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
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML3.2 EN">
<HTML>
<HEAD> <link rel="canonical" href="http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Sys/PetscSequentialPhaseBegin.html" />
<META NAME="GENERATOR" CONTENT="DOCTEXT">
<TITLE>PetscSequentialPhaseBegin</TITLE>
</HEAD>
<BODY BGCOLOR="FFFFFF">
<div id="version" align=right><b>petsc-3.4.2 2013-07-02</b></div>
<A NAME="PetscSequentialPhaseBegin"><H1>PetscSequentialPhaseBegin</H1></A>
Begins a sequential section of code.
<H3><FONT COLOR="#CC3333">Synopsis</FONT></H3>
<PRE>
#include "petscsys.h"
PetscErrorCode PetscSequentialPhaseBegin(MPI_Comm comm,int ng)
</PRE>
Collective on <A HREF="../Sys/MPI_Comm.html#MPI_Comm">MPI_Comm</A>
<P>
<H3><FONT COLOR="#CC3333">Input Parameters</FONT></H3>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>comm </B></TD><TD>- Communicator to sequentialize.
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>ng </B></TD><TD>- Number in processor group. This many processes are allowed to execute
at the same time (usually 1)
</TD></TR></TABLE>
<P>
<P>
<H3><FONT COLOR="#CC3333">Notes</FONT></H3>
<A HREF="../Sys/PetscSequentialPhaseBegin.html#PetscSequentialPhaseBegin">PetscSequentialPhaseBegin</A>() and <A HREF="../Sys/PetscSequentialPhaseEnd.html#PetscSequentialPhaseEnd">PetscSequentialPhaseEnd</A>() provide a
way to force a section of code to be executed by the processes in
rank order. Typically, this is done with
<PRE>
<A HREF="../Sys/PetscSequentialPhaseBegin.html#PetscSequentialPhaseBegin">PetscSequentialPhaseBegin</A>(comm, 1);
<code to be executed sequentially>
<A HREF="../Sys/PetscSequentialPhaseEnd.html#PetscSequentialPhaseEnd">PetscSequentialPhaseEnd</A>(comm, 1);
</PRE>
<P>
Often, the sequential code contains output statements (e.g., printf) to
be executed. Note that you may need to flush the I/O buffers before
calling <A HREF="../Sys/PetscSequentialPhaseEnd.html#PetscSequentialPhaseEnd">PetscSequentialPhaseEnd</A>(). Also, note that some systems do
not propagate I/O in any order to the controling terminal (in other words,
even if you flush the output, you may not get the data in the order
that you want).
<P>
<H3><FONT COLOR="#CC3333">See Also</FONT></H3>
<A HREF="../Sys/PetscSequentialPhaseEnd.html#PetscSequentialPhaseEnd">PetscSequentialPhaseEnd</A>()
<BR>
<P>
<P>
<P><B><P><B><FONT COLOR="#CC3333">Level:</FONT></B>intermediate
<BR><FONT COLOR="#CC3333">Location:</FONT></B><A HREF="../../../src/sys/utils/mpiu.c.html#PetscSequentialPhaseBegin">src/sys/utils/mpiu.c</A>
<BR><A HREF="./index.html">Index of all Sys routines</A>
<BR><A HREF="../../index.html">Table of Contents for all manual pages</A>
<BR><A HREF="../singleindex.html">Index of all manual pages</A>
</BODY></HTML>
|
