What evidence do you have of this? What exactly do you mean by a zombie thread?
I've been programming Java since sometime near when it came out -- well over a decade, on various platforms. I've never seen anything I'd term a zombie thread, nor a thread problem that would be solved by nulling thread references to null. I hesitate to say you're incorrect without more specifics, however. I'm not sure what sort of exit flag you're suggesting. One that indicates a thread has exited, or one that indicates it should exit? I'll add that it's certainly possible in Java to write a program that leaves a thread blocked forever, waiting for something that never happens. You can also introduce deadlocks -- when two thread each lock an object, and then try to get a lock on the object locked by the other. But this is an issue with ANY thread programming, not Java, and is not something I'd term zombie threads, nor a Java problem. Coordinating threads properly is tricky. That's one reason why AsyncTask is provided, so that you don't have to worry about how to do it correctly and safely. BTW, nulling out references to a thread isn't going to make the thread stop running. In fact, the thread's stack is one of the things that the GC has to trace through.to find things to keep. The GC cannot just eliminate the running thread during its run -- and at any point, the thread's code could ask for the current thread. Still, I'm not arguing against nulling out the references once you no longer need them. It documents where you no longer expect to reference them, and it forces any references after that point to get a NullPointerException, which will allow you to detect bugs closer to the point of origin (or worse, detect bugs that might not be noticed). On Mar 13, 9:44 am, Ken Warner <kwarner...@verizon.net> wrote: > Null out all references to the thread. Java has a problem > with zombie threads -- this is a java app right? > > I can't say exactly how you should do the following but make > sure there is an explicit way to exit each thread. I usually > set a flag to tell the thread to exit. > > Those two things -- null all references and setting an explicit > exit flag are the most you can do. > > After you null all references to the thread, do an explicit > gc() if that's available. > > > > Gabriel Sim es wrote: > > Hello, > > > Today, while debugging and app that uses AsyncTask to record audio and > > update UI I noticed that everytime that an AsyncTask object ends > > running (finishes doInBackground() and onPostExecute() or > > onCancelled()) it s thread stays alive (running status). > > At least for me that should not be the behavior of the class since the > > doInBackground task may not stay running forever (as an example the > > android manual says that a status bar should be updated by an > > asynctask, and it won t last for the whole app running time). > > > Is there anything I m missing, as a method to destroy it, or should I > > just ignore and keep creating threads as I need and the VM will handle > > them as it needs resources? > > > Thank you, > > Gabriel Sim es -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
