locks_pthreads.c

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/* This file checks to make sure the locking mechanisms work correctly on the platform.
 * Platforms where the locking mechanisms are not implemented or are incorrectly implemented
 * will fail.  -KSL
 */

#include <pthread.h>
#include "papi_test.h"

volatile long long count = 0;
volatile long long tmpcount = 0;
volatile int num_iters = 0;

void
lockloop( int iters, volatile long long *mycount )
{
    int i;
    for ( i = 0; i < iters; i++ ) {
        PAPI_lock( PAPI_USR1_LOCK );
        *mycount = *mycount + 1;
        PAPI_unlock( PAPI_USR1_LOCK );
    }
}

void *
Slave( void *arg )
{
    long long duration;

    ( void ) arg;

    sleep( 1 );
    duration = PAPI_get_real_usec(  );
    lockloop( 10000, &tmpcount );
    duration = PAPI_get_real_usec(  ) - duration;

    /* First one here set's the number */
    PAPI_lock( PAPI_USR2_LOCK );
    if ( num_iters == 0 ) {
        printf( "10000 iterations took %lld us.\n", duration );
        num_iters = ( int ) ( 10 * ( TIME_LIMIT_IN_US / duration ) );
        printf( "Running %d iterations\n", num_iters );
    }
    PAPI_unlock( PAPI_USR2_LOCK );

    lockloop( num_iters, &count );
    pthread_exit( NULL );
}


int
main( int argc, char **argv )
{
    pthread_t slaves[MAX_THREADS];
    int rc, i, nthr;
    int retval;
    const PAPI_hw_info_t *hwinfo = NULL;

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

    if ( ( retval =
           PAPI_library_init( PAPI_VER_CURRENT ) ) != PAPI_VER_CURRENT )
        test_fail( __FILE__, __LINE__, "PAPI_library_init", retval );

    if ( ( hwinfo = PAPI_get_hardware_info(  ) ) == NULL )
        test_fail( __FILE__, __LINE__, "PAPI_get_hardware_info", 2 );

    retval =
        PAPI_thread_init( ( unsigned long ( * )( void ) ) ( pthread_self ) );
    if ( retval != PAPI_OK ) {
        if ( retval == PAPI_ECMP )
            test_skip( __FILE__, __LINE__, "PAPI_thread_init", retval );
        else
            test_fail( __FILE__, __LINE__, "PAPI_thread_init", retval );
    }

    if ( hwinfo->ncpu > MAX_THREADS )
        nthr = MAX_THREADS;
    else
        nthr = hwinfo->ncpu;

    printf( "Creating %d threads\n", nthr );

    for ( i = 0; i < nthr; i++ ) {
        rc = pthread_create( &slaves[i], NULL, Slave, NULL );
        if ( rc ) {
            retval = PAPI_ESYS;
            test_fail( __FILE__, __LINE__, "pthread_create", retval );
        }
    }

    for ( i = 0; i < nthr; i++ ) {
        pthread_join( slaves[i], NULL );
    }

    printf( "Expected: %lld Received: %lld\n", ( long long ) nthr * num_iters,
            count );
    if ( nthr * num_iters != count )
        test_fail( __FILE__, __LINE__, "Thread Locks", 1 );

    test_pass( __FILE__, NULL, 0 );
    exit( 1 );
}