zephyr/kernel/fifo.c

161 lines
3.5 KiB
C

/*
* Copyright (c) 2010-2016 Wind River Systems, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file
*
* @brief dynamic-size FIFO queue object.
*/
#include <kernel.h>
#include <kernel_structs.h>
#include <debug/object_tracing_common.h>
#include <toolchain.h>
#include <sections.h>
#include <wait_q.h>
#include <ksched.h>
#include <misc/slist.h>
#include <init.h>
extern struct k_fifo _k_fifo_list_start[];
extern struct k_fifo _k_fifo_list_end[];
struct k_fifo *_trace_list_k_fifo;
#ifdef CONFIG_OBJECT_TRACING
/*
* Complete initialization of statically defined fifos.
*/
static int init_fifo_module(struct device *dev)
{
ARG_UNUSED(dev);
struct k_fifo *fifo;
for (fifo = _k_fifo_list_start; fifo < _k_fifo_list_end; fifo++) {
SYS_TRACING_OBJ_INIT(k_fifo, fifo);
}
return 0;
}
SYS_INIT(init_fifo_module, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_OBJECTS);
#endif /* CONFIG_OBJECT_TRACING */
void k_fifo_init(struct k_fifo *fifo)
{
sys_slist_init(&fifo->data_q);
sys_dlist_init(&fifo->wait_q);
SYS_TRACING_OBJ_INIT(k_fifo, fifo);
}
static void prepare_thread_to_run(struct k_thread *thread, void *data)
{
_abort_thread_timeout(thread);
_ready_thread(thread);
_set_thread_return_value_with_data(thread, 0, data);
}
void k_fifo_put(struct k_fifo *fifo, void *data)
{
struct k_thread *first_pending_thread;
unsigned int key;
key = irq_lock();
first_pending_thread = _unpend_first_thread(&fifo->wait_q);
if (first_pending_thread) {
prepare_thread_to_run(first_pending_thread, data);
if (!_is_in_isr() && _must_switch_threads()) {
(void)_Swap(key);
return;
}
} else {
sys_slist_append(&fifo->data_q, data);
}
irq_unlock(key);
}
void k_fifo_put_list(struct k_fifo *fifo, void *head, void *tail)
{
__ASSERT(head && tail, "invalid head or tail");
struct k_thread *first_thread, *thread;
unsigned int key;
key = irq_lock();
first_thread = _peek_first_pending_thread(&fifo->wait_q);
while (head && ((thread = _unpend_first_thread(&fifo->wait_q)))) {
prepare_thread_to_run(thread, head);
head = *(void **)head;
}
if (head) {
sys_slist_append_list(&fifo->data_q, head, tail);
}
if (first_thread) {
if (!_is_in_isr() && _must_switch_threads()) {
(void)_Swap(key);
return;
}
}
irq_unlock(key);
}
void k_fifo_put_slist(struct k_fifo *fifo, sys_slist_t *list)
{
__ASSERT(!sys_slist_is_empty(list), "list must not be empty");
/*
* note: this works as long as:
* - the slist implementation keeps the next pointer as the first
* field of the node object type
* - list->tail->next = NULL.
*/
return k_fifo_put_list(fifo, list->head, list->tail);
}
void *k_fifo_get(struct k_fifo *fifo, int32_t timeout)
{
unsigned int key;
void *data;
key = irq_lock();
if (likely(!sys_slist_is_empty(&fifo->data_q))) {
data = sys_slist_get_not_empty(&fifo->data_q);
irq_unlock(key);
return data;
}
if (timeout == K_NO_WAIT) {
irq_unlock(key);
return NULL;
}
_pend_current_thread(&fifo->wait_q, timeout);
return _Swap(key) ? NULL : _current->base.swap_data;
}