Hi, > So, why is deleting this variable and not the array? it sounds very > strange for me.
Again, in my tests using a real browser and looking at the memory used by the browser as reported by the operating system, the memory used by the elements in the array _is_ getting released, over time, and reasonably proactively -- by all of the browsers I tried. -- T.J. On Oct 25, 10:40 am, jose maria Cano <[email protected]> wrote: > Hi again, > Thanks a lot for your time and help. > But still something that I can't understand. > > The property object options has 3 variables inside: > > this.options = { > vari: '', > array: '', > testDiv: '' > }; > > What I can't understand is that for "vari" and "testDiv" is releasing > the memory. > > You can use this programhttp://home.orange.nl/jsrosman/to see the > memory and the DOM elements used and you'll see how after the destroy > 1 node is released, the node for the "testDiv" variable. > > So, why is deleting this variable and not the array? it sounds very > strange for me. > > Thanks a lot for your help!! > > Kr, Jose > > On 22 oct, 18:20, "T.J. Crowder" <[email protected]> wrote: > > > > > > > > > Hi, > > > Sorry, all of the numbers in my original post are off by 1,000. I was > > writing "32k" when I should have been writing "32,000k" (or ~31M). > > Sorry about that, misread the Chrome memory page and failed to > > think. :-) > > > > But the problem is still there, I don’t know how to release the memory > > > used by this.options, using your code, the variable is using almost > > > 450 MB in explorer and this memory is never released. > > > There's something different in your setup, then. When I ran that test > > page on my Windows 7 box, IE8 released the memory *much* more > > aggressively than that, it never once went above about 57M. You're > > really seeing 450MB of memory consumed using the test pages I posted? > > > Later: I've had IE8 open and runninghttp://pastie.org/1240613for > > about 25 minutes. It's done 4,180 loops, and so created and released > > ~8,364,180 divs (4,180 x 2,001). It's cycling between about 30M and > > 50M, which is what it's been doing since I started it. It's very > > nearly steady-state, as close to it as I would expect since I'm using > > a version of the code that's keeping the TestObject instances (which > > won't account for more than a few hundred k). No evidence of a memory > > leak at all. > > > > So, do you have any idea on how to release the memory? > > > Just what I said above: *You* can't release the memory, you can only > > release your references to it (which you are). It's up to IE to > > actually reclaim it, _if_ and _when_ it thinks it should. JavaScript > > is a garbage-collected[1] environment. > > > > I really need > > > to know how to delete a global variable like this.options > > > It's not a global variable, it's a property on an object. You delete > > it exactly as you originally tried to: > > > delete this.options; > > > At that point, it's down to the JavaScript implementation (IE's > > JScript, in this case) to actually release the memory. > > > In terms of actually dealing with the problem you're seeing, I hate to > > say it, but it sounds like you're probably not going to get a quick > > fix. :-( You'll have to audit the code, ensure there are no circular > > references anywhere (which _will_ cause memory leaks), make sure you > > don't have references being kept active by closures (you don't in your > > example code, but as we've said, that was just test code), etc. > > > [1]http://en.wikipedia.org/wiki/Garbage_collection_(computer_science) > > > Good luck, > > -- > > T.J. Crowder > > Independent Software Engineer > > tj / crowder software / com > > www / crowder software / com > > > On Oct 22, 3:02 pm, jose maria Cano <[email protected]> wrote: > > > > Hi, > > > First of all, thanks a lot for your time and help. > > > > I forgot to say that the problem is using windows and IE8 (of course…) > > > but I have to support IE for some clients. > > > Also, the class is a test class, is not doing anything “useful”, is > > > just to see how to release the memory in IE, the real application is a > > > huge application with thousands of nodes, variables, events… and after > > > 30 minutes working on IE you have like 500 MB used. > > > > I’ve been making some tests with your code and indeed the memory used > > > is the same doing null to the whole array or just doing delete > > > this.options > > > > But the problem is still there, I don’t know how to release the memory > > > used by this.options, using your code, the variable is using almost > > > 450 MB in explorer and this memory is never released. > > > > I don’t know how to attach a screenshot here to show you the memory…. > > > > So, do you have any idea on how to release the memory? I really need > > > to know how to delete a global variable like this.options and for the > > > moment I don’t see how to it….. > > > > Thanks a lot for your time > > > > kr, Jose > > > On 22 oct, 14:59, "T.J. Crowder" <[email protected]> wrote: > > > > > Hi, > > > > > > I have a big problem in my application, when I create a global class > > > > > object is impossible for me to release the memory and I'm having > > > > > memory leaks. > > > > > It looks to me like you're doing nearly everything you need to do (and > > > > a little bit more). Remember that all you can do is make sure that > > > > memory is no longer referenced (which it looks to me like you've done > > > > almost completely) and that you've broken any _circular_ references > > > > between DOM elements and JavaScript objects (you don't have any > > > > circular references, but you've broken all refs from JavaScript->DOM, > > > > which is a good thing to do). At that point, it's up to the JavaScript > > > > implementation when (and whether) to actually reclaim the memory. Some > > > > are more aggressive than others, and some are more effective than > > > > others. > > > > > Your actual quoted code ends up being very nearly a no-op, which I'm > > > > guessing is for testing purposes. It creates 2,000 divs and pushes > > > > them on an array (and another div it puts in a property) but never > > > > adds them to the document. It then removes the references to them from > > > > the array and releases the array (and clears the property). Assuming > > > > this code: > > > > > var t = new TestClass(); > > > > > ...by the time the line above is complete, the only remaining memory > > > > references I see are the instance itself (`t` above) and the fact that > > > > `t` has a property called `options` (which has the value null). If you > > > > uncomment the `delete this.options;` line, then even the `options` > > > > property that will be gone. > > > > > I took your code and put it (sans alerts) in a page that created 20 > > > > TestClass objects every 250ms and then threw them away. Using Chrome's > > > > excellent about:memory page, I was able to see that the memory does > > > > (eventually) get reclaimed by Chrome, Firefox, and Opera on Linux, IE6 > > > > on Windows 2000, and IE8 on Windows 7. They were wildly different > > > > about when they did it. Chrome started at using 12k for the page, > > > > which shot up to 60k almost immediately (certainly on the first 40-60 > > > > TestClass instances), and then allowed memory use to go up to 85-95k > > > > before reclaiming back down to 62-64k and letting it climb again. > > > > Firefox 3.6 started at about 50k and allowed use to creep up to 250k > > > > before reclaiming back down to ~70k again (rinse, repeat). Opera was > > > > the most aggressive about reclaiming the memory, starting at 38k, > > > > jumping almost immediately to 57k and then staying there, almost > > > > completely steady. On Windows, IE8 started at about 33k and allowed > > > > that to grow to about 57-59k before reclaiming back down to 33k again > > > > and allowing it to grow. (Wow is IE slow.) Even IE6 on Windows 2000 > > > > (measured via Task Manager rather than Chrome) reclaimed the memory > > > > (occillating between 7k and 25k). > > > > > Then I modified the code to retain the TestClass instances, to test > > > > whether the instances were somehow keeping the elements in memory. In > > > > all five cases (Chrome, Firefox, and Opera under Linux, IE8 under > > > > Windows, and IE6 under Windows), they weren't. The memory use was > > > > virtually identical to the first test, which shows that by the time > > > > you've done your "destroy", the instances *don't* retain any memory > > > > references that prevent cleanup. (The instances themselves will be > > > > very small.) > > > > > BTW, you don't need to explicitly null-out the array elements before > > > > releasing the array. I've heard people say you do, but it doesn't make > > > > any sense from a JavaScript specification perspective (not that that > > > > matters, particularly not when you're talking about IE) but this > > > > seemed like a good opportunity to test it for myself. Commenting out > > > > the loop in `destroy` that nulls out the elements made no difference, > > > > not even on IE6. I think it's a myth. > > > > > So that means your `destroy` can consist entirely of this: > > > > > destroy: function() { > > > > delete this.options; > > > > } > > > > > ...since you're keeping everything on the `options` object. > > > > > Here are the test files:http://pastie.org/1240577-thebasiccounter > > > > testhttp://pastie.org/1240579-keeptheinstances > > > > testhttp://pastie.org/1240582-don'tnullout array entries > > > > testhttp://pastie.org/1240613-usingtheone-liner `destroy` above > > > > > HTH, > > > > -- > > > > T.J. Crowder > > > > Independent Software Engineer > > > > tj / crowder software / com > > > > www / crowder software / com > > > > > On Oct 22, 10:52 am, jose maria Cano <[email protected]> wrote: > > > > > > Hi guys, > > > > > I have a big problem in my application, when I create a global class > > > > > object is impossible for me to release the memory and I'm having > > > > > memory leaks. > > > > > > I've made a small class as example. > > > > > > var TestClass = Class.create({ > > > > > > initialize: function() { > > > > > this.options = { > > > > > vari: '', > > > > > array: '', > > > > > testDiv: '' > > > > > }; > > > > > this.addElement(); > > > > > },... > > read more » -- You received this message because you are subscribed to the Google Groups "Prototype & script.aculo.us" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. 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