1MPI_Irecv(3) LAM/MPI MPI_Irecv(3)
2
6 MPI_Irecv - Begins a non-blocking receive
7
9 #include <mpi.h>
10 int MPI_Irecv(void *buf, int count, MPI_Datatype dtype,
11 int src, int tag, MPI_Comm comm,
12 MPI_Request *req)
13
15 buf - initial address of receive buffer (choice)
16 count - number of elements in receive buffer (integer)
17 dtype - datatype of each receive buffer element (handle)
18 src - rank of source (integer)
19 tag - message tag (integer)
20 comm - communicator (handle)
21
24 req - communication request (handle)
25
28 The communication started with this function is not guaranteed to
29 progress or complete until req has been given to one of the test or
30 wait functions ( MPI_Test , MPI_Testall , MPI_Testany , MPI_Testsome ,
31 MPI_Wait , MPI_Waitall , MPI_Waitany , MPI_Waitsome ).
32
35 All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
36 an additional argument ierr at the end of the argument list. ierr is
37 an integer and has the same meaning as the return value of the routine
38 in C. In Fortran, MPI routines are subroutines, and are invoked with
39 the call statement.
40 All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
42 Fortran.
43
46 If an error occurs in an MPI function, the current MPI error handler is
47 called to handle it. By default, this error handler aborts the MPI
48 job. The error handler may be changed with MPI_Errhandler_set ; the
49 predefined error handler MPI_ERRORS_RETURN may be used to cause error
50 values to be returned (in C and Fortran; this error handler is less
51 useful in with the C++ MPI bindings. The predefined error handler
52 MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value
53 needs to be recovered). Note that MPI does not guarantee that an MPI
54 program can continue past an error.
55 All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error
57 value; C routines as the value of the function and Fortran routines in
58 the last argument. The C++ bindings for MPI do not return error val‐
59 ues; instead, error values are communicated by throwing exceptions of
60 type MPI::Exception (but not by default). Exceptions are only thrown
61 if the error value is not MPI::SUCCESS .
62 Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI
65 functions will return upon an error, there will be no way to recover
66 what the actual error value was.
67 MPI_SUCCESS
68 - No error; MPI routine completed successfully.
69 MPI_ERR_COMM
70 - Invalid communicator. A common error is to use a null commu‐
71 nicator in a call (not even allowed in MPI_Comm_rank ).
72 MPI_ERR_TYPE
73 - Invalid datatype argument. May be an uncommitted MPI_Datatype
74 (see MPI_Type_commit ).
75 MPI_ERR_COUNT
76 - Invalid count argument. Count arguments must be non-negative;
77 a count of zero is often valid.
78 MPI_ERR_TAG
79 - Invalid tag argument. Tags must be non-negative; tags in a
80 receive ( MPI_Recv , MPI_Irecv , MPI_Sendrecv , etc.) may also
81 be MPI_ANY_TAG . The largest tag value is available through the
82 the attribute MPI_TAG_UB .
83 MPI_ERR_RANK
85 - Invalid source or destination rank. Ranks must be between
86 zero and the size of the communicator minus one; ranks in a
87 receive ( MPI_Recv , MPI_Irecv , MPI_Sendrecv , etc.) may also
88 be MPI_ANY_SOURCE .
89
93 MPI_Recv, MPI_Test, MPI_Testall, MPI_Testany, MPI_Testsome, MPI_Wait,
94 MPI_Waitall, MPI_Waitany, MPI_Waitsome
95
98 For more information, please see the official MPI Forum web site, which
99 contains the text of both the MPI-1 and MPI-2 standards. These docu‐
100 ments contain detailed information about each MPI function (most of
101 which is not duplicated in these man pages).
102 http://www.mpi-forum.org/
104
108 The LAM Team would like the thank the MPICH Team for the handy program
109 to generate man pages ("doctext" from ftp://ftp.mcs.anl.gov/pub/sow‐
110 ing/sowing.tar.gz ), the initial formatting, and some initial text for
111 most of the MPI-1 man pages.
112
114 irecv.c
115LAM/MPI 7.1.2 2/23/2006 MPI_Irecv(3)