AppletTalk.com Java discussions newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Simple GC question          AppletTalk.com Forum Index -> Java Help View previous topic :: View next topic   Author Message Araxes Tharsis Guest Posted: Mon Dec 22, 2003 2:29 pm    Post subject: Simple GC question When I create an object only with: new MyJFrame(); when will this object be Garbage Collected, as I have no explicit reference to it?! This is what is generally done in Swing, and I don't understand very well what goes on with GC (the object is not gc because the frame stays visible indefinitely...). Thank you very much, Araxes Tharsis Back to top Eric Sosman Guest Posted: Mon Dec 22, 2003 6:24 pm    Post subject: Re: Simple GC question Araxes Tharsis wrote: Quote: When I create an object only with: new MyJFrame(); when will this object be Garbage Collected, as I have no explicit reference to it?! The object becomes eligible for collection immediately, but there is no guarantee of exactly when the collection will occur. There is not even a guarantee that collection will occur at all: if your program never runs short of memory, the JVM may simply allow the garbage to hang around indefinitely. Quote: This is what is generally done in Swing, and I don't understand very well what goes on with GC (the object is not gc because the frame stays visible indefinitely...). Please provide more detail on what you think "is generally done in Swing." As far as I know, the JFrame will not become visible until you call its setVisible() method -- for which you need to have a reference to the JFrame. Once the JFrame has been made visible, Swing keeps its own internal references to it even if you discard your own. -- [email]Eric.Sosman (AT) sun (DOT) com[/email] Back to top Mark Haase Guest Posted: Sun Jan 11, 2004 1:46 am    Post subject: Re: Simple GC question In article <3fe700ec$0$8813$a729d347 (AT) news (DOT) telepac.pt>, "Araxes Tharsis" <pnrmaia (AT) hotmail (DOT) com> wrote: Quote: When I create an object only with: new MyJFrame(); when will this object be Garbage Collected, as I have no explicit reference to it?! This is what is generally done in Swing, and I don't understand very well what goes on with GC (the object is not gc because the frame stays visible indefinitely...). Thank you very much, Araxes Tharsis The GC will throw it away when no other objects reference it. So if you say new MyJFrame(); then yes, this will get GC'ed quickly, but who cares? You don't even have a reference to it, so its useless to you. If you passed it to another object however, ie. add(new MyJFrame()); then presumably that object will keep a reference to it, in which case it won't get GC'ed. -- Quote: /| /| |2 | mehaase(at)sas(dot)upenn(dot)edu Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         AppletTalk.com Forum Index -> Java Help All times are GMT Page 1 of 1   Jump to: Select a forum Java Newsgroups----------------Java DiscussionsWeb-based java games comp.lang.java 3D Graphics API's for Java Java: Support and criticism Java System Announcements comp.lang.java.api JavaBeans Java and CORBA Java and Databases comp.lang.java.developer Java GUI Toolkits Java Help comp.lang.java.javascript JVM, native methods and hardware comp.lang.java.misc Java Language Programming Security and Java comp.lang.java.setup Java Software Tools comp.lang.java.tech ibm.software.java.linux  Non-English Java Newsgroups----------------Java Language (German)Language Java (Français)Java (Italian)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.