/*
 * mutex4.c
 *
 * $DragonFly: src/test/sysperf/mutex4.c,v 1.1 2008/05/09 15:49:42 dillon Exp $
 */

#include "blib.h"

#include <sys/types.h>
#include <machine/atomic.h>
#include <machine/cpufunc.h>

struct globaldata {
        int gd_cpumask;
        int gd_spinlocks;
};

int *mtx;
struct globaldata gd;

typedef struct globaldata *globaldata_t;

void
rd_lock_contested(void)
{
}

static __inline void
rd_lock(void)
{
        atomic_set_int(mtx, 1);
        *mtx = 2;
        *mtx = 3;
}

static __inline void
rd_unlock(void)
{
}

int
main(int ac, char **av)
{
    long long count = 0;
    long long max;
    int j;
    int *counter;
    pid_t pid;

    printf("Test simple locked bus cycle mutex latency\n");
    printf("auto-forks two processes for the test with shared memory\n");
    printf("This test is only useful on a SMP box\n");

    start_timing();
    mtx = mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANON, -1, 0);
    counter = mtx + 64;
    gd.gd_cpumask = 0x00000001;
    gd.gd_spinlocks = 0;
    while (stop_timing(0, NULL) == 0) {
        for (j = 0; j < 100; ++j) {
            rd_lock();
            rd_unlock();
        }
        count += 100;
    }
    max = count;
    *mtx = 0;

    start_timing();
    for (count = 0; count < max; count += 100) {
        for (j = 0; j < 100; ++j) {
            rd_lock();
            rd_unlock();        /* release */
        }
    }
    stop_timing(count, "complex_mtx(uncontested/1cpu)");

    if ((pid = fork()) == 0) {
        for (;;) {
            for (j = 0; j < 100; ++j) {
                rd_lock();
                rd_unlock();    /* release */
                ++counter[128];
            }
        }
    } else {
        gd.gd_cpumask = 0x00000002;
        gd.gd_spinlocks = 0;
        start_timing();
        for (count = 0; count < max; count += 100) {
            for (j = 0; j < 100; ++j) {
                rd_lock();
                rd_unlock();    /* release */
                ++counter[64];
            }
        }
        stop_timing(count, "complex_mtx");
        printf("proc1=%d proc2=%d\n", counter[64], counter[128]);
        kill(pid, 9);
    }
    return(0);
}