a9511779a6
code and man pages. cmr:v1.4:reviewer=jsquyres and cmr:v1.5:reviewer=jsquyres This commit was SVN r25781.
105 строки
3.8 KiB
Plaintext
105 строки
3.8 KiB
Plaintext
.\" Copyright 2010 Cisco Systems, Inc. All rights reserved.
|
|
.\" Copyright 2006-2008 Sun Microsystems, Inc.
|
|
.\" Copyright (c) 1996 Thinking Machines Corporation
|
|
.TH MPI_Intercomm_create 3 "#OMPI_DATE#" "#PACKAGE_VERSION#" "#PACKAGE_NAME#"
|
|
.SH NAME
|
|
\fBMPI_Intercomm_create\fP \- Creates an intercommunicator from two intracommunicators.
|
|
|
|
.SH SYNTAX
|
|
.ft R
|
|
.SH C Syntax
|
|
.nf
|
|
#include <mpi.h>
|
|
int MPI_Intercomm_create(MPI_Comm \fIlocal_comm\fP, int\fI local_leader\fP,
|
|
MPI_Comm\fI peer_comm\fP, int\fI remote_leader\fP, int\fI tag\fP, MPI_Comm\fI *newintercomm\fP)
|
|
|
|
.fi
|
|
.SH Fortran Syntax
|
|
.nf
|
|
INCLUDE 'mpif.h'
|
|
MPI_INTERCOMM_CREATE(\fILOCAL_COMM, LOCAL_LEADER, PEER_COMM,
|
|
REMOTE_LEADER, TAG, NEWINTERCOMM, IERROR\fP)
|
|
INTEGER \fILOCAL_COMM, LOCAL_LEADER, PEER_COMM, REMOTE_LEADER\fP
|
|
INTEGER \fITAG, NEWINTERCOMM, IERROR\fP
|
|
|
|
.fi
|
|
.SH C++ Syntax
|
|
.nf
|
|
#include <mpi.h>
|
|
Intercomm Intracomm::Create_intercomm(int \fIlocal_leader\fP, const
|
|
Comm& \fIpeer_comm\fP, int \fIremote_leader\fP, int \fItag\fP) const
|
|
|
|
.fi
|
|
.SH INPUT PARAMETERS
|
|
.ft R
|
|
.TP 1i
|
|
local_comm
|
|
The communicator containing the process that initiates the inter-communication (handle).
|
|
.TP 1i
|
|
local_leader
|
|
Rank of local group leader in local_comm (integer).
|
|
.TP 1i
|
|
peer_comm
|
|
"Peer" communicator; significant only at the local_leader (handle).
|
|
.TP 1i
|
|
remote_leader
|
|
Rank of remote group leader in peer_comm; significant only at the local_leader (integer).
|
|
.TP 1i
|
|
tag
|
|
Message tag used to identify new intercommunicator (integer).
|
|
|
|
.SH OUTPUT PARAMETERS
|
|
.ft R
|
|
.TP 1i
|
|
newintercomm
|
|
Created intercommunicator (handle).
|
|
.ft R
|
|
.TP 1i
|
|
IERROR
|
|
Fortran only: Error status (integer).
|
|
|
|
.SH DESCRIPTION
|
|
.ft R
|
|
This call creates an intercommunicator. It is collective over the union of the local and remote groups. Processes should provide identical local_comm and local_leader arguments within each group. Wildcards are not permitted for remote_leader, local_leader, and tag.
|
|
.sp
|
|
This call uses point-to-point communication with communicator peer_comm,
|
|
and with tag tag between the leaders. Thus, care must be taken that there be no pending communication on peer_comm that could interfere with this communication.
|
|
|
|
If multiple MPI_Intercomm_creates are being made, they should use different tags (more precisely, they should ensure that the local and remote leaders are using different tags for each MPI_intercomm_create).
|
|
|
|
.SH NOTES
|
|
We recommend using a dedicated peer communicator, such as a duplicate of MPI_COMM_WORLD, to avoid trouble with peer communicators.
|
|
.sp
|
|
The MPI 1.1 Standard contains two mutually exclusive comments on the
|
|
input intracommunicators. One says that their respective groups must be
|
|
disjoint; the other that the leaders can be the same process. After
|
|
some discussion by the MPI Forum, it has been decided that the groups must
|
|
be disjoint. Note that the
|
|
.B reason
|
|
given for this in the standard is
|
|
.B not
|
|
the reason for this choice; rather, the
|
|
.B other
|
|
operations on
|
|
intercommunicators (like
|
|
.I MPI_Intercomm_merge
|
|
) do not make sense if the
|
|
groups are not disjoint.
|
|
|
|
.SH ERRORS
|
|
Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ functions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism will be used to throw an MPI::Exception object.
|
|
.sp
|
|
Before the error value is returned, the current MPI error handler is
|
|
called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.
|
|
|
|
.SH SEE ALSO
|
|
MPI_Intercomm_merge
|
|
.br
|
|
MPI_Comm_free
|
|
.br
|
|
MPI_Comm_remote_group
|
|
.br
|
|
MPI_Comm_remote_size
|
|
|
|
|