int
nk_rwlock_rd_unlock (nk_rwlock_t * l)
{
NK_PROFILE_ENTRY();
DEBUG_PRINT("rwlock read unlock: %p\n", (void*)l);
int flags = spin_lock_irq_save(&l->lock);
--l->readers;
spin_unlock_irq_restore(&l->lock, flags);
NK_PROFILE_EXIT();
return 0;
}
uint8_t
nk_rwlock_wr_lock_irq_save (nk_rwlock_t * l)
{
int flags;
NK_PROFILE_ENTRY();
DEBUG_PRINT("rwlock write lock (irq): %p\n", (void*)l);
while (1) {
flags = spin_lock_irq_save(&l->lock);
if (likely(l->readers == 0 )) {
break;
} else {
spin_unlock_irq_restore(&l->lock, flags);
}
}
NK_PROFILE_EXIT();
return flags;
}
/*
* get_runnable_thread
*
* get the next thread in the specified thread's CPU
*
* NOTE: assumes that this thread *will* be run after this
*
*
*/
static nk_thread_t *
get_runnable_thread (uint32_t cpu)
{
nk_thread_t * runnable = NULL;
nk_thread_queue_t * runq = NULL;
nk_queue_entry_t * elm = NULL;
struct sys_info * sys = per_cpu_get(system);
uint8_t flags;
if (unlikely(cpu >= sys->num_cpus || !sys->cpus[cpu])) {
ERROR_PRINT("Attempt to get thread on invalid CPU (%u)\n", cpu);
return NULL;
}
runq = sys->cpus[cpu]->run_q;
ASSERT(runq);
if (nk_queue_empty(runq)) {
return NULL;
}
flags = spin_lock_irq_save(&runq->lock);
elm = nk_dequeue_first(runq);
ASSERT(elm);
runnable = container_of(elm, nk_thread_t, runq_node);
if (!get_cur_thread()->is_idle &&
get_cur_thread()->status == NK_THR_RUNNING) {
/* the next thing is an idle thread, but do we have something else to run? */
if (runnable->is_idle) {
if (!nk_queue_empty(runq)) {
nk_thread_t * idle = runnable;
elm = nk_dequeue_first(runq);
ASSERT(elm);
runnable = container_of(elm, nk_thread_t, runq_node);
ASSERT(runnable);
idle->status = NK_THR_SUSPENDED;
nk_enqueue_entry(runq, &(idle->runq_node));
//nk_enqueue_thread_on_runq(idle, cpu);
} else {
/* we put the idle thread back when it is the only thing on the queue */
runnable->status = NK_THR_SUSPENDED;
nk_enqueue_entry(runq, &(runnable->runq_node));
//nk_enqueue_thread_on_runq(runnable, cpu);
runnable = NULL;
}
} else {
/* all good, we switch to runnable */
}
} else {
/* if we're the idle thread, we *ALWAYS* run the next thing */
}
if (runnable) {
runnable->status = NK_THR_RUNNING;
}
spin_unlock_irq_restore(&runq->lock, flags);
//irq_enable_restore(flags);
return runnable;
}