# Threads, do\_nanosleep and battery life **URL:** \ **Category:** Ruby\ **Created:** [March 13, 2008, 2:28pm UTC](https://www.ruby-forum.com/t/threads-do-nanosleep-and-battery-life/131812 "2008-03-13T14:28:54Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![mslagell](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e274bd/32.png) [@mslagell](https://www.ruby-forum.com/u/mslagell)\ **Post date:** [March 13, 2008, 2:28pm UTC](https://www.ruby-forum.com/t/threads-do-nanosleep-and-battery-life/131812/1 "2008-03-13T14:28:54Z")
I’m writing a Ruby GTK application that runs on a mobile device (Nokia N800). It’s starting to take shape now, but I have noticed that leaving it running for long periods of time is particularly bad for my battery life. I don’t really understand Ruby threads under the hood or what alterations to them ruby-gtk2 makes (but am keen to learn!). Powertop suggests that Ruby is waking up around 100 times a second when there is an active thread, even during a sleep state. Presumably this is to check for thread activity. Is there a way around this in Ruby 1.8? Will the new threading model in 1.9 help this? Any pointers are apprecited, Mark ---
**Author:** ![mslagell](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e274bd/32.png) [@mslagell](https://www.ruby-forum.com/u/mslagell)\ **Post date:** [March 15, 2008, 2:14am UTC](https://www.ruby-forum.com/t/threads-do-nanosleep-and-battery-life/131812/2 "2008-03-15T02:14:45Z")
Hi, In [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) “Threads, do\_nanosleep and battery life” on Thu, 13 Mar 2008 22:21:58 +0900, Mark S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > I’m writing a Ruby GTK application that runs on a mobile device (Nokia N800). > It’s starting to take shape now, but I have noticed that leaving it running for > long periods of time is particularly bad for my battery life. > > I don’t really understand Ruby threads under the hood or what alterations to > them ruby-gtk2 makes (but am keen to learn!). Powertop suggests that Ruby is > waking up around 100 times a second when there is an active thread, even > during a sleep state. Presumably this is to check for thread activity. This should be fixed in Ruby-GNOME2 trunk. Thanks, ---
**Author:** ![mslagell](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e274bd/32.png) [@mslagell](https://www.ruby-forum.com/u/mslagell)\ **Post date:** [September 23, 2008, 9:47pm UTC](https://www.ruby-forum.com/t/threads-do-nanosleep-and-battery-life/131812/3 "2008-09-23T21:47:06Z")
On Sat, Mar 15, 2008 at 4:06 AM, Kouhei S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > I’m writing a Ruby GTK application that runs on a mobile device (Nokia N800). > > It’s starting to take shape now, but I have noticed that leaving it running for > > long periods of time is particularly bad for my battery life. > > > > I don’t really understand Ruby threads under the hood or what alterations to > > them ruby-gtk2 makes (but am keen to learn!). Powertop suggests that Ruby is > > waking up around 100 times a second when there is an active thread, even > > during a sleep state. Presumably this is to check for thread activity. > > This should be fixed in Ruby-GNOME2 trunk. Hi all, Can you share some more details on how exactly it was addressed? I have a multi-threaded Ruby daemon that has nothing to do with Gtk, and it exhibits the same behaviour: 100 calls to do\_nanosleep per second. The deamon is a DRb based object cache, the whole source is these two files, 191 lines total: [http://cvs.savannah.gnu.org/viewvc/\*checkout\*/samizdat/samizdat/lib/samizdat/cache.rb?revision=1.99](http://cvs.savannah.gnu.org/viewvc/*checkout*/samizdat/samizdat/lib/samizdat/cache.rb?revision=1.99) [http://cvs.savannah.gnu.org/viewvc/\*checkout\*/samizdat/samizdat/bin/samizdat-drb-server?revision=1.99](http://cvs.savannah.gnu.org/viewvc/*checkout*/samizdat/samizdat/bin/samizdat-drb-server?revision=1.99) This definitely looks like a generic Ruby issue to me, but if there is a workaround, I don’t mind applying it on the application level. [ sorry for waking up this really old thread, but Google tells me that is the only case where Ruby do\_nanosleep issue was addressed ] ---
**Author:** ![mslagell](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e274bd/32.png) [@mslagell](https://www.ruby-forum.com/u/mslagell)\ **Post date:** [September 24, 2008, 11:14pm UTC](https://www.ruby-forum.com/t/threads-do-nanosleep-and-battery-life/131812/4 "2008-09-24T23:14:32Z")
> Hi all, > > Can you share some more details on how exactly it was addressed? I > have a multi-threaded Ruby daemon that has nothing to do with Gtk, and > it exhibits the same behaviour: 100 calls to do\_nanosleep per second. > The deamon is a DRb based object cache, the whole source is these two > files, 191 lines total: > > [http://cvs.savannah.gnu.org/viewvc/\*checkout\*/samizdat/samizdat/lib/samizdat/cache.rb?revision=1.99](http://cvs.savannah.gnu.org/viewvc/*checkout*/samizdat/samizdat/lib/samizdat/cache.rb?revision=1.99) > [http://cvs.savannah.gnu.org/viewvc/\*checkout\*/samizdat/samizdat/bin/samizdat-drb-server?revision=1.99](http://cvs.savannah.gnu.org/viewvc/*checkout*/samizdat/samizdat/bin/samizdat-drb-server?revision=1.99) > > This definitely looks like a generic Ruby issue to me, but if there is > a workaround, I don’t mind applying it on the application level. > > [ sorry for waking up this really old thread, but Google tells me that > is the only case where Ruby do\_nanosleep issue was addressed ] [http://groups.google.com/group/never-block/browse\_thread/thread/b806a8443ffb5f45?hl=en](http://groups.google.com/group/never-block/browse_thread/thread/b806a8443ffb5f45?hl=en) explains a little on how Ruby does threading. GL! -=R