81cb80d923
This commit adds a brief thread b suspend while the sample sets its affinity mask. If the call to `k_thread_cpu_pin` is being made while the thread is actively running, then we get `-EINVAL` and the affinity mask is left unchanged. Signed-off-by: Filip Kokosinski <fkokosinski@antmicro.com>
129 lines
3.4 KiB
C
129 lines
3.4 KiB
C
/* main.c - Synchronization demo */
|
|
|
|
/*
|
|
* Copyright (c) 2012-2014 Wind River Systems, Inc.
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
#include <zephyr/kernel.h>
|
|
#include <zephyr/sys/printk.h>
|
|
|
|
/*
|
|
* The synchronization 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.
|
|
*/
|
|
|
|
#define PIN_THREADS (IS_ENABLED(CONFIG_SMP) && IS_ENABLED(CONFIG_SCHED_CPU_MASK))
|
|
|
|
/* 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)
|
|
{
|
|
const char *tname;
|
|
uint8_t cpu;
|
|
struct k_thread *current_thread;
|
|
|
|
while (1) {
|
|
/* take my semaphore */
|
|
k_sem_take(my_sem, K_FOREVER);
|
|
|
|
current_thread = k_current_get();
|
|
tname = k_thread_name_get(current_thread);
|
|
#if CONFIG_SMP
|
|
cpu = arch_curr_cpu()->id;
|
|
#else
|
|
cpu = 0;
|
|
#endif
|
|
/* say "hello" */
|
|
if (tname == NULL) {
|
|
printk("%s: Hello World from cpu %d on %s!\n",
|
|
my_name, cpu, CONFIG_BOARD);
|
|
} else {
|
|
printk("%s: Hello World from cpu %d on %s!\n",
|
|
tname, cpu, CONFIG_BOARD);
|
|
}
|
|
|
|
/* wait a while, then let other thread have a turn */
|
|
k_busy_wait(100000);
|
|
k_msleep(SLEEPTIME);
|
|
k_sem_give(other_sem);
|
|
}
|
|
}
|
|
|
|
/* define semaphores */
|
|
K_SEM_DEFINE(thread_a_sem, 1, 1); /* starts off "available" */
|
|
K_SEM_DEFINE(thread_b_sem, 0, 1); /* starts off "not available" */
|
|
|
|
/* thread_a is a dynamic thread that is spawned in main */
|
|
void thread_a_entry_point(void *dummy1, void *dummy2, void *dummy3)
|
|
{
|
|
ARG_UNUSED(dummy1);
|
|
ARG_UNUSED(dummy2);
|
|
ARG_UNUSED(dummy3);
|
|
|
|
/* invoke routine to ping-pong hello messages with thread_b */
|
|
hello_loop(__func__, &thread_a_sem, &thread_b_sem);
|
|
}
|
|
K_THREAD_STACK_DEFINE(thread_a_stack_area, STACKSIZE);
|
|
static struct k_thread thread_a_data;
|
|
|
|
/* thread_b is a static thread spawned immediately */
|
|
void thread_b_entry_point(void *dummy1, void *dummy2, void *dummy3)
|
|
{
|
|
ARG_UNUSED(dummy1);
|
|
ARG_UNUSED(dummy2);
|
|
ARG_UNUSED(dummy3);
|
|
|
|
/* invoke routine to ping-pong hello messages with thread_a */
|
|
hello_loop(__func__, &thread_b_sem, &thread_a_sem);
|
|
}
|
|
K_THREAD_DEFINE(thread_b, STACKSIZE,
|
|
thread_b_entry_point, NULL, NULL, NULL,
|
|
PRIORITY, 0, 0);
|
|
extern const k_tid_t thread_b;
|
|
|
|
int main(void)
|
|
{
|
|
k_thread_create(&thread_a_data, thread_a_stack_area,
|
|
K_THREAD_STACK_SIZEOF(thread_a_stack_area),
|
|
thread_a_entry_point, NULL, NULL, NULL,
|
|
PRIORITY, 0, K_FOREVER);
|
|
k_thread_name_set(&thread_a_data, "thread_a");
|
|
|
|
#if PIN_THREADS
|
|
if (arch_num_cpus() > 1) {
|
|
k_thread_cpu_pin(&thread_a_data, 0);
|
|
|
|
/*
|
|
* Thread b is a static thread that is spawned immediately. This means that the
|
|
* following `k_thread_cpu_pin` call can fail with `-EINVAL` if the thread is
|
|
* actively running. Let's suspend the thread and resume it after the affinity mask
|
|
* is set.
|
|
*/
|
|
k_thread_suspend(thread_b);
|
|
k_thread_cpu_pin(thread_b, 1);
|
|
k_thread_resume(thread_b);
|
|
}
|
|
#endif
|
|
|
|
k_thread_start(&thread_a_data);
|
|
return 0;
|
|
}
|