Teuchos::DefaultComm< OrdinalType > Class Template Reference

Return a default global communicator appropriate for the build. More...

#include <Teuchos_DefaultComm.hpp>

Static Public Member Functions
static Teuchos::RCP< const Comm< OrdinalType > >	getComm ()
	Return the default global communicator. More...
static Teuchos::RCP< const Comm< OrdinalType > >	getDefaultSerialComm (const Teuchos::RCP< const Comm< OrdinalType > > &comm)
	Return a serial Comm if the input Comm is null. More...

Detailed Description

template<typename OrdinalType>
class Teuchos::DefaultComm< OrdinalType >

Return a default global communicator appropriate for the build.

Use this class to get a Comm instance representing the default global communicator. If Teuchos was built with MPI (i.e., if the HAVE_MPI macro is defined), then the default communicator wraps MPI_COMM_WORLD. Otherwise, it is a "serial" communicator (containing one process, whose rank is zero).

Template Parameters

OrdinalType

The ordinal type for the Comm communicator wrapper template class. Comm uses OrdinalType to represent things like array lengths and indices.

Note

(mfh 19 Jul 2011, 22 Dec 2011) OrdinalType is called OrdinalType and not Ordinal, because of a bug in Intel's C++ compiler (version 11.1). This compiler confuses the Ordinal template parameter of DefaultComm with the Teuchos::Ordinal typedef. The Ordinal template parameter should actually shadow the typedef in Teuchos, and it does with GCC 4.5.1, but does not with Intel's compiler. This may be the case with other compilers as well, but I haven't tested them yet. If this class' template parameter were named Ordinal, then the following line of code would result in a compile error:

RCP<const Comm<int> pComm = DefaultComm<int>::getDefaultSerialComm (null);

Definition at line 62 of file Teuchos_DefaultComm.hpp.

Member Function Documentation

template<typename OrdinalType >

Teuchos::RCP< const Teuchos::Comm< OrdinalType > > Teuchos::DefaultComm< OrdinalType >::getComm ( )

static

Return the default global communicator.

Warning

When running with MPI, do not call this function until after MPI_Init has been called. You can use GlobalMPISesssion to initialize MPI without explicitly depending on the MPI interface or the mpi.h header file. (If Trilinos was not built with MPI, GlobalMPISession will do the right thing, so you can use it unconditionally.)

Do not use or refer to the returned object after MPI_Finalize has been called. In a non-MPI build, do not use or refer to the returned object after main() has returned.

Definition at line 180 of file Teuchos_DefaultComm.hpp.

template<typename OrdinalType >

Teuchos::RCP< const Teuchos::Comm< OrdinalType > > Teuchos::DefaultComm< OrdinalType >::getDefaultSerialComm ( const Teuchos::RCP< const Comm< OrdinalType > > &  comm )

static

Return a serial Comm if the input Comm is null.

If the input communicator comm is null, return the default serial communicator. Otherwise, just return the input.

Warning

The same warnings as for getComm() apply here.

Definition at line 302 of file Teuchos_DefaultComm.hpp.

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

• Teuchos_DefaultComm.hpp