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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:

Inheritance graph
[legend]
List of all members.

Public Types

enum  {
  DEFAULT_HWM = 16 * 1024, DEFAULT_LWM = 16 * 1024, WAS_ACTIVE = 1, ACTIVATED = 1,
  WAS_INACTIVE = 2, DEACTIVATED = 2, PULSED = 3
}

Public Methods

 ACE_Message_Queue_Base (void)
virtual int close (void)=0
 Close down the message queue and release all resources. More...

virtual ~ACE_Message_Queue_Base (void)
 Close down the message queue and release all resources. More...

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 int is_full (void)=0
 True if queue is full, else false. More...

virtual int is_empty (void)=0
 True if queue is empty, else false. More...

virtual size_t message_bytes (void)=0
 Number of total bytes on the queue, i.e., sum of the message block sizes. More...

virtual size_t message_length (void)=0
 Number of total length on the queue, i.e., sum of the message block lengths. More...

virtual int message_count (void)=0
 Number of total messages on the queue. More...

virtual void message_bytes (size_t new_size)=0
 New value of the number of total bytes on the queue, i.e., sum of the message block sizes. More...

virtual void message_length (size_t new_length)=0
 New value of the number of total length on the queue, i.e., sum of the message block lengths. More...

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. More...

virtual int deactivated (void)=0
 Returns 1 if the state of the queue is DEACTIVATED, and 0 if the queue's state is ACTIVATED or PULSED. More...

virtual ACE_Notification_Strategy * notification_strategy (void)=0
 Get the notification strategy for the <Message_Queue>. More...

virtual void notification_strategy (ACE_Notification_Strategy *s)=0
 Set the notification strategy for the <Message_Queue>. More...

virtual void dump (void) const=0
 Dump the state of an object. More...


Public Attributes

 ACE_ALLOC_HOOK_DECLARE
 Declare the dynamic allocation hooks. More...


Protected Attributes

int state_
 Indicates the state of the queue, which can be <ACTIVATED>, <DEACTIVATED>, or <PULSED>. More...


Private Methods

void operator= (const ACE_Message_Queue_Base &)
 ACE_Message_Queue_Base (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

Definition at line 47 of file Message_Queue.h.

Member Enumeration Documentation

anonymous enum
 

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

Definition at line 50 of file Message_Queue.h. 

00051   {
00052     // Default high and low watermarks.
00053 
00054     /// Default high watermark (16 K).
00055     DEFAULT_HWM = 16 * 1024,
00056     /// Default low watermark (same as high water mark).
00057     DEFAULT_LWM = 16 * 1024,
00058 
00059     // Queue states.  Before PULSED state was added, the activate()
00060     // and deactivate() methods returned WAS_INACTIVE or WAS_ACTIVE
00061     // to indicate the previous condition.  Now those methods
00062     // return the state the queue was previously in.  WAS_ACTIVE
00063     // and WAS_INACTIVE are defined to match previous semantics for
00064     // applications that don't use the PULSED state.
00065 
00066     WAS_ACTIVE = 1, /* DEPRECATED */
00067     /// Message queue is active and processing normally
00068     ACTIVATED = 1,
00069 
00070     WAS_INACTIVE = 2, /* DEPRECATED */
00071     /// Queue is deactivated; no enqueue or dequeue operations allowed.
00072     DEACTIVATED = 2,
00073 
00074     /// Message queue was pulsed; enqueue and dequeue may proceed normally.
00075     PULSED = 3
00076 
00077   };

Constructor & Destructor Documentation

ACE_INLINE ACE_Message_Queue_Base::ACE_Message_Queue_Base (  void    ) 
 

Definition at line 5 of file Message_Queue.i. 

00006 {
00007 }

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

Close down the message queue and release all resources.

Definition at line 10 of file Message_Queue.i. 

00011 {
00012 }

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

Member Function Documentation

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.

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

Close down the message queue and release all resources.

Implemented in ACE_Message_Queue.

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.

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

Returns 1 if the state of the queue is DEACTIVATED, and 0 if the queue's state is ACTIVATED or PULSED.

Implemented in ACE_Message_Queue.

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

Implemented in ACE_Message_Queue.

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.

virtual void ACE_Message_Queue_Base::dump (  void    )  const [pure virtual]
 

Dump the state of an object.

Implemented in ACE_Message_Queue.

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

Implemented in ACE_Message_Queue.

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.

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

True if queue is empty, else false.

Implemented in ACE_Message_Queue.

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

True if queue is full, else false.

Implemented in ACE_Message_Queue.

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.

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.

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

Number of total messages on the queue.

Implemented in ACE_Message_Queue.

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.

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.

virtual void ACE_Message_Queue_Base::notification_strategy (  ACE_Notification_Strategy *    s )  [pure virtual]
 

Set the notification strategy for the <Message_Queue>.

Implemented in ACE_Message_Queue.

virtual ACE_Notification_Strategy* ACE_Message_Queue_Base::notification_strategy (  void    )  [pure virtual]
 

Get the notification strategy for the <Message_Queue>.

Implemented in ACE_Message_Queue.

void ACE_Message_Queue_Base::operator= (  const ACE_Message_Queue_Base &    )  [private]
 

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.

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.

Return values:
The  queue's state before this call.

Implemented in ACE_Message_Queue.

ACE_INLINE int ACE_Message_Queue_Base::state (  void    )  [virtual]
 

Returns the current state of the queue.

Reimplemented in ACE_Message_Queue.

Definition at line 15 of file Message_Queue.i.

References ACE_TRACE, and state_. 

00016 {
00017   ACE_TRACE ("ACE_Message_Queue_Base::state");
00018 
00019   return this->state_;
00020 }

Member Data Documentation

ACE_Message_Queue_Base::ACE_ALLOC_HOOK_DECLARE
 

Declare the dynamic allocation hooks.

Reimplemented in ACE_Message_Queue.

Definition at line 206 of file Message_Queue.h.

int ACE_Message_Queue_Base::state_ [protected]
 

Indicates the state of the queue, which can be <ACTIVATED>, <DEACTIVATED>, or <PULSED>.

Definition at line 211 of file Message_Queue.h.

Referenced by ACE_Message_Queue< ACE_SYNCH_USE >::activate_i, ACE_Message_Queue< ACE_SYNCH_USE >::deactivate_i, ACE_Message_Queue< ACE_SYNCH_USE >::deactivated, ACE_Message_Queue< ACE_SYNCH_USE >::dequeue_deadline, ACE_Dynamic_Message_Queue::dequeue_head, ACE_Message_Queue< ACE_SYNCH_USE >::dequeue_head, ACE_Message_Queue< ACE_SYNCH_USE >::dequeue_prio, ACE_Message_Queue< ACE_SYNCH_USE >::dequeue_tail, ACE_Message_Queue< ACE_SYNCH_USE >::dump, ACE_Message_Queue< ACE_SYNCH_USE >::enqueue_deadline, ACE_Message_Queue< ACE_SYNCH_USE >::enqueue_head, ACE_Message_Queue< ACE_SYNCH_USE >::enqueue_prio, ACE_Message_Queue< ACE_SYNCH_USE >::enqueue_tail, ACE_Message_Queue< ACE_SYNCH_USE >::open, ACE_Message_Queue< ACE_SYNCH_USE >::peek_dequeue_head, ACE_Message_Queue< ACE_SYNCH_USE >::state, and state.

The documentation for this class was generated from the following files:
Generated on Mon Jun 16 12:50:34 2003 for ACE by doxygen1.2.14 written by Dimitri van Heesch, © 1997-2002