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path: root/src/Xmobar/App/Timer.hs
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2022-02-04Xmobar.App.Timer -> Xmobar.Run.Timerjao
2020-10-09hlintingjao
2020-02-23Timer coalescing: handle exceptions in timer coordination threadTomas Janousek
This corrects my (wrong) assumption that the timer coordination thread will only fail if there's an error in the code, and in that case any attempt to recover is futile. It turns out that the thread does fail recoverably in one notable case: when running in the non-threaded RTS, registerDelay fails immediately. And we probably still wish for xmobar to support the non-threaded RTS. One way to solve this issue is to add a bunch of #ifdefs and compile the code only in the threaded case. This would double the number of configurations that need to be tested, though. Instead, let's make the code robust against all kinds of exceptions in the timer coordination thread, and get non-threaded RTS support for free.
2020-02-22Timer coalescing: gracefully uncoalesce slow timersTomas Janousek
The first implementation assumed all timers (monitors) are fast and frequent (which happens to be the case in my configuration). This meant that a single on-line weather monitor could block the entire xmobar instance for a long time due to the refresh pausing (meant to reduce power consumption). This commit attempts to fix that by limiting the refresh pause time and using the old periodic sleep method for these slow timers (monitors).
2020-02-22Implement timer coalescing (noticeably less CPU/power usage)Tomas Janousek
xmobar currently runs every monitor in its own thread. Monitors that do periodic updates simply sleep and loop. This unfortunately leads to these threads coming out of sync, and xmobar ends up waking up and redrawing for every periodic monitor. In my case, that is 7 times per second, which is enough for xmobar to be at the top of "top" with more than 1% CPU usage, and to have a noticeable impact on battery life. This commit adds a central timer coordination thread which makes sure that periodic updates happen together and that we only redraw once they're all done. Together with PR #409, I managed to lower the idle power draw of my laptop from 4W to 3W.