Re: [whatwg] BroadcastChannel memory leak
On Fri, 23 May 2014, Adam Barth wrote: > > When is it safe for a user agent to garbage collect a BroadcastChannel > instance? > > http://www.whatwg.org/specs/web-apps/current-work/multipage/web-messaging.html#broadcasting-to-other-browsing-contexts When there's no strong references to it from an object that itself can't be GC'ed. Per the spec: "While a BroadcastChannel object has an event listener registered for message events, there must be a strong reference from global object specified by the BroadcastChannel object's BroadcastChannel settings object to the BroadcastChannel object itself." > Given that another document might create a new BroadcastChannel instance > at any time, the |message| event of the object might fire any time its > responsible document is fully active. For web application that have > long-lived documents, the BroadcastChannel might not be eligible for > garbage collection for a long time. Yeah. If the page doesn't keep an explicit reference to it, but does attach an event handler, it could be around forever. > Proposal: Add a |close| method to the BroadcastChannel interface similar > to the |close| method on MessagePort. The |close| method would just > neuter the instance of the channel and prevent it from receiving further > messages. This would merely be a convenience method (you could always just remove the event handlers), but it seems reasonable. On Fri, 23 May 2014, Adam Barth wrote: > > That doesn't play nicely with anonymous JavaScript functions that can't > ever be removed as event listeners... Well, they can remove themselves (no?). But yeah, it's not great. On Fri, 23 May 2014, Jonas Sicking wrote: > > > > Proposal: Add a |close| method to the BroadcastChannel interface > > similar to the |close| method on MessagePort. The |close| method > > would just neuter the instance of the channel and prevent it from > > receiving further messages. > > Sounds good to me. Done. -- Ian Hickson U+1047E)\._.,--,'``.fL http://ln.hixie.ch/ U+263A/, _.. \ _\ ;`._ ,. Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
Re: [whatwg] BroadcastChannel memory leak
On Fri, May 23, 2014 at 5:23 PM, Adam Barth wrote: > When is it safe for a user agent to garbage collect a BroadcastChannel > instance? > > http://www.whatwg.org/specs/web-apps/current-work/multipage/web-messaging.html#broadcasting-to-other-browsing-contexts > > Given that another document might create a new BroadcastChannel > instance at any time, the |message| event of the object might fire any > time its responsible document is fully active. For web application > that have long-lived documents, the BroadcastChannel might not be > eligible for garbage collection for a long time. > > Proposal: Add a |close| method to the BroadcastChannel interface > similar to the |close| method on MessagePort. The |close| method > would just neuter the instance of the channel and prevent it from > receiving further messages. Sounds good to me. / Jonas
Re: [whatwg] BroadcastChannel memory leak
On Fri, May 23, 2014 at 5:54 PM, Michael Nordman wrote: >> When is it safe for a user agent to garbage collect a BroadcastChannel >> instance? > > When there's no direct reference to the object and no onmessage handler > attached to it. (?) That doesn't play nicely with anonymous JavaScript functions that can't ever be removed as event listeners... Adam > On Fri, May 23, 2014 at 5:23 PM, Adam Barth wrote: >> >> When is it safe for a user agent to garbage collect a BroadcastChannel >> instance? >> >> >> http://www.whatwg.org/specs/web-apps/current-work/multipage/web-messaging.html#broadcasting-to-other-browsing-contexts >> >> Given that another document might create a new BroadcastChannel >> instance at any time, the |message| event of the object might fire any >> time its responsible document is fully active. For web application >> that have long-lived documents, the BroadcastChannel might not be >> eligible for garbage collection for a long time. >> >> Proposal: Add a |close| method to the BroadcastChannel interface >> similar to the |close| method on MessagePort. The |close| method >> would just neuter the instance of the channel and prevent it from >> receiving further messages. >> >> Adam > >
Re: [whatwg] BroadcastChannel memory leak
> When is it safe for a user agent to garbage collect a BroadcastChannel instance? When there's no direct reference to the object and no onmessage handler attached to it. (?) On Fri, May 23, 2014 at 5:23 PM, Adam Barth wrote: > When is it safe for a user agent to garbage collect a BroadcastChannel > instance? > > > http://www.whatwg.org/specs/web-apps/current-work/multipage/web-messaging.html#broadcasting-to-other-browsing-contexts > > Given that another document might create a new BroadcastChannel > instance at any time, the |message| event of the object might fire any > time its responsible document is fully active. For web application > that have long-lived documents, the BroadcastChannel might not be > eligible for garbage collection for a long time. > > Proposal: Add a |close| method to the BroadcastChannel interface > similar to the |close| method on MessagePort. The |close| method > would just neuter the instance of the channel and prevent it from > receiving further messages. > > Adam >
[whatwg] BroadcastChannel memory leak
When is it safe for a user agent to garbage collect a BroadcastChannel instance? http://www.whatwg.org/specs/web-apps/current-work/multipage/web-messaging.html#broadcasting-to-other-browsing-contexts Given that another document might create a new BroadcastChannel instance at any time, the |message| event of the object might fire any time its responsible document is fully active. For web application that have long-lived documents, the BroadcastChannel might not be eligible for garbage collection for a long time. Proposal: Add a |close| method to the BroadcastChannel interface similar to the |close| method on MessagePort. The |close| method would just neuter the instance of the channel and prevent it from receiving further messages. Adam
