ThreadWeaver::QueuePolicy Class Reference

#include <QueuePolicy.h>

Inheritance diagram for ThreadWeaver::QueuePolicy:

Public Member Functions
virtual	~QueuePolicy ()
virtual bool	canRun (Job *)=0
virtual void	destructed (Job *)=0
virtual void	free (Job *)=0
virtual void	release (Job *)=0

Detailed Description

QueuePolicy is an interface for customizations of the queueing behaviour of sets of jobs.

A job can have a queueing policy assigned. In that case, the job is only executed when the method canRun() of the assigned policy returns true. For every call to canRun() that returns true, it is guaranteed that the method free() or the method release() is called. Calling free() means the job has been executed, while calling release() means the job was not executed for external reasons, and will be retried later on.

As an example, dependencies can be implemented using a QueuePolicy: canRun() returns true when the job has no unresolved dependencies. free() and release() are empty.

A job can have multiple queue policies assigned, and will only be executed if all of them return true from canRun() within the same execution attempt. Jobs only keep a reference to the QueuePolicy. Therefore, the same object can be assigned to multiple jobs and this way control the way all those jobs are executed. Jobs never assume ownership of their assigned queue policies.

Definition at line 59 of file QueuePolicy.h.

Constructor & Destructor Documentation

virtual ThreadWeaver::QueuePolicy::~QueuePolicy ( )

inlinevirtual

Definition at line 62 of file QueuePolicy.h.

Member Function Documentation

virtual bool ThreadWeaver::QueuePolicy::canRun ( Job *  )

pure virtual

canRun() is called before the job is executed.

The job will only be executed if canRun() returns true.

Implemented in ThreadWeaver::DependencyPolicy, and ThreadWeaver::ResourceRestrictionPolicy.

virtual void ThreadWeaver::QueuePolicy::destructed ( Job *  )

pure virtual

destructing() is called when a Job that has this queue policy assigned gets destructed.

Implemented in ThreadWeaver::DependencyPolicy, and ThreadWeaver::ResourceRestrictionPolicy.

virtual void ThreadWeaver::QueuePolicy::free ( Job *  )

pure virtual

free() is called after the job has been executed.

It is guaranteed that free is called only after canRun() returned true at an earlier time.

Implemented in ThreadWeaver::DependencyPolicy, and ThreadWeaver::ResourceRestrictionPolicy.

virtual void ThreadWeaver::QueuePolicy::release ( Job *  )

pure virtual

release() is called if canRun() returned true, but the job has not been executed for external reasons.

For example, a second QueuePolicy could have returned false from canRun() for the same job.

Implemented in ThreadWeaver::DependencyPolicy, and ThreadWeaver::ResourceRestrictionPolicy.

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

• QueuePolicy.h