1MPI_Pack(3) LAM/MPI MPI_Pack(3)
2
6 MPI_Pack - Packs a datatype into contiguous memory
7
9 #include <mpi.h>
10 int MPI_Pack(void *buf, int count, MPI_Datatype dtype,
11 void *packbuf, int packsize, int *packpos,
12 MPI_Comm comm)
13
15 buf - input buffer start (choice)
16 count - number of input data items (integer)
17 dtype - datatype of each input data item (handle)
18 packsize
19 - output buffer size, in bytes (integer)
20 comm - communicator for packed message (handle)
21
24 packpos
25 - current position in buffer, in bytes (integer)
26
29 packbuf
30 - output buffer start (choice)
31
34 All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
35 an additional argument ierr at the end of the argument list. ierr is
36 an integer and has the same meaning as the return value of the routine
37 in C. In Fortran, MPI routines are subroutines, and are invoked with
38 the call statement.
39 All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
41 Fortran.
42
45 If an error occurs in an MPI function, the current MPI error handler is
46 called to handle it. By default, this error handler aborts the MPI
47 job. The error handler may be changed with MPI_Errhandler_set ; the
48 predefined error handler MPI_ERRORS_RETURN may be used to cause error
49 values to be returned (in C and Fortran; this error handler is less
50 useful in with the C++ MPI bindings. The predefined error handler
51 MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value
52 needs to be recovered). Note that MPI does not guarantee that an MPI
53 program can continue past an error.
54 All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error
56 value; C routines as the value of the function and Fortran routines in
57 the last argument. The C++ bindings for MPI do not return error val‐
58 ues; instead, error values are communicated by throwing exceptions of
59 type MPI::Exception (but not by default). Exceptions are only thrown
60 if the error value is not MPI::SUCCESS .
61 Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI
64 functions will return upon an error, there will be no way to recover
65 what the actual error value was.
66 MPI_SUCCESS
67 - No error; MPI routine completed successfully.
68 MPI_ERR_COMM
69 - Invalid communicator. A common error is to use a null commu‐
70 nicator in a call (not even allowed in MPI_Comm_rank ).
71 MPI_ERR_TYPE
72 - Invalid datatype argument. May be an uncommitted MPI_Datatype
73 (see MPI_Type_commit ).
74 MPI_ERR_COUNT
75 - Invalid count argument. Count arguments must be non-negative;
76 a count of zero is often valid.
77 MPI_ERR_ARG
78 - Invalid argument. Some argument is invalid and is not identi‐
79 fied by a specific error class. This is typically a NULL
80 pointer or other such error.
81 MPI_ERR_BUFFER
82 - Invalid buffer pointer. Usually a null buffer where one is
83 not valid.
84 MPI_ERR_TRUNCATE
85 - Message truncated on receive. The buffer size specified was
86 too small for the received message. This is a recoverable error
87 in the LAM/MPI implementation.
88
91 MPI_Pack_size, MPI_Unpack
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95 For more information, please see the official MPI Forum web site, which
96 contains the text of both the MPI-1 and MPI-2 standards. These docu‐
97 ments contain detailed information about each MPI function (most of
98 which is not duplicated in these man pages).
99 http://www.mpi-forum.org/
101
105 The LAM Team would like the thank the MPICH Team for the handy program
106 to generate man pages ("doctext" from ftp://ftp.mcs.anl.gov/pub/sow‐
107 ing/sowing.tar.gz ), the initial formatting, and some initial text for
108 most of the MPI-1 man pages.
109
111 pack.c
112LAM/MPI 7.1.2 2/23/2006 MPI_Pack(3)