Basic multithreaded program Post: 302325339

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Top Forums Programming Basic multithreaded program Post 302325339 by pludi on Sunday 14th of June 2009 04:53:23 PM

06-14-2009

Registered User

OK, from what you've posted 'till now, the basic structure would be something like this (pseudo-code)

Code:

Read numbers from file
Process them
Create output files
Create array of commands to run
Total processes=0
While there are commands left
    pop a command from the stack
    fork() a subprocess
    In the child
        system() the command
    In the parent
        Total processes++
    If total processes >= 4
        wait() until any process returns

Input isn't really a problem here, since fork()ed processes inherit the parents file descriptors. Output is, since as far as I know it's hard to return data from the child to the parent without shared memory or something similar. You could save the output to a file in each child my changing stdout just before the system().
Alternatively, you could run exec() the program yourself, to reduce the fork-rate, but I'm not sure how well this would work.
Plus, with shed_setaffinity you can set the affinity of the processes (direct it which CPU to use), but you'd have to track which CPU the last process used.

Anyone with more experience with algorithms has a better idea?

pludi

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LEARN ABOUT DEBIAN

coala

COALA(1)						      General Commands Manual							  COALA(1)

NAME

       coala - a versatile compiler from action languages to answer set programs

SYNOPSIS

       coala [options]file[number]

DESCRIPTION

       This manual page documents briefly the coala command.

       coala  is  a  versatile	compiler  from	action	languages to answer set programs. It supports different encodings, variables and LTL style
       queries. It translates an action language into a logic program under the answer set semantics. After being grounded by  lparse  or  gringo,
       the  logic program can be solved by an answer set solver such as clasp. At the moment coala is able to translate the action language AL, B,
       C, a subset of C+ and the action language CTAID. The type of input language can be specified with a command line option.

OPTIONS

       These programs follow the usual GNU command line syntax, with long options starting with  two  dashes  (`-').   A  summary  of  options	is
       included below.	For a complete description, see the potassco-guide.

       -h, --help
	      Show summary of options.

       --version
	      Show version of program.

SEE ALSO

       clasp(1), gringo(1).

AUTHOR

       coala was written by Torsten Grote <Torsten.Grote@uni-potsdam.de>

       This manual page was written by Thomas Krennwallner <tkren@kr.tuwien.ac.at>, for the Debian project (and may be used by others).

								  March  4, 2010							  COALA(1)