What is a AWT thread?
What is a AWT thread?
The event dispatching thread (EDT) is a background thread used in Java to process events from the Abstract Window Toolkit (AWT) graphical user interface event queue. The AWT uses a single-threaded painting model in which all screen updates must be performed from a single thread.
Is AWT thread safe?
There are a few exceptions to the rule that all code that might affect a realized Swing component must run in the event-dispatching thread: A few methods are thread-safe. In the Swing API documentation, thread-safe methods are marked with this text: This method is thread safe, although most Swing methods are not.
Which Swing method is thread safe?
Since most Swing object methods are not thread safe, they should be invoked from a single thread, the EDT.
Why is Java Swing not thread safe?
Why Swing Components are not thread-safe One of the main reason for Java Swing is not thread-safe is to simplify the task of extending its components. Another reason for the Java Swing is not thread-safe due to the overhead involved in obtaining and releasing locks and restoring the state.
What is SwingUtilities InvokeAndWait?
It is started as soon as a Swing top-level component is displayed, and it’s bascially a worker thread that has a FIFO queue of event objects that it executes one after another. And now for the finish: invokeAndWait() places the Runnable you pass to it into the EDT event queue and waits until the EDT has executed it.
What is Java AWT EventQueue invokeLater new runnable?
invokeLater. Causes runnable to have its run method called in the dispatch thread of the system EventQueue . This will happen after all pending events are processed.
Is Swing single threaded?
Swing’s threading model is utterly simple: it’s called single-threaded. If you don’t understand what you’ve ‘heard’, you can’t expect people who haven’t heard it to understand either. Maybe you should make more of an effort. Swing is single-threaded.
Are all Swing components thread safe?
Most Swing object methods are not “thread safe”. This means that if those (non thread safe) method are invoked from multiple threads this could result in thread interference or memory consistency errors. Only thread safe methods can be safely invoked from any thread.
Is repaint thread safe?
The specific implementation of repaint in OpenJDK 7 appears to be thread-safe, a fact which has nothing to do with guarantees given by the specification. Code which relies on the thread safety of repaint or other methods is broken and is not guaranteed to behave properly on all Java implementations.
What is SwingUtilities?
SwingUtilities class has two useful function to help with GUI rendering task: 1) invokeLater(Runnable):Causes doRun. run() to be executed asynchronously on the AWT event dispatching thread(EDT). This will happen after all pending AWT events have been processed, as is described above.
Why does my AWT program crash?
Most of the AWT crashes occur on the Windows platform and are caused by thread traces. Many of these problems were fixed in Java SE 6, so if your crash occurred in an earlier release, then first try to determine if the problem is already fixed in the latest release. One of the possible causes of crashes is that many AWT operations are asynchronous.
Is it safe to remove AWT listeners from the Event Dispatch Thread?
Unless otherwise noted all AWT listeners are notified on the event dispatch thread. It is safe to remove/add listeners from any thread during dispatching, but the changes only effect subsequent notification. For example, if a key listeners is added from another key listener, the newly added listener is only notified on subsequent key events.
Why does AWT start non-daemon helper threads for its internal purposes?
The reason is that AWT encapsulates asynchronous event dispatch machinery to process events AWT or Swing components can fire. The exact behavior of this machinery is implementation-dependent. In particular, it can start non-daemon helper threads for its internal purposes. In fact, these are the threads that prevent the example above from exiting.
How do I know if AWT DLL is bad?
In such cases, the indication awt.dll does not appear as a problematic frame, and you need to look further in the file, in the section Stack: Native frames: Java frames as shown in the following example. If the text awt.dll appears somewhere in the native frames, then the crash might be related to AWT.
