Java™ Platform
Standard Ed. 6

java.awt
Interface ActiveEvent

All Known Implementing Classes:
InvocationEvent

public interface ActiveEvent

An interface for events that know how to dispatch themselves. By implementing this interface an event can be placed upon the event queue and its dispatch() method will be called when the event is dispatched, using the EventDispatchThread.

This is a very useful mechanism for avoiding deadlocks. If a thread is executing in a critical section (i.e., it has entered one or more monitors), calling other synchronized code may cause deadlocks. To avoid the potential deadlocks, an ActiveEvent can be created to run the second section of code at later time. If there is contention on the monitor, the second thread will simply block until the first thread has finished its work and exited its monitors.

For security reasons, it is often desirable to use an ActiveEvent to avoid calling untrusted code from a critical thread. For instance, peer implementations can use this facility to avoid making calls into user code from a system thread. Doing so avoids potential deadlocks and denial-of-service attacks.

Since:
1.2

Method Summary
 void dispatch()
          Dispatch the event to its target, listeners of the events source, or do whatever it is this event is supposed to do.
 

Method Detail

dispatch

void dispatch()
Dispatch the event to its target, listeners of the events source, or do whatever it is this event is supposed to do.


Java™ Platform
Standard Ed. 6

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For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

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