BarrierNotifiable Class Reference

A BarrierNotifiable allows to create a number of child Notifiable and wait for all of them to finish. More...

#include <Notifiable.hxx>

Inheritance diagram for BarrierNotifiable:

Public Member Functions
	BarrierNotifiable ()
	Constructs a barrier notifiable that is done.
	BarrierNotifiable (Notifiable *done)
	Constructs a barrier notifiable that is live.
BarrierNotifiable *	reset (Notifiable *done)
	Resets the barrier. Returns &*this. Asserts that is_done().
BarrierNotifiable *	new_child ()
	Call this for each child task.
void	maybe_done ()
	When there are no more child tasks to add, call maybe_done().
void	notify () override
	Implementation of the barrier semantics.
bool	is_done ()
bool	abort_if_almost_done ()
	Checks if there is exactly one outstanding notification left in the barrier.

Protected Attributes
unsigned	count_
	How many outstanding notifications we are still waiting for.
Notifiable *	done_
	Notifiable to call when the barrier reaches zero.

Additional Inherited Members
Protected Member Functions inherited from Atomic
void	lock ()
void	unlock ()

Detailed Description

A BarrierNotifiable allows to create a number of child Notifiable and wait for all of them to finish.

When the last one is finished, the parent done callback is called.

Definition at line 174 of file Notifiable.hxx.

Constructor & Destructor Documentation

BarrierNotifiable() [1/2]

BarrierNotifiable::BarrierNotifiable ( )

inline

Constructs a barrier notifiable that is done.

Users should call reset() later.

Definition at line 179 of file Notifiable.hxx.

BarrierNotifiable() [2/2]

BarrierNotifiable::BarrierNotifiable ( Notifiable *  done )

inline

Constructs a barrier notifiable that is live.

Parameters

done	will be called when the barrier reaches zero (all children are notified and the parent is notified).

Definition at line 185 of file Notifiable.hxx.

~BarrierNotifiable()

BarrierNotifiable::~BarrierNotifiable

(

)

Definition at line 75 of file Notifiable.cxx.

Member Function Documentation

abort_if_almost_done()

bool BarrierNotifiable::abort_if_almost_done ( )

inline

Checks if there is exactly one outstanding notification left in the barrier.

It is required that the caller be actually holding on to a child. Effectively this tests whether there were either no children created, or all were notified inline.

The use-case is that the owner of the barrier wants to figure out whether all children completed inline or not. If the children were completed inline, we may want to call the next phase immediately instead of yielding to the executor. For that the barrier must swallow the notification.

Returns

true, if there were exactly one outstanding notify pending, and in such case sets the barrier to done. Otherwise returns false and has no side-effect.

Definition at line 228 of file Notifiable.hxx.

is_done()

bool BarrierNotifiable::is_done ( )

inline

Returns

true if the barrier condition is true, i.e., the owner has called maybe_done() and all children have called Done.

Definition at line 209 of file Notifiable.hxx.

maybe_done()

void BarrierNotifiable::maybe_done ( )

inline

When there are no more child tasks to add, call maybe_done().

Then once all previously added child tasks are done, the parent callback will be called. If you haven't added any children, this will call the parent callback inline.

Definition at line 200 of file Notifiable.hxx.

new_child()

BarrierNotifiable * BarrierNotifiable::new_child

(

)

Call this for each child task.

Definition at line 56 of file Notifiable.cxx.

notify()

void BarrierNotifiable::notify ( )

overridevirtual

Implementation of the barrier semantics.

Implements Notifiable.

Reimplemented in AsyncNotifiableBlock::QueuedBarrier.

Definition at line 62 of file Notifiable.cxx.

reset()

BarrierNotifiable * BarrierNotifiable::reset

(

Notifiable *

done

)

Resets the barrier. Returns &*this. Asserts that is_done().

Definition at line 77 of file Notifiable.cxx.

Member Data Documentation

count_

unsigned BarrierNotifiable::count_

protected

How many outstanding notifications we are still waiting for.

When 0, the barrier is not live; when reaches zero, done_ will be called.

Definition at line 246 of file Notifiable.hxx.

done_

Notifiable* BarrierNotifiable::done_

protected

Notifiable to call when the barrier reaches zero.

Definition at line 248 of file Notifiable.hxx.

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

• Notifiable.hxx
• Notifiable.cxx