[flexcoders] garbage collection question
I'm trying to track down a memory leak in one of my applications, having already employed the use weak reference in dictionaries and eventListeners guideline. I have an wrapper object, that has (among other properties) a reference to another object, which contains an array of a third object. Does simply nulling the parent effectively mark the embedded object(s) for GC, or do I need to iterate over the internal object array and null them out individually?
Re: [flexcoders] garbage collection question
1. Using weak references is the last thing you should do, whenever possible
you should avoid it. By doing so you leave all means of control of the
object, and if the object has some kind of behavior that will keep it
alive, you won't be able to delete it ever (example, the *deleted* object
did not close LocalConnection).
It is not possible to conclude from what you describe whether objects will
be removed or not. The objects will be removed when there will be no
reference to the roots. Roots are local variables, or field
initializers. These are either persistent or temporary, local variables
would be an example of temporary roots.
Imagine this life span of an object:
public var persistent:Object;
public var anotherProperty:Object;
public var revealPresense:Dictionary = new Dictionary(true);
public function DocumentClass()
{
super();
var temporary:Object = new Object(); // the object created, put into the
heap, bound to the temporary toot
persistent = temporary; // the object is in heap, now referenced by two
variables.
} // temporary variable is destroyed, now the object is only referenced by
persistent root.
public function anotherMethod():void
{
anotherProperty = persistent; // the object is still in heap, but now
has two persistent roots.
persistent = null; // the object is still not eligible for GC, it is
referenced by persistent root.
revealPresense[anotherProperty] = true; // let's store a weak reference
and observe the object deletion.
anotherProperty = null; // the object is no longer referenced, but may
exist for some time.
for (var obj:Object in revealPresense) trace( obj ); // it may be still
here...
setInterval(checkPresense, 1);
}
public function checkPresense():void
{
for (var obj:Object in revealPresense) trace( obj ); // it may be still
here...
}
Re: [flexcoders] garbage collection question
The profiler will show you who is still referencing the object. On 7/29/10 1:01 PM, djbrown_rotonews djbrown_roton...@yahoo.com wrote: I'm trying to track down a memory leak in one of my applications, having already employed the use weak reference in dictionaries and eventListeners guideline. I have an wrapper object, that has (among other properties) a reference to another object, which contains an array of a third object. Does simply nulling the parent effectively mark the embedded object(s) for GC, or do I need to iterate over the internal object array and null them out individually? -- Alex Harui Flex SDK Team Adobe System, Inc. http://blogs.adobe.com/aharui
[flexcoders] Garbage Collection question
Guys, just a quick question for anybody skilled up on the voodoo - I'm not 100% sure of a way to test this yet so I thought I'd ask: I assume the Garabage Collector is a background thread so far as mark-and-sweep etc, but does it do actual collecting while AVM2 is processing bytecode? I'm just worried about bugs creeping into some funky-stuff I'm doing using the Dictionary class :) -Josh -- Therefore, send not to know For whom the bell tolls. It tolls for thee. http://flex.joshmcdonald.info/ :: Josh 'G-Funk' McDonald :: 0437 221 380 :: [EMAIL PROTECTED]
RE: [flexcoders] Garbage Collection question
Dude, read my blog :) There is no background/threading in the player per-se. GC is kicked off when try to allocate memory from the player's heap and the player is trying to avoid asking the OS for more memory. Totally synchronous, happens during the new, and can delay the time until the next render. From: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Josh McDonald Sent: Wednesday, September 10, 2008 8:24 PM To: flexcoders@yahoogroups.com Subject: [flexcoders] Garbage Collection question Guys, just a quick question for anybody skilled up on the voodoo - I'm not 100% sure of a way to test this yet so I thought I'd ask: I assume the Garabage Collector is a background thread so far as mark-and-sweep etc, but does it do actual collecting while AVM2 is processing bytecode? I'm just worried about bugs creeping into some funky-stuff I'm doing using the Dictionary class :) -Josh -- Therefore, send not to know For whom the bell tolls. It tolls for thee. http://flex.joshmcdonald.info/ :: Josh 'G-Funk' McDonald :: 0437 221 380 :: [EMAIL PROTECTED]mailto:[EMAIL PROTECTED]
Re: [flexcoders] Garbage Collection question
Hey I read it, it didn't answer *this* question :) I know it's started when you allocated something, I just didn't know whether the actual collection would pause the vm or if it simply went and cleaned up on another thread. I know the VM's single threaded, I just figured the player would have all sort of threads for useful stuff like rendering, watching keyboard / mouse, mark-and-sweep for the GC, etc. But it looks like I needn't be worried, which is good news to me :) Cheers, -Josh On Thu, Sep 11, 2008 at 2:30 PM, Alex Harui [EMAIL PROTECTED] wrote: Dude, read my blog J There is no background/threading in the player per-se. GC is kicked off when try to allocate memory from the player's heap and the player is trying to avoid asking the OS for more memory. Totally synchronous, happens during the new, and can delay the time until the next render. *From:* flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] *On Behalf Of *Josh McDonald *Sent:* Wednesday, September 10, 2008 8:24 PM *To:* flexcoders@yahoogroups.com *Subject:* [flexcoders] Garbage Collection question Guys, just a quick question for anybody skilled up on the voodoo - I'm not 100% sure of a way to test this yet so I thought I'd ask: I assume the Garabage Collector is a background thread so far as mark-and-sweep etc, but does it do actual collecting while AVM2 is processing bytecode? I'm just worried about bugs creeping into some funky-stuff I'm doing using the Dictionary class :) -Josh -- Therefore, send not to know For whom the bell tolls. It tolls for thee. http://flex.joshmcdonald.info/ :: Josh 'G-Funk' McDonald :: 0437 221 380 :: [EMAIL PROTECTED] -- Therefore, send not to know For whom the bell tolls. It tolls for thee. http://flex.joshmcdonald.info/ :: Josh 'G-Funk' McDonald :: 0437 221 380 :: [EMAIL PROTECTED]
RE: [flexcoders] Garbage Collection question
Player is pretty simple, at least in Windows. I haven't seen many threads if any. Input is based on Windows messages, I/O uses non-blocking, etc. From: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Josh McDonald Sent: Wednesday, September 10, 2008 9:57 PM To: flexcoders@yahoogroups.com Subject: Re: [flexcoders] Garbage Collection question Hey I read it, it didn't answer *this* question :) I know it's started when you allocated something, I just didn't know whether the actual collection would pause the vm or if it simply went and cleaned up on another thread. I know the VM's single threaded, I just figured the player would have all sort of threads for useful stuff like rendering, watching keyboard / mouse, mark-and-sweep for the GC, etc. But it looks like I needn't be worried, which is good news to me :) Cheers, -Josh On Thu, Sep 11, 2008 at 2:30 PM, Alex Harui [EMAIL PROTECTED]mailto:[EMAIL PROTECTED] wrote: Dude, read my blog :) There is no background/threading in the player per-se. GC is kicked off when try to allocate memory from the player's heap and the player is trying to avoid asking the OS for more memory. Totally synchronous, happens during the new, and can delay the time until the next render. From: flexcoders@yahoogroups.commailto:flexcoders@yahoogroups.com [mailto:flexcoders@yahoogroups.commailto:flexcoders@yahoogroups.com] On Behalf Of Josh McDonald Sent: Wednesday, September 10, 2008 8:24 PM To: flexcoders@yahoogroups.commailto:flexcoders@yahoogroups.com Subject: [flexcoders] Garbage Collection question Guys, just a quick question for anybody skilled up on the voodoo - I'm not 100% sure of a way to test this yet so I thought I'd ask: I assume the Garabage Collector is a background thread so far as mark-and-sweep etc, but does it do actual collecting while AVM2 is processing bytecode? I'm just worried about bugs creeping into some funky-stuff I'm doing using the Dictionary class :) -Josh -- Therefore, send not to know For whom the bell tolls. It tolls for thee. http://flex.joshmcdonald.info/ :: Josh 'G-Funk' McDonald :: 0437 221 380 :: [EMAIL PROTECTED]mailto:[EMAIL PROTECTED] -- Therefore, send not to know For whom the bell tolls. It tolls for thee. http://flex.joshmcdonald.info/ :: Josh 'G-Funk' McDonald :: 0437 221 380 :: [EMAIL PROTECTED]mailto:[EMAIL PROTECTED]
[flexcoders] Garbage Collection question
I've been digging into memory management techniques recently, and have a question regarding the timing of the two methods. The articles on Adobe.com suggest that both methods (Ref Count and Mark Sweep) run at some arbitrary point in the future defined by current memory usage. I found a discussion about the Virtual Machine though that indicated garbage collection happens on a 30ms interval. These two suggest that the two methods run on different intervals, and given that Mark and Sweep is more processor intensive I assume that it is the one whose timing is triggered by memory usage, while Reference counting operates on the mentioned 30ms. Is that correct? Links: http://www.adobe.com/devnet/flashplayer/articles/garbage_collection.html (some point in the future) http://techpolesen.blogspot.com/2007/11/avm2-vs-jvm-and-actionscript3.ht ml (30ms time slice) Michael Krotscheck Senior Developer RESOURCE INTERACTIVE http://www.resource.com/ www.resource.com http://www.resource.com [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] This email and any of its attachments may contain Resource Interactive proprietary information, which is privileged, confidential and may be subject to copyright or other intellectual property rights belonging to Resource Interactive. This email is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient of this email, you are hereby notified that any dissemination, distribution, copying or action taken in relation to the contents of and attachments to this email is strictly prohibited and may be unlawful. If you have received this email in error, please notify the sender immediately and permanently delete the original and any copy of this email and any printout.
RE: [flexcoders] Garbage Collection question
I can pretty much guarantee that mark and sweep does not run via timer, and only on allocation. I don't think there's a timer for DRC, but I could be wrong about that. From: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Mike Krotscheck Sent: Saturday, November 17, 2007 7:02 AM To: flexcoders@yahoogroups.com Subject: [flexcoders] Garbage Collection question I've been digging into memory management techniques recently, and have a question regarding the timing of the two methods. The articles on Adobe.com suggest that both methods (Ref Count and Mark Sweep) run at some arbitrary point in the future defined by current memory usage. I found a discussion about the Virtual Machine though that indicated garbage collection happens on a 30ms interval. These two suggest that the two methods run on different intervals, and given that Mark and Sweep is more processor intensive I assume that it is the one whose timing is triggered by memory usage, while Reference counting operates on the mentioned 30ms. Is that correct? Links: http://www.adobe.com/devnet/flashplayer/articles/garbage_collection.html http://www.adobe.com/devnet/flashplayer/articles/garbage_collection.htm l (some point in the future) http://techpolesen.blogspot.com/2007/11/avm2-vs-jvm-and-actionscript3.ht ml http://techpolesen.blogspot.com/2007/11/avm2-vs-jvm-and-actionscript3.h tml (30ms time slice) Michael Krotscheck Senior Developer RESOURCE INTERACTIVE http://www.resource.com/ www.resource.com http://www.resource.com [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] This email and any of its attachments may contain Resource Interactive proprietary information, which is privileged, confidential and may be subject to copyright or other intellectual property rights belonging to Resource Interactive. This email is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient of this email, you are hereby notified that any dissemination, distribution, copying or action taken in relation to the contents of and attachments to this email is strictly prohibited and may be unlawful. If you have received this email in error, please notify the sender immediately and permanently delete the original and any copy of this email and any printout.
