ctests/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             */

#define MAX_THREADS 256
#define APPR_TOTAL_ITER 1000000

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include <math.h>

#include "papi.h"
#include "papi_test.h"

volatile long long count = 0;
volatile long long tmpcount = 0;
volatile long long thread_iter = 0;

static int quiet=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;

    duration = PAPI_get_real_usec(  );
    lockloop( thread_iter, &count );
    duration = PAPI_get_real_usec(  ) - duration;

    if (!quiet) {
        printf("%f lock/unlocks per us\n",
            (float)thread_iter/(float)duration);
    }
    pthread_exit( arg );
}


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 */
    quiet = tests_quiet( argc, argv );

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

    hwinfo = PAPI_get_hardware_info(  );
    if (hwinfo == 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;
    }

    /* Scale the per thread work to keep the serial runtime about the same. */
    thread_iter = APPR_TOTAL_ITER/sqrt(nthr);

    if (!quiet) {
        printf( "Creating %d threads, %lld lock/unlock\n",
            nthr , thread_iter);
    }

    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 );
    }

    if (!quiet) {
        printf( "Expected: %lld Received: %lld\n",
            ( long long ) nthr * thread_iter,
            count );
    }

    if ( nthr * thread_iter != count ) {
        test_fail( __FILE__, __LINE__, "Thread Locks", 1 );
    }

    test_pass( __FILE__ );

    return 0;

}