blob: f683a5384ff2588982caab27a5d7dd4cb7e2c204 [file] [log] [blame]
/* main.c - Hello World demo */
/*
* Copyright (c) 2012-2014 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr.h>
#include <misc/printk.h>
/*
* The hello world demo has two threads that utilize semaphores and sleeping
* to take turns printing a greeting message at a controlled rate. The demo
* shows both the static and dynamic approaches for spawning a thread; a real
* world application would likely use the static approach for both threads.
*/
/* size of stack area used by each thread */
#define STACKSIZE 1024
/* scheduling priority used by each thread */
#define PRIORITY 7
/* delay between greetings (in ms) */
#define SLEEPTIME 500
/*
* @param my_name thread identification string
* @param my_sem thread's own semaphore
* @param other_sem other thread's semaphore
*/
void hello_loop(const char *my_name,
struct k_sem *my_sem, struct k_sem *other_sem)
{
while (1) {
/* take my semaphore */
k_sem_take(my_sem, K_FOREVER);
/* say "hello" */
printk("%s: Hello World from %s!\n", my_name, CONFIG_ARCH);
/* wait a while, then let other thread have a turn */
k_sleep(SLEEPTIME);
k_sem_give(other_sem);
}
}
/* define semaphores */
K_SEM_DEFINE(threada_sem, 1, 1); /* starts off "available" */
K_SEM_DEFINE(threadb_sem, 0, 1); /* starts off "not available" */
/* threadb is a dynamic thread that is spawned by threadA */
void threadb(void *dummy1, void *dummy2, void *dummy3)
{
/* invoke routine to ping-pong hello messages with threadA */
hello_loop(__func__, &threadb_sem, &threada_sem);
}
K_THREAD_STACK_DEFINE(threadb_stack_area, STACKSIZE);
static struct k_thread threadb_data;
/* threada is a static thread that is spawned automatically */
void threada(void *dummy1, void *dummy2, void *dummy3)
{
/* spawn threadB */
k_thread_create(&threadb_data, threadb_stack_area, STACKSIZE, threadb,
NULL, NULL, NULL, PRIORITY, 0, K_NO_WAIT);
/* invoke routine to ping-pong hello messages with threadB */
hello_loop(__func__, &threada_sem, &threadb_sem);
}
K_THREAD_DEFINE(threada_id, STACKSIZE, threada, NULL, NULL, NULL,
PRIORITY, 0, K_NO_WAIT);