kernel/poll.c - third_party/github/zephyrproject-rtos/zephyr - Git at Google

 /*
  * Copyright (c) 2017 Wind River Systems, Inc.
  *
  * SPDX-License-Identifier: Apache-2.0
  */

 /**
  * @file
  *
  * @brief Kernel asynchronous event polling interface.
  *
  * This polling mechanism allows waiting on multiple events concurrently,
  * either events triggered directly, or from kernel objects or other kernel
  * constructs.
  */

 #include <kernel.h>
 #include <kernel_structs.h>
 #include <kernel_internal.h>
 #include <wait_q.h>
 #include <ksched.h>
 #include <syscall_handler.h>
 #include <misc/slist.h>
 #include <misc/dlist.h>
 #include <misc/util.h>
 #include <misc/__assert.h>

 void k_poll_event_init(struct k_poll_event *event, u32_t type,
 		       int mode, void *obj)
 {
 	__ASSERT(mode == K_POLL_MODE_NOTIFY_ONLY,
 		 "only NOTIFY_ONLY mode is supported\n");
 	__ASSERT(type < (BIT(_POLL_NUM_TYPES)), "invalid type\n");
 	__ASSERT(obj, "must provide an object\n");

 	event->poller = NULL;
 	/* event->tag is left uninitialized: the user will set it if needed */
 	event->type = type;
 	event->state = K_POLL_STATE_NOT_READY;
 	event->mode = mode;
 	event->unused = 0;
 	event->obj = obj;
 }

 /* must be called with interrupts locked */
 static inline int is_condition_met(struct k_poll_event *event, u32_t *state)
 {
 	switch (event->type) {
 	case K_POLL_TYPE_SEM_AVAILABLE:
 		if (k_sem_count_get(event->sem) > 0) {
 			*state = K_POLL_STATE_SEM_AVAILABLE;
 			return 1;
 		}
 		break;
 	case K_POLL_TYPE_DATA_AVAILABLE:
 		if (!k_queue_is_empty(event->queue)) {
 			*state = K_POLL_STATE_FIFO_DATA_AVAILABLE;
 			return 1;
 		}
 		break;
 	case K_POLL_TYPE_SIGNAL:
 		if (event->signal->signaled) {
 			*state = K_POLL_STATE_SIGNALED;
 			return 1;
 		}
 		break;
 	case K_POLL_TYPE_IGNORE:
 		return 0;
 	default:
 		__ASSERT(0, "invalid event type (0x%x)\n", event->type);
 	}

 	return 0;
 }

 static inline void add_event(sys_dlist_t *events, struct k_poll_event *event,
 			     struct _poller *poller)
 {
 	struct k_poll_event *pending;

 	pending = (struct k_poll_event *)sys_dlist_peek_tail(events);
 	if (!pending || _is_t1_higher_prio_than_t2(pending->poller->thread,
 						   poller->thread)) {
 		sys_dlist_append(events, &event->_node);
 		return;
 	}

 	SYS_DLIST_FOR_EACH_CONTAINER(events, pending, _node) {
 		if (_is_t1_higher_prio_than_t2(poller->thread,
 					       pending->poller->thread)) {
 			sys_dlist_insert_before(events, &pending->_node,
 						&event->_node);
 			return;
 		}
 	}

 	sys_dlist_append(events, &event->_node);
 }

 /* must be called with interrupts locked */
 static inline int register_event(struct k_poll_event *event,
 				 struct _poller *poller)
 {
 	switch (event->type) {
 	case K_POLL_TYPE_SEM_AVAILABLE:
 		__ASSERT(event->sem, "invalid semaphore\n");
 		add_event(&event->sem->poll_events, event, poller);
 		break;
 	case K_POLL_TYPE_DATA_AVAILABLE:
 		__ASSERT(event->queue, "invalid queue\n");
 		add_event(&event->queue->poll_events, event, poller);
 		break;
 	case K_POLL_TYPE_SIGNAL:
 		__ASSERT(event->signal, "invalid poll signal\n");
 		add_event(&event->signal->poll_events, event, poller);
 		break;
 	case K_POLL_TYPE_IGNORE:
 		/* nothing to do */
 		break;
 	default:
 		__ASSERT(0, "invalid event type\n");
 	}

 	event->poller = poller;

 	return 0;
 }

 /* must be called with interrupts locked */
 static inline void clear_event_registration(struct k_poll_event *event)
 {
 	event->poller = NULL;

 	switch (event->type) {
 	case K_POLL_TYPE_SEM_AVAILABLE:
 		__ASSERT(event->sem, "invalid semaphore\n");
 		sys_dlist_remove(&event->_node);
 		break;
 	case K_POLL_TYPE_DATA_AVAILABLE:
 		__ASSERT(event->queue, "invalid queue\n");
 		sys_dlist_remove(&event->_node);
 		break;
 	case K_POLL_TYPE_SIGNAL:
 		__ASSERT(event->signal, "invalid poll signal\n");
 		sys_dlist_remove(&event->_node);
 		break;
 	case K_POLL_TYPE_IGNORE:
 		/* nothing to do */
 		break;
 	default:
 		__ASSERT(0, "invalid event type\n");
 	}
 }

 /* must be called with interrupts locked */
 static inline void clear_event_registrations(struct k_poll_event *events,
 					      int last_registered,
 					      unsigned int key)
 {
 	for (; last_registered >= 0; last_registered--) {
 		clear_event_registration(&events[last_registered]);
 		irq_unlock(key);
 		key = irq_lock();
 	}
 }

 static inline void set_event_ready(struct k_poll_event *event, u32_t state)
 {
 	event->poller = NULL;
 	event->state |= state;
 }

 int _impl_k_poll(struct k_poll_event *events, int num_events, s32_t timeout)
 {
 	__ASSERT(!_is_in_isr(), "");
 	__ASSERT(events, "NULL events\n");
 	__ASSERT(num_events > 0, "zero events\n");

 	int last_registered = -1, rc;
 	unsigned int key;

 	struct _poller poller = { .thread = _current, .is_polling = 1, };

 	/* find events whose condition is already fulfilled */
 	for (int ii = 0; ii < num_events; ii++) {
 		u32_t state;

 		key = irq_lock();
 		if (is_condition_met(&events[ii], &state)) {
 			set_event_ready(&events[ii], state);
 			poller.is_polling = 0;
 		} else if (timeout != K_NO_WAIT && poller.is_polling) {
 			rc = register_event(&events[ii], &poller);
 			if (rc == 0) {
 				++last_registered;
 			} else {
 				__ASSERT(0, "unexpected return code\n");
 			}
 		}
 		irq_unlock(key);
 	}

 	key = irq_lock();

 	/*
 	 * If we're not polling anymore, it means that at least one event
 	 * condition is met, either when looping through the events here or
 	 * because one of the events registered has had its state changed.
 	 */
 	if (!poller.is_polling) {
 		clear_event_registrations(events, last_registered, key);
 		irq_unlock(key);
 		return 0;
 	}

 	poller.is_polling = 0;

 	if (timeout == K_NO_WAIT) {
 		irq_unlock(key);
 		return -EAGAIN;
 	}

 	_wait_q_t wait_q = _WAIT_Q_INIT(&wait_q);

 	int swap_rc = _pend_current_thread(key, &wait_q, timeout);

 	/*
 	 * Clear all event registrations. If events happen while we're in this
 	 * loop, and we already had one that triggered, that's OK: they will
 	 * end up in the list of events that are ready; if we timed out, and
 	 * events happen while we're in this loop, that is OK as well since
 	 * we've already know the return code (-EAGAIN), and even if they are
 	 * added to the list of events that occurred, the user has to check the
 	 * return code first, which invalidates the whole list of event states.
 	 */
 	key = irq_lock();
 	clear_event_registrations(events, last_registered, key);
 	irq_unlock(key);

 	return swap_rc;
 }

 #ifdef CONFIG_USERSPACE
 Z_SYSCALL_HANDLER(k_poll, events, num_events, timeout)
 {
 	int ret, key;
 	struct k_poll_event *events_copy = NULL;
 	unsigned int bounds;

 	/* Validate the events buffer and make a copy of it in an
 	 * allocated kernel-side buffer.
 	 */
 	if (Z_SYSCALL_VERIFY(num_events > 0)) {
 		ret = -EINVAL;
 		goto out;
 	}
 	if (Z_SYSCALL_VERIFY_MSG(
 		!__builtin_umul_overflow(num_events,
 					sizeof(struct k_poll_event),
 					&bounds), "num_events too large")) {
 		ret = -EINVAL;
 		goto out;
 	}
 	events_copy = z_thread_malloc(bounds);
 	if (!events_copy) {
 		ret = -ENOMEM;
 		goto out;
 	}

 	key = irq_lock();
 	if (Z_SYSCALL_MEMORY_WRITE(events, bounds)) {
 		irq_unlock(key);
 		goto oops_free;
 	}
 	(void)memcpy(events_copy, (void *)events, bounds);
 	irq_unlock(key);

 	/* Validate what's inside events_copy */
 	for (int i = 0; i < num_events; i++) {
 		struct k_poll_event *e = &events_copy[i];

 		if (Z_SYSCALL_VERIFY(e->mode == K_POLL_MODE_NOTIFY_ONLY)) {
 			ret = -EINVAL;
 			goto out_free;
 		}

 		switch (e->type) {
 		case K_POLL_TYPE_IGNORE:
 			break;
 		case K_POLL_TYPE_SIGNAL:
 			Z_OOPS(Z_SYSCALL_OBJ(e->signal, K_OBJ_POLL_SIGNAL));
 			break;
 		case K_POLL_TYPE_SEM_AVAILABLE:
 			Z_OOPS(Z_SYSCALL_OBJ(e->sem, K_OBJ_SEM));
 			break;
 		case K_POLL_TYPE_DATA_AVAILABLE:
 			Z_OOPS(Z_SYSCALL_OBJ(e->queue, K_OBJ_QUEUE));
 			break;
 		default:
 			ret = -EINVAL;
 			goto out_free;
 		}
 	}

 	ret = k_poll(events_copy, num_events, timeout);
 	(void)memcpy((void *)events, events_copy, bounds);
 out_free:
 	k_free(events_copy);
 out:
 	return ret;
 oops_free:
 	k_free(events_copy);
 	Z_OOPS(1);
 }
 #endif

 /* must be called with interrupts locked */
 static int signal_poll_event(struct k_poll_event *event, u32_t state)
 {
 	if (!event->poller) {
 		goto ready_event;
 	}

 	struct k_thread *thread = event->poller->thread;

 	__ASSERT(event->poller->thread, "poller should have a thread\n");

 	event->poller->is_polling = 0;

 	if (!_is_thread_pending(thread)) {
 		goto ready_event;
 	}

 	if (_is_thread_timeout_expired(thread)) {
 		return -EAGAIN;
 	}

 	_unpend_thread(thread);
 	_set_thread_return_value(thread,
 				 state == K_POLL_STATE_CANCELLED ? -EINTR : 0);

 	if (!_is_thread_ready(thread)) {
 		goto ready_event;
 	}

 	_ready_thread(thread);

 ready_event:
 	set_event_ready(event, state);
 	return 0;
 }

 void _handle_obj_poll_events(sys_dlist_t *events, u32_t state)
 {
 	struct k_poll_event *poll_event;

 	poll_event = (struct k_poll_event *)sys_dlist_get(events);
 	if (poll_event) {
 		(void) signal_poll_event(poll_event, state);
 	}
 }

 void _impl_k_poll_signal_init(struct k_poll_signal *signal)
 {
 	sys_dlist_init(&signal->poll_events);
 	signal->signaled = 0;
 	/* signal->result is left unitialized */
 	_k_object_init(signal);
 }

 #ifdef CONFIG_USERSPACE
 Z_SYSCALL_HANDLER(k_poll_signal_init, signal)
 {
 	Z_OOPS(Z_SYSCALL_OBJ_INIT(signal, K_OBJ_POLL_SIGNAL));
 	_impl_k_poll_signal_init((struct k_poll_signal *)signal);
 	return 0;
 }
 #endif

 void _impl_k_poll_signal_check(struct k_poll_signal *signal,
 			       unsigned int *signaled, int *result)
 {
 	*signaled = signal->signaled;
 	*result = signal->result;
 }

 #ifdef CONFIG_USERSPACE
 Z_SYSCALL_HANDLER(k_poll_signal_check, signal, signaled, result)
 {
 	Z_OOPS(Z_SYSCALL_OBJ(signal, K_OBJ_POLL_SIGNAL));
 	Z_OOPS(Z_SYSCALL_MEMORY_WRITE(signaled, sizeof(unsigned int)));
 	Z_OOPS(Z_SYSCALL_MEMORY_WRITE(result, sizeof(int)));

 	_impl_k_poll_signal_check((struct k_poll_signal *)signal,
 				  (unsigned int *)signaled, (int *)result);
 	return 0;
 }
 #endif

 int _impl_k_poll_signal(struct k_poll_signal *signal, int result)
 {
 	unsigned int key = irq_lock();
 	struct k_poll_event *poll_event;

 	signal->result = result;
 	signal->signaled = 1;

 	poll_event = (struct k_poll_event *)sys_dlist_get(&signal->poll_events);
 	if (!poll_event) {
 		irq_unlock(key);
 		return 0;
 	}

 	int rc = signal_poll_event(poll_event, K_POLL_STATE_SIGNALED);

 	_reschedule(key);
 	return rc;
 }

 #ifdef CONFIG_USERSPACE
 Z_SYSCALL_HANDLER(k_poll_signal, signal, result)
 {
 	Z_OOPS(Z_SYSCALL_OBJ(signal, K_OBJ_POLL_SIGNAL));
 	return _impl_k_poll_signal((struct k_poll_signal *)signal, result);
 }
 Z_SYSCALL_HANDLER1_SIMPLE_VOID(k_poll_signal_reset, K_OBJ_POLL_SIGNAL,
 			       struct k_poll_signal *);
 #endif
	/*
	* Copyright (c) 2017 Wind River Systems, Inc.
	*
	* SPDX-License-Identifier: Apache-2.0
	*/

	/**
	* @file
	*
	* @brief Kernel asynchronous event polling interface.
	*
	* This polling mechanism allows waiting on multiple events concurrently,
	* either events triggered directly, or from kernel objects or other kernel
	* constructs.
	*/

	#include <kernel.h>
	#include <kernel_structs.h>
	#include <kernel_internal.h>
	#include <wait_q.h>
	#include <ksched.h>
	#include <syscall_handler.h>
	#include <misc/slist.h>
	#include <misc/dlist.h>
	#include <misc/util.h>
	#include <misc/__assert.h>

	void k_poll_event_init(struct k_poll_event *event, u32_t type,
	int mode, void *obj)
	{
	__ASSERT(mode == K_POLL_MODE_NOTIFY_ONLY,
	"only NOTIFY_ONLY mode is supported\n");
	__ASSERT(type < (BIT(_POLL_NUM_TYPES)), "invalid type\n");
	__ASSERT(obj, "must provide an object\n");

	event->poller = NULL;
	/* event->tag is left uninitialized: the user will set it if needed */
	event->type = type;
	event->state = K_POLL_STATE_NOT_READY;
	event->mode = mode;
	event->unused = 0;
	event->obj = obj;
	}

	/* must be called with interrupts locked */
	static inline int is_condition_met(struct k_poll_event event, u32_t state)
	{
	switch (event->type) {
	case K_POLL_TYPE_SEM_AVAILABLE:
	if (k_sem_count_get(event->sem) > 0) {
	*state = K_POLL_STATE_SEM_AVAILABLE;
	return 1;
	}
	break;
	case K_POLL_TYPE_DATA_AVAILABLE:
	if (!k_queue_is_empty(event->queue)) {
	*state = K_POLL_STATE_FIFO_DATA_AVAILABLE;
	return 1;
	}
	break;
	case K_POLL_TYPE_SIGNAL:
	if (event->signal->signaled) {
	*state = K_POLL_STATE_SIGNALED;
	return 1;
	}
	break;
	case K_POLL_TYPE_IGNORE:
	return 0;
	default:
	__ASSERT(0, "invalid event type (0x%x)\n", event->type);
	}

	return 0;
	}

	static inline void add_event(sys_dlist_t events, struct k_poll_event event,
	struct _poller *poller)
	{
	struct k_poll_event *pending;

	pending = (struct k_poll_event *)sys_dlist_peek_tail(events);
	if (!pending \|\| _is_t1_higher_prio_than_t2(pending->poller->thread,
	poller->thread)) {
	sys_dlist_append(events, &event->_node);
	return;
	}

	SYS_DLIST_FOR_EACH_CONTAINER(events, pending, _node) {
	if (_is_t1_higher_prio_than_t2(poller->thread,
	pending->poller->thread)) {
	sys_dlist_insert_before(events, &pending->_node,
	&event->_node);
	return;
	}
	}

	sys_dlist_append(events, &event->_node);
	}

	/* must be called with interrupts locked */
	static inline int register_event(struct k_poll_event *event,
	struct _poller *poller)
	{
	switch (event->type) {
	case K_POLL_TYPE_SEM_AVAILABLE:
	__ASSERT(event->sem, "invalid semaphore\n");
	add_event(&event->sem->poll_events, event, poller);
	break;
	case K_POLL_TYPE_DATA_AVAILABLE:
	__ASSERT(event->queue, "invalid queue\n");
	add_event(&event->queue->poll_events, event, poller);
	break;
	case K_POLL_TYPE_SIGNAL:
	__ASSERT(event->signal, "invalid poll signal\n");
	add_event(&event->signal->poll_events, event, poller);
	break;
	case K_POLL_TYPE_IGNORE:
	/* nothing to do */
	break;
	default:
	__ASSERT(0, "invalid event type\n");
	}

	event->poller = poller;

	return 0;
	}

	/* must be called with interrupts locked */
	static inline void clear_event_registration(struct k_poll_event *event)
	{
	event->poller = NULL;

	switch (event->type) {
	case K_POLL_TYPE_SEM_AVAILABLE:
	__ASSERT(event->sem, "invalid semaphore\n");
	sys_dlist_remove(&event->_node);
	break;
	case K_POLL_TYPE_DATA_AVAILABLE:
	__ASSERT(event->queue, "invalid queue\n");
	sys_dlist_remove(&event->_node);
	break;
	case K_POLL_TYPE_SIGNAL:
	__ASSERT(event->signal, "invalid poll signal\n");
	sys_dlist_remove(&event->_node);
	break;
	case K_POLL_TYPE_IGNORE:
	/* nothing to do */
	break;
	default:
	__ASSERT(0, "invalid event type\n");
	}
	}

	/* must be called with interrupts locked */
	static inline void clear_event_registrations(struct k_poll_event *events,
	int last_registered,
	unsigned int key)
	{
	for (; last_registered >= 0; last_registered--) {
	clear_event_registration(&events[last_registered]);
	irq_unlock(key);
	key = irq_lock();
	}
	}

	static inline void set_event_ready(struct k_poll_event *event, u32_t state)
	{
	event->poller = NULL;
	event->state \|= state;
	}

	int _impl_k_poll(struct k_poll_event *events, int num_events, s32_t timeout)
	{
	__ASSERT(!_is_in_isr(), "");
	__ASSERT(events, "NULL events\n");
	__ASSERT(num_events > 0, "zero events\n");

	int last_registered = -1, rc;
	unsigned int key;

	struct _poller poller = { .thread = _current, .is_polling = 1, };

	/* find events whose condition is already fulfilled */
	for (int ii = 0; ii < num_events; ii++) {
	u32_t state;

	key = irq_lock();
	if (is_condition_met(&events[ii], &state)) {
	set_event_ready(&events[ii], state);
	poller.is_polling = 0;
	} else if (timeout != K_NO_WAIT && poller.is_polling) {
	rc = register_event(&events[ii], &poller);
	if (rc == 0) {
	++last_registered;
	} else {
	__ASSERT(0, "unexpected return code\n");
	}
	}
	irq_unlock(key);
	}

	key = irq_lock();

	/*
	* If we're not polling anymore, it means that at least one event
	* condition is met, either when looping through the events here or
	* because one of the events registered has had its state changed.
	*/
	if (!poller.is_polling) {
	clear_event_registrations(events, last_registered, key);
	irq_unlock(key);
	return 0;
	}

	poller.is_polling = 0;

	if (timeout == K_NO_WAIT) {
	irq_unlock(key);
	return -EAGAIN;
	}

	_wait_q_t wait_q = _WAIT_Q_INIT(&wait_q);

	int swap_rc = _pend_current_thread(key, &wait_q, timeout);

	/*
	* Clear all event registrations. If events happen while we're in this
	* loop, and we already had one that triggered, that's OK: they will
	* end up in the list of events that are ready; if we timed out, and
	* events happen while we're in this loop, that is OK as well since
	* we've already know the return code (-EAGAIN), and even if they are
	* added to the list of events that occurred, the user has to check the
	* return code first, which invalidates the whole list of event states.
	*/
	key = irq_lock();
	clear_event_registrations(events, last_registered, key);
	irq_unlock(key);

	return swap_rc;
	}

	#ifdef CONFIG_USERSPACE
	Z_SYSCALL_HANDLER(k_poll, events, num_events, timeout)
	{
	int ret, key;
	struct k_poll_event *events_copy = NULL;
	unsigned int bounds;

	/* Validate the events buffer and make a copy of it in an
	* allocated kernel-side buffer.
	*/
	if (Z_SYSCALL_VERIFY(num_events > 0)) {
	ret = -EINVAL;
	goto out;
	}
	if (Z_SYSCALL_VERIFY_MSG(
	!__builtin_umul_overflow(num_events,
	sizeof(struct k_poll_event),
	&bounds), "num_events too large")) {
	ret = -EINVAL;
	goto out;
	}
	events_copy = z_thread_malloc(bounds);
	if (!events_copy) {
	ret = -ENOMEM;
	goto out;
	}

	key = irq_lock();
	if (Z_SYSCALL_MEMORY_WRITE(events, bounds)) {
	irq_unlock(key);
	goto oops_free;
	}
	(void)memcpy(events_copy, (void *)events, bounds);
	irq_unlock(key);

	/* Validate what's inside events_copy */
	for (int i = 0; i < num_events; i++) {
	struct k_poll_event *e = &events_copy[i];

	if (Z_SYSCALL_VERIFY(e->mode == K_POLL_MODE_NOTIFY_ONLY)) {
	ret = -EINVAL;
	goto out_free;
	}

	switch (e->type) {
	case K_POLL_TYPE_IGNORE:
	break;
	case K_POLL_TYPE_SIGNAL:
	Z_OOPS(Z_SYSCALL_OBJ(e->signal, K_OBJ_POLL_SIGNAL));
	break;
	case K_POLL_TYPE_SEM_AVAILABLE:
	Z_OOPS(Z_SYSCALL_OBJ(e->sem, K_OBJ_SEM));
	break;
	case K_POLL_TYPE_DATA_AVAILABLE:
	Z_OOPS(Z_SYSCALL_OBJ(e->queue, K_OBJ_QUEUE));
	break;
	default:
	ret = -EINVAL;
	goto out_free;
	}
	}

	ret = k_poll(events_copy, num_events, timeout);
	(void)memcpy((void *)events, events_copy, bounds);
	out_free:
	k_free(events_copy);
	out:
	return ret;
	oops_free:
	k_free(events_copy);
	Z_OOPS(1);
	}
	#endif

	/* must be called with interrupts locked */
	static int signal_poll_event(struct k_poll_event *event, u32_t state)
	{
	if (!event->poller) {
	goto ready_event;
	}

	struct k_thread *thread = event->poller->thread;

	__ASSERT(event->poller->thread, "poller should have a thread\n");

	event->poller->is_polling = 0;

	if (!_is_thread_pending(thread)) {
	goto ready_event;
	}

	if (_is_thread_timeout_expired(thread)) {
	return -EAGAIN;
	}

	_unpend_thread(thread);
	_set_thread_return_value(thread,
	state == K_POLL_STATE_CANCELLED ? -EINTR : 0);

	if (!_is_thread_ready(thread)) {
	goto ready_event;
	}

	_ready_thread(thread);

	ready_event:
	set_event_ready(event, state);
	return 0;
	}

	void _handle_obj_poll_events(sys_dlist_t *events, u32_t state)
	{
	struct k_poll_event *poll_event;

	poll_event = (struct k_poll_event *)sys_dlist_get(events);
	if (poll_event) {
	(void) signal_poll_event(poll_event, state);
	}
	}

	void _impl_k_poll_signal_init(struct k_poll_signal *signal)
	{
	sys_dlist_init(&signal->poll_events);
	signal->signaled = 0;
	/* signal->result is left unitialized */
	_k_object_init(signal);
	}

	#ifdef CONFIG_USERSPACE
	Z_SYSCALL_HANDLER(k_poll_signal_init, signal)
	{
	Z_OOPS(Z_SYSCALL_OBJ_INIT(signal, K_OBJ_POLL_SIGNAL));
	_impl_k_poll_signal_init((struct k_poll_signal *)signal);
	return 0;
	}
	#endif

	void _impl_k_poll_signal_check(struct k_poll_signal *signal,
	unsigned int signaled, int result)
	{
	*signaled = signal->signaled;
	*result = signal->result;
	}

	#ifdef CONFIG_USERSPACE
	Z_SYSCALL_HANDLER(k_poll_signal_check, signal, signaled, result)
	{
	Z_OOPS(Z_SYSCALL_OBJ(signal, K_OBJ_POLL_SIGNAL));
	Z_OOPS(Z_SYSCALL_MEMORY_WRITE(signaled, sizeof(unsigned int)));
	Z_OOPS(Z_SYSCALL_MEMORY_WRITE(result, sizeof(int)));

	_impl_k_poll_signal_check((struct k_poll_signal *)signal,
	(unsigned int )signaled, (int )result);
	return 0;
	}
	#endif

	int _impl_k_poll_signal(struct k_poll_signal *signal, int result)
	{
	unsigned int key = irq_lock();
	struct k_poll_event *poll_event;

	signal->result = result;
	signal->signaled = 1;

	poll_event = (struct k_poll_event *)sys_dlist_get(&signal->poll_events);
	if (!poll_event) {
	irq_unlock(key);
	return 0;
	}

	int rc = signal_poll_event(poll_event, K_POLL_STATE_SIGNALED);

	_reschedule(key);
	return rc;
	}

	#ifdef CONFIG_USERSPACE
	Z_SYSCALL_HANDLER(k_poll_signal, signal, result)
	{
	Z_OOPS(Z_SYSCALL_OBJ(signal, K_OBJ_POLL_SIGNAL));
	return _impl_k_poll_signal((struct k_poll_signal *)signal, result);
	}
	Z_SYSCALL_HANDLER1_SIMPLE_VOID(k_poll_signal_reset, K_OBJ_POLL_SIGNAL,
	struct k_poll_signal *);
	#endif