fork_overflow.c

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/*
 *  Test PAPI with fork() and exec().
 */

#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "papi.h"
#include "papi_test.h"

#define MAX_EVENTS  3

static int Event[MAX_EVENTS] = {
    PAPI_TOT_CYC,
    PAPI_FP_INS,
    PAPI_FAD_INS,
};

static int Threshold[MAX_EVENTS] = {
    8000000,
    4000000,
    4000000,
};

static int num_events = 1;
static int EventSet = PAPI_NULL;
static const char *name = "unknown";
static struct timeval start, last;
static long count, total;

static void
my_handler( int EventSet, void *pc, long long ovec, void *context )
{
    ( void ) EventSet;
    ( void ) pc;
    ( void ) ovec;
    ( void ) context;

    count++;
    total++;
}

static void
zero_count( void )
{
    gettimeofday( &start, NULL );
    last = start;
    count = 0;
    total = 0;
}

static void
print_here( const char *str) {

    if (!TESTS_QUIET) printf("[%d] %s, %s\n", getpid(), name, str);
}

static void
print_rate( const char *str )
{
    static int last_count = -1;
    struct timeval now;
    double st_secs, last_secs;

    gettimeofday( &now, NULL );
    st_secs = ( double ) ( now.tv_sec - start.tv_sec )
        + ( ( double ) ( now.tv_usec - start.tv_usec ) ) / 1000000.0;
    last_secs = ( double ) ( now.tv_sec - last.tv_sec )
        + ( ( double ) ( now.tv_usec - last.tv_usec ) ) / 1000000.0;
    if ( last_secs <= 0.001 )
        last_secs = 0.001;

    if (!TESTS_QUIET) {
        printf( "[%d] %s, time = %.3f, total = %ld, last = %ld, rate = %.1f/sec\n",
            getpid(  ), str, st_secs, total, count,
            ( ( double ) count ) / last_secs );
    }

    if ( last_count != -1 ) {
        if ( count < .1 * last_count ) {
            test_fail( name, __LINE__, "Interrupt rate changed!", 1 );
            exit( 1 );
        }
    }
    last_count = ( int ) count;
    count = 0;
    last = now;
}

static void
do_cycles( int program_time )
{
    struct timeval start, now;
    double x, sum;

    gettimeofday( &start, NULL );

    for ( ;; ) {
        sum = 1.0;
        for ( x = 1.0; x < 250000.0; x += 1.0 )
            sum += x;
        if ( sum < 0.0 )
            printf( "==>>  SUM IS NEGATIVE !!  <<==\n" );

        gettimeofday( &now, NULL );
        if ( now.tv_sec >= start.tv_sec + program_time )
            break;
    }
}

static void
my_papi_init( void )
{
    if ( PAPI_library_init( PAPI_VER_CURRENT ) != PAPI_VER_CURRENT )
        test_fail( name, __LINE__, "PAPI_library_init failed", 1 );
}

static void
my_papi_start( void )
{
    int ev;

    EventSet = PAPI_NULL;

    if ( PAPI_create_eventset( &EventSet ) != PAPI_OK )
        test_fail( name, __LINE__, "PAPI_create_eventset failed", 1 );

    for ( ev = 0; ev < num_events; ev++ ) {
        if ( PAPI_add_event( EventSet, Event[ev] ) != PAPI_OK ) {
            if (!TESTS_QUIET) printf("Trouble adding event\n");
            test_skip( name, __LINE__, "PAPI_add_event failed", 1 );
        }
    }

    for ( ev = 0; ev < num_events; ev++ ) {
        if ( PAPI_overflow( EventSet, Event[ev], Threshold[ev], 0, my_handler )
             != PAPI_OK ) {
            test_fail( name, __LINE__, "PAPI_overflow failed", 1 );
        }
    }

    if ( PAPI_start( EventSet ) != PAPI_OK )
        test_fail( name, __LINE__, "PAPI_start failed", 1 );
}

static void
my_papi_stop( void )
{
    if ( PAPI_stop( EventSet, NULL ) != PAPI_OK )
        test_fail( name, __LINE__, "PAPI_stop failed", 1 );
}

static void
run( const char *str, int len )
{
    int n;

    for ( n = 1; n <= len; n++ ) {
        do_cycles( 1 );
        print_rate( str );
    }
}

int
main( int argc, char **argv )
{
    char buf[100];

    int quiet,retval;

    /* Used to be able to set this via command line */
    num_events=1;

    /* Set TESTS_QUIET variable */
    quiet=tests_quiet( argc, argv );

    do_cycles( 1 );

    zero_count(  );

    retval=PAPI_library_init( PAPI_VER_CURRENT );
    if (retval!=PAPI_VER_CURRENT) {
        test_fail( name, __LINE__, "PAPI_library_init failed", 1 );
    }

    name = argv[0];
    if (!quiet) printf( "[%d] %s, num_events = %d\n", getpid(  ), name, num_events );
    sprintf( buf, "%d", num_events );
    my_papi_start(  );
    run( name, 3 );

    print_here( "fork" );
    {
        int ret = fork(  );
        if ( ret < 0 )
            test_fail( name, __LINE__, "fork failed", 1 );
        if ( ret == 0 ) {
            /*
             * Child process.
             */
            zero_count(  );
            my_papi_init(  );
            my_papi_start(  );
            run( "child", 5 );
            print_here( "stop" );
            my_papi_stop(  );
            sleep( 3 );
            print_here( "end" );
            exit( 0 );
        }
        run( "main", 14 );
        my_papi_stop(  );
        {
            int status;
            wait( &status );
            print_here( "end" );
            if ( WEXITSTATUS( status ) != 0 )
                test_fail( name, __LINE__, "child failed", 1 );
            else
                test_pass( name);
        }
    }

    return 0;
}