timer_overflow.c

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/*
 * File:    timer_overflow.c
 * Author:  Kevin London
 *      london@cs.utk.edu
 * Mods:    <your name here>
 *      <your email address>
 */
 
/* This file looks for possible timer overflows. */
 
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
 
#include "papi.h"
#include "papi_test.h"
 
#define TIMER_THRESHOLD 100
 
int
main( int argc, char **argv )
{
    int sleep_time = TIMER_THRESHOLD;
    int retval, i;
    long long timer;
 
    if ( argc > 1 ) {
        if ( !strcmp( argv[1], "TESTS_QUIET" ) )
            tests_quiet( argc, argv );
        else {
            sleep_time = atoi( argv[1] );
            if ( sleep_time <= 0 )
                sleep_time = TIMER_THRESHOLD;
        }
    }
 
    if ( TESTS_QUIET ) {
        /* Skip the test in TESTS_QUIET so that the main script doesn't
         * run this as it takes a long time to check for overflow
         */
        printf( "%-40s SKIPPED\nLine # %d\n", __FILE__, __LINE__ );
        printf( "timer_overflow takes a long time to run, run separately.\n" );
        exit( 0 );
    }
 
    printf( "This test will take about: %f minutes.\n",
            ( float ) ( 20 * ( sleep_time / 60.0 ) ) );
    if ( ( retval =
           PAPI_library_init( PAPI_VER_CURRENT ) ) != PAPI_VER_CURRENT )
        test_fail( __FILE__, __LINE__, "PAPI_library_init", retval );
 
    timer = PAPI_get_real_usec(  );
    for ( i = 0; i <= 20; i++ ) {
        if ( timer < 0 )
            break;
        sleep( ( unsigned int ) sleep_time );
        timer = PAPI_get_real_usec(  );
    }
    if ( timer < 0 )
        test_fail( __FILE__, __LINE__, "PAPI_get_real_usec: overflow", 1 );
    else
        test_pass( __FILE__ );
 
    return 0;
}