Bug #4680: [PATCH] io.c: fix busy wait with sendfile()

• Status: Closed
• Assignee: akr (Akira Tanaka)
• Target version: 1.9.3
• ruby -v: ruby 1.9.3dev (2011-05-11 trunk 31521) [x86_64-linux]

[normalperson (Eric Wong)]

io.c: fix busy wait with sendfile()

When combined with a non-blocking descriptor for sendfile(),
select() is used improperly to wait on the writer in the
read FD set along with the reader.

This causes select() to return immediately if src_fd is a
regular file and select() always returns immediately for regular
files (at least under Linux).

Thus, we need to wait on the writer independently of the reader.
Under Linux, we know the reader must must be a regular file if
sendfile() is to be used so we avoid waiting on the reader.

Test script attached maxes out my CPU.

[normalperson (Eric Wong)]

Eric Wong [e-mail] wrote:

Test script attached maxes out my CPU.

And with this I also noticed signals aren't handled gracefully
with IO.copy_stream. Fixing now.

--
Eric Wong

[normalperson (Eric Wong)]

Eric Wong [e-mail] wrote:

Eric Wong [e-mail] wrote:

Test script attached maxes out my CPU.

And with this I also noticed signals aren't handled gracefully
with IO.copy_stream. Fixing now.

Reported separately: http://redmine.ruby-lang.org/issues/4683

--
Eric Wong

[naruse (Yui NARUSE)]

• Status changed from Open to Assigned
• Assignee set to akr (Akira Tanaka)

[akr (Akira Tanaka)]

• Status changed from Assigned to Closed