From: "Ara.T.Howard" <Ara.T.Howard@...>
Date: 2004-02-21T03:24:52+09:00
Subject: threads and blocking



under which conditions will a blocking operation in a thread block the entire
process?

i thought i understood this but was suprised that

  ~ > ruby -e 'Thread.new{gets}; Thread.new{select nil}; Thread.new{puts 42}'
  42

does not seem to block the entire process.

i also was suprised that this worked:

  ~ > printf "4\n2\n" | ruby -e '[Thread.new{p gets.chop},Thread.new{p
  gets.chop}].map{|t| t.join}'
  "4"
  "2"

i have been in situations before where one thread blocking has blocked my
entire application and remember thinking to myself - "don't do blocking i/o
from threads".  but that appears to be too strong of a statement.

can someone concisely enumerate the things to avoid?

regards.

-a
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