/* * Copyright (c) 2018 Intel Corporation * * SPDX-License-Identifier: Apache-2.0 */ #include #include #include #include #include #include #include #include #include #include #include #include #include LOG_MODULE_DECLARE(os, CONFIG_KERNEL_LOG_LEVEL); #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 struct k_spinlock sched_spinlock; static void update_cache(int); static void end_thread(struct k_thread *thread); static inline int is_preempt(struct k_thread *thread) { /* explanation in kernel_struct.h */ return thread->base.preempt <= _PREEMPT_THRESHOLD; } 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 /* * Return value same as e.g. memcmp * > 0 -> thread 1 priority > thread 2 priority * = 0 -> thread 1 priority == thread 2 priority * < 0 -> thread 1 priority < thread 2 priority * Do not rely on the actual value returned aside from the above. * (Again, like memcmp.) */ int32_t z_sched_prio_cmp(struct k_thread *thread_1, struct k_thread *thread_2) { /* `prio` is <32b, so the below cannot overflow. */ int32_t b1 = thread_1->base.prio; int32_t b2 = thread_2->base.prio; if (b1 != b2) { return b2 - b1; } #ifdef CONFIG_SCHED_DEADLINE /* If we assume all deadlines live within the same "half" of * the 32 bit modulus space (this is a documented API rule), * then the latest deadline in the queue minus the earliest is * guaranteed to be (2's complement) non-negative. We can * leverage that to compare the values without having to check * the current time. */ uint32_t d1 = thread_1->base.prio_deadline; uint32_t d2 = thread_2->base.prio_deadline; if (d1 != d2) { /* Sooner deadline means higher effective priority. * Doing the calculation with unsigned types and casting * to signed isn't perfect, but at least reduces this * from UB on overflow to impdef. */ return (int32_t) (d2 - d1); } #endif return 0; } 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; } 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 /* _current is never in the run queue until context switch on * SMP configurations, see z_requeue_current() */ static inline bool should_queue_thread(struct k_thread *th) { return !IS_ENABLED(CONFIG_SMP) || th != _current; } static ALWAYS_INLINE void queue_thread(void *pq, struct k_thread *thread) { thread->base.thread_state |= _THREAD_QUEUED; if (should_queue_thread(thread)) { _priq_run_add(pq, thread); } #ifdef CONFIG_SMP if (thread == _current) { /* add current to end of queue means "yield" */ _current_cpu->swap_ok = true; } #endif } static ALWAYS_INLINE void dequeue_thread(void *pq, struct k_thread *thread) { thread->base.thread_state &= ~_THREAD_QUEUED; if (should_queue_thread(thread)) { _priq_run_remove(pq, thread); } } #ifdef CONFIG_SMP /* Called out of z_swap() when CONFIG_SMP. The current thread can * never live in the run queue until we are inexorably on the context * switch path on SMP, otherwise there is a deadlock condition where a * set of CPUs pick a cycle of threads to run and wait for them all to * context switch forever. */ void z_requeue_current(struct k_thread *curr) { if (z_is_thread_queued(curr)) { _priq_run_add(&_kernel.ready_q.runq, curr); } } #endif static inline bool is_aborting(struct k_thread *thread) { return (thread->base.thread_state & _THREAD_ABORTING) != 0U; } static ALWAYS_INLINE struct k_thread *next_up(void) { struct k_thread *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 #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 != NULL) ? 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". */ if (is_aborting(_current)) { end_thread(_current); } 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) { int32_t cmp = z_sched_prio_cmp(_current, thread); /* Ties only switch if state says we yielded */ if ((cmp > 0) || ((cmp == 0) && !_current_cpu->swap_ok)) { 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) { queue_thread(&_kernel.ready_q.runq, _current); } /* Take the new _current out of the queue */ if (z_is_thread_queued(thread)) { dequeue_thread(&_kernel.ready_q.runq, thread); } _current_cpu->swap_ok = false; return thread; #endif } static void move_thread_to_end_of_prio_q(struct k_thread *thread) { if (z_is_thread_queued(thread)) { dequeue_thread(&_kernel.ready_q.runq, thread); } queue_thread(&_kernel.ready_q.runq, thread); update_cache(thread == _current); } #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 + sys_clock_elapsed(); z_set_timeout_expiry(slice_time, false); } } void k_sched_time_slice_set(int32_t slice, int prio) { LOCKED(&sched_spinlock) { _current_cpu->slice_ticks = 0; slice_time = k_ms_to_ticks_ceil32(slice); if (IS_ENABLED(CONFIG_TICKLESS_KERNEL) && slice > 0) { /* It's not possible to reliably set a 1-tick * timeout if ticks aren't regular. */ slice_time = MAX(2, slice_time); } slice_max_prio = prio; z_reset_time_slice(); } } static inline int sliceable(struct k_thread *thread) { return is_preempt(thread) && !z_is_thread_prevented_from_running(thread) && !z_is_prio_higher(thread->base.prio, slice_max_prio) && !z_is_idle_thread_object(thread); } /* Called out of each timer interrupt */ void z_time_slice(int ticks) { /* Hold sched_spinlock, so that activity on another CPU * (like a call to k_thread_abort() at just the wrong time) * won't affect the correctness of the decisions made here. * Also prevents any nested interrupts from changing * thread state to avoid similar issues, since this would * normally run with IRQs enabled. */ k_spinlock_key_t key = k_spin_lock(&sched_spinlock); #ifdef CONFIG_SWAP_NONATOMIC if (pending_current == _current) { z_reset_time_slice(); k_spin_unlock(&sched_spinlock, key); return; } pending_current = NULL; #endif if (slice_time && sliceable(_current)) { if (ticks >= _current_cpu->slice_ticks) { move_thread_to_end_of_prio_q(_current); z_reset_time_slice(); } else { _current_cpu->slice_ticks -= ticks; } } else { _current_cpu->slice_ticks = 0; } k_spin_unlock(&sched_spinlock, key); } #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) && !z_is_idle_thread_object(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 bool thread_active_elsewhere(struct k_thread *thread) { /* True if the thread is currently running on another CPU. * There are more scalable designs to answer this question in * constant time, but this is fine for now. */ #ifdef CONFIG_SMP int currcpu = _current_cpu->id; for (int i = 0; i < CONFIG_MP_NUM_CPUS; i++) { if ((i != currcpu) && (_kernel.cpus[i].current == thread)) { return true; } } #endif return false; } static void ready_thread(struct k_thread *thread) { #ifdef CONFIG_KERNEL_COHERENCE __ASSERT_NO_MSG(arch_mem_coherent(thread)); #endif /* If thread is queued already, do not try and added it to the * run queue again */ if (!z_is_thread_queued(thread) && z_is_thread_ready(thread)) { SYS_PORT_TRACING_OBJ_FUNC(k_thread, sched_ready, thread); queue_thread(&_kernel.ready_q.runq, 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) { if (!thread_active_elsewhere(thread)) { ready_thread(thread); } } } void z_move_thread_to_end_of_prio_q(struct k_thread *thread) { LOCKED(&sched_spinlock) { move_thread_to_end_of_prio_q(thread); } } 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) { SYS_PORT_TRACING_OBJ_FUNC_ENTER(k_thread, suspend, thread); (void)z_abort_thread_timeout(thread); LOCKED(&sched_spinlock) { if (z_is_thread_queued(thread)) { dequeue_thread(&_kernel.ready_q.runq, thread); } z_mark_thread_as_suspended(thread); update_cache(thread == _current); } if (thread == _current) { z_reschedule_unlocked(); } SYS_PORT_TRACING_OBJ_FUNC_EXIT(k_thread, suspend, thread); } #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 #endif void z_impl_k_thread_resume(struct k_thread *thread) { SYS_PORT_TRACING_OBJ_FUNC_ENTER(k_thread, resume, thread); k_spinlock_key_t key = k_spin_lock(&sched_spinlock); /* Do not try to resume a thread that was not suspended */ if (!z_is_thread_suspended(thread)) { k_spin_unlock(&sched_spinlock, key); return; } z_mark_thread_as_not_suspended(thread); ready_thread(thread); z_reschedule(&sched_spinlock, key); SYS_PORT_TRACING_OBJ_FUNC_EXIT(k_thread, resume, thread); } #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 #endif static _wait_q_t *pended_on_thread(struct k_thread *thread) { __ASSERT_NO_MSG(thread->base.pended_on); return thread->base.pended_on; } static void unready_thread(struct k_thread *thread) { if (z_is_thread_queued(thread)) { dequeue_thread(&_kernel.ready_q.runq, thread); } update_cache(thread == _current); } /* 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_PORT_TRACING_FUNC(k_thread, sched_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)) { z_add_thread_timeout(thread, timeout); } } static void pend(struct k_thread *thread, _wait_q_t *wait_q, k_timeout_t timeout) { #ifdef CONFIG_KERNEL_COHERENCE __ASSERT_NO_MSG(wait_q == NULL || arch_mem_coherent(wait_q)); #endif 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); } static inline void unpend_thread_no_timeout(struct k_thread *thread) { _priq_wait_remove(&pended_on_thread(thread)->waitq, thread); z_mark_thread_as_not_pending(thread); thread->base.pended_on = NULL; } ALWAYS_INLINE void z_unpend_thread_no_timeout(struct k_thread *thread) { LOCKED(&sched_spinlock) { unpend_thread_no_timeout(thread); } } #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); LOCKED(&sched_spinlock) { bool killed = ((thread->base.thread_state & _THREAD_DEAD) || (thread->base.thread_state & _THREAD_ABORTING)); if (!killed) { if (thread->base.pended_on != NULL) { unpend_thread_no_timeout(thread); } z_mark_thread_as_started(thread); z_mark_thread_as_not_suspended(thread); ready_thread(thread); } } } #endif int z_pend_curr_irqlock(uint32_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_unpend1_no_timeout(_wait_q_t *wait_q) { struct k_thread *thread = NULL; LOCKED(&sched_spinlock) { thread = _priq_wait_best(&wait_q->waitq); if (thread != NULL) { unpend_thread_no_timeout(thread); } } return thread; } struct k_thread *z_unpend_first_thread(_wait_q_t *wait_q) { struct k_thread *thread = NULL; LOCKED(&sched_spinlock) { thread = _priq_wait_best(&wait_q->waitq); if (thread != NULL) { unpend_thread_no_timeout(thread); (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)) { dequeue_thread(&_kernel.ready_q.runq, thread); thread->base.prio = prio; queue_thread(&_kernel.ready_q.runq, thread); } else { thread->base.prio = prio; } update_cache(1); } else { thread->base.prio = prio; } } SYS_PORT_TRACING_OBJ_FUNC(k_thread, sched_priority_set, thread, prio); 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 == 0U) { z_reschedule_unlocked(); } } static inline bool resched(uint32_t key) { #ifdef CONFIG_SMP _current_cpu->swap_ok = 0; #endif return arch_irq_unlocked(key) && !arch_is_in_isr(); } /* * Check if the next ready thread is the same as the current thread * and save the trip if true. */ static inline bool need_swap(void) { /* the SMP case will be handled in C based z_swap() */ #ifdef CONFIG_SMP return true; #else struct k_thread *new_thread; /* Check if the next ready thread is the same as the current thread */ new_thread = _kernel.ready_q.cache; return new_thread != _current; #endif } void z_reschedule(struct k_spinlock *lock, k_spinlock_key_t key) { if (resched(key.key) && need_swap()) { z_swap(lock, key); } else { k_spin_unlock(lock, key); } } void z_reschedule_irqlock(uint32_t key) { if (resched(key)) { z_swap_irqlock(key); } else { irq_unlock(key); } } void k_sched_lock(void) { LOCKED(&sched_spinlock) { SYS_PORT_TRACING_FUNC(k_thread, sched_lock); z_sched_lock(); } } void k_sched_unlock(void) { LOCKED(&sched_spinlock) { __ASSERT(_current->base.sched_locked != 0U, ""); __ASSERT(!arch_is_in_isr(), ""); ++_current->base.sched_locked; update_cache(0); } LOG_DBG("scheduler unlocked (%p:%d)", _current, _current->base.sched_locked); SYS_PORT_TRACING_FUNC(k_thread, sched_unlock); z_reschedule_unlocked(); } struct k_thread *z_swap_next_thread(void) { #ifdef CONFIG_SMP return next_up(); #else return _kernel.ready_q.cache; #endif } /* Just a wrapper around _current = xxx with tracing */ static inline void set_current(struct k_thread *new_thread) { z_thread_mark_switched_out(); _current_cpu->current = new_thread; } #ifdef CONFIG_USE_SWITCH void *z_get_next_switch_handle(void *interrupted) { z_check_stack_sentinel(); #ifdef CONFIG_SMP void *ret = NULL; LOCKED(&sched_spinlock) { struct k_thread *old_thread = _current, *new_thread; if (IS_ENABLED(CONFIG_SMP)) { old_thread->switch_handle = NULL; } new_thread = next_up(); if (old_thread != new_thread) { update_metairq_preempt(new_thread); wait_for_switch(new_thread); arch_cohere_stacks(old_thread, interrupted, new_thread); #ifdef CONFIG_TIMESLICING z_reset_time_slice(); #endif _current_cpu->swap_ok = 0; set_current(new_thread); #ifdef CONFIG_SPIN_VALIDATE /* Changed _current! Update the spinlock * bookkeeping so the validation doesn't get * confused when the "wrong" thread tries to * release the lock. */ z_spin_lock_set_owner(&sched_spinlock); #endif /* A queued (runnable) old/current thread * needs to be added back to the run queue * here, and atomically with its switch handle * being set below. This is safe now, as we * will not return into it. */ if (z_is_thread_queued(old_thread)) { _priq_run_add(&_kernel.ready_q.runq, old_thread); } } old_thread->switch_handle = interrupted; ret = new_thread->switch_handle; if (IS_ENABLED(CONFIG_SMP)) { /* Active threads MUST have a null here */ new_thread->switch_handle = NULL; } } return ret; #else _current->switch_handle = interrupted; set_current(_kernel.ready_q.cache); return _current->switch_handle; #endif } #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_sched_prio_cmp(thread, t) > 0) { 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) { __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; int32_t cmp; thread_a = CONTAINER_OF(a, struct k_thread, base.qnode_rb); thread_b = CONTAINER_OF(b, struct k_thread, base.qnode_rb); cmp = z_sched_prio_cmp(thread_a, thread_b); if (cmp > 0) { return true; } else if (cmp < 0) { 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) { __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) { 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 #endif void z_impl_k_thread_priority_set(k_tid_t thread, 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 *th = (struct k_thread *)thread; z_thread_priority_set(th, 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((int8_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 #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)) { dequeue_thread(&_kernel.ready_q.runq, thread); queue_thread(&_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 #endif #endif void z_impl_k_yield(void) { __ASSERT(!arch_is_in_isr(), ""); SYS_PORT_TRACING_FUNC(k_thread, yield); k_spinlock_key_t key = k_spin_lock(&sched_spinlock); if (!IS_ENABLED(CONFIG_SMP) || z_is_thread_queued(_current)) { dequeue_thread(&_kernel.ready_q.runq, _current); } queue_thread(&_kernel.ready_q.runq, _current); update_cache(1); z_swap(&sched_spinlock, key); } #ifdef CONFIG_USERSPACE static inline void z_vrfy_k_yield(void) { z_impl_k_yield(); } #include #endif static int32_t z_tick_sleep(k_ticks_t ticks) { #ifdef CONFIG_MULTITHREADING uint32_t expected_wakeup_ticks; __ASSERT(!arch_is_in_isr(), ""); #ifndef CONFIG_TIMEOUT_64BIT /* LOG subsys does not handle 64-bit values * https://github.com/zephyrproject-rtos/zephyr/issues/26246 */ LOG_DBG("thread %p for %u ticks", _current, ticks); #endif /* wait of 0 ms is treated as a 'yield' */ if (ticks == 0) { k_yield(); return 0; } k_timeout_t timeout = Z_TIMEOUT_TICKS(ticks); if (Z_TICK_ABS(ticks) <= 0) { expected_wakeup_ticks = ticks + sys_clock_tick_get_32(); } else { expected_wakeup_ticks = Z_TICK_ABS(ticks); } k_spinlock_key_t key = k_spin_lock(&sched_spinlock); #if defined(CONFIG_TIMESLICING) && defined(CONFIG_SWAP_NONATOMIC) pending_current = _current; #endif unready_thread(_current); z_add_thread_timeout(_current, timeout); z_mark_thread_as_suspended(_current); (void)z_swap(&sched_spinlock, key); __ASSERT(!z_is_thread_state_set(_current, _THREAD_SUSPENDED), ""); ticks = (k_ticks_t)expected_wakeup_ticks - sys_clock_tick_get_32(); if (ticks > 0) { return ticks; } #endif return 0; } int32_t z_impl_k_sleep(k_timeout_t timeout) { k_ticks_t ticks; __ASSERT(!arch_is_in_isr(), ""); SYS_PORT_TRACING_FUNC_ENTER(k_thread, sleep, timeout); /* in case of K_FOREVER, we suspend */ if (K_TIMEOUT_EQ(timeout, K_FOREVER)) { k_thread_suspend(_current); SYS_PORT_TRACING_FUNC_EXIT(k_thread, sleep, timeout, (int32_t) K_TICKS_FOREVER); return (int32_t) K_TICKS_FOREVER; } ticks = timeout.ticks; ticks = z_tick_sleep(ticks); int32_t ret = k_ticks_to_ms_floor64(ticks); SYS_PORT_TRACING_FUNC_EXIT(k_thread, sleep, timeout, ret); return ret; } #ifdef CONFIG_USERSPACE static inline int32_t z_vrfy_k_sleep(k_timeout_t timeout) { return z_impl_k_sleep(timeout); } #include #endif int32_t z_impl_k_usleep(int us) { int32_t ticks; SYS_PORT_TRACING_FUNC_ENTER(k_thread, usleep, us); ticks = k_us_to_ticks_ceil64(us); ticks = z_tick_sleep(ticks); SYS_PORT_TRACING_FUNC_EXIT(k_thread, usleep, us, k_ticks_to_us_floor64(ticks)); return k_ticks_to_us_floor64(ticks); } #ifdef CONFIG_USERSPACE static inline int32_t z_vrfy_k_usleep(int us) { return z_impl_k_usleep(us); } #include #endif void z_impl_k_wakeup(k_tid_t thread) { SYS_PORT_TRACING_OBJ_FUNC(k_thread, wakeup, 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_TRACE_SCHED_IPI extern void z_trace_sched_ipi(void); #endif #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. */ #ifdef CONFIG_TRACE_SCHED_IPI z_trace_sched_ipi(); #endif } #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 #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 #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 #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, uint32_t enable_mask, uint32_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 */ static inline void unpend_all(_wait_q_t *wait_q) { struct k_thread *thread; while ((thread = z_waitq_head(wait_q)) != NULL) { unpend_thread_no_timeout(thread); (void)z_abort_thread_timeout(thread); arch_thread_return_value_set(thread, 0); ready_thread(thread); } } static void end_thread(struct k_thread *thread) { /* We hold the lock, and the thread is known not to be running * anywhere. */ if ((thread->base.thread_state & _THREAD_DEAD) == 0U) { thread->base.thread_state |= _THREAD_DEAD; thread->base.thread_state &= ~_THREAD_ABORTING; if (z_is_thread_queued(thread)) { dequeue_thread(&_kernel.ready_q.runq, thread); } if (thread->base.pended_on != NULL) { unpend_thread_no_timeout(thread); } (void)z_abort_thread_timeout(thread); unpend_all(&thread->join_queue); update_cache(1); SYS_PORT_TRACING_FUNC(k_thread, sched_abort, thread); z_thread_monitor_exit(thread); #ifdef CONFIG_USERSPACE z_mem_domain_exit_thread(thread); z_thread_perms_all_clear(thread); z_object_uninit(thread->stack_obj); z_object_uninit(thread); #endif } } void z_thread_abort(struct k_thread *thread) { k_spinlock_key_t key = k_spin_lock(&sched_spinlock); if ((thread->base.thread_state & _THREAD_DEAD) != 0U) { k_spin_unlock(&sched_spinlock, key); return; } #ifdef CONFIG_SMP if (is_aborting(thread) && thread == _current && arch_is_in_isr()) { /* Another CPU is spinning for us, don't deadlock */ end_thread(thread); } bool active = thread_active_elsewhere(thread); if (active) { /* It's running somewhere else, flag and poke */ thread->base.thread_state |= _THREAD_ABORTING; #ifdef CONFIG_SCHED_IPI_SUPPORTED arch_sched_ipi(); #endif } if (is_aborting(thread) && thread != _current) { if (arch_is_in_isr()) { /* ISRs can only spin waiting another CPU */ k_spin_unlock(&sched_spinlock, key); while (is_aborting(thread)) { } } else if (active) { /* Threads can join */ add_to_waitq_locked(_current, &thread->join_queue); z_swap(&sched_spinlock, key); } return; /* lock has been released */ } #endif end_thread(thread); if (thread == _current && !arch_is_in_isr()) { z_swap(&sched_spinlock, key); __ASSERT(false, "aborted _current back from dead"); } k_spin_unlock(&sched_spinlock, key); } #if !defined(CONFIG_ARCH_HAS_THREAD_ABORT) void z_impl_k_thread_abort(struct k_thread *thread) { SYS_PORT_TRACING_OBJ_FUNC_ENTER(k_thread, abort, thread); z_thread_abort(thread); SYS_PORT_TRACING_OBJ_FUNC_EXIT(k_thread, abort, thread); } #endif int z_impl_k_thread_join(struct k_thread *thread, k_timeout_t timeout) { k_spinlock_key_t key = k_spin_lock(&sched_spinlock); int ret = 0; SYS_PORT_TRACING_OBJ_FUNC_ENTER(k_thread, join, thread, timeout); if ((thread->base.thread_state & _THREAD_DEAD) != 0U) { ret = 0; } else if (K_TIMEOUT_EQ(timeout, K_NO_WAIT)) { ret = -EBUSY; } else if ((thread == _current) || (thread->base.pended_on == &_current->join_queue)) { ret = -EDEADLK; } else { __ASSERT(!arch_is_in_isr(), "cannot join in ISR"); add_to_waitq_locked(_current, &thread->join_queue); add_thread_timeout(_current, timeout); SYS_PORT_TRACING_OBJ_FUNC_BLOCKING(k_thread, join, thread, timeout); ret = z_swap(&sched_spinlock, key); SYS_PORT_TRACING_OBJ_FUNC_EXIT(k_thread, join, thread, timeout, ret); return ret; } SYS_PORT_TRACING_OBJ_FUNC_EXIT(k_thread, join, thread, timeout, ret); 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; /* LCOV_EXCL_LINE */ } 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 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 #endif /* CONFIG_USERSPACE */ /* * future scheduler.h API implementations */ bool z_sched_wake(_wait_q_t *wait_q, int swap_retval, void *swap_data) { struct k_thread *thread; bool ret = false; LOCKED(&sched_spinlock) { thread = _priq_wait_best(&wait_q->waitq); if (thread != NULL) { z_thread_return_value_set_with_data(thread, swap_retval, swap_data); unpend_thread_no_timeout(thread); (void)z_abort_thread_timeout(thread); ready_thread(thread); ret = true; } } return ret; } int z_sched_wait(struct k_spinlock *lock, k_spinlock_key_t key, _wait_q_t *wait_q, k_timeout_t timeout, void **data) { int ret = z_pend_curr(lock, key, wait_q, timeout); if (data != NULL) { *data = _current->base.swap_data; } return ret; }