Dune::MPIGuard Class Reference

detects a thrown exception and communicates to all other processes More...

#include <dune/common/parallel/mpiguard.hh>

Public Member Functions
	MPIGuard (bool active=true)
	create an MPIGuard operating on the Communicator of the global Dune::MPIHelper More...
	MPIGuard (MPIHelper &m, bool active=true)
	create an MPIGuard operating on the Communicator of a special Dune::MPIHelper m More...
template<class C >
	MPIGuard (const C &comm, bool active=true)
	create an MPIGuard operating on an arbitrary communicator. More...
	~MPIGuard ()
	destroy the guard and check for undetected exceptions
void	reactivate ()
	reactivate the guard. More...
void	finalize (bool success=true)
	stop the guard. More...

Detailed Description

detects a thrown exception and communicates to all other processes

{
  MPIGuard guard(...);
 
  do_something();
 
  // tell the guard that you successfully passed a critical operation
  guard.finalize();
  // reactivate the guard for the next critical operation
  guard.reactivate();
 
  int result = do_something_else();
 
  // tell the guard the result of your operation
  guard.finalize(result == success);
}

You create a MPIGuard object. If an exception is risen on a process the MPIGuard detects the exception, because the finalize method was not called. When reaching the finalize call all other processes are informed that an error occurred and the MPIGuard throws an exception of type MPIGuardError.

Note

You can initialize the MPIGuard from different types of communication objects:

• MPIHelper
• CollectiveCommunication
• MPI_Comm

Constructor & Destructor Documentation

MPIGuard() [1/3]

Dune::MPIGuard::MPIGuard ( bool  active = true )

inline

create an MPIGuard operating on the Communicator of the global Dune::MPIHelper

Parameters

active

should the MPIGuard be active upon creation?

MPIGuard() [2/3]

Dune::MPIGuard::MPIGuard ( MPIHelper &  m, bool  active = true  )

inline

create an MPIGuard operating on the Communicator of a special Dune::MPIHelper m

Parameters

m	a reference to an MPIHelper
active	should the MPIGuard be active upon creation?

MPIGuard() [3/3]

template<class C >

Dune::MPIGuard::MPIGuard ( const C &  comm, bool  active = true  )

inline

create an MPIGuard operating on an arbitrary communicator.

Supported types for the communication object are:

• MPIHelper
• CollectiveCommunication
• MPI_Comm

Parameters

comm	reference to a communication object
active	should the MPIGuard be active upon creation?

Member Function Documentation

finalize()

void Dune::MPIGuard::finalize ( bool  success = true )

inline

stop the guard.

If no success parameter is passed, the guard assumes that everything worked as planned. All errors are communicated and an exception of type MPIGuardError is thrown if an error (or exception) occurred on any of the processors in the communicator.

Parameters

success

inform the guard about possible errors

References DUNE_THROW.

Referenced by reactivate(), and ~MPIGuard().

reactivate()

void Dune::MPIGuard::reactivate ( )

inline

reactivate the guard.

If the guard is still active finalize(true) is called first.

References finalize().

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

• dune/common/parallel/mpiguard.hh