ACE_Message_Queue_Base Class Reference

Base class for ACE_Message_Queue, which is the central queueing facility for messages in the ACE framework. More...

#include <Message_Queue.h>

Inheritance diagram for ACE_Message_Queue_Base:


Public Types
enum	{ DEFAULT_HWM = 16 * 1024, DEFAULT_LWM = 16 * 1024, WAS_ACTIVE = 1, ACTIVATED = 1, WAS_INACTIVE = 2, DEACTIVATED = 2, PULSED = 3 }
Public Member Functions
	ACE_Message_Queue_Base (void)
virtual int	close (void)=0
	Close down the message queue and release all resources.
virtual	~ACE_Message_Queue_Base (void)
	Close down the message queue and release all resources.
virtual int	peek_dequeue_head (ACE_Message_Block &first_item, ACE_Time_Value timeout=0)=0
virtual int	enqueue_tail (ACE_Message_Block new_item, ACE_Time_Value timeout=0)=0
virtual int	enqueue (ACE_Message_Block new_item, ACE_Time_Value timeout=0)=0
virtual int	dequeue_head (ACE_Message_Block &first_item, ACE_Time_Value timeout=0)=0
virtual int	dequeue (ACE_Message_Block &first_item, ACE_Time_Value timeout=0)=0
virtual bool	is_full (void)=0
	True if queue is full, else false.
virtual bool	is_empty (void)=0
	True if queue is empty, else false.
virtual size_t	message_bytes (void)=0
virtual size_t	message_length (void)=0
virtual size_t	message_count (void)=0
	Number of total messages on the queue.
virtual void	message_bytes (size_t new_size)=0
virtual void	message_length (size_t new_length)=0
virtual int	deactivate (void)=0
virtual int	activate (void)=0
virtual int	pulse (void)=0
virtual int	state (void)
	Returns the current state of the queue.
virtual int	deactivated (void)=0
virtual ACE_Notification_Strategy *	notification_strategy (void)=0
	Get the notification strategy for the <Message_Queue>.
virtual void	notification_strategy (ACE_Notification_Strategy *s)=0
	Set the notification strategy for the <Message_Queue>.
virtual void	dump (void) const =0
	Dump the state of an object.
Public Attributes
	ACE_ALLOC_HOOK_DECLARE
	Declare the dynamic allocation hooks.
Protected Attributes
int	state_
Private Member Functions
	ACE_Message_Queue_Base (const ACE_Message_Queue_Base &)
void	operator= (const ACE_Message_Queue_Base &)

Detailed Description

Base class for ACE_Message_Queue, which is the central queueing facility for messages in the ACE framework.

For all the ACE_Time_Value pointer parameters the caller will block until action is possible if timeout == 0. Otherwise, it will wait until the absolute time specified in *timeout elapses.

A queue is always in one of three states: . ACTIVATED . DEACTIVATED . PULSED

Member Enumeration Documentation

anonymous enum

Enumerator:

DEFAULT_HWM	Default high watermark (16 K).
DEFAULT_LWM	Default low watermark (same as high water mark).
WAS_ACTIVE	Deprecated: Use ACTIVATED instead.
ACTIVATED	Message queue is active and processing normally.
WAS_INACTIVE	Deprecated: Use DEACTIVATED instead.
DEACTIVATED	Queue is deactivated; no enqueue or dequeue operations allowed.
PULSED	Message queue was pulsed; enqueue and dequeue may proceed normally.

Constructor & Destructor Documentation

ACE_BEGIN_VERSIONED_NAMESPACE_DECL ACE_INLINE ACE_Message_Queue_Base::ACE_Message_Queue_Base ( void )

ACE_BEGIN_VERSIONED_NAMESPACE_DECL ACE_Message_Queue_Base::~ACE_Message_Queue_Base ( void ) [virtual]

Close down the message queue and release all resources.

ACE_Message_Queue_Base::ACE_Message_Queue_Base ( const ACE_Message_Queue_Base & ) [private]

Member Function Documentation

virtual int ACE_Message_Queue_Base::close ( void ) [pure virtual]

Close down the message queue and release all resources.

Implemented in ACE_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual int ACE_Message_Queue_Base::peek_dequeue_head	(	ACE_Message_Block *&	first_item,
		ACE_Time_Value *	timeout = `0`
	)			`[pure virtual]`

Retrieve the first ACE_Message_Block without removing it. Note that timeout uses <{absolute}> time rather than <{relative}> time. If the timeout elapses without receiving a message -1 is returned and errno is set to EWOULDBLOCK. If the queue is deactivated -1 is returned and errno is set to <ESHUTDOWN>. Otherwise, returns -1 on failure, else the number of items still on the queue.

Implemented in ACE_Message_Queue<>, ACE_Dynamic_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual int ACE_Message_Queue_Base::enqueue_tail	(	ACE_Message_Block *	new_item,
		ACE_Time_Value *	timeout = `0`
	)			`[pure virtual]`

Enqueue a <ACE_Message_Block *> into the tail of the queue. Returns number of items in queue if the call succeeds or -1 otherwise. These calls return -1 when queue is closed, deactivated (in which case errno == <ESHUTDOWN>), when a signal occurs (in which case errno == <EINTR>, or if the time specified in timeout elapses (in which case errno == EWOULDBLOCK).

Implemented in ACE_Message_Queue<>, ACE_Dynamic_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual int ACE_Message_Queue_Base::enqueue	(	ACE_Message_Block *	new_item,
		ACE_Time_Value *	timeout = `0`
	)			`[pure virtual]`

Implemented in ACE_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual int ACE_Message_Queue_Base::dequeue_head	(	ACE_Message_Block *&	first_item,
		ACE_Time_Value *	timeout = `0`
	)			`[pure virtual]`

Dequeue and return the <ACE_Message_Block *> at the head of the queue. Returns number of items in queue if the call succeeds or -1 otherwise. These calls return -1 when queue is closed, deactivated (in which case errno == <ESHUTDOWN>), when a signal occurs (in which case errno == <EINTR>, or if the time specified in timeout elapses (in which case errno == EWOULDBLOCK).

Implemented in ACE_Message_Queue<>, ACE_Dynamic_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual int ACE_Message_Queue_Base::dequeue	(	ACE_Message_Block *&	first_item,
		ACE_Time_Value *	timeout = `0`
	)			`[pure virtual]`

Implemented in ACE_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual bool ACE_Message_Queue_Base::is_full ( void ) [pure virtual]

True if queue is full, else false.

Implemented in ACE_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual bool ACE_Message_Queue_Base::is_empty ( void ) [pure virtual]

True if queue is empty, else false.

Implemented in ACE_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual size_t ACE_Message_Queue_Base::message_bytes ( void ) [pure virtual]

Number of total bytes on the queue, i.e., sum of the message block sizes.

Implemented in ACE_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual size_t ACE_Message_Queue_Base::message_length ( void ) [pure virtual]

Number of total length on the queue, i.e., sum of the message block lengths.

Implemented in ACE_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual size_t ACE_Message_Queue_Base::message_count ( void ) [pure virtual]

Number of total messages on the queue.

Implemented in ACE_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual void ACE_Message_Queue_Base::message_bytes ( size_t new_size ) [pure virtual]

New value of the number of total bytes on the queue, i.e., sum of the message block sizes.

Implemented in ACE_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual void ACE_Message_Queue_Base::message_length ( size_t new_length ) [pure virtual]

New value of the number of total length on the queue, i.e., sum of the message block lengths.

Implemented in ACE_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual int ACE_Message_Queue_Base::deactivate ( void ) [pure virtual]

Deactivate the queue and wake up all threads waiting on the queue so they can continue. No messages are removed from the queue, however. Any other operations called until the queue is activated again will immediately return -1 with errno ESHUTDOWN.

Return values:

The

queue's state before this call.

Implemented in ACE_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual int ACE_Message_Queue_Base::activate ( void ) [pure virtual]

Reactivate the queue so that threads can enqueue and dequeue messages again.

Return values:

The

queue's state before this call.

Implemented in ACE_Message_Queue<>, ACE_Message_Queue< ACE_SYNCH >, and ACE_Message_Queue< ACE_SYNCH_USE >.

virtual int ACE_Message_Queue_Base::pulse ( void ) [pure virtual]

Pulse the queue to wake up any waiting threads. Changes the queue state to PULSED; future enqueue/dequeue operations proceed as in ACTIVATED state.