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/* main.c - Hello World demo */ /* * Copyright (c) 2012-2014 Wind River Systems, Inc. * * SPDX-License-Identifier: Apache-2.0 */ #include <zephyr.h> #include <sys/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 helloLoop(const char *my_name, struct k_sem *my_sem, struct k_sem *other_sem) { const char *tname; while (1) { /* take my semaphore */ k_sem_take(my_sem, K_FOREVER); /* say "hello" */ tname = k_thread_name_get(k_current_get()); if (tname == NULL) { printk("%s: Hello World from %s!\n", my_name, CONFIG_BOARD); } else { printk("%s: Hello World from %s!\n", tname, CONFIG_BOARD); } /* 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) { ARG_UNUSED(dummy1); ARG_UNUSED(dummy2); ARG_UNUSED(dummy3); /* invoke routine to ping-pong hello messages with threadA */ helloLoop(__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) { ARG_UNUSED(dummy1); ARG_UNUSED(dummy2); ARG_UNUSED(dummy3); /* spawn threadB */ k_tid_t tid = k_thread_create(&threadB_data, threadB_stack_area, STACKSIZE, threadB, NULL, NULL, NULL, PRIORITY, 0, K_NO_WAIT); k_thread_name_set(tid, "thread_b"); /* invoke routine to ping-pong hello messages with threadB */ helloLoop(__func__, &threadA_sem, &threadB_sem); } K_THREAD_DEFINE(thread_a, STACKSIZE, threadA, NULL, NULL, NULL, PRIORITY, 0, K_NO_WAIT); |