# Parallel map
# Originally from http://project.ioni.st/post/2332#snippet_2332
class Array
def pmap
threads = []
0.upto(size - 1) do |n|
threads « Thread.new do
yield(at(n))
end
end
threads.collect {|thread| thread.value}
end
end
# Trade-off between resource consumption
# and speed of execution.
# Much faster in some scenarios,
# much slower in others.
# e.g.
def expensive_operation
open(‘http://google.com’).read
end
# Expensive operation 50 times
# user system total real
# map 50x 0.3400 0.2100 0.5500 ( 17.334429)
# pmap 50x 0.3000 0.2500 0.5500 ( 1.200705)
