[DRE-maint] [Bug 670743] Re: poor i/o performance in thread parallel to Gtk.main (time overhead can be as bad as 2500%)

[Sebastian Thürrschmidt]

Same thing here. Rubyripper (GTK) used to work very well in Karmic,
where a two-pass CD rip to flac would take about 20 minutes on average.
Then in Lucid and now in Maverick, the exact same process may take up to
two hours or more, with long pauses in between tracks during which
Rubyripper does esentially nothing.

The bug affects the older Rubyripper packages from aheck's ppa
(https://launchpad.net/~aheck/+archive/ppa) as well as the more current
packages from debian-multimedia (http://www.debian-
multimedia.org/dists/unstable/main/binary-amd64/package/rubyripper.php).
The workaround suggested in [2], locally installing ruby 1.9 plus gtk2
bindings, is rather complicated and didn't ultimately work for me, for
whatever reason.

A working Rubyripper would be much appreciated, ideally one from
universe.

-- 
poor i/o performance in thread parallel to Gtk.main (time overhead can be as bad as 2500%)
https://bugs.launchpad.net/bugs/670743
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Status in “ruby-gnome2” package in Ubuntu: New

Bug description:
Binary package hint: ruby-gnome2

rubyripper [1] is performing poorly in maverik x86-64 (up-to-date). They have an open issue for this [2].

Apparently there is nothing wrong with rubyripper. So I managed to reduce it to a small test case. It is based in the very first ruby-gnome2 example I could find.

The test function reads 3 MB from /dev/zero. This function is called from a new thread.

This is done 3 times. Before the call to Gtk.main, during it (from a button callback signal) and after it.

These are the times for each one (in seconds).
0.004285
9.689063
0.021076

Something is wrong.

Test code follows.

[1]
http://code.google.com/p/rubyripper

[2]
http://code.google.com/p/rubyripper/issues/detail?id=348

--
#!/usr/bin/env ruby

require 'gtk2'

def simpleRead
	puts "simpleRead begin\n"
	index = 0
	file = File.open("/dev/zero", 'r')
	while (index < 3 * 1024 * 1024)
		file.read(16 * 1024)
		index += 16 * 1024
	end
	file.close()
	puts "simpleRead end\n"
end

def newThreadSimpleRead
	Thread.new do
		require "benchmark"
		puts Benchmark.measure { simpleRead }
#simpleRead
	end
end

button = Gtk::Button.new("Hello World")
button.signal_connect("clicked") {
	newThreadSimpleRead
}

window = Gtk::Window.new
window.signal_connect("delete_event") {
	puts "delete event occurred"
	#true
	false
}

window.signal_connect("destroy") {
	  puts "destroy event occurred"
		    Gtk.main_quit
}

window.border_width = 10
window.add(button)
window.show_all

newThreadSimpleRead
STDIN.readchar

Gtk.main

newThreadSimpleRead
STDIN.readchar