1MPI_Bsend_init(3) LAM/MPI MPI_Bsend_init(3)
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6 MPI_Bsend_init - Builds a handle for a buffered send
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9 #include <mpi.h>
10 int MPI_Bsend_init(void *buf, int count, MPI_Datatype dtype,
11 int dest, int tag, MPI_Comm comm,
12 MPI_Request *req)
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15 buf - initial address of send buffer (choice)
16 count - number of elements sent (integer)
17 dtype - type of each element (handle)
18 dest - rank of destination (integer)
19 tag - message tag (integer)
20 comm - communicator (handle)
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24 req - communication request (handle)
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28 It is generally a bad idea to use the MPI_Bsend_init function, as it
29 guarantees that the entire message will suffer the overhead of an addi‐
30 tional memory copy. For large messages, or when shared memory message
31 transports are being used, this overhead can be quite expensive.
32 The communication initialized by this function will not be started
34 until req is given to MPI_Start or MPI_Startall .
35 The communication is then not guaranteed to progress or complete until
38 req has been given to one of the test or wait functions ( MPI_Test ,
39 MPI_Testall , MPI_Testany , MPI_Testsome , MPI_Wait , MPI_Waitall ,
40 MPI_Waitany , MPI_Waitsome ).
41 Once any of the test or wait functions indicate that the communication
43 has finished, the communication cycle can be started again with
44 MPI_Start or MPI_Startall .
45 However, once the communication has finished and it is no longer going
48 to be used, req should be freed with MPI_Request_free .
49
53 All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
54 an additional argument ierr at the end of the argument list. ierr is
55 an integer and has the same meaning as the return value of the routine
56 in C. In Fortran, MPI routines are subroutines, and are invoked with
57 the call statement.
58 All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
60 Fortran.
61
64 If an error occurs in an MPI function, the current MPI error handler is
65 called to handle it. By default, this error handler aborts the MPI
66 job. The error handler may be changed with MPI_Errhandler_set ; the
67 predefined error handler MPI_ERRORS_RETURN may be used to cause error
68 values to be returned (in C and Fortran; this error handler is less
69 useful in with the C++ MPI bindings. The predefined error handler
70 MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value
71 needs to be recovered). Note that MPI does not guarantee that an MPI
72 program can continue past an error.
73 All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error
75 value; C routines as the value of the function and Fortran routines in
76 the last argument. The C++ bindings for MPI do not return error val‐
77 ues; instead, error values are communicated by throwing exceptions of
78 type MPI::Exception (but not by default). Exceptions are only thrown
79 if the error value is not MPI::SUCCESS .
80 Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI
83 functions will return upon an error, there will be no way to recover
84 what the actual error value was.
85 MPI_SUCCESS
86 - No error; MPI routine completed successfully.
87 MPI_ERR_COMM
88 - Invalid communicator. A common error is to use a null commu‐
89 nicator in a call (not even allowed in MPI_Comm_rank ).
90 MPI_ERR_COUNT
91 - Invalid count argument. Count arguments must be non-negative;
92 a count of zero is often valid.
93 MPI_ERR_TYPE
94 - Invalid datatype argument. May be an uncommitted MPI_Datatype
95 (see MPI_Type_commit ).
96 MPI_ERR_RANK
97 - Invalid source or destination rank. Ranks must be between
98 zero and the size of the communicator minus one; ranks in a
99 receive ( MPI_Recv , MPI_Irecv , MPI_Sendrecv , etc.) may also
100 be MPI_ANY_SOURCE .
101 MPI_ERR_TAG
103 - Invalid tag argument. Tags must be non-negative; tags in a
104 receive ( MPI_Recv , MPI_Irecv , MPI_Sendrecv , etc.) may also
105 be MPI_ANY_TAG . The largest tag value is available through the
106 the attribute MPI_TAG_UB .
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111 MPI_Buffer_attach, MPI_Buffer_detach, MPI_Bsend, MPI_Start, MPI_Star‐
112 tall, MPI_Test, MPI_Testall, MPI_Testany, MPI_Testsome, MPI_Wait,
113 MPI_Waitall, MPI_Waitany, MPI_Waitsome
114
117 For more information, please see the official MPI Forum web site, which
118 contains the text of both the MPI-1 and MPI-2 standards. These docu‐
119 ments contain detailed information about each MPI function (most of
120 which is not duplicated in these man pages).
121 http://www.mpi-forum.org/
123
127 The LAM Team would like the thank the MPICH Team for the handy program
128 to generate man pages ("doctext" from ftp://ftp.mcs.anl.gov/pub/sow‐
129 ing/sowing.tar.gz ), the initial formatting, and some initial text for
130 most of the MPI-1 man pages.
131
133 bsendinit.c
134LAM/MPI 7.1.2 2/23/2006 MPI_Bsend_init(3)