Threads Section Index | Page 3

Any ordering that you are observing is not mandated by the spec. It is therefore subject to change and should not be relied on (even using a multi-processor machine instead of a single processor o...more

Is there an example of a chat server (aka Threaded Virtual Meeting Place) ?

Here's how to print the trace in a string: Exception ex = new Exception("something went wrong"); StringWriter sw = new StringWriter(); ex.printStackTrace(new PrintWriter(sw)); String stacktrace =...more

Double-checked locking (DCL) is an idiom recommended by a number of Java books and articles as a way to reduce synchronization overhead when performing lazy initialization. The DCL idiom was des...more

http://java.sun.com/docs/hotspot/threads/threads.html

Every object instance in Java has a little piece of data hanging off of it called a "monitor lock." This is similar to a semaphore. When you use the synchronized keyword, the current thread at...more

I can do it in the following way class RemindTask extends TimerTask { public void run() { System.out.println("run task"); } } Timer timer = new Timer(); ti...more

Sure it is, since it is a Vector which is thread-safe.

My servlet reads the contents of a text file which I access using a File object. What issues are involved when this file is read concurrently by several different threads? Do I have to synchronize...more

[Short answer: you can't stop the thread, but you can close the socket, which causes accept to return. -Alex] Hope that I've understood you properly. So I assume, that you've got something like: ...more

Yes. See Is there some way to implement multi-tasking in Java? and also look at the docs for java.lang.Runtime.exec(). See also What is the difference between multithreading and multitasking (et ...more

You seem to think that a new thread is created for each image you download. That's simply not the case. Most AWT implementations use a small pool of threads (usually 4) for downloading images. The...more

Your run() method is not guarenteed to run immediately after the Thread.start() method is called. The Java Language Specification gives implementations lots of legroom with respect to the schedul...more

The piped I/O streams are for inter-thread communication. They manage the synchronization across thread boundaries of the buffer. See Is there any way to communicate between two classes... for an ...more

You probably want to use object.notify. Like this: Object lock = new Object(); Thread t1 = new MyThread(lock); Thread t2 = new MyThread(lock); synchronized (lock) { t1.start(); t2.start();...more