Threads Section Index

The fork/join framework in Java 7 allows developers to take advantage of multiple processors.

The thread class provides a method which can be called on an instance of a Thread to determine if it is currently executing. If isAlive() returns false the thread is either a new thread that is ...more

I have written plenty of non-thread-safe Singletons but it wasn't until recently when I tracked it down that I realized that thread-safety could be a big problem. The problem is that in the typic...more

The start() method tells the Java Virtual Machine that it needs to create a system specific thread. After creating the system resource, it passes the Runnable object to it to execute its run() met...more

There is a pretty standard way to check for this type of thing. You'll have to re-check your condition after the call to wait(timeout) returns: public synchronized boolean acquire(long waitfor){ ...more

The solution is to use a different monitor. When you make a method synchronized, you are specifying that the currently running thread should obtain a monitor (lock) on the object which has the me...more

I am looking for a monitoring tool that will give me the status of the threads inside Weblogic? We are running Weblogic Server 5.1.0 service pack 8 on HPUX 11 servers in our production environment....more

No. The local variable only holds a pointer to an object; if other threads can also point to this object, then it needs to be made thread-safe. See also How do I ensure that my servlet is thread-...more

There isn't anything very portable, but (if you're willing to provide an implementation for each of your target platforms) you can either: Have the host OS execute a new JVM (typically by calling...more

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Synchronized operations are costly and if you aren't modifying a collection much, it is best not to synchronize all collection accesses. The CopyOnWriteXXX collections avoid concurrent modificatio...more

Pessimistic assumes conflicts will occur and avoids them through exclusive locks and explicit synchronization. With the optimistic approach, it is assumed conflicts won't occur, and they are dealt...more