queue

Multi-core and IRQ safe queue implementation. More...

Functions
void	queue_init_with_spinlock (queue_t *q, uint element_size, uint element_count, uint spinlock_num)
	Initialise a queue with a specific spinlock for concurrency protection. More...
static void	queue_init (queue_t *q, uint element_size, uint element_count)
	Initialise a queue, allocating a (possibly shared) spinlock. More...
void	queue_free (queue_t *q)
	Destroy the specified queue. More...
static uint	queue_get_level_unsafe (queue_t *q)
	Unsafe check of level of the specified queue. More...
static uint	queue_get_level (queue_t *q)
	Check of level of the specified queue. More...
static bool	queue_is_empty (queue_t *q)
	Check if queue is empty. More...
static bool	queue_is_full (queue_t *q)
	Check if queue is full. More...
bool	queue_try_add (queue_t *q, const void *data)
	Non-blocking add value queue if not full. More...
bool	queue_try_remove (queue_t *q, void *data)
	Non-blocking removal of entry from the queue if non empty. More...
bool	queue_try_peek (queue_t *q, void *data)
	Non-blocking peek at the next item to be removed from the queue. More...
void	queue_add_blocking (queue_t *q, const void *data)
	Blocking add of value to queue. More...
void	queue_remove_blocking (queue_t *q, void *data)
	Blocking remove entry from queue. More...
void	queue_peek_blocking (queue_t *q, void *data)
	Blocking peek at next value to be removed from queue. More...

Detailed Description

Multi-core and IRQ safe queue implementation.

Note that this queue stores values of a specified size, and pushed values are copied into the queue

Function Documentation

queue_add_blocking()

void queue_add_blocking	(	queue_t *	q,
		const void *	data
	)

Blocking add of value to queue.

Parameters

q	Pointer to a queue_t structure, used as a handle
data	Pointer to value to be copied into the queue

If the queue is full this function will block, until a removal happens on the queue

queue_free()

void queue_free

(

queue_t *

q

)

Destroy the specified queue.

Parameters

q	Pointer to a queue_t structure, used as a handle

Does not deallocate the queue_t structure itself.

queue_get_level()

static uint queue_get_level ( queue_t *  q )

inlinestatic

Check of level of the specified queue.

Parameters

q	Pointer to a queue_t structure, used as a handle

Returns

Number of entries in the queue

queue_get_level_unsafe()

static uint queue_get_level_unsafe ( queue_t *  q )

inlinestatic

Unsafe check of level of the specified queue.

Parameters

q	Pointer to a queue_t structure, used as a handle

Returns

Number of entries in the queue

This does not use the spinlock, so may return incorrect results if the spin lock is not externally locked

queue_init()

static void queue_init ( queue_t *  q, uint  element_size, uint  element_count  )

inlinestatic

Initialise a queue, allocating a (possibly shared) spinlock.

Parameters

q	Pointer to a queue_t structure, used as a handle
element_size	Size of each value in the queue
element_count	Maximum number of entries in the queue

queue_init_with_spinlock()

void queue_init_with_spinlock	(	queue_t *	q,
		uint	element_size,
		uint	element_count,
		uint	spinlock_num
	)

Initialise a queue with a specific spinlock for concurrency protection.

Parameters

q	Pointer to a queue_t structure, used as a handle
element_size	Size of each value in the queue
element_count	Maximum number of entries in the queue
spinlock_num	The spin ID used to protect the queue

queue_is_empty()

static bool queue_is_empty ( queue_t *  q )

inlinestatic

Check if queue is empty.

Parameters

q	Pointer to a queue_t structure, used as a handle

Returns

true if queue is empty, false otherwise

This function is interrupt and multicore safe.

queue_is_full()

static bool queue_is_full ( queue_t *  q )

inlinestatic

Check if queue is full.

Parameters

q	Pointer to a queue_t structure, used as a handle

Returns

true if queue is full, false otherwise

This function is interrupt and multicore safe.

queue_peek_blocking()

void queue_peek_blocking	(	queue_t *	q,
		void *	data
	)

Blocking peek at next value to be removed from queue.

Parameters

q	Pointer to a queue_t structure, used as a handle
data	Pointer to the location to receive the peeked value

If the queue is empty function will block until a value is added

queue_remove_blocking()

void queue_remove_blocking	(	queue_t *	q,
		void *	data
	)

Blocking remove entry from queue.

Parameters

q	Pointer to a queue_t structure, used as a handle
data	Pointer to the location to receive the removed value

If the queue is empty this function will block until a value is added.

queue_try_add()

bool queue_try_add	(	queue_t *	q,
		const void *	data
	)

Non-blocking add value queue if not full.

Parameters

q	Pointer to a queue_t structure, used as a handle
data	Pointer to value to be copied into the queue

Returns

true if the value was added

If the queue is full this function will return immediately with false, otherwise the data is copied into a new value added to the queue, and this function will return true.

queue_try_peek()

bool queue_try_peek	(	queue_t *	q,
		void *	data
	)

Non-blocking peek at the next item to be removed from the queue.

Parameters

q	Pointer to a queue_t structure, used as a handle
data	Pointer to the location to receive the peeked value

Returns

true if there was a value to peek

If the queue is not empty this function will return immediately with true with the peeked entry copied into the location specified by the data parameter, otherwise the function will return false.

queue_try_remove()

bool queue_try_remove	(	queue_t *	q,
		void *	data
	)

Non-blocking removal of entry from the queue if non empty.

Parameters

q	Pointer to a queue_t structure, used as a handle
data	Pointer to the location to receive the removed value

Returns

true if a value was removed

If the queue is not empty function will copy the removed value into the location provided and return immediately with true, otherwise the function will return immediately with false.