File: MPI_Intercomm_merge.3

package info (click to toggle)
mpich 1.1.0-3
  • links: PTS
  • area: main
  • in suites: hamm
  • size: 22,116 kB
  • ctags: 27,349
  • sloc: ansic: 193,435; sh: 11,172; fortran: 6,545; makefile: 5,801; cpp: 5,020; tcl: 3,548; asm: 3,536; csh: 1,079; java: 614; perl: 183; awk: 168; sed: 70; f90: 62
file content (107 lines) | stat: -rw-r--r-- 2,174 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
.TH MPI_Intercomm_merge 3 "1/6/1997" " " "MPI"
.SH NAME
MPI_Intercomm_merge \-  Creates an intracommuncator from an intercommunicator 
.SH SYNOPSIS
.nf
#include "mpi.h"
int MPI_Intercomm_merge ( comm, high, comm_out )
MPI_Comm  comm;
int       high;
MPI_Comm *comm_out;
.fi
.SH INPUT PARAMETERS
.PD 0
.TP
.B comm 
- Intercommunicator
.PD 1
.PD 0
.TP
.B high 
- Used to order the groups of the two intracommunicators within comm
when creating the new communicator.  
.PD 1

.SH OUTPUT PARAMETER
.PD 0
.TP
.B comm_out 
- Created intracommunicator
.PD 1

.SH NOTES FOR FORTRAN
All MPI routines in Fortran (except for 
.I MPI_WTIME
and 
.I MPI_WTICK
) have
an additional argument 
.I ierr
at the end of the argument list.  
.I ierr
is an integer and has the same meaning as the return value of the routine
in C.  In Fortran, MPI routines are subroutines, and are invoked with the
.I call
statement.

All MPI objects (e.g., 
.I MPI_Datatype
, 
.I MPI_Comm
) are of type 
.I INTEGER
in Fortran.

.SH ALGORITHM
.nf
1) Allocate two contexts 
2) Local and remote group leaders swap high values
3) Determine the high value.
4) Merge the two groups and make the intra-communicator
.fi

.SH ERRORS

All MPI routines (except 
.I MPI_Wtime
and 
.I MPI_Wtick
) return an error value;
C routines as the value of the function and Fortran routines in the last
argument.  Before the value is returned, the current MPI error handler is
called.  By default, this error handler aborts the MPI job.  The error handler
may be changed with 
.I MPI_Errhandler_set
; the predefined error handler
.I MPI_ERRORS_RETURN
may be used to cause error values to be returned.
Note that MPI does 
.B not
guarentee that an MPI program can continue past
an error.

.PD 0
.TP
.B MPI_SUCCESS 
- No error; MPI routine completed successfully.
.PD 1
.PD 0
.TP
.B MPI_ERR_COMM 
- Invalid communicator.  A common error is to use a null
communicator in a call (not even allowed in 
.I MPI_Comm_rank
).
.PD 1
.PD 0
.TP
.B MPI_ERR_INTERN 
- This error is returned when some part of the MPICH 
implementation is unable to acquire memory.  
.PD 1

.SH SEE ALSO
MPI_Intercomm_create, MPI_Comm_free
.br
.SH LOCATION
ic_merge.c