1MPI_Waitall(3) LAM/MPI MPI_Waitall(3)
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6 MPI_Waitall - Waits for all given communications to complete
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9 #include <mpi.h>
10 int MPI_Waitall(int count, MPI_Request *reqs,
11 MPI_Status *stats)
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14 count - lists length (integer)
15 reqs - array of requests (array of handles)
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19 stats - array of status objects (array of Status), which may be the
20 MPI constant MPI_STATUSES_IGNORE
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25 For send operations, the only use of status is for MPI_Test_cancelled
26 in the case that there is an error, in which case the MPI_ERROR field
27 of status will be set.
28
31 All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
32 an additional argument ierr at the end of the argument list. ierr is
33 an integer and has the same meaning as the return value of the routine
34 in C. In Fortran, MPI routines are subroutines, and are invoked with
35 the call statement.
36 All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
38 Fortran.
39
42 If an error occurs in an MPI function, the current MPI error handler is
43 called to handle it. By default, this error handler aborts the MPI
44 job. The error handler may be changed with MPI_Errhandler_set ; the
45 predefined error handler MPI_ERRORS_RETURN may be used to cause error
46 values to be returned (in C and Fortran; this error handler is less
47 useful in with the C++ MPI bindings. The predefined error handler
48 MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value
49 needs to be recovered). Note that MPI does not guarantee that an MPI
50 program can continue past an error.
51 All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error
53 value; C routines as the value of the function and Fortran routines in
54 the last argument. The C++ bindings for MPI do not return error val‐
55 ues; instead, error values are communicated by throwing exceptions of
56 type MPI::Exception (but not by default). Exceptions are only thrown
57 if the error value is not MPI::SUCCESS .
58 Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI
61 functions will return upon an error, there will be no way to recover
62 what the actual error value was.
63 MPI_SUCCESS
64 - No error; MPI routine completed successfully.
65 MPI_ERR_REQUEST
66 - Invalid MPI_Request ; either null or, MPI_REQUEST_NULL , in
67 the case of a MPI_Start or MPI_Startall , not a persistent
68 request.
69 MPI_ERR_ARG
70 - Invalid argument. Some argument is invalid and is not identi‐
71 fied by a specific error class. This is typically a NULL
72 pointer or other such error.
73 MPI_ERR_COUNT
74 - Invalid count argument. Count arguments must be non-negative;
75 a count of zero is often valid.
76 MPI_ERR_IN_STATUS
78 - The actual error value is in the MPI_Status argument. Note
79 that if this error occurs and MPI_STATUS_IGNORE or MPI_STA‐
80 TUSES_IGNORE was used as the status argument, the actual error
81 will be lost. This error class is returned only from the multi‐
82 ple-completion routines ( MPI_Testall , MPI_Testany , MPI_Test‐
83 some , MPI_Waitall , MPI_Waitany , and MPI_Waitsome ). The
84 field MPI_ERROR in the status argument contains the error value
85 or MPI_SUCCESS (no error and complete) or MPI_ERR_PENDING to
86 indicate that the request has not completed. The MPI Standard
87 does not specify what the result of the multiple completion rou‐
88 tines is when an error occurs. For example, in an MPI_WAITALL ,
89 does the routine wait for all requests to either fail or com‐
90 plete, or does it return immediately (with the MPI definition of
91 immediately, which means independent of actions of other MPI
92 processes)? LAM/MPI has chosen to make the return immediate
93 (alternately, local in MPI terms), and to use the error class
94 MPI_ERR_PENDING (introduced in MPI 1.1) to indicate which
95 requests have not completed. In most cases, only one request
96 with an error will be detected in each call to an MPI routine
97 that tests multiple requests. The requests that have not been
98 processed (because an error occured in one of the requests) will
99 have their MPI_ERROR field marked with MPI_ERR_PENDING .
100 MPI_ERR_PENDING
102 - Pending request (not an error). See MPI_ERR_IN_STATUS . This
103 value indicates that the request is not complete nor has a
104 encountered a detected error.
105
108 For more information, please see the official MPI Forum web site, which
109 contains the text of both the MPI-1 and MPI-2 standards. These docu‐
110 ments contain detailed information about each MPI function (most of
111 which is not duplicated in these man pages).
112 http://www.mpi-forum.org/
114
118 The LAM Team would like the thank the MPICH Team for the handy program
119 to generate man pages ("doctext" from ftp://ftp.mcs.anl.gov/pub/sow‐
120 ing/sowing.tar.gz ), the initial formatting, and some initial text for
121 most of the MPI-1 man pages.
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124 waitall.c
125LAM/MPI 7.1.2 2/23/2006 MPI_Waitall(3)