Issue #4528 has been reported by Eric Wong.

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Feature #4528: [PATCH] ext/io/nonblock: avoid unnecessary fcntl F_SETFL calls
http://redmine.ruby-lang.org/issues/4528

Author: Eric Wong
Status: Open
Priority: Low
Assignee: 
Category: ext
Target version: 1.9.x


Avoid F_SETFL if we're not changing the O_NONBLOCK bit.  F_SETFL
is an expensive operation since it needs to affect all processes
with the same file object.

rb_io_set_nonblock() implements similar logic to avoid F_SETFL
in io.c


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