kernel: Add k_queue API

This unifies k_fifo and k_lifo APIs thus making it more flexible regarding
where the data elements are inserted.

Change-Id: Icd6e2f62fc8b374c8273bb763409e9e22c40f9f8
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

include/kernel.h

@@ -113,6 +113,7 @@ struct k_alert;
 struct k_msgq;
 struct k_mbox;
 struct k_pipe;
+struct k_queue;
 struct k_fifo;
 struct k_lifo;
 struct k_stack;
@@ -1104,6 +1105,183 @@ extern uint32_t k_uptime_delta_32(int64_t *reftime);
  * @cond INTERNAL_HIDDEN
  */
 
+struct k_queue {
+	_wait_q_t wait_q;
+	sys_slist_t data_q;
+	_POLL_EVENT;
+
+	_OBJECT_TRACING_NEXT_PTR(k_queue);
+};
+
+#define K_QUEUE_INITIALIZER(obj) \
+	{ \
+	.wait_q = SYS_DLIST_STATIC_INIT(&obj.wait_q), \
+	.data_q = SYS_SLIST_STATIC_INIT(&obj.data_q), \
+	_POLL_EVENT_OBJ_INIT \
+	_OBJECT_TRACING_INIT \
+	}
+
+/**
+ * INTERNAL_HIDDEN @endcond
+ */
+
+/**
+ * @defgroup queue_apis Queue APIs
+ * @ingroup kernel_apis
+ * @{
+ */
+
+/**
+ * @brief Initialize a queue.
+ *
+ * This routine initializes a queue object, prior to its first use.
+ *
+ * @param queue Address of the queue.
+ *
+ * @return N/A
+ */
+extern void k_queue_init(struct k_queue *queue);
+
+/**
+ * @brief Append an element to the end of a queue.
+ *
+ * This routine appends a data item to @a queue. A queue data item must be
+ * aligned on a 4-byte boundary, and the first 32 bits of the item are
+ * reserved for the kernel's use.
+ *
+ * @note Can be called by ISRs.
+ *
+ * @param queue Address of the queue.
+ * @param data Address of the data item.
+ *
+ * @return N/A
+ */
+extern void k_queue_append(struct k_queue *queue, void *data);
+
+/**
+ * @brief Prepend an element to a queue.
+ *
+ * This routine prepends a data item to @a queue. A queue data item must be
+ * aligned on a 4-byte boundary, and the first 32 bits of the item are
+ * reserved for the kernel's use.
+ *
+ * @note Can be called by ISRs.
+ *
+ * @param queue Address of the queue.
+ * @param data Address of the data item.
+ *
+ * @return N/A
+ */
+extern void k_queue_prepend(struct k_queue *queue, void *data);
+
+/**
+ * @brief Inserts an element to a queue.
+ *
+ * This routine inserts a data item to @a queue after previous item. A queue
+ * data item must be aligned on a 4-byte boundary, and the first 32 bits of the
+ * item are reserved for the kernel's use.
+ *
+ * @note Can be called by ISRs.
+ *
+ * @param queue Address of the queue.
+ * @param prev Address of the previous data item.
+ * @param data Address of the data item.
+ *
+ * @return N/A
+ */
+extern void k_queue_insert(struct k_queue *queue, void *prev, void *data);
+
+/**
+ * @brief Atomically append a list of elements to a queue.
+ *
+ * This routine adds a list of data items to @a queue in one operation.
+ * The data items must be in a singly-linked list, with the first 32 bits
+ * in each data item pointing to the next data item; the list must be
+ * NULL-terminated.
+ *
+ * @note Can be called by ISRs.
+ *
+ * @param queue Address of the queue.
+ * @param head Pointer to first node in singly-linked list.
+ * @param tail Pointer to last node in singly-linked list.
+ *
+ * @return N/A
+ */
+extern void k_queue_append_list(struct k_queue *queue, void *head, void *tail);
+
+/**
+ * @brief Atomically add a list of elements to a queue.
+ *
+ * This routine adds a list of data items to @a queue in one operation.
+ * The data items must be in a singly-linked list implemented using a
+ * sys_slist_t object. Upon completion, the original list is empty.
+ *
+ * @note Can be called by ISRs.
+ *
+ * @param queue Address of the queue.
+ * @param list Pointer to sys_slist_t object.
+ *
+ * @return N/A
+ */
+extern void k_queue_merge_slist(struct k_queue *queue, sys_slist_t *list);
+
+/**
+ * @brief Get an element from a queue.
+ *
+ * This routine removes first data item from @a queue. The first 32 bits of the
+ * data item are reserved for the kernel's use.
+ *
+ * @note Can be called by ISRs, but @a timeout must be set to K_NO_WAIT.
+ *
+ * @param queue Address of the queue.
+ * @param timeout Waiting period to obtain a data item (in milliseconds),
+ *                or one of the special values K_NO_WAIT and K_FOREVER.
+ *
+ * @return Address of the data item if successful; NULL if returned
+ * without waiting, or waiting period timed out.
+ */
+extern void *k_queue_get(struct k_queue *queue, int32_t timeout);
+
+/**
+ * @brief Query a queue to see if it has data available.
+ *
+ * Note that the data might be already gone by the time this function returns
+ * if other threads are also trying to read from the queue.
+ *
+ * @note Can be called by ISRs.
+ *
+ * @param queue Address of the queue.
+ *
+ * @return Non-zero if the queue is empty.
+ * @return 0 if data is available.
+ */
+static inline int k_queue_is_empty(struct k_queue *queue)
+{
+	return (int)sys_slist_is_empty(&queue->data_q);
+}
+
+/**
+ * @brief Statically define and initialize a queue.
+ *
+ * The queue can be accessed outside the module where it is defined using:
+ *
+ * @code extern struct k_queue <name>; @endcode
+ *
+ * @param name Name of the queue.
+ */
+#define K_QUEUE_DEFINE(name) \
+	struct k_queue name \
+		__in_section(_k_queue, static, name) = \
+		K_QUEUE_INITIALIZER(name)
+
+/**
+ * @} end defgroup queue_apis
+ */
+
+/**
+ * @cond INTERNAL_HIDDEN
+ */
+
 struct k_fifo {
 	_wait_q_t wait_q;
 	sys_slist_t data_q;
@@ -3129,8 +3307,8 @@ enum _poll_types_bits {
 	/* semaphore availability */
 	_POLL_TYPE_SEM_AVAILABLE,
 
-	/* fifo data availability */
+	/* queue/fifo/lifo data availability */
-	_POLL_TYPE_FIFO_DATA_AVAILABLE,
+	_POLL_TYPE_DATA_AVAILABLE,
 
 	_POLL_NUM_TYPES
 };
@@ -3151,8 +3329,8 @@ enum _poll_states_bits {
 	/* semaphore is available */
 	_POLL_STATE_SEM_AVAILABLE,
 
-	/* data is available to read on fifo */
+	/* data is available to read on queue/fifo/lifo */
-	_POLL_STATE_FIFO_DATA_AVAILABLE,
+	_POLL_STATE_DATA_AVAILABLE,
 
 	_POLL_NUM_STATES
 };
@@ -3186,8 +3364,8 @@ enum _poll_states_bits {
 #define K_POLL_TYPE_IGNORE 0
 #define K_POLL_TYPE_SIGNAL _POLL_TYPE_BIT(_POLL_TYPE_SIGNAL)
 #define K_POLL_TYPE_SEM_AVAILABLE _POLL_TYPE_BIT(_POLL_TYPE_SEM_AVAILABLE)
-#define K_POLL_TYPE_FIFO_DATA_AVAILABLE \
+#define K_POLL_TYPE_DATA_AVAILABLE _POLL_TYPE_BIT(_POLL_TYPE_DATA_AVAILABLE)
-	_POLL_TYPE_BIT(_POLL_TYPE_FIFO_DATA_AVAILABLE)
+#define K_POLL_TYPE_FIFO_DATA_AVAILABLE K_POLL_TYPE_DATA_AVAILABLE
 
 /* public - polling modes */
 enum k_poll_modes {
@@ -3202,8 +3380,8 @@ enum k_poll_modes {
 #define K_POLL_STATE_EADDRINUSE _POLL_STATE_BIT(_POLL_STATE_EADDRINUSE)
 #define K_POLL_STATE_SIGNALED _POLL_STATE_BIT(_POLL_STATE_SIGNALED)
 #define K_POLL_STATE_SEM_AVAILABLE _POLL_STATE_BIT(_POLL_STATE_SEM_AVAILABLE)
-#define K_POLL_STATE_FIFO_DATA_AVAILABLE \
+#define K_POLL_STATE_DATA_AVAILABLE _POLL_STATE_BIT(_POLL_STATE_DATA_AVAILABLE)
-	_POLL_STATE_BIT(_POLL_STATE_FIFO_DATA_AVAILABLE)
+#define K_POLL_STATE_FIFO_DATA_AVAILABLE K_POLL_STATE_DATA_AVAILABLE
 
 /* public - poll signal object */
 struct k_poll_signal {

include/linker/common-ram.ld

@@ -65,6 +65,13 @@
 		_k_alert_list_end = .;
 	} GROUP_DATA_LINK_IN(RAMABLE_REGION, ROMABLE_REGION)
 
+	SECTION_DATA_PROLOGUE(_k_queue_area, (OPTIONAL),)
+	{
+		_k_queue_list_start = .;
+		KEEP(*(SORT_BY_NAME("._k_queue.static.*")))
+		_k_queue_list_end = .;
+	} GROUP_DATA_LINK_IN(RAMABLE_REGION, ROMABLE_REGION)
+
 	SECTION_DATA_PROLOGUE(_k_fifo_area, (OPTIONAL),)
 	{
 		_k_fifo_list_start = .;

kernel/Makefile

@@ -18,6 +18,7 @@ lib-y += $(strip \
 	idle.o \
 	sched.o \
 	mutex.o \
+	queue.o \
 	lifo.o \
 	fifo.o \
 	stack.o \

kernel/queue.c

@@ -0,0 +1,185 @@
+/*
+ * Copyright (c) 2010-2016 Wind River Systems, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file
+ *
+ * @brief dynamic-size 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_queue _k_queue_list_start[];
+extern struct k_queue _k_queue_list_end[];
+
+struct k_queue *_trace_list_k_queue;
+
+#ifdef CONFIG_OBJECT_TRACING
+
+/*
+ * Complete initialization of statically defined queues.
+ */
+static int init_queue_module(struct device *dev)
+{
+	ARG_UNUSED(dev);
+
+	struct k_queue *queue;
+
+	for (queue = _k_queue_list_start; queue < _k_queue_list_end; queue++) {
+		SYS_TRACING_OBJ_INIT(k_queue, queue);
+	}
+	return 0;
+}
+
+SYS_INIT(init_queue_module, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_OBJECTS);
+
+#endif /* CONFIG_OBJECT_TRACING */
+
+void k_queue_init(struct k_queue *queue)
+{
+	sys_slist_init(&queue->data_q);
+	sys_dlist_init(&queue->wait_q);
+
+	_INIT_OBJ_POLL_EVENT(queue);
+
+	SYS_TRACING_OBJ_INIT(k_queue, queue);
+}
+
+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);
+}
+
+/* returns 1 if a reschedule must take place, 0 otherwise */
+static inline int handle_poll_event(struct k_queue *queue)
+{
+#ifdef CONFIG_POLL
+	uint32_t state = K_POLL_STATE_DATA_AVAILABLE;
+
+	return queue->poll_event ?
+	       _handle_obj_poll_event(&queue->poll_event, state) : 0;
+#else
+	return 0;
+#endif
+}
+
+void k_queue_insert(struct k_queue *queue, void *prev, void *data)
+{
+	struct k_thread *first_pending_thread;
+	unsigned int key;
+
+	key = irq_lock();
+
+	first_pending_thread = _unpend_first_thread(&queue->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_insert(&queue->data_q, prev, data);
+		if (handle_poll_event(queue)) {
+			(void)_Swap(key);
+			return;
+		}
+	}
+
+	irq_unlock(key);
+}
+
+void k_queue_append(struct k_queue *queue, void *data)
+{
+	return k_queue_insert(queue, queue->data_q.tail, data);
+}
+
+void k_queue_prepend(struct k_queue *queue, void *data)
+{
+	return k_queue_insert(queue, NULL, data);
+}
+
+void k_queue_append_list(struct k_queue *queue, 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(&queue->wait_q);
+	while (head && ((thread = _unpend_first_thread(&queue->wait_q)))) {
+		prepare_thread_to_run(thread, head);
+		head = *(void **)head;
+	}
+
+	if (head) {
+		sys_slist_append_list(&queue->data_q, head, tail);
+	}
+
+	if (first_thread) {
+		if (!_is_in_isr() && _must_switch_threads()) {
+			(void)_Swap(key);
+			return;
+		}
+	} else {
+		if (handle_poll_event(queue)) {
+			(void)_Swap(key);
+			return;
+		}
+	}
+
+	irq_unlock(key);
+}
+
+void k_queue_merge_slist(struct k_queue *queue, 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.
+	 */
+	k_queue_append_list(queue, list->head, list->tail);
+	sys_slist_init(list);
+}
+
+void *k_queue_get(struct k_queue *queue, int32_t timeout)
+{
+	unsigned int key;
+	void *data;
+
+	key = irq_lock();
+
+	if (likely(!sys_slist_is_empty(&queue->data_q))) {
+		data = sys_slist_get_not_empty(&queue->data_q);
+		irq_unlock(key);
+		return data;
+	}
+
+	if (timeout == K_NO_WAIT) {
+		irq_unlock(key);
+		return NULL;
+	}
+
+	_pend_current_thread(&queue->wait_q, timeout);
+
+	return _Swap(key) ? NULL : _current->base.swap_data;
+}