asdk-libdrm

        err(1, "failed to send event %d", event);

}

​

static void

client_auth(int drmfd)

{

    struct drm_auth auth;

    int ret;

​

    /* Get a client magic number and pass it to the master for auth. */

    ret = ioctl(drmfd, DRM_IOCTL_GET_MAGIC, &auth);

    if (ret == -1)

        err(1, "Couldn't get client magic");

    send_event(0, CLIENT_MAGIC);

    ret = write(commfd[0], &auth.magic, sizeof(auth.magic));

    if (ret == -1)

        err(1, "Couldn't write auth data");

}

​

​

    ret = drmGetLock(drmfd, lock1, 0);

    assert(ret == 0);

    /* XXX: Need to make sure that this is the same device as drmfd */

    tempfd = drm_open_any();

    close(tempfd);

    ret = drmUnlock(drmfd, lock1);

    if (ret != 0)

        errx(1, "lock lost during open/close by same pid");

}

​

static void client()

{

    int drmfd, ret;

    unsigned int time;

​

    /* XXX: Should make sure we open the same DRM as the master */

    drmfd = drm_open_any();

​

    client_auth(drmfd);

​

    /* Wait for the server to grab the lock, then grab it ourselves (to

     * contest it).  Hopefully we hit it within the window of when the

     * server locks.

     */

    wait_event(0, SERVER_LOCKED);

    ret = drmGetLock(drmfd, lock2, 0);

    time = get_millis();

    if (ret != 0)

        err(1, "Failed to get lock on client\n");

    drmUnlock(drmfd, lock2);

​

    /* Tell the server that our locking completed, and when it did */

    send_event(0, CLIENT_LOCKED);

    ret = write(commfd[0], &time, sizeof(time));

​

    exit(0);

}

​

static void server()

{

    int drmfd, tempfd, ret;

    unsigned int client_time, unlock_time;

​

    drmfd = drm_open_any_master();

​

    unlock_time = get_millis();

​

    wait_event(1, CLIENT_LOCKED);

    ret = read(commfd[1], &client_time, sizeof(client_time));

    if (ret == -1)

        err(1, "Failure to read client magic");

​

    if (client_time < unlock_time)

        errx(1, "Client took lock before server released it");

}

​

int main(int argc, char **argv)

{

    int ret;

​

​

    ret = pipe(commfd);

    if (ret == -1)

        err(1, "Couldn't create pipe");