1MPI_Comm_rank(3) LAM/MPI MPI_Comm_rank(3)
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6 MPI_Comm_rank - Determines the rank of the calling process in the com‐
7 municator
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10 #include <mpi.h>
11 int MPI_Comm_rank(MPI_Comm comm, int *rank)
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14 comm - communicator (handle)
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18 rank - rank of the calling process in group of comm (integer)
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22 All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
23 an additional argument ierr at the end of the argument list. ierr is
24 an integer and has the same meaning as the return value of the routine
25 in C. In Fortran, MPI routines are subroutines, and are invoked with
26 the call statement.
27 All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
29 Fortran.
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33 If an error occurs in an MPI function, the current MPI error handler is
34 called to handle it. By default, this error handler aborts the MPI
35 job. The error handler may be changed with MPI_Errhandler_set ; the
36 predefined error handler MPI_ERRORS_RETURN may be used to cause error
37 values to be returned (in C and Fortran; this error handler is less
38 useful in with the C++ MPI bindings. The predefined error handler
39 MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value
40 needs to be recovered). Note that MPI does not guarantee that an MPI
41 program can continue past an error.
42 All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error
44 value; C routines as the value of the function and Fortran routines in
45 the last argument. The C++ bindings for MPI do not return error val‐
46 ues; instead, error values are communicated by throwing exceptions of
47 type MPI::Exception (but not by default). Exceptions are only thrown
48 if the error value is not MPI::SUCCESS .
49 Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI
52 functions will return upon an error, there will be no way to recover
53 what the actual error value was.
54 MPI_SUCCESS
55 - No error; MPI routine completed successfully.
56 MPI_ERR_COMM
57 - Invalid communicator. A common error is to use a null commu‐
58 nicator in a call (not even allowed in MPI_Comm_rank ).
59 MPI_ERR_ARG
60 - Invalid argument. Some argument is invalid and is not identi‐
61 fied by a specific error class. This is typically a NULL
62 pointer or other such error.
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66 For more information, please see the official MPI Forum web site, which
67 contains the text of both the MPI-1 and MPI-2 standards. These docu‐
68 ments contain detailed information about each MPI function (most of
69 which is not duplicated in these man pages).
70 http://www.mpi-forum.org/
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76 The LAM Team would like the thank the MPICH Team for the handy program
77 to generate man pages ("doctext" from ftp://ftp.mcs.anl.gov/pub/sow‐
78 ing/sowing.tar.gz ), the initial formatting, and some initial text for
79 most of the MPI-1 man pages.
80
82 crank.c
83LAM/MPI 7.1.2 2/23/2006 MPI_Comm_rank(3)