OpenDDS::DCPS::ScheduleOutputHandler Class Reference

event handler used to enable and disable output processing. More...

#include <ScheduleOutputHandler.h>

Inheritance diagram for OpenDDS::DCPS::ScheduleOutputHandler:

[legend]Collaboration diagram for OpenDDS::DCPS::ScheduleOutputHandler:

[legend]List of all members.

Public Member Functions
	ScheduleOutputHandler (TransportSendStrategy *strategy, ACE_Reactor *reactor)
	Construct with the reactor and strategy.
void	schedule_output ()
	Update output processing in the reactor.
ACE_Event_Handler methods
virtual int	handle_exception (ACE_HANDLE)
	modify the reactor mask for the handle.
Private Types
	Disabled
	Enabled
enum	HandlerState { Disabled, Enabled }
	Cache the state that we have set the reactor into. More...
Private Attributes
TransportSendStrategy *	strategy_
	Strategy sending data to be scheduled (or not).
HandlerState	state_

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Detailed Description

event handler used to enable and disable output processing.

This class implements a simple notification handler that is used to schedule or cancel output processing for queued data according to the current mode state of the TransportSendStrategy. If the send strategy is queueing data, then the reactor is enabled to process on output events. Otherwise the output processing callbacks are cancelled.

Definition at line 30 of file ScheduleOutputHandler.h.

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Member Enumeration Documentation

enum OpenDDS::DCPS::ScheduleOutputHandler::HandlerState [private]

Cache the state that we have set the reactor into.

Enumerator:

Disabled
Enabled

Definition at line 51 of file ScheduleOutputHandler.h.

{ Disabled, Enabled };

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Constructor & Destructor Documentation

ACE_INLINE OpenDDS::DCPS::ScheduleOutputHandler::ScheduleOutputHandler	(	TransportSendStrategy *	strategy,
		ACE_Reactor *	reactor
	)

Construct with the reactor and strategy.

Definition at line 12 of file ScheduleOutputHandler.inl.

References DBG_ENTRY_LVL, and OpenDDS::DCPS::ENABLED.

  : ACE_Event_Handler( reactor),
    strategy_( strategy),
    state_( Disabled)
{
  DBG_ENTRY_LVL("ScheduleOutputHandler","ScheduleOutputHandler",6);

  reference_counting_policy().value(
    ACE_Event_Handler::Reference_Counting_Policy::ENABLED);
}

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Member Function Documentation

int OpenDDS::DCPS::ScheduleOutputHandler::handle_exception

(

ACE_HANDLE

)

[virtual]

modify the reactor mask for the handle.

Definition at line 37 of file ScheduleOutputHandler.cpp.

References DBG_ENTRY_LVL, OpenDDS::DCPS::DCPS_debug_level, Disabled, Enabled, OpenDDS::DCPS::TransportSendStrategy::get_handle(), OpenDDS::DCPS::ThreadSynchWorker::id(), OpenDDS::DCPS::TransportSendStrategy::mode(), OpenDDS::DCPS::TransportSendStrategy::MODE_DIRECT, OpenDDS::DCPS::TransportSendStrategy::MODE_QUEUE, OpenDDS::DCPS::TransportSendStrategy::MODE_SUSPEND, state_, and strategy_.

{
  DBG_ENTRY_LVL("ScheduleOutputHandler","handle_exception",6);

  if( reference_count_ == 1) {
    // The containing TransportSendStrategy has unregistered, so we are
    // going away and can't determine the mode, don't process.
    return -1;
  }

  // Check the *current* mode value as it might have been changed since
  // we were scheduled to run.
  //
  // We already hold the Reactor::token_ (since we are being called from
  // the reactor), and it will see the recursion and allow the call back
  // into the reactor.  We hold no other locks, and so avoid deadlock.
  TransportSendStrategy::SendMode mode = strategy_->mode();
  bool changed = false;

  ACE_HANDLE handle = strategy_->get_handle();
  // We need to recheck the mode here since it might have already changed.
  if( mode == TransportSendStrategy::MODE_DIRECT) {
    // Don't cancel a canceled handle.
    if( state_ == Enabled) {
      reactor()->cancel_wakeup(handle, ACE_Event_Handler::WRITE_MASK);
      state_ = Disabled;
      changed = true;
    }

  } else if( (mode == TransportSendStrategy::MODE_QUEUE)
          || (mode == TransportSendStrategy::MODE_SUSPEND)) {

    // Don't schedule a scheduled handle.
    if( state_ == Disabled) {
      reactor()->schedule_wakeup(handle, ACE_Event_Handler::WRITE_MASK);
      state_ = Enabled;
      changed = true;
    }
  }

  if (DCPS_debug_level > 4) {
    ACE_DEBUG((LM_DEBUG,
               ACE_TEXT("(%P|%t) ScheduleOutputHandler::handle_exception() - [%d] ")
               ACE_TEXT("%C data queueing for handle %d.\n"),
               strategy_->id(),
               (changed? ((state_ == Enabled)? "starting": "canceling"): "declining to change"),
               handle));
  }

  // Terminate the upcall and remove from the reactor, if there (and
  // decrement_reference()).
  return -1;
}

void OpenDDS::DCPS::ScheduleOutputHandler::schedule_output

(

)

Update output processing in the reactor.

Filter the notifications here to reduce load.

Definition at line 18 of file ScheduleOutputHandler.cpp.

References DBG_ENTRY_LVL, Disabled, Enabled, OpenDDS::DCPS::TransportSendStrategy::mode(), OpenDDS::DCPS::TransportSendStrategy::MODE_DIRECT, OpenDDS::DCPS::TransportSendStrategy::MODE_QUEUE, OpenDDS::DCPS::TransportSendStrategy::MODE_SUSPEND, state_, and strategy_.

Referenced by OpenDDS::DCPS::ReactorSynch::work_available().

{
  DBG_ENTRY_LVL("ScheduleOutputHandler","schedule_output",6);

  // Only emit once into the notification queue since we check which
  // operation to perform when we process.
  if( reference_count_ == 1) {
    /// Filter the notifications here to reduce load.
    TransportSendStrategy::SendMode mode = strategy_->mode();

    if( ( (state_ ==  Enabled) && (mode == TransportSendStrategy::MODE_DIRECT))
     || ( (state_ == Disabled) && ( (mode == TransportSendStrategy::MODE_QUEUE)
                                 || (mode == TransportSendStrategy::MODE_SUSPEND)))) {
      reactor()->notify(this);
    }
  }
}

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Member Data Documentation

HandlerState OpenDDS::DCPS::ScheduleOutputHandler::state_ [private]

Definition at line 52 of file ScheduleOutputHandler.h.

Referenced by handle_exception(), and schedule_output().

TransportSendStrategy* OpenDDS::DCPS::ScheduleOutputHandler::strategy_ [private]

Strategy sending data to be scheduled (or not).

Definition at line 48 of file ScheduleOutputHandler.h.

Referenced by handle_exception(), and schedule_output().

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

• ScheduleOutputHandler.h
• ScheduleOutputHandler.cpp
• ScheduleOutputHandler.inl

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