source: mainline/uspace/app/tester/thread/deadlock.c

/*
 * Copyright (c) 2025 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <errno.h>
#include <fibril.h>
#include <fibril_synch.h>
//#include <stdio.h>
//#include <stddef.h>
#include "../tester.h"

static fibril_mutex_t fm1, fm2;

static errno_t fibril_fn(void *data)
{
        TPRINTF("F2: Lock M2\n");
        fibril_mutex_lock(&fm2);
        fibril_sleep(1);
        TPRINTF("F2: Lock M1\n");
        fibril_mutex_lock(&fm1);
        TPRINTF("F2: Unlock M1, M2\n");
        fibril_mutex_unlock(&fm1);
        fibril_mutex_unlock(&fm2);
        return EOK;
}

const char *test_deadlock(void)
{
        fid_t fid;

        fibril_mutex_initialize(&fm1);
        fibril_mutex_initialize(&fm2);

        TPRINTF("Creating fibril\n");
        fid = fibril_create(fibril_fn, NULL);
        if (fid == 0) {
                TPRINTF("\nCould not create fibril.\n");
                goto error;
        }

        fibril_add_ready(fid);

        TPRINTF("F1: Lock M1\n");
        fibril_mutex_lock(&fm1);
        fibril_sleep(1);
        TPRINTF("F1: Lock M2\n");
        fibril_mutex_lock(&fm2);

        TPRINTF("F1: Unlock M2, M1\n");
        fibril_mutex_unlock(&fm2);
        fibril_mutex_unlock(&fm1);

        return NULL;
error:
        return "Test failed";
}