MPI_Query_thread(3)

1MPI_Query_thread(3)                 LAM/MPI                MPI_Query_thread(3)
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NAME

6       MPI_Query_thread -  Check level of thread support in MPI
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SYNOPSIS

9       #include <mpi.h>
10       int
11       MPI_Query_thread(int *pprovided)
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OUTPUT PARAMETER

14       pprovided
15              - provided level of thread support
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DESCRIPTION

19       This  function  is  mainly  here for link-compatability.  It will [cur‐
20       rently] only ever return MPI_THREAD_SINGLE in pprovided .
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22       Future versions of LAM/MPI will support multi-threaded  user  programs,
23       in  which  case MPI_Init_thread must be used to initialize MPI.  Hence,
24       programmers can use this function now in order to  program  for  future
25       flexibility.
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NOTES FOR FORTRAN

29       All  MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
30       an additional argument ierr at the end of the argument list.   ierr  is
31       an  integer and has the same meaning as the return value of the routine
32       in C.  In Fortran, MPI routines are subroutines, and are  invoked  with
33       the call statement.
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35       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
36       Fortran.
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ERRORS

40       If an error occurs in an MPI function, the current MPI error handler is
41       called  to  handle  it.   By default, this error handler aborts the MPI
42       job.  The error handler may be changed with  MPI_Errhandler_set  ;  the
43       predefined  error  handler MPI_ERRORS_RETURN may be used to cause error
44       values to be returned (in C and Fortran; this  error  handler  is  less
45       useful  in  with  the  C++  MPI bindings.  The predefined error handler
46       MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the  error  value
47       needs  to  be recovered).  Note that MPI does not guarantee that an MPI
48       program can continue past an error.
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50       All MPI routines (except MPI_Wtime and  MPI_Wtick  )  return  an  error
51       value;  C routines as the value of the function and Fortran routines in
52       the last argument.  The C++ bindings for MPI do not return  error  val‐
53       ues;  instead,  error values are communicated by throwing exceptions of
54       type MPI::Exception (but not by default).  Exceptions are  only  thrown
55       if the error value is not MPI::SUCCESS .
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58       Note  that  if  the MPI::ERRORS_RETURN handler is set in C++, while MPI
59       functions will return upon an error, there will be no  way  to  recover
60       what the actual error value was.
61       MPI_SUCCESS
62              - No error; MPI routine completed successfully.
63       MPI_ERR_ARG
64              - Invalid argument.  Some argument is invalid and is not identi‐
65              fied by a specific  error  class.   This  is  typically  a  NULL
66              pointer or other such error.
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MORE INFORMATION

74       For more information, please see the official MPI Forum web site, which
75       contains the text of both the MPI-1 and MPI-2 standards.   These  docu‐
76       ments  contain  detailed  information  about each MPI function (most of
77       which is not duplicated in these man pages).
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79       http://www.mpi-forum.org/
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LOCATION

82       querythr.c
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86LAM/MPI 7.1.2                      2/23/2006               MPI_Query_thread(3)