This class provides ANSI/ISO C signal support. A Java program can register signal handlers for the current process. There are two restrictions:

• Java code cannot register a handler for signals that are already used by the Java VM implementation. The Signal.handle function raises an IllegalArgumentException if such an attempt is made.
• When Signal.handle is called, the VM internally registers a special C signal handler. There is no way to force the Java signal handler to run synchronously before the C signal handler returns. Instead, when the VM receives a signal, the special C signal handler creates a new thread (at priority Thread.MAX_PRIORITY) to run the registered Java signal handler. The C signal handler immediately returns. Note that because the Java signal handler runs in a newly created thread, it may not actually be executed until some time after the C signal handler returns.

Signal objects are created based on their names. For example:

new Signal("INT");

constructs a signal object corresponding to SIGINT, which is typically produced when the user presses Ctrl-C at the command line. The Signal constructor throws IllegalArgumentException when it is passed an unknown signal.

This is an example of how Java code handles SIGINT:

SignalHandler handler = new SignalHandler () {
    public void handle(Signal sig) {
      ... // handle SIGINT
    }
};
Signal.handle(new Signal("INT"), handler);