101 строка
2.6 KiB
Groff
101 строка
2.6 KiB
Groff
.\"Copyright 2006, Sun Microsystems, Inc. All rights reserved. Use is subject to license terms.
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.\" Copyright (c) 1996 Thinking Machines Corporation
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.TH MPI_Init 3OpenMPI "September 2006" "Open MPI 1.2" " "
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.SH NAME
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\fBMPI_Init\fP \- Initializes the MPI execution environment
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.SH SYNTAX
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.ft R
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.SH C Syntax
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.nf
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#include <mpi.h>
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int MPI_Init(int *\fIargc\fP, char ***\fIargv\fP)
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.SH Fortran Syntax
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.nf
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INCLUDE 'mpif.h'
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MPI_INIT(\fIIERROR\fP)
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INTEGER \fIIERROR\fP
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.SH C++ Syntax
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.nf
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#include <mpi.h>
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void MPI::Init(int& \fIargc\fP, char**& \fIargv\fP)
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void MPI::Init()
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.SH INPUT PARAMETERS
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.ft R
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.TP 1i
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argc
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C/C++ only: Pointer to the number of arguments.
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.TP 1i
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argv
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C/C++ only: Argument vector.
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.SH OUTPUT PARAMETER
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.ft R
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.TP 1i
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IERROR
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Fortran only: Error status (integer).
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.SH DESCRIPTION
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.ft R
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This routine, or MPI_Init_thread, must be called before any other MPI
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routine (apart from MPI_Initialized) is called. MPI can be initialized
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at most once; subsequent calls to MPI_Init or MPI_Init_thread are
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erroneous.
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.sp
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All MPI programs must contain a call to MPI_Init or
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MPI_Init_thread. Open MPI accepts the C/C++ \fIargc\fP and \fIargv\fP
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arguments to main, but neither modifies, interprets, nor distributes
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them:
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.sp
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.nf
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{
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/* declare variables */
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MPI_Init(&argc, &argv);
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/* parse arguments */
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/* main program */
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MPI_Finalize();
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}
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.fi
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.SH NOTES
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.ft R
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The Fortran version does not have provisions for \fIargc\fP and
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\fIargv\fP and takes only IERROR.
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.sp
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The MPI Standard does not say what a program can do before an MPI_Init
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or after an MPI_Finalize. In the Open MPI implementation, it should do
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as little as possible. In particular, avoid anything that changes the
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external state of the program, such as opening files, reading standard
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input, or writing to standard output.
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.SH ERRORS
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.ft R
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Almost all MPI routines return an error value; C routines as
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the value of the function and Fortran routines in the last argument. C++
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functions do not return errors. If the default error handler is set to
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MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism
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will be used to throw an MPI:Exception object.
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.sp
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Before the error value is returned, the current MPI error handler is
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called. By default, this error handler aborts the MPI job, except for
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I/O function errors. The error handler may be changed with
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MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN
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may be used to cause error values to be returned. Note that MPI does not
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guarantee that an MPI program can continue past an error.
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.sp
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See the MPI man page for a full list of MPI error codes.
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.SH SEE ALSO
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.ft R
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.nf
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MPI_Init_thread
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MPI_Initialized
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MPI_Finalize
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' @(#)MPI_Init.3 1.24 06/03/09
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