Ruby poor performance in thread -


i have function io/computation. made demo function copies ~300mb here there. if run in thread join, slower if run without thread. checked with:

def cp   start = time.now   fileutils.cp_r("c:/tmp", "c:/tmp1")   fin = time.now - start   p fin end

comparing these:

cp  thread.new{cp}.join

the first cp call 2 4 times faster threaded call. same happens if do

cp  thread.new{cp}  sleep 200

i heard gil, etc., here, 1 thread runs @ time, no race running time. ideas on how can make faster or why happening?

threading isn't guarantee things run faster, or same speed, non-threaded code, @ least mri. jruby might better. cp isn't getting full attention of cpu, why doing without threading, , allowing block until done, faster.

consider using fork instead.

"a dozen (or so) ways start sub-processes in ruby: part 1" looks useful. "how spawn child process in ruby?".


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