UL + temp.tv_nsec / 1000);
}

long *round_trip_time;
Int MessageQApp_execute(UInt32 numLoops, UInt16 procId)
{
    Int32                    status = 0;
    MessageQ_Msg             msg = NULL;
    MessageQ_Params          msgParams;
    UInt16                   i;
    MessageQ_QueueId         queueId = MessageQ_INVALIDMESSAGEQ;
    MessageQ_Handle          msgqHandle;
    struct timespec          start, end;
    char                     remoteQueueName[64];
    long                     average_time = 0;
    float avg_one_trip_time, avg_round_trip_time;

    printf("Entered MessageQApp_execute\n");

    /* Create the local Message Queue for receiving. */
    MessageQ_Params_init(&msgParams);
    msgqHandle = MessageQ_create(MPU_MESSAGEQNAME, &msgParams);
    if (msgqHandle == NULL) {
        printf("Error in MessageQ_create\n");
        goto exit;
    }
    else {
        printf("Local MessageQId: 0x%x\n", MessageQ_getQueueId(msgqHandle));
    }

    sprintf(remoteQueueName, "%s_%s", SLAVE_MESSAGEQNAME,
             MultiProc_getName(procId));

    /* Poll until remote side has it's messageQ created before we send: */
    do {
        status = MessageQ_open(remoteQueueName, &queueId);
        sleep (1);
    } while (status == MessageQ_E_NOTFOUND);

    if (status < 0) {
        printf("Error in MessageQ_open [%d]\n", status);
        goto cleanup;
    }
    else {
        printf("Remote queueId  [0x%x]\n", queueId);
    }

    msg = MessageQ_alloc(HEAPID, sizeof(SyncMsg));
    if (msg == NULL) {
        printf("Error in MessageQ_alloc\n");
        MessageQ_close(&queueId);
        goto cleanup;
    }

    /* handshake with remote to set the number of loops */
    MessageQ_setReplyQueue(msgqHandle, msg);
    ((SyncMsg *)msg)->numLoops = numLoops;
    ((SyncMsg *)msg)->print = TRUE;
    MessageQ_put(queueId, msg);
    MessageQ_get(msgqHandle, &msg, MessageQ_FOREVER);

    printf("Exchanging %d messages with remote processor %s...\n",
           numLoops, MultiProc_getName(procId));

    round_trip_time = malloc(numLoops * sizeof(long));
    for (i = 0 ; i < numLoops; i++) {
        MessageQ_setMsgId(msg, i);

        /* Have the remote proc reply to this message queue */
        MessageQ_setReplyQueue(msgqHandle, msg);

        clock_gettime(CLOCK_REALTIME, &start);
        status = MessageQ_put(queueId, msg);
        if (status < 0) {
            printf("Error in MessageQ_put [%d]\n", status);
            break;
        }

        status = MessageQ_get(msgqHandle, &msg, MessageQ_FOREVER);
        clock_gettime(CLOCK_REALTIME, &end);
        if (status < 0) {
            printf("Error in MessageQ_get [%d]\n", status);
            break;
        }
        else {
          round_trip_time[i] = diff(start, end);
            printf("MessageQ_get #%d Msg = 0x%x\n %ld %ld %ld\n",
                i, (UInt)msg, end.tv_nsec, start.tv_nsec, round_trip_time[i]);

            /* Validate the returned message. */
            if ((msg != NULL) && (MessageQ_getMsgId (msg) != i)) {
                printf("Data integrity failure!\n"
                        "    Expected %d\n"
                        "    Received %d\n",
                        i, MessageQ_getMsgId(msg));
                break;
            }
        }

        printf("Exchanged %d messages with remote processor %s\n",
            (i+1), MultiProc_getName(procId));
    }

    if (status >= 0) {
       printf("Sample application successfully completed!\n");
    }

    for (i = 0; i < numLoops; i++) {
      average_time = average_time + round_trip_time[i];
    }

    avg_one_trip_time = (average_time / numLoops);
    avg_round_trip_time = (average_time / (numLoops * 2));

    printf("Average round trip time %fusec, Average one trip time %fusec\n",
        avg_one_trip_time, avg_round_trip_time);

    MessageQ_free(msg);
    MessageQ_close(&queueId);

cleanup:
    /* Clean-up */
    status = MessageQ_delete(&msgqHandle);
    if (status < 0) {
        printf("Error in MessageQ_delete [%d]\n", status);
    }

exit:
    printf("Leaving MessageQApp_execute\n\n");

    return (status);
}

int main (int argc, char ** argv)
{
    Int32 status = 0;
    UInt32 numLoops = NUM_LOOPS_DFLT;
    UInt16 procId = PROC_ID_DFLT;

    /* Parse Args: */
    switch (argc) {
        case 1:
           /* use defaults */
           break;
        case 2:
           numLoops   = atoi(argv[1]);
           break;
        case 3:
           numLoops   = atoi(argv[1]);
           procId     = atoi(argv[2]);
           break;
        default:
           printf("Usage: %s [<numLoops>] [<ProcId>]\n", argv[0]);
           printf("\tDefaults: numLoops: %d; ProcId: %d\n",
                   NUM_LOOPS_DFLT, PROC_ID_DFLT);
           exit(0);
    }

    status = Ipc_start();

    if (procId >= MultiProc_getNumProcessors()) {
        printf("ProcId must be less than %d\n", MultiProc_getNumProcessors());
        Ipc_stop();
        exit(0);
    }
    printf("Using numLoops: %d; procId : %d\n", numLoops, procId);

    if (status >= 0) {
        MessageQApp_execute(numLoops, procId);
        Ipc_stop();
    }
    else {
        printf("Ipc_start failed: status = %d\n", status);
    }

    return(0);
}