Queue

About

Use a queue to communicate between two threads.

Source code

/**
 * @section License
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2014-2016, Erik Moqvist
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * This file is part of the Simba project.
 */

#include "simba.h"

static struct queue_t queue;

static THRD_STACK(writer_stack, 256);

static void *writer_main(void *arg_p)
{
    int value;

    /* Write to the queue. */
    value = 1;
    queue_write(&queue, &value, sizeof(value));

    return (NULL);
}

int main()
{
    int value;

    sys_start();
    queue_init(&queue, NULL, 0);
    thrd_spawn(writer_main, NULL, 0, writer_stack, sizeof(writer_stack));

    /* Read from the queue. */
    queue_read(&queue, &value, sizeof(value));

    std_printf(FSTR("read value = %d\r\n"), value);

    return (0);
}

The source code can also be found on Github in the examples/queue folder.

Build and run

Build and upload the application.

$ cd examples/queue
$ make -s BOARD=<board> run
read value = 1