4 ms·

Initially, Chrome attempted to allow setTimeout()s under the 15ms or so that was standard across browsers, which led to it winning some benchmarks and some accu

by evmar 13y ago

Initially, Chrome attempted to allow setTimeout()s under the 15ms or so that was standard across browsers, which led to it winning some benchmarks and some accusations of foul play. The intent was pure -- why artificially clamp JavaScript timers to a Windows quirk? -- but eventually Chrome was changed to make timers behave like in other browsers. It appears that the spec now says 4ms is the minimum. This bug (helpfully linked from MDN) has more of the story. https://code.google.com/p/chromium/issues/detail?id=792 https://code.google.com/p/chromium/issues/detail?id=792 I remember the Chrome timer code of years ago was careful to only adjust the interval when needed. From reading other bugs it looks like today's behavior is an accidental regression and will likely be fixed (until the next time it regresses).

rossy 13y ago
> It appears that the spec now says 4ms is the minimum. I was playing with Windows timers a little while ago and I noticed that with IE11 open the timer interval sat at 15.6ms, occasionally changing to 4ms while the page was doing things. That was the first time I've heard of a program calling timeBeginPeriod without setting it to 1ms. I hope it catches on.
ddeck 13y ago
> I remember the Chrome timer code of years ago was careful to only adjust the interval when needed. From reading other bugs it looks like today's behavior is an accidental regression and will likely be fixed (until the next time it regresses). Indeed, although it seems the current behavior has been oustanding for some time: https://code.google.com/p/chromium/issues/detail?id=153139 https://code.google.com/p/chromium/issues/detail?id=153139 The original justification for lowering the resolution is an interesting read: At one point during our development, we were about to give up on using the high resolution timers, because they just seemed too scary. But then we discovered something. Using WinDbg to monitor Chrome, we discovered that every major multi-media browser plugin was already using this API. And this included Flash, Windows Media Player, and even QuickTime. Once we discovered this, we stopped worrying about Chrome's use of the API. After all – what percentage of the time is Flash open when your browser is open? I don't have an exact number, but it's a lot. And since this API effects the system globally, most browsers are already running in this mode.[1] [1] http://www.belshe.com/2010/06/04/chrome-cranking-up-the-clock/ http://www.belshe.com/2010/06/04/chrome-cranking-up-the-cloc...

by evmar 13y ago

rossy 13y ago

> It appears that the spec now says 4ms is the minimum. I was playing with Windows timers a little while ago and I noticed that with IE11 open the timer interval sat at 15.6ms, occasionally changing to 4ms while the page was doing things. That was the first time I've heard of a program calling timeBeginPeriod without setting it to 1ms. I hope it catches on.

ddeck 13y ago

> I remember the Chrome timer code of years ago was careful to only adjust the interval when needed. From reading other bugs it looks like today's behavior is an accidental regression and will likely be fixed (until the next time it regresses). Indeed, although it seems the current behavior has been oustanding for some time: https://code.google.com/p/chromium/issues/detail?id=153139 https://code.google.com/p/chromium/issues/detail?id=153139 The original justification for lowering the resolution is an interesting read: At one point during our development, we were about to give up on using the high resolution timers, because they just seemed too scary. But then we discovered something. Using WinDbg to monitor Chrome, we discovered that every major multi-media browser plugin was already using this API. And this included Flash, Windows Media Player, and even QuickTime. Once we discovered this, we stopped worrying about Chrome's use of the API. After all – what percentage of the time is Flash open when your browser is open? I don't have an exact number, but it's a lot. And since this API effects the system globally, most browsers are already running in this mode.[1] [1] http://www.belshe.com/2010/06/04/chrome-cranking-up-the-clock/ http://www.belshe.com/2010/06/04/chrome-cranking-up-the-cloc...