CODEWITHSUNDEEP
javaswingevent-dispatch-thread
kotoko
kotoko

Reputation: 597

Out of EDT for isEventDispatchThread but running from EventDispatchThread.run

Why isEventDispatchThread() return false when dumpStackTrace's first element is at java.awt.EventDispatchThread.run?

    SwingUtilities.invokeLater(new Runnable() {

        @Override
        public void run() {
            doStuff();
        }
    });

    public void doStuff(){
       Thread.dumpStack();
       System.out.print(" [addToParents] "
           + ((SwingUtilities.isEventDispatchThread() 
           ? "out of EDT" : " in EDT ")));
    }

Yields:

[addToParents] out of EDT
java.lang.Exception: Stack trace
    at java.lang.Thread.dumpStack(Thread.java:1342)
    at pt.up.fe.dceg.neptus.gui.MissionBrowser.doStuff(MissionBrowser.java:899)
    at pt.up.fe.dceg.neptus.gui.MissionBrowser.access$6(MissionBrowser.java:883)
    at pt.up.fe.dceg.neptus.gui.MissionBrowser$3.run(MissionBrowser.java:1221)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:721)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:682)
    at java.awt.EventQueue$3.run(EventQueue.java:680)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:691)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)

This is simplified code (not MWS). As I suspect it's a concept I didn't get I didn't include one, if MWS is needed please tell me.

Upvotes: 1

Views: 276

Answers (1)

Sage
Sage

Reputation: 15418

No, it isn't. In your ternary operator's expression:

(SwingUtilities.isEventDispatchThread() ? "out of EDT" : " in EDT ")))

SwingUtilities.isEventDispatchThread() is returning true that is why it is printing "Out of EDT".

for an expression condition ? value1 : value2 : If the condition is true then the result is value1 otherwise the result is value2.

Upvotes: 4

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