OpenDDS::DCPS::DirectPriorityMapper Class Reference

map TRANSPORT_PRIORITY values directly. More...

#include <DirectPriorityMapper.h>

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List of all members.

Public Member Functions
	DirectPriorityMapper (Priority priority=0)
	Construct with a priority value.
virtual	~DirectPriorityMapper ()
virtual short	codepoint () const
	Access the mapped DiffServ codepoint value.
virtual short	thread_priority () const
	Access the mapped thread priority value.

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Detailed Description

map TRANSPORT_PRIORITY values directly.

This implementation maps TRANSPORT_PRIORITY values directly to both DiffServ codepoint and thread priority values. The behavior is saturating - that is when the TRANSPORT_PRIORITY value is out of the target range, it is mapped to the nearest extremum.

DiffServ codepoint values are mapped within the closed interval [0,63], with the corresponding TRANSPORT_PRIORITY values mapped directly within this range.

Thread priorities are mapped to the system thread scheduler minimum value (obtained from the sched_get_priority_min(sched) system call, where available) up to the maximum value (obtained from the sched_get_priority_max(sched) system call, where available). The TRANSPORT_PRIORITY value of 0 is mapped to the minimum and a value of |max-min| is mapped to the maximum.

Definition at line 42 of file DirectPriorityMapper.h.

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Constructor & Destructor Documentation

ACE_INLINE OpenDDS::DCPS::DirectPriorityMapper::DirectPriorityMapper

(

Priority

priority = 0

)

Construct with a priority value.

Definition at line 14 of file DirectPriorityMapper.inl.

  : PriorityMapper(priority)
{
}

OPENDDS_BEGIN_VERSIONED_NAMESPACE_DECL OpenDDS::DCPS::DirectPriorityMapper::~DirectPriorityMapper

(

)

[virtual]

Definition at line 22 of file DirectPriorityMapper.cpp.

{
}

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Member Function Documentation

short OpenDDS::DCPS::DirectPriorityMapper::codepoint

(

)

const [virtual]

Access the mapped DiffServ codepoint value.

Implements OpenDDS::DCPS::PriorityMapper.

Definition at line 27 of file DirectPriorityMapper.cpp.

References ACE_TEXT(), OpenDDS::DCPS::DCPS_debug_level, LM_DEBUG, and OpenDDS::DCPS::PriorityMapper::priority().

Referenced by OpenDDS::DCPS::TcpConnection::active_establishment(), and OpenDDS::DCPS::UdpDataLink::open().

{
  static const Priority dscp_min = 0;
  static const Priority dscp_max = 63;

  // We know that the DiffServ codepoints range from a low number to a
  // high number, with the high number being a higher priority - which
  // is the ordering that the TRANSPORT_PRIORIY value has.
  short value = std::min(dscp_max, std::max(dscp_min, this->priority()));

  if (OpenDDS::DCPS::DCPS_debug_level > 4) {
    ACE_DEBUG((LM_DEBUG,
               ACE_TEXT("(%P|%t) DirectPriorityMapper:codepoint() - ")
               ACE_TEXT("mapped TRANSPORT_PRIORITY value %d ")
               ACE_TEXT("to codepoint %d.\n"),
               this->priority(),
               value));
  }

  return value;
}

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short OpenDDS::DCPS::DirectPriorityMapper::thread_priority

(

)

const [virtual]

Access the mapped thread priority value.

Implements OpenDDS::DCPS::PriorityMapper.

Definition at line 50 of file DirectPriorityMapper.cpp.

References ACE_TEXT(), OpenDDS::DCPS::DCPS_debug_level, LM_DEBUG, OpenDDS::DCPS::PriorityMapper::priority(), and TheServiceParticipant.

Referenced by OpenDDS::DCPS::TransportSendStrategy::TransportSendStrategy().

{
  static const int thread_min = TheServiceParticipant->priority_min();
  static const int thread_max = TheServiceParticipant->priority_max();
  static const int direction  = (thread_max < thread_min)? -1: 1;
  static const int range      = direction * (thread_max - thread_min);

  short value = thread_min + direction * this->priority();

  if (this->priority() < 0) {
    value = thread_min;
  }

  if (this->priority() > range) {
    value = thread_max;
  }

  if (OpenDDS::DCPS::DCPS_debug_level > 4) {
    ACE_DEBUG((LM_DEBUG,
               ACE_TEXT("(%P|%t) DirectPriorityMapper:thread_priority() - ")
               ACE_TEXT("mapped TRANSPORT_PRIORITY value %d ")
               ACE_TEXT("to thread priority %d.\n"),
               this->priority(),
               value));
  }

  return value;
}

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The documentation for this class was generated from the following files:

• DirectPriorityMapper.h
• DirectPriorityMapper.cpp
• DirectPriorityMapper.inl