Function rt_sched_thread_bind_cpu

src/scheduler_mp.c:1501–1582

* @brief Bind a thread to a specific CPU core * * @param thread The thread to be bound * @param cpu The target CPU core index (RT_CPUS_NR for no binding) * * @return rt_err_t * - RT_EOK: Operation successful * * @details This function handles thread-CPU binding with the following logic: * - If thread is READY: * * Removes from current ready queue * * Updates bind CPU informa

 *       nothing and always returns -RT_EINVAL.
 */
rt_err_t rt_sched_thread_bind_cpu(struct rt_thread *thread, int cpu)
{
    rt_sched_lock_level_t slvl;
    rt_uint8_t thread_stat;

    RT_SCHED_DEBUG_IS_UNLOCKED;

    if (cpu >= RT_CPUS_NR)
    {
        cpu = RT_CPUS_NR;
    }

    rt_sched_lock(&slvl);

    thread_stat = rt_sched_thread_get_stat(thread);

    if (thread_stat == RT_THREAD_READY)
    {
        /* unbind */
        /* remove from old ready queue */
        rt_sched_remove_thread(thread);
        /* change thread bind cpu */
        RT_SCHED_CTX(thread).bind_cpu = cpu;
        /* add to new ready queue */
        rt_sched_insert_thread(thread);

        if (rt_thread_self() != RT_NULL)
        {
            rt_sched_unlock_n_resched(slvl);
        }
        else
        {
            rt_sched_unlock(slvl);
        }
    }
    else
    {
        RT_SCHED_CTX(thread).bind_cpu = cpu;
        if (thread_stat == RT_THREAD_RUNNING)
        {
            /* thread is running on a cpu */
            int current_cpu = rt_hw_cpu_id();

            if (cpu != RT_CPUS_NR)
            {
                if (RT_SCHED_CTX(thread).oncpu == current_cpu)
                {
                    /* current thread on current cpu */
                    if (cpu != current_cpu)
                    {
                        /* bind to other cpu */
                        rt_hw_ipi_send(RT_SCHEDULE_IPI, 1U << cpu);
                        /* self cpu need reschedule */
                        rt_sched_unlock_n_resched(slvl);
                    }
                    else
                    {
                        /* else do nothing */