ACE_Dynamic_Message_Strategy Class Reference

An abstract base class which provides dynamic priority evaluation methods for use by the <ACE_Dynamic_Message_Queue> class or any other class which needs to manage the priorities of a collection of <ACE_Message_Block>s dynamically. More...

#include <Message_Block.h>

Inheritance diagram for ACE_Dynamic_Message_Strategy:

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Collaboration diagram for ACE_Dynamic_Message_Strategy:

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List of all members.

Public Types

enum  Priority_Status { PENDING = 0x01, LATE = 0x02, BEYOND_LATE = 0x04, ANY_STATUS = 0x07 }

Public Member Functions

 ACE_Dynamic_Message_Strategy (unsigned long static_bit_field_mask, unsigned long static_bit_field_shift, unsigned long dynamic_priority_max, unsigned long dynamic_priority_offset)
 Constructor.
virtual ~ACE_Dynamic_Message_Strategy (void)
 Virtual destructor.
Priority_Status priority_status (ACE_Message_Block &mb, const ACE_Time_Value &tv)
 Updates the message's priority and returns its priority status.
unsigned long static_bit_field_mask (void) const
 Get static bit field mask.
void static_bit_field_mask (unsigned long)
 Set static bit field mask.
unsigned long static_bit_field_shift (void) const
 Get left shift value to make room for static bit field.
void static_bit_field_shift (unsigned long)
 Set left shift value to make room for static bit field.
unsigned long dynamic_priority_max (void) const
 Get maximum supported priority value.
void dynamic_priority_max (unsigned long)
 Set maximum supported priority value.
unsigned long dynamic_priority_offset (void) const
 Get offset to boundary between signed range and unsigned range.
void dynamic_priority_offset (unsigned long)
 Set offset to boundary between signed range and unsigned range.
virtual void dump (void) const
 Dump the state of the strategy.

Protected Member Functions

virtual void convert_priority (ACE_Time_Value &priority, const ACE_Message_Block &mb)=0
 Hook method for dynamic priority conversion.

Protected Attributes

unsigned long static_bit_field_mask_
 This is a bit mask with all ones in the static bit field.
unsigned long static_bit_field_shift_
unsigned long dynamic_priority_max_
 Maximum supported priority value.
unsigned long dynamic_priority_offset_
 Offset to boundary between signed range and unsigned range.
ACE_Time_Value max_late_
 Maximum late time value that can be represented.
ACE_Time_Value min_pending_
 Minimum pending time value that can be represented.
ACE_Time_Value pending_shift_
 Time value by which to shift pending priority.

Detailed Description

An abstract base class which provides dynamic priority evaluation methods for use by the <ACE_Dynamic_Message_Queue> class or any other class which needs to manage the priorities of a collection of <ACE_Message_Block>s dynamically.

Methods for deadline and laxity based priority evaluation are provided. These methods assume a specific partitioning of the message priority number into a higher order dynamic bit field and a lower order static priority bit field. The default partitioning assumes an unsigned dynamic message priority field of 22 bits and an unsigned static message priority field of 10 bits. This corresponds to the initial values of the static class members. To provide a different partitioning, assign a different set of values to the static class memebers before using the static member functions.


Member Enumeration Documentation

enum ACE_Dynamic_Message_Strategy::Priority_Status
 

Enumerator:
PENDING  Message can still make its deadline.
LATE  Message cannot make its deadline.
BEYOND_LATE  Message is so late its priority is undefined.
ANY_STATUS  Mask to match any priority status.


Constructor & Destructor Documentation

ACE_Dynamic_Message_Strategy::ACE_Dynamic_Message_Strategy unsigned long  static_bit_field_mask,
unsigned long  static_bit_field_shift,
unsigned long  dynamic_priority_max,
unsigned long  dynamic_priority_offset
 

Constructor.

ACE_Dynamic_Message_Strategy::~ACE_Dynamic_Message_Strategy void   )  [virtual]
 

Virtual destructor.


Member Function Documentation

virtual void ACE_Dynamic_Message_Strategy::convert_priority ACE_Time_Value priority,
const ACE_Message_Block mb
[protected, pure virtual]
 

Hook method for dynamic priority conversion.

Implemented in ACE_Deadline_Message_Strategy, and ACE_Laxity_Message_Strategy.

void ACE_Dynamic_Message_Strategy::dump void   )  const [virtual]
 

Dump the state of the strategy.

Reimplemented in ACE_Deadline_Message_Strategy, and ACE_Laxity_Message_Strategy.

ACE_INLINE void ACE_Dynamic_Message_Strategy::dynamic_priority_max unsigned  long  ) 
 

Set maximum supported priority value.

ACE_INLINE unsigned long ACE_Dynamic_Message_Strategy::dynamic_priority_max void   )  const
 

Get maximum supported priority value.

ACE_INLINE void ACE_Dynamic_Message_Strategy::dynamic_priority_offset unsigned  long  ) 
 

Set offset to boundary between signed range and unsigned range.

ACE_INLINE unsigned long ACE_Dynamic_Message_Strategy::dynamic_priority_offset void   )  const
 

Get offset to boundary between signed range and unsigned range.

ACE_INLINE ACE_Dynamic_Message_Strategy::Priority_Status ACE_Dynamic_Message_Strategy::priority_status ACE_Message_Block mb,
const ACE_Time_Value tv
 

Updates the message's priority and returns its priority status.

ACE_INLINE void ACE_Dynamic_Message_Strategy::static_bit_field_mask unsigned  long  ) 
 

Set static bit field mask.

ACE_INLINE unsigned long ACE_Dynamic_Message_Strategy::static_bit_field_mask void   )  const
 

Get static bit field mask.

ACE_INLINE void ACE_Dynamic_Message_Strategy::static_bit_field_shift unsigned  long  ) 
 

Set left shift value to make room for static bit field.

ACE_INLINE unsigned long ACE_Dynamic_Message_Strategy::static_bit_field_shift void   )  const
 

Get left shift value to make room for static bit field.


Member Data Documentation

unsigned long ACE_Dynamic_Message_Strategy::dynamic_priority_max_ [protected]
 

Maximum supported priority value.

unsigned long ACE_Dynamic_Message_Strategy::dynamic_priority_offset_ [protected]
 

Offset to boundary between signed range and unsigned range.

ACE_Time_Value ACE_Dynamic_Message_Strategy::max_late_ [protected]
 

Maximum late time value that can be represented.

ACE_Time_Value ACE_Dynamic_Message_Strategy::min_pending_ [protected]
 

Minimum pending time value that can be represented.

ACE_Time_Value ACE_Dynamic_Message_Strategy::pending_shift_ [protected]
 

Time value by which to shift pending priority.

unsigned long ACE_Dynamic_Message_Strategy::static_bit_field_mask_ [protected]
 

This is a bit mask with all ones in the static bit field.

unsigned long ACE_Dynamic_Message_Strategy::static_bit_field_shift_ [protected]
 

This is a left shift value to make room for static bit field: this value should be the logarithm base 2 of (static_bit_field_mask_ + 1).


The documentation for this class was generated from the following files:
Generated on Wed Nov 23 15:48:33 2005 for ACE by  doxygen 1.4.5