xref/libmicro/mutex.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms
 * of the Common Development and Distribution License
 * (the "License").  You may not use this file except
 * in compliance with the License.
 *
 * You can obtain a copy of the license at
 * src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing
 * permissions and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL
 * HEADER in each file and include the License file at
 * usr/src/OPENSOLARIS.LICENSE.  If applicable,
 * add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your
 * own identifying information: Portions Copyright [yyyy]
 * [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * mutex
 */

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <sys/mman.h>

#include "libmicro.h"

static int          optt = 0;
static int          optp = 0;
static int          opth = 0;
static int          opto = 0;

pthread_mutex_t         *lock;

typedef struct {
    int         ts_once;
    pthread_mutex_t     *ts_lock;
} tsd_t;

int
benchmark_init()
{
    lm_tsdsize = sizeof (tsd_t);

    (void) sprintf(lm_usage,
        "       [-t] (create dummy thread so we are multithreaded)\n"
        "       [-p] (use inter-process mutex (not support everywhere))\n"
        "       [-h usecs] (specify mutex hold time (default 0)\n"
        "notes: measures uncontended pthread_mutex_[un,]lock\n");

    (void) sprintf(lm_optstr, "tph:o:");

    (void) sprintf(lm_header, "%8s", "holdtime");

    return (0);
}

/*ARGSUSED*/
int
benchmark_optswitch(int opt, char *optarg)
{
    switch (opt) {
    case 'p':
        optp = 1;
        break;

    case 't':
        optt = 1;
        break;

    case 'h':
        opth = sizetoint(optarg);
        break;

    case 'o':
        opto = sizetoint(optarg);
        break;

    default:
        return (-1);
    }
    return (0);
}

void *
dummy(void *arg)
{
    (void) pause();
    return (arg);
}

int
benchmark_initrun()
{
    pthread_mutexattr_t attr;
    int errors = 0;

    /*LINTED*/
    lock = (pthread_mutex_t *)mmap(NULL,
        getpagesize(),
        PROT_READ | PROT_WRITE,
        optp?(MAP_ANON | MAP_SHARED):MAP_ANON|MAP_PRIVATE,
        -1, 0L) + opto;

    if (lock == MAP_FAILED) {
        errors++;
    } else {
        (void) pthread_mutexattr_init(&attr);
        if (optp)
            (void) pthread_mutexattr_setpshared(&attr,
                PTHREAD_PROCESS_SHARED);

        if (pthread_mutex_init(lock, &attr) != 0)
            errors++;
    }

    return (errors);
}

int
benchmark_initworker(void *tsd)
{
    int errors = 0;
    tsd_t           *ts = (tsd_t *)tsd;


    if (optt) {
        pthread_t       tid;


        if (pthread_create(&tid, NULL, dummy, NULL) != 0) {
            errors++;
        }
    }

    ts->ts_lock = lock;

    return (errors);
}

void
spinme(int usecs)
{
    long long s = getusecs();

    while (getusecs() - s < usecs)
        ;
}

int
benchmark(void *tsd, result_t *res)
{
    tsd_t           *ts = (tsd_t *)tsd;
    int         i;

    for (i = 0; i < lm_optB; i ++) {

        (void) pthread_mutex_lock(ts->ts_lock);
        if (opth)
            spinme(opth);
        (void) pthread_mutex_unlock(ts->ts_lock);

    }

    res->re_count = lm_optB;

    return (0);
}

char *
benchmark_result()
{
    static char     result[256];

    (void) sprintf(result, "%8d", opth);

    return (result);
}