/*
* Copyright (c) 2018 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <kernel.h>
#include <ksched.h>
#include <spinlock.h>
#include <sched_priq.h>
#include <wait_q.h>
#include <kswap.h>
#include <kernel_arch_func.h>
#include <syscall_handler.h>
#include <drivers/timer/system_timer.h>
#include <stdbool.h>
#include <kernel_internal.h>
/* Maximum time between the time a self-aborting thread flags itself
* DEAD and the last read or write to its stack memory (i.e. the time
* of its next swap()). In theory this might be tuned per platform,
* but in practice this conservative value should be safe.
*/
#define THREAD_ABORT_DELAY_US 500
#if defined(CONFIG_SCHED_DUMB)
#define _priq_run_add z_priq_dumb_add
#define _priq_run_remove z_priq_dumb_remove
# if defined(CONFIG_SCHED_CPU_MASK)
# define _priq_run_best _priq_dumb_mask_best
# else
# define _priq_run_best z_priq_dumb_best
# endif
#elif defined(CONFIG_SCHED_SCALABLE)
#define _priq_run_add z_priq_rb_add
#define _priq_run_remove z_priq_rb_remove
#define _priq_run_best z_priq_rb_best
#elif defined(CONFIG_SCHED_MULTIQ)
#define _priq_run_add z_priq_mq_add
#define _priq_run_remove z_priq_mq_remove
#define _priq_run_best z_priq_mq_best
#endif
#if defined(CONFIG_WAITQ_SCALABLE)
#define z_priq_wait_add z_priq_rb_add
#define _priq_wait_remove z_priq_rb_remove
#define _priq_wait_best z_priq_rb_best
#elif defined(CONFIG_WAITQ_DUMB)
#define z_priq_wait_add z_priq_dumb_add
#define _priq_wait_remove z_priq_dumb_remove
#define _priq_wait_best z_priq_dumb_best
#endif
/* the only struct z_kernel instance */
struct z_kernel _kernel;
static struct k_spinlock sched_spinlock;
#define LOCKED(lck) for (k_spinlock_key_t __i = {}, \
__key = k_spin_lock(lck); \
!__i.key; \
k_spin_unlock(lck, __key), __i.key = 1)
static inline int is_preempt(struct k_thread *thread)
{
#ifdef CONFIG_PREEMPT_ENABLED
/* explanation in kernel_struct.h */
return thread->base.preempt <= _PREEMPT_THRESHOLD;
#else
return 0;
#endif
}
static inline int is_metairq(struct k_thread *thread)
{
#if CONFIG_NUM_METAIRQ_PRIORITIES > 0
return (thread->base.prio - K_HIGHEST_THREAD_PRIO)
< CONFIG_NUM_METAIRQ_PRIORITIES;
#else
return 0;
#endif
}
#if CONFIG_ASSERT
static inline bool is_thread_dummy(struct k_thread *thread)
{
return (thread->base.thread_state & _THREAD_DUMMY) != 0U;
}
#endif
bool z_is_t1_higher_prio_than_t2(struct k_thread *thread_1,
struct k_thread *thread_2)
{
if (thread_1->base.prio < thread_2->base.prio) {
return true;
}
#ifdef CONFIG_SCHED_DEADLINE
/* Note that we don't care about wraparound conditions. The
* expectation is that the application will have arranged to
* block the threads, change their priorities or reset their
* deadlines when the job is complete. Letting the deadlines
* go negative is fine and in fact prevents aliasing bugs.
*/
if (thread_1->base.prio == thread_2->base.prio) {
int now = (int) k_cycle_get_32();
int dt1 = thread_1->base.prio_deadline - now;
int dt2 = thread_2->base.prio_deadline - now;
return dt1 < dt2;
}
#endif
return false;
}
static ALWAYS_INLINE bool should_preempt(struct k_thread *thread,
int preempt_ok)
{
/* Preemption is OK if it's being explicitly allowed by
* software state (e.g. the thread called k_yield())
*/
if (preempt_ok != 0) {
return true;
}
__ASSERT(_current != NULL, "");
/* Or if we're pended/suspended/dummy (duh) */
if (z_is_thread_prevented_from_running(_current)) {
return true;
}
/* Edge case on ARM where a thread can be pended out of an
* interrupt handler before the "synchronous" swap starts
* context switching. Platforms with atomic swap can never
* hit this.
*/
if (IS_ENABLED(CONFIG_SWAP_NONATOMIC)
&& z_is_thread_timeout_active(thread)) {
return true;
}
/* Otherwise we have to be running a preemptible thread or
* switching to a metairq
*/
if (is_preempt(_current) || is_metairq(thread)) {
return true;
}
/* The idle threads can look "cooperative" if there are no
* preemptible priorities (this is sort of an API glitch).
* They must always be preemptible.
*/
if (!IS_ENABLED(CONFIG_PREEMPT_ENABLED) &&
z_is_idle_thread_object(_current)) {
return true;
}
return false;
}
#ifdef CONFIG_SCHED_CPU_MASK
static ALWAYS_INLINE struct k_thread *_priq_dumb_mask_best(sys_dlist_t *pq)
{
/* With masks enabled we need to be prepared to walk the list
* looking for one we can run
*/
struct k_thread *thread;
SYS_DLIST_FOR_EACH_CONTAINER(pq, thread, base.qnode_dlist) {
if ((thread->base.cpu_mask & BIT(_current_cpu->id)) != 0) {
return thread;
}
}
return NULL;
}
#endif
static ALWAYS_INLINE struct k_thread *next_up(void)
{
struct k_thread *thread = _priq_run_best(&_kernel.ready_q.runq);
#if (CONFIG_NUM_METAIRQ_PRIORITIES > 0) && (CONFIG_NUM_COOP_PRIORITIES > 0)
/* MetaIRQs must always attempt to return back to a
* cooperative thread they preempted and not whatever happens
* to be highest priority now. The cooperative thread was
* promised it wouldn't be preempted (by non-metairq threads)!
*/
struct k_thread *mirqp = _current_cpu->metairq_preempted;
if (mirqp != NULL && (thread == NULL || !is_metairq(thread))) {
if (!z_is_thread_prevented_from_running(mirqp)) {
thread = mirqp;
} else {
_current_cpu->metairq_preempted = NULL;
}
}
#endif
/* If the current thread is marked aborting, mark it
* dead so it will not be scheduled again.
*/
if (_current->base.thread_state & _THREAD_ABORTING) {
_current->base.thread_state |= _THREAD_DEAD;
#ifdef CONFIG_SMP
_current_cpu->swap_ok = true;
#endif
}
#ifndef CONFIG_SMP
/* In uniprocessor mode, we can leave the current thread in
* the queue (actually we have to, otherwise the assembly
* context switch code for all architectures would be
* responsible for putting it back in z_swap and ISR return!),
* which makes this choice simple.
*/
return thread ? thread : _current_cpu->idle_thread;
#else
/* Under SMP, the "cache" mechanism for selecting the next
* thread doesn't work, so we have more work to do to test
* _current against the best choice from the queue. Here, the
* thread selected above represents "the best thread that is
* not current".
*
* Subtle note on "queued": in SMP mode, _current does not
* live in the queue, so this isn't exactly the same thing as
* "ready", it means "is _current already added back to the
* queue such that we don't want to re-add it".
*/
int queued = z_is_thread_queued(_current);
int active = !z_is_thread_prevented_from_running(_current);
if (thread == NULL) {
thread = _current_cpu->idle_thread;
}
if (active) {
if (!queued &&
!z_is_t1_higher_prio_than_t2(thread, _current)) {
thread = _current;
}
if (!should_preempt(thread, _current_cpu->swap_ok)) {
thread = _current;
}
}
/* Put _current back into the queue */
if (thread != _current && active &&
!z_is_idle_thread_object(_current) && !queued) {
_priq_run_add(&_kernel.ready_q.runq, _current);
z_mark_thread_as_queued(_current);
}
/* Take the new _current out of the queue */
if (z_is_thread_queued(thread)) {
_priq_run_remove(&_kernel.ready_q.runq, thread);
}
z_mark_thread_as_not_queued(thread);
return thread;
#endif
}
#ifdef CONFIG_TIMESLICING
static int slice_time;
static int slice_max_prio;
#ifdef CONFIG_SWAP_NONATOMIC
/* If z_swap() isn't atomic, then it's possible for a timer interrupt
* to try to timeslice away _current after it has already pended
* itself but before the corresponding context switch. Treat that as
* a noop condition in z_time_slice().
*/
static struct k_thread *pending_current;
#endif
void z_reset_time_slice(void)
{
/* Add the elapsed time since the last announced tick to the
* slice count, as we'll see those "expired" ticks arrive in a
* FUTURE z_time_slice() call.
*/
if (slice_time != 0) {
_current_cpu->slice_ticks = slice_time + z_clock_elapsed();
z_set_timeout_expiry(slice_time, false);
}
}
void k_sched_time_slice_set(s32_t slice, int prio)
{
LOCKED(&sched_spinlock) {
_current_cpu->slice_ticks = 0;
slice_time = k_ms_to_ticks_ceil32(slice);
slice_max_prio = prio;
z_reset_time_slice();
}
}
static inline int sliceable(struct k_thread *thread)
{
return is_preempt(thread)
&& !z_is_prio_higher(thread->base.prio, slice_max_prio)
&& !z_is_idle_thread_object(thread)
&& !z_is_thread_timeout_active(thread);
}
/* Called out of each timer interrupt */
void z_time_slice(int ticks)
{
#ifdef CONFIG_SWAP_NONATOMIC
if (pending_current == _current) {
z_reset_time_slice();
return;
}
pending_current = NULL;
#endif
if (slice_time && sliceable(_current)) {
if (ticks >= _current_cpu->slice_ticks) {
z_move_thread_to_end_of_prio_q(_current);
z_reset_time_slice();
} else {
_current_cpu->slice_ticks -= ticks;
}
} else {
_current_cpu->slice_ticks = 0;
}
}
#endif
/* Track cooperative threads preempted by metairqs so we can return to
* them specifically. Called at the moment a new thread has been
* selected to run.
*/
static void update_metairq_preempt(struct k_thread *thread)
{
#if (CONFIG_NUM_METAIRQ_PRIORITIES > 0) && (CONFIG_NUM_COOP_PRIORITIES > 0)
if (is_metairq(thread) && !is_metairq(_current) &&
!is_preempt(_current)) {
/* Record new preemption */
_current_cpu->metairq_preempted = _current;
} else if (!is_metairq(thread)) {
/* Returning from existing preemption */
_current_cpu->metairq_preempted = NULL;
}
#endif
}
static void update_cache(int preempt_ok)
{
#ifndef CONFIG_SMP
struct k_thread *thread = next_up();
if (should_preempt(thread, preempt_ok)) {
#ifdef CONFIG_TIMESLICING
if (thread != _current) {
z_reset_time_slice();
}
#endif
update_metairq_preempt(thread);
_kernel.ready_q.cache = thread;
} else {
_kernel.ready_q.cache = _current;
}
#else
/* The way this works is that the CPU record keeps its
* "cooperative swapping is OK" flag until the next reschedule
* call or context switch. It doesn't need to be tracked per
* thread because if the thread gets preempted for whatever
* reason the scheduler will make the same decision anyway.
*/
_current_cpu->swap_ok = preempt_ok;
#endif
}
static void ready_thread(struct k_thread *thread)
{
if (z_is_thread_ready(thread)) {
sys_trace_thread_ready(thread);
_priq_run_add(&_kernel.ready_q.runq, thread);
z_mark_thread_as_queued(thread);
update_cache(0);
#if defined(CONFIG_SMP) && defined(CONFIG_SCHED_IPI_SUPPORTED)
arch_sched_ipi();
#endif
}
}
void z_ready_thread(struct k_thread *thread)
{
LOCKED(&sched_spinlock) {
ready_thread(thread);
}
}
void z_move_thread_to_end_of_prio_q(struct k_thread *thread)
{
LOCKED(&sched_spinlock) {
if (z_is_thread_queued(thread)) {
_priq_run_remove(&_kernel.ready_q.runq, thread);
}
_priq_run_add(&_kernel.ready_q.runq, thread);
z_mark_thread_as_queued(thread);
update_cache(thread == _current);
}
}
void z_sched_start(struct k_thread *thread)
{
k_spinlock_key_t key = k_spin_lock(&sched_spinlock);
if (z_has_thread_started(thread)) {
k_spin_unlock(&sched_spinlock, key);
return;
}
z_mark_thread_as_started(thread);
ready_thread(thread);
z_reschedule(&sched_spinlock, key);
}
void z_impl_k_thread_suspend(struct k_thread *thread)
{
(void)z_abort_thread_timeout(thread);
LOCKED(&sched_spinlock) {
if (z_is_thread_queued(thread)) {
_priq_run_remove(&_kernel.ready_q.runq, thread);
z_mark_thread_as_not_queued(thread);
}
z_mark_thread_as_suspended(thread);
update_cache(thread == _current);
}
if (thread == _current) {
z_reschedule_unlocked();
}
}
#ifdef CONFIG_USERSPACE
static inline void z_vrfy_k_thread_suspend(struct k_thread *thread)
{
Z_OOPS(Z_SYSCALL_OBJ(thread, K_OBJ_THREAD));
z_impl_k_thread_suspend(thread);
}
#include <syscalls/k_thread_suspend_mrsh.c>
#endif
void z_impl_k_thread_resume(struct k_thread *thread)
{
k_spinlock_key_t key = k_spin_lock(&sched_spinlock);
z_mark_thread_as_not_suspended(thread);
ready_thread(thread);
z_reschedule(&sched_spinlock, key);
}
#ifdef CONFIG_USERSPACE
static inline void z_vrfy_k_thread_resume(struct k_thread *thread)
{
Z_OOPS(Z_SYSCALL_OBJ(thread, K_OBJ_THREAD));
z_impl_k_thread_resume(thread);
}
#include <syscalls/k_thread_resume_mrsh.c>
#endif
static _wait_q_t *pended_on(struct k_thread *thread)
{
__ASSERT_NO_MSG(thread->base.pended_on);
return thread->base.pended_on;
}
void z_thread_single_abort(struct k_thread *thread)
{
if (thread->fn_abort != NULL) {
thread->fn_abort();
}
(void)z_abort_thread_timeout(thread);
if (IS_ENABLED(CONFIG_SMP)) {
z_sched_abort(thread);
}
LOCKED(&sched_spinlock) {
struct k_thread *waiter;
if (z_is_thread_ready(thread)) {
if (z_is_thread_queued(thread)) {
_priq_run_remove(&_kernel.ready_q.runq,
thread);
z_mark_thread_as_not_queued(thread);
}
update_cache(thread == _current);
} else {
if (z_is_thread_pending(thread)) {
_priq_wait_remove(&pended_on(thread)->waitq,
thread);
z_mark_thread_as_not_pending(thread);
thread->base.pended_on = NULL;
}
}
u32_t mask = _THREAD_DEAD;
/* If the abort is happening in interrupt context,
* that means that execution will never return to the
* thread's stack and that the abort is known to be
* complete. Otherwise the thread still runs a bit
* until it can swap, requiring a delay.
*/
if (IS_ENABLED(CONFIG_SMP) && arch_is_in_isr()) {
mask |= _THREAD_ABORTED_IN_ISR;
}
thread->base.thread_state |= mask;
#ifdef CONFIG_USERSPACE
/* Clear initialized state so that this thread object may be
* re-used and triggers errors if API calls are made on it from
* user threads
*
* For a whole host of reasons this is not ideal and should be
* iterated on.
*/
z_object_uninit(thread->stack_obj);
z_object_uninit(thread);
/* Revoke permissions on thread's ID so that it may be
* recycled
*/
z_thread_perms_all_clear(thread);
#endif
/* Wake everybody up who was trying to join with this thread.
* A reschedule is invoked later by k_thread_abort().
*/
while ((waiter = z_waitq_head(&thread->base.join_waiters)) !=
NULL) {
(void)z_abort_thread_timeout(waiter);
_priq_wait_remove(&pended_on(waiter)->waitq, waiter);
z_mark_thread_as_not_pending(waiter);
waiter->base.pended_on = NULL;
arch_thread_return_value_set(waiter, 0);
ready_thread(waiter);
}
}
sys_trace_thread_abort(thread);
}
static void unready_thread(struct k_thread *thread)
{
if (z_is_thread_queued(thread)) {
_priq_run_remove(&_kernel.ready_q.runq, thread);
z_mark_thread_as_not_queued(thread);
}
update_cache(thread == _current);
}
void z_remove_thread_from_ready_q(struct k_thread *thread)
{
LOCKED(&sched_spinlock) {
unready_thread(thread);
}
}
/* sched_spinlock must be held */
static void add_to_waitq_locked(struct k_thread *thread, _wait_q_t *wait_q)
{
unready_thread(thread);
z_mark_thread_as_pending(thread);
sys_trace_thread_pend(thread);
if (wait_q != NULL) {
thread->base.pended_on = wait_q;
z_priq_wait_add(&wait_q->waitq, thread);
}
}
static void add_thread_timeout(struct k_thread *thread, k_timeout_t timeout)
{
if (!K_TIMEOUT_EQ(timeout, K_FOREVER)) {
#ifdef CONFIG_LEGACY_TIMEOUT_API
timeout = _TICK_ALIGN + k_ms_to_ticks_ceil32(timeout);
#endif
z_add_thread_timeout(thread, timeout);
}
}
static void pend(struct k_thread *thread, _wait_q_t *wait_q,
k_timeout_t timeout)
{
LOCKED(&sched_spinlock) {
add_to_waitq_locked(thread, wait_q);
}
add_thread_timeout(thread, timeout);
}
void z_pend_thread(struct k_thread *thread, _wait_q_t *wait_q,
k_timeout_t timeout)
{
__ASSERT_NO_MSG(thread == _current || is_thread_dummy(thread));
pend(thread, wait_q, timeout);
}
ALWAYS_INLINE struct k_thread *z_find_first_thread_to_unpend(_wait_q_t *wait_q,
struct k_thread *from)
{
ARG_UNUSED(from);
struct k_thread *ret = NULL;
LOCKED(&sched_spinlock) {
ret = _priq_wait_best(&wait_q->waitq);
}
return ret;
}
ALWAYS_INLINE void z_unpend_thread_no_timeout(struct k_thread *thread)
{
LOCKED(&sched_spinlock) {
_priq_wait_remove(&pended_on(thread)->waitq, thread);
z_mark_thread_as_not_pending(thread);
thread->base.pended_on = NULL;
}
}
#ifdef CONFIG_SYS_CLOCK_EXISTS
/* Timeout handler for *_thread_timeout() APIs */
void z_thread_timeout(struct _timeout *timeout)
{
struct k_thread *thread = CONTAINER_OF(timeout,
struct k_thread, base.timeout);
if (thread->base.pended_on != NULL) {
z_unpend_thread_no_timeout(thread);
}
z_mark_thread_as_started(thread);
z_mark_thread_as_not_suspended(thread);
z_ready_thread(thread);
}
#endif
int z_pend_curr_irqlock(u32_t key, _wait_q_t *wait_q, k_timeout_t timeout)
{
pend(_current, wait_q, timeout);
#if defined(CONFIG_TIMESLICING) && defined(CONFIG_SWAP_NONATOMIC)
pending_current = _current;
int ret = z_swap_irqlock(key);
LOCKED(&sched_spinlock) {
if (pending_current == _current) {
pending_current = NULL;
}
}
return ret;
#else
return z_swap_irqlock(key);
#endif
}
int z_pend_curr(struct k_spinlock *lock, k_spinlock_key_t key,
_wait_q_t *wait_q, k_timeout_t timeout)
{
#if defined(CONFIG_TIMESLICING) && defined(CONFIG_SWAP_NONATOMIC)
pending_current = _current;
#endif
pend(_current, wait_q, timeout);
return z_swap(lock, key);
}
struct k_thread *z_unpend_first_thread(_wait_q_t *wait_q)
{
struct k_thread *thread = z_unpend1_no_timeout(wait_q);
if (thread != NULL) {
(void)z_abort_thread_timeout(thread);
}
return thread;
}
void z_unpend_thread(struct k_thread *thread)
{
z_unpend_thread_no_timeout(thread);
(void)z_abort_thread_timeout(thread);
}
/* Priority set utility that does no rescheduling, it just changes the
* run queue state, returning true if a reschedule is needed later.
*/
bool z_set_prio(struct k_thread *thread, int prio)
{
bool need_sched = 0;
LOCKED(&sched_spinlock) {
need_sched = z_is_thread_ready(thread);
if (need_sched) {
/* Don't requeue on SMP if it's the running thread */
if (!IS_ENABLED(CONFIG_SMP) || z_is_thread_queued(thread)) {
_priq_run_remove(&_kernel.ready_q.runq, thread);
thread->base.prio = prio;
_priq_run_add(&_kernel.ready_q.runq, thread);
} else {
thread->base.prio = prio;
}
update_cache(1);
} else {
thread->base.prio = prio;
}
}
sys_trace_thread_priority_set(thread);
return need_sched;
}
void z_thread_priority_set(struct k_thread *thread, int prio)
{
bool need_sched = z_set_prio(thread, prio);
#if defined(CONFIG_SMP) && defined(CONFIG_SCHED_IPI_SUPPORTED)
arch_sched_ipi();
#endif
if (need_sched && _current->base.sched_locked == 0) {
z_reschedule_unlocked();
}
}
static inline int resched(u32_t key)
{
#ifdef CONFIG_SMP
_current_cpu->swap_ok = 0;
#endif
return arch_irq_unlocked(key) && !arch_is_in_isr();
}
void z_reschedule(struct k_spinlock *lock, k_spinlock_key_t key)
{
if (resched(key.key)) {
z_swap(lock, key);
} else {
k_spin_unlock(lock, key);
}
}
void z_reschedule_irqlock(u32_t key)
{
if (resched(key)) {
z_swap_irqlock(key);
} else {
irq_unlock(key);
}
}
void k_sched_lock(void)
{
LOCKED(&sched_spinlock) {
z_sched_lock();
}
}
void k_sched_unlock(void)
{
#ifdef CONFIG_PREEMPT_ENABLED
LOCKED(&sched_spinlock) {
__ASSERT(_current->base.sched_locked != 0, "");
__ASSERT(!arch_is_in_isr(), "");
++_current->base.sched_locked;
update_cache(0);
}
K_DEBUG("scheduler unlocked (%p:%d)\n",
_current, _current->base.sched_locked);
z_reschedule_unlocked();
#endif
}
#ifdef CONFIG_SMP
struct k_thread *z_get_next_ready_thread(void)
{
struct k_thread *ret = 0;
LOCKED(&sched_spinlock) {
ret = next_up();
}
return ret;
}
#endif
/* Just a wrapper around _current = xxx with tracing */
static inline void set_current(struct k_thread *new_thread)
{
_current_cpu->current = new_thread;
}
#ifdef CONFIG_USE_SWITCH
void *z_get_next_switch_handle(void *interrupted)
{
_current->switch_handle = interrupted;
z_check_stack_sentinel();
#ifdef CONFIG_SMP
LOCKED(&sched_spinlock) {
struct k_thread *thread = next_up();
if (_current != thread) {
update_metairq_preempt(thread);
#ifdef CONFIG_TIMESLICING
z_reset_time_slice();
#endif
_current_cpu->swap_ok = 0;
set_current(thread);
#ifdef CONFIG_SPIN_VALIDATE
/* Changed _current! Update the spinlock
* bookeeping so the validation doesn't get
* confused when the "wrong" thread tries to
* release the lock.
*/
z_spin_lock_set_owner(&sched_spinlock);
#endif
}
}
#else
set_current(z_get_next_ready_thread());
#endif
wait_for_switch(_current);
return _current->switch_handle;
}
#endif
ALWAYS_INLINE void z_priq_dumb_add(sys_dlist_t *pq, struct k_thread *thread)
{
struct k_thread *t;
__ASSERT_NO_MSG(!z_is_idle_thread_object(thread));
SYS_DLIST_FOR_EACH_CONTAINER(pq, t, base.qnode_dlist) {
if (z_is_t1_higher_prio_than_t2(thread, t)) {
sys_dlist_insert(&t->base.qnode_dlist,
&thread->base.qnode_dlist);
return;
}
}
sys_dlist_append(pq, &thread->base.qnode_dlist);
}
void z_priq_dumb_remove(sys_dlist_t *pq, struct k_thread *thread)
{
#if defined(CONFIG_SWAP_NONATOMIC) && defined(CONFIG_SCHED_DUMB)
if (pq == &_kernel.ready_q.runq && thread == _current &&
z_is_thread_prevented_from_running(thread)) {
return;
}
#endif
__ASSERT_NO_MSG(!z_is_idle_thread_object(thread));
sys_dlist_remove(&thread->base.qnode_dlist);
}
struct k_thread *z_priq_dumb_best(sys_dlist_t *pq)
{
struct k_thread *thread = NULL;
sys_dnode_t *n = sys_dlist_peek_head(pq);
if (n != NULL) {
thread = CONTAINER_OF(n, struct k_thread, base.qnode_dlist);
}
return thread;
}
bool z_priq_rb_lessthan(struct rbnode *a, struct rbnode *b)
{
struct k_thread *thread_a, *thread_b;
thread_a = CONTAINER_OF(a, struct k_thread, base.qnode_rb);
thread_b = CONTAINER_OF(b, struct k_thread, base.qnode_rb);
if (z_is_t1_higher_prio_than_t2(thread_a, thread_b)) {
return true;
} else if (z_is_t1_higher_prio_than_t2(thread_b, thread_a)) {
return false;
} else {
return thread_a->base.order_key < thread_b->base.order_key
? 1 : 0;
}
}
void z_priq_rb_add(struct _priq_rb *pq, struct k_thread *thread)
{
struct k_thread *t;
__ASSERT_NO_MSG(!z_is_idle_thread_object(thread));
thread->base.order_key = pq->next_order_key++;
/* Renumber at wraparound. This is tiny code, and in practice
* will almost never be hit on real systems. BUT on very
* long-running systems where a priq never completely empties
* AND that contains very large numbers of threads, it can be
* a latency glitch to loop over all the threads like this.
*/
if (!pq->next_order_key) {
RB_FOR_EACH_CONTAINER(&pq->tree, t, base.qnode_rb) {
t->base.order_key = pq->next_order_key++;
}
}
rb_insert(&pq->tree, &thread->base.qnode_rb);
}
void z_priq_rb_remove(struct _priq_rb *pq, struct k_thread *thread)
{
#if defined(CONFIG_SWAP_NONATOMIC) && defined(CONFIG_SCHED_SCALABLE)
if (pq == &_kernel.ready_q.runq && thread == _current &&
z_is_thread_prevented_from_running(thread)) {
return;
}
#endif
__ASSERT_NO_MSG(!z_is_idle_thread_object(thread));
rb_remove(&pq->tree, &thread->base.qnode_rb);
if (!pq->tree.root) {
pq->next_order_key = 0;
}
}
struct k_thread *z_priq_rb_best(struct _priq_rb *pq)
{
struct k_thread *thread = NULL;
struct rbnode *n = rb_get_min(&pq->tree);
if (n != NULL) {
thread = CONTAINER_OF(n, struct k_thread, base.qnode_rb);
}
return thread;
}
#ifdef CONFIG_SCHED_MULTIQ
# if (K_LOWEST_THREAD_PRIO - K_HIGHEST_THREAD_PRIO) > 31
# error Too many priorities for multiqueue scheduler (max 32)
# endif
#endif
ALWAYS_INLINE void z_priq_mq_add(struct _priq_mq *pq, struct k_thread *thread)
{
int priority_bit = thread->base.prio - K_HIGHEST_THREAD_PRIO;
sys_dlist_append(&pq->queues[priority_bit], &thread->base.qnode_dlist);
pq->bitmask |= BIT(priority_bit);
}
ALWAYS_INLINE void z_priq_mq_remove(struct _priq_mq *pq, struct k_thread *thread)
{
#if defined(CONFIG_SWAP_NONATOMIC) && defined(CONFIG_SCHED_MULTIQ)
if (pq == &_kernel.ready_q.runq && thread == _current &&
z_is_thread_prevented_from_running(thread)) {
return;
}
#endif
int priority_bit = thread->base.prio - K_HIGHEST_THREAD_PRIO;
sys_dlist_remove(&thread->base.qnode_dlist);
if (sys_dlist_is_empty(&pq->queues[priority_bit])) {
pq->bitmask &= ~BIT(priority_bit);
}
}
struct k_thread *z_priq_mq_best(struct _priq_mq *pq)
{
if (!pq->bitmask) {
return NULL;
}
struct k_thread *thread = NULL;
sys_dlist_t *l = &pq->queues[__builtin_ctz(pq->bitmask)];
sys_dnode_t *n = sys_dlist_peek_head(l);
if (n != NULL) {
thread = CONTAINER_OF(n, struct k_thread, base.qnode_dlist);
}
return thread;
}
int z_unpend_all(_wait_q_t *wait_q)
{
int need_sched = 0;
struct k_thread *thread;
while ((thread = z_waitq_head(wait_q)) != NULL) {
z_unpend_thread(thread);
z_ready_thread(thread);
need_sched = 1;
}
return need_sched;
}
void z_sched_init(void)
{
#ifdef CONFIG_SCHED_DUMB
sys_dlist_init(&_kernel.ready_q.runq);
#endif
#ifdef CONFIG_SCHED_SCALABLE
_kernel.ready_q.runq = (struct _priq_rb) {
.tree = {
.lessthan_fn = z_priq_rb_lessthan,
}
};
#endif
#ifdef CONFIG_SCHED_MULTIQ
for (int i = 0; i < ARRAY_SIZE(_kernel.ready_q.runq.queues); i++) {
sys_dlist_init(&_kernel.ready_q.runq.queues[i]);
}
#endif
#ifdef CONFIG_TIMESLICING
k_sched_time_slice_set(CONFIG_TIMESLICE_SIZE,
CONFIG_TIMESLICE_PRIORITY);
#endif
}
int z_impl_k_thread_priority_get(k_tid_t thread)
{
return thread->base.prio;
}
#ifdef CONFIG_USERSPACE
static inline int z_vrfy_k_thread_priority_get(k_tid_t thread)
{
Z_OOPS(Z_SYSCALL_OBJ(thread, K_OBJ_THREAD));
return z_impl_k_thread_priority_get(thread);
}
#include <syscalls/k_thread_priority_get_mrsh.c>
#endif
void z_impl_k_thread_priority_set(k_tid_t tid, int prio)
{
/*
* Use NULL, since we cannot know what the entry point is (we do not
* keep track of it) and idle cannot change its priority.
*/
Z_ASSERT_VALID_PRIO(prio, NULL);
__ASSERT(!arch_is_in_isr(), "");
struct k_thread *thread = (struct k_thread *)tid;
z_thread_priority_set(thread, prio);
}
#ifdef CONFIG_USERSPACE
static inline void z_vrfy_k_thread_priority_set(k_tid_t thread, int prio)
{
Z_OOPS(Z_SYSCALL_OBJ(thread, K_OBJ_THREAD));
Z_OOPS(Z_SYSCALL_VERIFY_MSG(_is_valid_prio(prio, NULL),
"invalid thread priority %d", prio));
Z_OOPS(Z_SYSCALL_VERIFY_MSG((s8_t)prio >= thread->base.prio,
"thread priority may only be downgraded (%d < %d)",
prio, thread->base.prio));
z_impl_k_thread_priority_set(thread, prio);
}
#include <syscalls/k_thread_priority_set_mrsh.c>
#endif
#ifdef CONFIG_SCHED_DEADLINE
void z_impl_k_thread_deadline_set(k_tid_t tid, int deadline)
{
struct k_thread *thread = tid;
LOCKED(&sched_spinlock) {
thread->base.prio_deadline = k_cycle_get_32() + deadline;
if (z_is_thread_queued(thread)) {
_priq_run_remove(&_kernel.ready_q.runq, thread);
_priq_run_add(&_kernel.ready_q.runq, thread);
}
}
}
#ifdef CONFIG_USERSPACE
static inline void z_vrfy_k_thread_deadline_set(k_tid_t tid, int deadline)
{
struct k_thread *thread = tid;
Z_OOPS(Z_SYSCALL_OBJ(thread, K_OBJ_THREAD));
Z_OOPS(Z_SYSCALL_VERIFY_MSG(deadline > 0,
"invalid thread deadline %d",
(int)deadline));
z_impl_k_thread_deadline_set((k_tid_t)thread, deadline);
}
#include <syscalls/k_thread_deadline_set_mrsh.c>
#endif
#endif
void z_impl_k_yield(void)
{
__ASSERT(!arch_is_in_isr(), "");
if (!z_is_idle_thread_object(_current)) {
LOCKED(&sched_spinlock) {
if (!IS_ENABLED(CONFIG_SMP) ||
z_is_thread_queued(_current)) {
_priq_run_remove(&_kernel.ready_q.runq,
_current);
}
_priq_run_add(&_kernel.ready_q.runq, _current);
z_mark_thread_as_queued(_current);
update_cache(1);
}
}
z_swap_unlocked();
}
#ifdef CONFIG_USERSPACE
static inline void z_vrfy_k_yield(void)
{
z_impl_k_yield();
}
#include <syscalls/k_yield_mrsh.c>
#endif
static s32_t z_tick_sleep(s32_t ticks)
{
#ifdef CONFIG_MULTITHREADING
u32_t expected_wakeup_time;
__ASSERT(!arch_is_in_isr(), "");
K_DEBUG("thread %p for %d ticks\n", _current, ticks);
/* wait of 0 ms is treated as a 'yield' */
if (ticks == 0) {
k_yield();
return 0;
}
k_timeout_t timeout;
#ifndef CONFIG_LEGACY_TIMEOUT_API
timeout = Z_TIMEOUT_TICKS(ticks);
#else
ticks += _TICK_ALIGN;
timeout = (k_ticks_t) ticks;
#endif
expected_wakeup_time = ticks + z_tick_get_32();
/* Spinlock purely for local interrupt locking to prevent us
* from being interrupted while _current is in an intermediate
* state. Should unify this implementation with pend().
*/
struct k_spinlock local_lock = {};
k_spinlock_key_t key = k_spin_lock(&local_lock);
#if defined(CONFIG_TIMESLICING) && defined(CONFIG_SWAP_NONATOMIC)
pending_current = _current;
#endif
z_remove_thread_from_ready_q(_current);
z_add_thread_timeout(_current, timeout);
z_mark_thread_as_suspended(_current);
(void)z_swap(&local_lock, key);
__ASSERT(!z_is_thread_state_set(_current, _THREAD_SUSPENDED), "");
ticks = expected_wakeup_time - z_tick_get_32();
if (ticks > 0) {
return ticks;
}
#endif
return 0;
}
s32_t z_impl_k_sleep(k_timeout_t timeout)
{
k_ticks_t ticks;
__ASSERT(!arch_is_in_isr(), "");
if (K_TIMEOUT_EQ(timeout, K_FOREVER)) {
k_thread_suspend(_current);
return (s32_t) K_TICKS_FOREVER;
}
#ifdef CONFIG_LEGACY_TIMEOUT_API
ticks = k_ms_to_ticks_ceil32(timeout);
#else
ticks = timeout.ticks;
#endif
ticks = z_tick_sleep(ticks);
return k_ticks_to_ms_floor64(ticks);
}
#ifdef CONFIG_USERSPACE
static inline s32_t z_vrfy_k_sleep(k_timeout_t timeout)
{
return z_impl_k_sleep(timeout);
}
#include <syscalls/k_sleep_mrsh.c>
#endif
s32_t z_impl_k_usleep(int us)
{
s32_t ticks;
ticks = k_us_to_ticks_ceil64(us);
ticks = z_tick_sleep(ticks);
return k_ticks_to_us_floor64(ticks);
}
#ifdef CONFIG_USERSPACE
static inline s32_t z_vrfy_k_usleep(int us)
{
return z_impl_k_usleep(us);
}
#include <syscalls/k_usleep_mrsh.c>
#endif
void z_impl_k_wakeup(k_tid_t thread)
{
if (z_is_thread_pending(thread)) {
return;
}
if (z_abort_thread_timeout(thread) < 0) {
/* Might have just been sleeping forever */
if (thread->base.thread_state != _THREAD_SUSPENDED) {
return;
}
}
z_mark_thread_as_not_suspended(thread);
z_ready_thread(thread);
#if defined(CONFIG_SMP) && defined(CONFIG_SCHED_IPI_SUPPORTED)
arch_sched_ipi();
#endif
if (!arch_is_in_isr()) {
z_reschedule_unlocked();
}
}
#ifdef CONFIG_SMP
void z_sched_ipi(void)
{
/* NOTE: When adding code to this, make sure this is called
* at appropriate location when !CONFIG_SCHED_IPI_SUPPORTED.
*/
}
void z_sched_abort(struct k_thread *thread)
{
k_spinlock_key_t key;
if (thread == _current) {
z_remove_thread_from_ready_q(thread);
return;
}
/* First broadcast an IPI to the other CPUs so they can stop
* it locally. Not all architectures support that, alas. If
* we don't have it, we need to wait for some other interrupt.
*/
key = k_spin_lock(&sched_spinlock);
thread->base.thread_state |= _THREAD_ABORTING;
k_spin_unlock(&sched_spinlock, key);
#ifdef CONFIG_SCHED_IPI_SUPPORTED
arch_sched_ipi();
#endif
/* Wait for it to be flagged dead either by the CPU it was
* running on or because we caught it idle in the queue
*/
while ((thread->base.thread_state & _THREAD_DEAD) == 0U) {
key = k_spin_lock(&sched_spinlock);
if (z_is_thread_prevented_from_running(thread)) {
__ASSERT(!z_is_thread_queued(thread), "");
thread->base.thread_state |= _THREAD_DEAD;
k_spin_unlock(&sched_spinlock, key);
} else if (z_is_thread_queued(thread)) {
_priq_run_remove(&_kernel.ready_q.runq, thread);
z_mark_thread_as_not_queued(thread);
thread->base.thread_state |= _THREAD_DEAD;
k_spin_unlock(&sched_spinlock, key);
} else {
k_spin_unlock(&sched_spinlock, key);
k_busy_wait(100);
}
}
/* If the thread self-aborted (e.g. its own exit raced with
* this external abort) then even though it is flagged DEAD,
* it's still running until its next swap and thus the thread
* object is still in use. We have to resort to a fallback
* delay in that circumstance.
*/
if ((thread->base.thread_state & _THREAD_ABORTED_IN_ISR) == 0U) {
k_busy_wait(THREAD_ABORT_DELAY_US);
}
}
#endif
#ifdef CONFIG_USERSPACE
static inline void z_vrfy_k_wakeup(k_tid_t thread)
{
Z_OOPS(Z_SYSCALL_OBJ(thread, K_OBJ_THREAD));
z_impl_k_wakeup(thread);
}
#include <syscalls/k_wakeup_mrsh.c>
#endif
k_tid_t z_impl_k_current_get(void)
{
#ifdef CONFIG_SMP
/* In SMP, _current is a field read from _current_cpu, which
* can race with preemption before it is read. We must lock
* local interrupts when reading it.
*/
unsigned int k = arch_irq_lock();
#endif
k_tid_t ret = _current_cpu->current;
#ifdef CONFIG_SMP
arch_irq_unlock(k);
#endif
return ret;
}
#ifdef CONFIG_USERSPACE
static inline k_tid_t z_vrfy_k_current_get(void)
{
return z_impl_k_current_get();
}
#include <syscalls/k_current_get_mrsh.c>
#endif
int z_impl_k_is_preempt_thread(void)
{
return !arch_is_in_isr() && is_preempt(_current);
}
#ifdef CONFIG_USERSPACE
static inline int z_vrfy_k_is_preempt_thread(void)
{
return z_impl_k_is_preempt_thread();
}
#include <syscalls/k_is_preempt_thread_mrsh.c>
#endif
#ifdef CONFIG_SCHED_CPU_MASK
# ifdef CONFIG_SMP
/* Right now we use a single byte for this mask */
BUILD_ASSERT(CONFIG_MP_NUM_CPUS <= 8, "Too many CPUs for mask word");
# endif
static int cpu_mask_mod(k_tid_t thread, u32_t enable_mask, u32_t disable_mask)
{
int ret = 0;
LOCKED(&sched_spinlock) {
if (z_is_thread_prevented_from_running(thread)) {
thread->base.cpu_mask |= enable_mask;
thread->base.cpu_mask &= ~disable_mask;
} else {
ret = -EINVAL;
}
}
return ret;
}
int k_thread_cpu_mask_clear(k_tid_t thread)
{
return cpu_mask_mod(thread, 0, 0xffffffff);
}
int k_thread_cpu_mask_enable_all(k_tid_t thread)
{
return cpu_mask_mod(thread, 0xffffffff, 0);
}
int k_thread_cpu_mask_enable(k_tid_t thread, int cpu)
{
return cpu_mask_mod(thread, BIT(cpu), 0);
}
int k_thread_cpu_mask_disable(k_tid_t thread, int cpu)
{
return cpu_mask_mod(thread, 0, BIT(cpu));
}
#endif /* CONFIG_SCHED_CPU_MASK */
int z_impl_k_thread_join(struct k_thread *thread, k_timeout_t timeout)
{
k_spinlock_key_t key;
int ret;
__ASSERT(((arch_is_in_isr() == false) ||
K_TIMEOUT_EQ(timeout, K_NO_WAIT)), "");
key = k_spin_lock(&sched_spinlock);
if ((thread->base.pended_on == &_current->base.join_waiters) ||
(thread == _current)) {
ret = -EDEADLK;
goto out;
}
if ((thread->base.thread_state & _THREAD_DEAD) != 0) {
ret = 0;
goto out;
}
if (K_TIMEOUT_EQ(timeout, K_NO_WAIT)) {
ret = -EBUSY;
goto out;
}
#if defined(CONFIG_TIMESLICING) && defined(CONFIG_SWAP_NONATOMIC)
pending_current = _current;
#endif
add_to_waitq_locked(_current, &thread->base.join_waiters);
add_thread_timeout(_current, timeout);
return z_swap(&sched_spinlock, key);
out:
k_spin_unlock(&sched_spinlock, key);
return ret;
}
#ifdef CONFIG_USERSPACE
/* Special case: don't oops if the thread is uninitialized. This is because
* the initialization bit does double-duty for thread objects; if false, means
* the thread object is truly uninitialized, or the thread ran and exited for
* some reason.
*
* Return true in this case indicating we should just do nothing and return
* success to the caller.
*/
static bool thread_obj_validate(struct k_thread *thread)
{
struct z_object *ko = z_object_find(thread);
int ret = z_object_validate(ko, K_OBJ_THREAD, _OBJ_INIT_TRUE);
switch (ret) {
case 0:
return false;
case -EINVAL:
return true;
default:
#ifdef CONFIG_LOG
z_dump_object_error(ret, thread, ko, K_OBJ_THREAD);
#endif
Z_OOPS(Z_SYSCALL_VERIFY_MSG(ret, "access denied"));
}
CODE_UNREACHABLE;
}
static inline int z_vrfy_k_thread_join(struct k_thread *thread,
k_timeout_t timeout)
{
if (thread_obj_validate(thread)) {
return 0;
}
return z_impl_k_thread_join(thread, timeout);
}
#include <syscalls/k_thread_join_mrsh.c>
static inline void z_vrfy_k_thread_abort(k_tid_t thread)
{
if (thread_obj_validate(thread)) {
return;
}
Z_OOPS(Z_SYSCALL_VERIFY_MSG(!(thread->base.user_options & K_ESSENTIAL),
"aborting essential thread %p", thread));
z_impl_k_thread_abort((struct k_thread *)thread);
}
#include <syscalls/k_thread_abort_mrsh.c>
#endif /* CONFIG_USERSPACE */