/*
 * Copyright (C) by Argonne National Laboratory
 *     See COPYRIGHT in top-level directory
 */

#include "mpl.h"

MPL_SUPPRESS_OSX_HAS_NO_SYMBOLS_WARNING;

#if MPL_TIMER_KIND == MPL_TIMER_KIND__LINUX86_CYCLE

#include <sys/time.h>

static double seconds_per_tick = 0.0;
static int is_initialized = 0;

int MPL_wtick(double *wtick)
{
    *wtick = seconds_per_tick;

    return MPL_SUCCESS;
}

int MPL_wtime_init(void)
{
    MPL_time_t t1, t2;
    struct timeval tv1, tv2;
    double td1, td2;

    if (is_initialized)
        goto fn_exit;

    gettimeofday(&tv1, NULL);
    MPL_wtime(&t1);
    usleep(250000);
    gettimeofday(&tv2, NULL);
    MPL_wtime(&t2);

    td1 = tv1.tv_sec + tv1.tv_usec / 1000000.0;
    td2 = tv2.tv_sec + tv2.tv_usec / 1000000.0;

    seconds_per_tick = (td2 - td1) / (double) (t2 - t1);

    is_initialized = 1;

  fn_exit:
    return MPL_SUCCESS;
}

/* Time stamps created by a macro */
int MPL_wtime_diff(MPL_time_t * t1, MPL_time_t * t2, double *diff)
{
    *diff = (double) (*t2 - *t1) * seconds_per_tick;

    return MPL_SUCCESS;
}

int MPL_wtime_touint(MPL_time_t * t, unsigned int *val)
{
    *val = (unsigned int) (*t & 0xffffffffUL);

    return MPL_SUCCESS;
}

int MPL_wtime_todouble(MPL_time_t * t, double *val)
{
    /* This returns the number of cycles as the "time".  This isn't correct
     * for implementing MPI_Wtime, but it does allow us to insert cycle
     * counters into test programs */
    *val = (double) *t * seconds_per_tick;

    return MPL_SUCCESS;
}

int MPL_wtime_acc(MPL_time_t * t1, MPL_time_t * t2, MPL_time_t * t3)
{
    *t3 += (*t2 - *t1);

    return MPL_SUCCESS;
}

#endif
