# Forkoff-0.0.4

**URL:** <https://www.ruby-forum.com/t/forkoff-0-0-4/148502>\
**Category:** Ruby\
**Created:** [September 13, 2008, 7:53pm UTC](https://www.ruby-forum.com/t/forkoff-0-0-4/148502 "2008-09-13T19:53:06Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![ahoward](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/779978/32.png) [@ahoward](https://www.ruby-forum.com/u/ahoward)\
**Post date:** [September 13, 2008, 7:53pm UTC](https://www.ruby-forum.com/t/forkoff-0-0-4/148502/1 "2008-09-13T19:53:06Z")

</div>

NAME

forkoff

SYNOPSIS

brain-dead simple parallel processing for ruby

URI

[http://rubyforge.org/projects/codeforpeople](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! :processes => 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/](http://codeforpeople.com/)