Bug 313899

Description Markus Schorn 2010-05-21 07:35:53 EDT

When I run a user job ('job.setUser(true)') the UI shows a busy cursor for 250ms, even if the job does not do anything. This becomes apparent when I schedule 20 user-jobs that complete immediately, then the UI shows a busy-cursor for 5 seconds.

My expectation is, that the busy cursor is at the maximum shown as long as the job is actually running.


Here is a test-case:

public class UIJobTest extends TestCase {
	
	public void testUIJob() {
		int count= 20;
		
		assertTrue(runEventLoop() < 1000);
		for (int i=0; i<count; i++) {
			Job j= new Job("dummy") {
				@Override
				protected IStatus run(IProgressMonitor monitor) {
					return Status.OK_STATUS;
				}
			};
			j.setUser(true);
			j.schedule();
		}
		long time = runEventLoop();
		assertTrue("Main thread busy for " + time + 
                           " ms when runnning " + count + " user jobs.", 
                           time < 1000);
	}

	private long runEventLoop() {
		long startTime= System.currentTimeMillis();
		
		Display disp= Display.getCurrent();
		assertNotNull(disp);
		while(disp.readAndDispatch()) {
		}
		
		return System.currentTimeMillis() - startTime;
	}			
}