89 строки
2.4 KiB
Groff
89 строки
2.4 KiB
Groff
.\"Copyright 2006, Sun Microsystems, Inc.
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.\"Copyright (c) 1996 Thinking Machines
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.TH MPI_Query_thread 3OpenMPI "September 2006" "Open MPI 1.2" " "
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.SH NAME
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\fBMPI_Query_thread\fP \- Returns the current level of thread support
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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_Query_thread(int *\fIprovided\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_QUERY_THREAD(\fIPROVIDED, IERROR\fP)
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INTEGER \fIPROVIDED, IERROR \fP
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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::Query_thread()
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.SH OUTPUT PARAMETERS
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.ft R
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.TP 1i
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provided
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C/Fortran only: Level of thread support (integer).
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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 returns in \fIprovided\fP the current level of thread
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support. If MPI was initialized by a call to MPI_Init_thread,
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\fIprovided\fP will have the same value as was returned by that
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function.
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.sp
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The possible values of \fIprovided\fP are as follows:
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.TP 2.4i
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MPI_THREAD_SINGLE
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Only one thread may execute.
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.TP 2.4i
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MPI_THREAD_FUNNELED
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If the process is multithreaded, only the thread
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that called MPI_Init[_thread] may make MPI calls.
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.TP 2.4i
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MPI_THREAD_SERIALIZED
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If the process is multithreaded, only one thread
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may make MPI library calls at one time.
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.TP 2.4i
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MPI_THREAD_MULTIPLE
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If the process is multithreaded, multiple threads
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may call MPI at once with no restrictions.
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.SH NOTES
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.ft R
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In Open MPI, \fIprovided\fP is always MPI_THREAD_SINGLE, unless the
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program has been linked with the multithreaded library, in which case
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\fIprovided\fP is MPI_THREAD_MULTIPLE.
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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
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MPI_Init_thread
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