1MPI_Group_size(3) LAM/MPI MPI_Group_size(3)
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6 MPI_Group_size - Returns the size of a group
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9 #include <mpi.h>
10 int MPI_Group_size(MPI_Group group, int *psize)
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13 group - group (handle)
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17 psize - number of processes in the group (integer)
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21 All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
22 an additional argument ierr at the end of the argument list. ierr is
23 an integer and has the same meaning as the return value of the routine
24 in C. In Fortran, MPI routines are subroutines, and are invoked with
25 the call statement.
26 All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
28 Fortran.
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32 If an error occurs in an MPI function, the current MPI error handler is
33 called to handle it. By default, this error handler aborts the MPI
34 job. The error handler may be changed with MPI_Errhandler_set ; the
35 predefined error handler MPI_ERRORS_RETURN may be used to cause error
36 values to be returned (in C and Fortran; this error handler is less
37 useful in with the C++ MPI bindings. The predefined error handler
38 MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value
39 needs to be recovered). Note that MPI does not guarantee that an MPI
40 program can continue past an error.
41 All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error
43 value; C routines as the value of the function and Fortran routines in
44 the last argument. The C++ bindings for MPI do not return error val‐
45 ues; instead, error values are communicated by throwing exceptions of
46 type MPI::Exception (but not by default). Exceptions are only thrown
47 if the error value is not MPI::SUCCESS .
48 Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI
51 functions will return upon an error, there will be no way to recover
52 what the actual error value was.
53 MPI_SUCCESS
54 - No error; MPI routine completed successfully.
55 MPI_ERR_GROUP
56 - Null group passed to function.
57 MPI_ERR_ARG
58 - Invalid argument. Some argument is invalid and is not identi‐
59 fied by a specific error class. This is typically a NULL
60 pointer or other such error.
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64 For more information, please see the official MPI Forum web site, which
65 contains the text of both the MPI-1 and MPI-2 standards. These docu‐
66 ments contain detailed information about each MPI function (most of
67 which is not duplicated in these man pages).
68 http://www.mpi-forum.org/
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74 The LAM Team would like the thank the MPICH Team for the handy program
75 to generate man pages ("doctext" from ftp://ftp.mcs.anl.gov/pub/sow‐
76 ing/sowing.tar.gz ), the initial formatting, and some initial text for
77 most of the MPI-1 man pages.
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80 gsize.c
81LAM/MPI 7.1.2 2/23/2006 MPI_Group_size(3)