/*
 * syscall2.c
 *
 * All-threads getuid timing test.
 */

#include <sys/types.h>
#include <sys/errno.h>
#include <sys/mman.h>
#include <time.h>
#include <stdio.h>

#include <machine/atomic.h>

#include "blib.h"

extern int getuid_test(void);

int
main(void)
{
        struct timespec ts, ts2;
        int error;
        long long count = 0;
        long long max;
        int j;
        int cpuno;
        int ncpu;
        int *done;
        size_t ncpu_size;

        done = mmap(NULL, 4096, PROT_READ|PROT_WRITE,
                     MAP_SHARED|MAP_ANON, -1, 0);

        /*
         * How many cpu threads are there?
         */
        ncpu = 0;
        ncpu_size = sizeof(ncpu);
        if (sysctlbyname("hw.ncpu", &ncpu, &ncpu_size, NULL, 0) < 0) {
                perror("sysctl hw.ncpu");
                exit(1);
        }
        printf("timing standard getuid() syscall, %d threads\n", ncpu);
        printf("if using powerd, run several times\n");
        *done = 0;

        /*
         * Approximate timing run length
         */
        start_timing();
        while (stop_timing(0, NULL) == 0) {
                for (j = 0; j < 100; ++j)
                        getuid();
                count += 100;
        }
        max = count;

        /*
         * Run same length on all threads.
         */
        for (cpuno = 0; cpuno < ncpu; ++cpuno) {
                if (fork() == 0) {
                        /*
                         * Give scheduler time to move threads around
                         */
                        start_timing();
                        while (stop_timing(0, NULL) == 0) {
                                for (j = 0; j < 100; ++j)
                                        getuid();
                        }

                        /*
                         * Actual timing test is here.
                         */
                        start_timing();
                        for (count = 0; count < max; count += 100) {
                                for (j = 0; j < 100; ++j)
                                        getuid();
                        }
                        stop_timing(count, "getuid() sysmsg");

                        /*
                         * Don't unbusy the cpu until the other threads are
                         * done.
                         */
                        atomic_add_int(done, 1);
                        while (*done < ncpu)    /* wait for other threads */
                                getuid();
                        exit(0);
                }
        }
        while (wait3(NULL, 0, NULL) > 0 || errno == EINTR)
                ;
        return 0;
}