Ar::StaticQueue< T, N > Class Template Reference

#include <ar_classes.h>

Inheritance diagram for Ar::StaticQueue< T, N >:

Description

template<typename T, unsigned N>
class Ar::StaticQueue< T, N >

Template class to help statically allocate a Queue.

This template class helps create a Queue instance by defining a static array of queue elements. The array length is one of the template parameters.

Example of creating a queue and adding an element:

// MyQueueType holds up to five uint32_t elements.
typedef StaticQueue<uint32_t, 5> MyQueueType;

MyQueueType q; // Can statically allocate MyQueueType!
q.init("my queue");

uint32_t element = 512;
q.send(element);

q.send(1024);

ar_status_t s;

s = q.receive(&element);

element = q.receive(&s);

Parameters

T	The queue element type.
N	Maximum number of elements the queue will hold.

Collaboration diagram for Ar::StaticQueue< T, N >:

Public Member Functions
	StaticQueue ()
	Default constructor.
	StaticQueue (const char *name)
	Constructor.
ar_status_t	init (const char *name)
	Initialiser method.
ar_status_t	receive (T *element, uint32_t timeout=kArInfiniteTimeout)
	Remove an item from the queue. More...
T	receive (uint32_t timeout=kArInfiniteTimeout, ar_status_t *resultStatus=NULL)
	Alternate form of typed receive. More...
ar_status_t	send (T element, uint32_t timeout=kArInfiniteTimeout)
	Add an item to the queue. More...
Public Member Functions inherited from Ar::Queue
	Queue ()
	Default constructor.
	Queue (const char *name, void *storage, unsigned elementSize, unsigned capacity)
	Constructor.
	~Queue ()
	Queue cleanup.
unsigned	getCount () const
	Returns the current number of elements in the queue.
const char *	getName () const
	Get the queue's name.
ar_status_t	init (const char *name, void *storage, unsigned elementSize, unsigned capacity)
	Queue initialiser. More...
bool	isEmpty () const
	Returns whether the queue is currently empty.
ar_status_t	receive (void *element, uint32_t timeout=kArInfiniteTimeout)
	Remove an item from the queue. More...
ar_status_t	send (const void *element, uint32_t timeout=kArInfiniteTimeout)
	Add an item to the queue. More...

Protected Attributes
T	m_storage [N]
	Static storage for the queue elements.

Additional Inherited Members
Public Attributes inherited from ar_queue_t
unsigned	m_capacity
	Maximum number of elements the queue can hold.
unsigned	m_count
	Current number of elements in the queue.
uint8_t *	m_elements
	Pointer to element storage.
unsigned	m_elementSize
	Number of bytes occupied by each element.
unsigned	m_head
	Index of queue head.
const char *	m_name
	Name of the queue.
ar_list_t	m_receiveBlockedList
	List of threads blocked waiting to receive data.
ar_runloop_t *	m_runLoop
	Runloop the queue is bound to.
ar_runloop_queue_handler_t	m_runLoopHandler
	Handler function.
void *	m_runLoopHandlerParam
	User parameter for handler function.
ar_list_node_t	m_runLoopNode
	List node for the runloop's queue list.
ar_list_t	m_sendBlockedList
	List of threads blocked waiting to send.
unsigned	m_tail
	Index of queue tail.

Member Function Documentation

receive() [1/2]

template<typename T, unsigned N>

ar_status_t Ar::StaticQueue< T, N >::receive ( T *  element, uint32_t  timeout = kArInfiniteTimeout  )

inline

Remove an item from the queue.

Parameters

[out]	element
	timeout	The maximum number of milliseconds that the caller is willing to wait in a blocked state before an element is received. If this value is 0, or kArNoTimeout, then this method will return immediately if the queue is empty. Setting the timeout to kArInfiniteTimeout will cause the thread to wait forever for receive an element.

Return values

kArSuccess
kArQueueEmptyError

receive() [2/2]

template<typename T, unsigned N>

T Ar::StaticQueue< T, N >::receive ( uint32_t  timeout = kArInfiniteTimeout, ar_status_t *  resultStatus = NULL  )

inline

Alternate form of typed receive.

Parameters

[out]	resultStatus	The status of the receive operation is placed here. May be NULL, in which case no status is returned.
	timeout	Maximum time in ticks to wait for a queue element.

send()

template<typename T, unsigned N>

ar_status_t Ar::StaticQueue< T, N >::send ( T  element, uint32_t  timeout = kArInfiniteTimeout  )

inline

Add an item to the queue.

The caller will block if the queue is full.

Parameters

element	Pointer to the element to post to the queue. The element size was specified in the init() call.
timeout	The maximum number of milliseconds that the caller is willing to wait in a blocked state before the element can be sent. If this value is 0, or kArNoTimeout, then this method will return immediately if the queue is full. Setting the timeout to kArInfiniteTimeout will cause the thread to wait forever for a chance to send.

Return values

kArSuccess
kArQueueFullError