1MPI_Waitany(3) LAM/MPI MPI_Waitany(3)
2
6 MPI_Waitany - Waits for any specified send or receive to complete
7
9 #include <mpi.h>
10 int MPI_Waitany(int count, MPI_Request *reqs, int *index,
11 MPI_Status *stat)
12
14 count - list length (integer)
15 reqs - array of requests (array of handles)
16
19 index - index of handle for operation that completed (integer). In
20 the range 0 to count-1 . In Fortran, the range is 1 to count .
21 stat - status object (Status), or the MPI constant MPI_STATUS_IGNORE
23
27 If all of the requests are MPI_REQUEST_NULL , then index is returned as
28 MPI_UNDEFINED , and stat is returned as an empty status.
29
32 For send operations, the only use of status is for MPI_Test_cancelled
33 in the case that there is an error, in which case the MPI_ERROR field
34 of status will be set.
35
38 All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
39 an additional argument ierr at the end of the argument list. ierr is
40 an integer and has the same meaning as the return value of the routine
41 in C. In Fortran, MPI routines are subroutines, and are invoked with
42 the call statement.
43 All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
45 Fortran.
46
49 If an error occurs in an MPI function, the current MPI error handler is
50 called to handle it. By default, this error handler aborts the MPI
51 job. The error handler may be changed with MPI_Errhandler_set ; the
52 predefined error handler MPI_ERRORS_RETURN may be used to cause error
53 values to be returned (in C and Fortran; this error handler is less
54 useful in with the C++ MPI bindings. The predefined error handler
55 MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value
56 needs to be recovered). Note that MPI does not guarantee that an MPI
57 program can continue past an error.
58 All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error
60 value; C routines as the value of the function and Fortran routines in
61 the last argument. The C++ bindings for MPI do not return error val‐
62 ues; instead, error values are communicated by throwing exceptions of
63 type MPI::Exception (but not by default). Exceptions are only thrown
64 if the error value is not MPI::SUCCESS .
65 Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI
68 functions will return upon an error, there will be no way to recover
69 what the actual error value was.
70 MPI_SUCCESS
71 - No error; MPI routine completed successfully.
72 MPI_ERR_REQUEST
73 - Invalid MPI_Request ; either null or, MPI_REQUEST_NULL , in
74 the case of a MPI_Start or MPI_Startall , not a persistent
75 request.
76 MPI_ERR_COUNT
77 - Invalid count argument. Count arguments must be non-negative;
78 a count of zero is often valid.
79 MPI_ERR_ARG
80 - Invalid argument. Some argument is invalid and is not identi‐
81 fied by a specific error class. This is typically a NULL
82 pointer or other such error.
83
86 For more information, please see the official MPI Forum web site, which
87 contains the text of both the MPI-1 and MPI-2 standards. These docu‐
88 ments contain detailed information about each MPI function (most of
89 which is not duplicated in these man pages).
90 http://www.mpi-forum.org/
92
96 The LAM Team would like the thank the MPICH Team for the handy program
97 to generate man pages ("doctext" from ftp://ftp.mcs.anl.gov/pub/sow‐
98 ing/sowing.tar.gz ), the initial formatting, and some initial text for
99 most of the MPI-1 man pages.
100
102 waitany.c
103LAM/MPI 7.1.2 2/23/2006 MPI_Waitany(3)