[ANN] forkoff-0.0.4

[ara howard]

NAME

forkoff

SYNOPSIS

brain-dead simple parallel processing for ruby

URI

http://rubyforge.org/projects/codeforpeople

INSTALL

gem install forkoff

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.

HISTORY
0.0.4
- code re-org
- add :strategy option
- default number of processes is 2, not 8


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 1032
you from 1033


<========< 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: 4.25545883178711
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: 1048
elapsed: 3.14415812492371

---
a: |
-+- 01048 ahoward ruby -Ilib samples/c.rb
|-+- 01049 ahoward ruby -Ilib samples/c.rb
|-+- 01050 ahoward ruby -Ilib samples/c.rb
\-+- 01051 ahoward ruby -Ilib samples/c.rb

---
b: |
-+- 01048 ahoward ruby -Ilib samples/c.rb
|-+- 01049 ahoward (ruby)
|-+- 01050 ahoward ruby -Ilib samples/c.rb
\-+- 01051 ahoward ruby -Ilib samples/c.rb

---
c: |
-+- 01048 ahoward ruby -Ilib samples/c.rb
|-+- 01049 ahoward ruby -Ilib samples/c.rb
|-+- 01050 ahoward ruby -Ilib samples/c.rb
\-+- 01051 ahoward ruby -Ilib samples/c.rb

---
d: |
-+- 01048 ahoward ruby -Ilib samples/c.rb
|-+- 01061 ahoward ruby -Ilib samples/c.rb
|-+- 01062 ahoward ruby -Ilib samples/c.rb
\-+- 01063 ahoward ruby -Ilib samples/c.rb

---
e: |
-+- 01048 ahoward ruby -Ilib samples/c.rb
|-+- 01061 ahoward (ruby)
|-+- 01062 ahoward ruby -Ilib samples/c.rb
\-+- 01063 ahoward ruby -Ilib samples/c.rb

---
f: |
-+- 01048 ahoward ruby -Ilib samples/c.rb
|-+- 01061 ahoward ruby -Ilib samples/c.rb
|-+- 01062 ahoward ruby -Ilib samples/c.rb
\-+- 01063 ahoward ruby -Ilib samples/c.rb

---
g: |
-+- 01048 ahoward ruby -Ilib samples/c.rb
|-+- 01090 ahoward ruby -Ilib samples/c.rb
|-+- 01091 ahoward ruby -Ilib samples/c.rb
\-+- 01092 ahoward ruby -Ilib samples/c.rb

---
h: |
-+- 01048 ahoward ruby -Ilib samples/c.rb
|-+- 01090 ahoward ruby -Ilib samples/c.rb
|-+- 01091 ahoward ruby -Ilib samples/c.rb
\-+- 01092 ahoward ruby -Ilib samples/c.rb

---
i: |
-+- 01048 ahoward ruby -Ilib samples/c.rb
|-+- 01090 ahoward ruby -Ilib samples/c.rb
|-+- 01091 ahoward ruby -Ilib samples/c.rb
\-+- 01092 ahoward ruby -Ilib samples/c.rb



<========< samples/d.rb >========>

~ > cat samples/d.rb

# forkoff supports two strategies of reading the result from the
child: via
# pipe (the default) or via file. you can select which to use
using the
# :strategy option.
#

require 'forkoff'

%w( hey you guys ).forkoff :strategy => :file do |word|
puts "#{ word } from #{ Process.pid }"
end

~ > ruby samples/d.rb

hey from 1102
you from 1103
guys from 1104




a @ http://codeforpeople.com/