Colony » Colony Scout

/*

 * Copyright (c) 2005, Kohsuke Ohtani

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. 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.

 * 3. Neither the name of the author nor the names of any co-contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.

 */

/*

 * sem.c - sample program for semaphore.

 */

#include <sys/prex.h>

#include <stdio.h>

static sem_t sem;

void

thread_run(void (*start)(void), void *stack)

{

        thread_t t;

        if (thread_create(task_self(), &t) != 0)

                panic("thread_create is failed");

        if (thread_load(t, start, stack) != 0)

                panic("thread_load is failed");

        if (thread_resume(t) != 0)

                panic("thread_resume failed");

        return;

}

/*

 * The main routine create 10 copy of this thread. But, since the

 * initial semaphore value is 3, only 3 threads can run at same time.

 */

static void

new_thread(void)

{

        thread_t t;

        t = thread_self();

        printf("Start thread=%x\n", (u_int)t);

        thread_yield();

        /*

         * Acquire semaphore

         */

        sem_wait(&sem, 0);

        /*

         * Sleep 2000 ms

         */

        printf("Running thread=%x\n", (u_int)t);

        timer_sleep(2000, 0);

        /*

         * Release semaphore

         */

        sem_post(&sem);        

        printf("End thread=%x\n", (u_int)t);

        thread_terminate(t);

}

int

main(int argc, char *argv[])

{

        static char stack[10][1024];

        int i;

        printf("Semaphore sample program\n");

        /*

         * Initialize semaphore with initial count 3

         */

        sem_init(&sem, 3);

        /*

         * Boost the priority of this thread

         */

        thread_setpri(thread_self(), 100);

        /*

         * Create 10 threads

         */

        for (i = 0; i < 10; i++)

                thread_run(new_thread, stack[i]+1024);

        /*

         * Wait...

         */

        thread_suspend(thread_self());

        return 0;

}