[ANN] forkoff-0.0.1

[ara howard]

NAME

forkoff

SYNOPSIS

brain-dead simple parallel processing for ruby

URI

http://rubyforge.org/projects/codeforpeople

INSTALL

gem install forkoff

HISTORY

0.0.1

- updated to use producer threds pushing onto a SizedQueue for each
consumer
channel. in this way the producers do not build up a massize
parllel data
structure but provide data to the consumers only as fast as they
can fork
and proccess it. basically for a 4 process run you'll end up
with 4
channels of size 1 between 4 produces and 4 consumers, each
consumer is a
thread popping of jobs, forking, and yielding results.

- removed use of Queue for capturing the output. now it's simply
an array
of arrays which removed some sync overhead.

- you can configure the number of processes globally with

Forkoff.default['proccess'] = 4

- you can now pass either an options hash

forkoff( rocesses => 2 ) ...

or plain vanilla number

forkoff( 2 ) ...

to the forkoff call

- default number of processes is 2, not 8


DESCRIPTION

forkoff works for any enumerable object, iterating a code block to
run in a
child process and collecting the results. forkoff can limit the
number of
child processes which is, by default, 2.

SAMPLES

<========< samples/a.rb >========>

~ > cat samples/a.rb

#
# forkoff makes it trivial to do parallel processing with ruby,
the following
# prints out each word in a separate process
#

require 'forkoff'

%w( hey you ).forkoff!{|word| puts "#{ word } from
#{ Process.pid }"}

~ > ruby samples/a.rb

hey from 19511
you from 19512


<========< samples/b.rb >========>

~ > cat samples/b.rb

#
# for example, this takes only 4 seconds or so to complete (8
iterations
# running in two processes = twice as fast)
#

require 'forkoff'

a = Time.now.to_f

results =
(0..7).forkoff do |i|
sleep 1
i ** 2
end

b = Time.now.to_f

elapsed = b - a

puts "elapsed: #{ elapsed }"
puts "results: #{ results.inspect }"

~ > ruby samples/b.rb

elapsed: 4.19796895980835
results: [0, 1, 4, 9, 16, 25, 36, 49]


<========< samples/c.rb >========>

~ > cat samples/c.rb

#
# forkoff does *NOT* spawn processes in batches, waiting for each
batch to
# complete. rather, it keeps a certain number of processes busy
until all
# results have been gathered. in otherwords the following will
ensure that 3
# processes are running at all times, until the list is complete.
note that
# the following will take about 3 seconds to run (3 sets of 3 @ 1
second).
#

require 'forkoff'

pid = Process.pid

a = Time.now.to_f

pstrees =
%w( a b c d e f g h i ).forkoff! rocesses => 3 do |letter|
sleep 1
{ letter => ` pstree -l 2 #{ pid } ` }
end


b = Time.now.to_f

puts
puts "pid: #{ pid }"
puts "elapsed: #{ b - a }"
puts

require 'yaml'

pstrees.each do |pstree|
y pstree
end

~ > ruby samples/c.rb


pid: 19526
elapsed: 3.39831399917603

---
a: |
-+- 19526 ahoward ruby -Ilib samples/c.rb
|-+- 19527 ahoward ruby -Ilib samples/c.rb
|-+- 19528 ahoward ruby -Ilib samples/c.rb
\-+- 19529 ahoward ruby -Ilib samples/c.rb

---
b: |
-+- 19526 ahoward ruby -Ilib samples/c.rb
|-+- 19527 ahoward ruby -Ilib samples/c.rb
|-+- 19528 ahoward ruby -Ilib samples/c.rb
\-+- 19529 ahoward ruby -Ilib samples/c.rb

---
c: |
-+- 19526 ahoward ruby -Ilib samples/c.rb
|-+- 19527 ahoward (ruby)
|-+- 19528 ahoward (ruby)
\-+- 19529 ahoward ruby -Ilib samples/c.rb

---
d: |
-+- 19526 ahoward ruby -Ilib samples/c.rb
|-+- 19536 ahoward ruby -Ilib samples/c.rb
|-+- 19537 ahoward (ruby)
\--- 19538 ahoward ruby -Ilib samples/c.rb

---
e: |
-+- 19526 ahoward ruby -Ilib samples/c.rb
|-+- 19536 ahoward ruby -Ilib samples/c.rb
|-+- 19537 ahoward ruby -Ilib samples/c.rb
\--- 19538 ahoward ruby -Ilib samples/c.rb

---
f: |
-+- 19526 ahoward ruby -Ilib samples/c.rb
|--- 19536 ahoward (ruby)
|-+- 19538 ahoward ruby -Ilib samples/c.rb
\--- 19543 ahoward ruby -Ilib samples/c.rb

---
g: |
-+- 19526 ahoward ruby -Ilib samples/c.rb
|--- 19543 ahoward (ruby)
|-+- 19546 ahoward ruby -Ilib samples/c.rb
\--- 19547 ahoward ruby -Ilib samples/c.rb

---
h: |
-+- 19526 ahoward ruby -Ilib samples/c.rb
|-+- 19543 ahoward ruby -Ilib samples/c.rb
|--- 19546 ahoward ruby -Ilib samples/c.rb
\--- 19547 ahoward ruby -Ilib samples/c.rb

---
i: |
-+- 19526 ahoward ruby -Ilib samples/c.rb
|-+- 19543 ahoward ruby -Ilib samples/c.rb
|-+- 19546 ahoward ruby -Ilib samples/c.rb
\-+- 19547 ahoward ruby -Ilib samples/c.rb







a @ http://codeforpeople.com/