1MPI_Testsome(3) LAM/MPI MPI_Testsome(3)
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6 MPI_Testsome - Tests for some given communications to complete
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9 #include <mpi.h>
10 int MPI_Testsome(int count, MPI_Request *reqs,
11 int *outcount, int *indices, MPI_Status *stats)
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14 count - length of array_of_requests (integer)
15 reqs - array of requests (array of handles)
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19 outcount
20 - number of completed requests (integer)
21 indices
22 - array of indices of operations that completed (array of inte‐
23 gers)
24 stats - array of status objects for operations that completed (array
25 of Status), or the MPI constant MPI_STATUSES_IGNORE
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30 For send operations, the only use of status is for MPI_Test_cancelled
31 in the case that there is an error, in which case the MPI_ERROR field
32 of status will be set.
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36 All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
37 an additional argument ierr at the end of the argument list. ierr is
38 an integer and has the same meaning as the return value of the routine
39 in C. In Fortran, MPI routines are subroutines, and are invoked with
40 the call statement.
41 All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
43 Fortran.
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47 If an error occurs in an MPI function, the current MPI error handler is
48 called to handle it. By default, this error handler aborts the MPI
49 job. The error handler may be changed with MPI_Errhandler_set ; the
50 predefined error handler MPI_ERRORS_RETURN may be used to cause error
51 values to be returned (in C and Fortran; this error handler is less
52 useful in with the C++ MPI bindings. The predefined error handler
53 MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value
54 needs to be recovered). Note that MPI does not guarantee that an MPI
55 program can continue past an error.
56 All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error
58 value; C routines as the value of the function and Fortran routines in
59 the last argument. The C++ bindings for MPI do not return error val‐
60 ues; instead, error values are communicated by throwing exceptions of
61 type MPI::Exception (but not by default). Exceptions are only thrown
62 if the error value is not MPI::SUCCESS .
63 Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI
66 functions will return upon an error, there will be no way to recover
67 what the actual error value was.
68 MPI_SUCCESS
69 - No error; MPI routine completed successfully.
70 MPI_ERR_COUNT
71 - Invalid count argument. Count arguments must be non-negative;
72 a count of zero is often valid.
73 MPI_ERR_ARG
74 - Invalid argument. Some argument is invalid and is not identi‐
75 fied by a specific error class. This is typically a NULL
76 pointer or other such error.
77 MPI_ERR_IN_STATUS
79 - The actual error value is in the MPI_Status argument. Note
80 that if this error occurs and MPI_STATUS_IGNORE or MPI_STA‐
81 TUSES_IGNORE was used as the status argument, the actual error
82 will be lost. This error class is returned only from the multi‐
83 ple-completion routines ( MPI_Testall , MPI_Testany , MPI_Test‐
84 some , MPI_Waitall , MPI_Waitany , and MPI_Waitsome ). The
85 field MPI_ERROR in the status argument contains the error value
86 or MPI_SUCCESS (no error and complete) or MPI_ERR_PENDING to
87 indicate that the request has not completed. The MPI Standard
88 does not specify what the result of the multiple completion rou‐
89 tines is when an error occurs. For example, in an MPI_WAITALL ,
90 does the routine wait for all requests to either fail or com‐
91 plete, or does it return immediately (with the MPI definition of
92 immediately, which means independent of actions of other MPI
93 processes)? LAM/MPI has chosen to make the return immediate
94 (alternately, local in MPI terms), and to use the error class
95 MPI_ERR_PENDING (introduced in MPI 1.1) to indicate which
96 requests have not completed. In most cases, only one request
97 with an error will be detected in each call to an MPI routine
98 that tests multiple requests. The requests that have not been
99 processed (because an error occured in one of the requests) will
100 have their MPI_ERROR field marked with MPI_ERR_PENDING .
101
105 For more information, please see the official MPI Forum web site, which
106 contains the text of both the MPI-1 and MPI-2 standards. These docu‐
107 ments contain detailed information about each MPI function (most of
108 which is not duplicated in these man pages).
109 http://www.mpi-forum.org/
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115 The LAM Team would like the thank the MPICH Team for the handy program
116 to generate man pages ("doctext" from ftp://ftp.mcs.anl.gov/pub/sow‐
117 ing/sowing.tar.gz ), the initial formatting, and some initial text for
118 most of the MPI-1 man pages.
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121 testsome.c
122LAM/MPI 7.1.2 2/23/2006 MPI_Testsome(3)