1MPI_Send(3) LAM/MPI MPI_Send(3)
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6 MPI_Send - Performs a basic send
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9 #include <mpi.h>
10 int MPI_Send(void *buf, int count, MPI_Datatype dtype, int dest,
11 int tag, MPI_Comm comm)
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14 buf - initial address of send buffer (choice)
15 count - number of elements in send buffer (nonnegative integer)
16 dtyp - datatype of each send buffer element (handle)
17 dest - rank of destination (integer)
18 tag - message tag (integer)
19 comm - communicator (handle)
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23 This function may block until the message is received. Whether or not
24 MPI_Send blocks depends on factors such as how large the message is,
25 how many messages are pending to the specific destination, whether LAMD
26 or C2C communication is being used, etc.
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30 All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
31 an additional argument ierr at the end of the argument list. ierr is
32 an integer and has the same meaning as the return value of the routine
33 in C. In Fortran, MPI routines are subroutines, and are invoked with
34 the call statement.
35 All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
37 Fortran.
38
41 If an error occurs in an MPI function, the current MPI error handler is
42 called to handle it. By default, this error handler aborts the MPI
43 job. The error handler may be changed with MPI_Errhandler_set ; the
44 predefined error handler MPI_ERRORS_RETURN may be used to cause error
45 values to be returned (in C and Fortran; this error handler is less
46 useful in with the C++ MPI bindings. The predefined error handler
47 MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value
48 needs to be recovered). Note that MPI does not guarantee that an MPI
49 program can continue past an error.
50 All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error
52 value; C routines as the value of the function and Fortran routines in
53 the last argument. The C++ bindings for MPI do not return error val‐
54 ues; instead, error values are communicated by throwing exceptions of
55 type MPI::Exception (but not by default). Exceptions are only thrown
56 if the error value is not MPI::SUCCESS .
57 Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI
60 functions will return upon an error, there will be no way to recover
61 what the actual error value was.
62 MPI_SUCCESS
63 - No error; MPI routine completed successfully.
64 MPI_ERR_COMM
65 - Invalid communicator. A common error is to use a null commu‐
66 nicator in a call (not even allowed in MPI_Comm_rank ).
67 MPI_ERR_COUNT
68 - Invalid count argument. Count arguments must be non-negative;
69 a count of zero is often valid.
70 MPI_ERR_TYPE
71 - Invalid datatype argument. May be an uncommitted MPI_Datatype
72 (see MPI_Type_commit ).
73 MPI_ERR_TAG
74 - Invalid tag argument. Tags must be non-negative; tags in a
75 receive ( MPI_Recv , MPI_Irecv , MPI_Sendrecv , etc.) may also
76 be MPI_ANY_TAG . The largest tag value is available through the
77 the attribute MPI_TAG_UB .
78 MPI_ERR_RANK
80 - Invalid source or destination rank. Ranks must be between
81 zero and the size of the communicator minus one; ranks in a
82 receive ( MPI_Recv , MPI_Irecv , MPI_Sendrecv , etc.) may also
83 be MPI_ANY_SOURCE .
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88 MPI_Isend, MPI_Send_init
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92 For more information, please see the official MPI Forum web site, which
93 contains the text of both the MPI-1 and MPI-2 standards. These docu‐
94 ments contain detailed information about each MPI function (most of
95 which is not duplicated in these man pages).
96 http://www.mpi-forum.org/
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102 The LAM Team would like the thank the MPICH Team for the handy program
103 to generate man pages ("doctext" from ftp://ftp.mcs.anl.gov/pub/sow‐
104 ing/sowing.tar.gz ), the initial formatting, and some initial text for
105 most of the MPI-1 man pages.
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108 send.c
109LAM/MPI 7.1.2 2/23/2006 MPI_Send(3)