FDR::Canceller Class Reference

Allows cancellation of a running task to be requested. More...

#include <canceller.h>

Public Member Functions
	Canceller ()
	Creates a new canceller.
	Canceller (const Canceller &)=delete
void	cancel ()
	Mark this canceller as cancelled. More...
bool	cancelled () const
	Returns true if this canceller has been cancelled.
Canceller &	operator= (const Canceller &)=delete

Friends
struct	CancellerHelper

Detailed Description

Allows cancellation of a running task to be requested.

Many of the tasks in FDR, such as checking a refinement assertion can be long-running, and thus may need to be cancelled before their natural completion. Cancellers allow this by supplying a cancel() method that requests cancellation of a certain task, which will endeavour to return as soon as it is safe to do so.

For example, a refinement assertion may be cancelled by using code similar to the following:

std::shared_ptr<Assertion> assertion = ...;
std::unique_ptr<Canceller> canceller(new Canceller());
std::thread refinement_thread([&canceller, assertion]){
    try {
        assertion->execute(canceller.get());
    }
    catch (const CancellerError&) {
        std::cout << "Cancellation took place." << std::endl;
    }
}
 
// .. perform some other task
 
// Cancel the refinement check
canceller.cancel();
// Wait for the cancellation to complete.
refinement_thread.join();

If you do not wish to allow for cancellation, then nullptr can always be passed to any function in place of a Canceller.

Member Function Documentation

cancel()

void FDR::Canceller::cancel

(

)

Mark this canceller as cancelled.

This is NOT safe to call from a signal handler.

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

• libfdr/include/fdr/tasks/canceller.h