MPI_Is_thread_main(3)

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

6       MPI_Is_thread_main -  determine if the caller is the main thread
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SYNOPSIS

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

14       pflag  - true if calling thread is main thread, false otherwise
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DESCRIPTION

18       This  function  is  mainly here for link-compatability.  Since only the
19       MPI_THREAD_SINGLE level of thread concurrency is supported in  LAM/MPI,
20       this  function has limited usefulness.  Future versions of LAM/MPI will
21       support multi-threaded user programs,  in  which  case  MPI_Init_thread
22       must  be used to initialize MPI.  Hence, programmers can use this func‐
23       tion now in order to program for future flexibility.
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NOTES FOR FORTRAN

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

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

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

80       isthrmain.c
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84LAM/MPI 7.1.2                      2/23/2006             MPI_Is_thread_main(3)