Bug 155273 [Markers] Visibility of problems view columns should be configurable
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/CachedMarkerBuilder.java
* @see org.eclipse.core.runtime.jobs.Job#belongsTo(java.lang.Object)
			 */
			public boolean belongsTo(Object family) {
				return MarkerContentGenerator.CACHE_UPDATE_FAMILY == family;
			}
			/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.core.runtime.jobs.Job#run(org.eclipse.core.runtime.IProgressMonitor)
			 */
			protected IStatus run(IProgressMonitor monitor) {
				updateJob.cancel();
				buildAllMarkers(monitor);
				updateJob.schedule();
				return Status.OK_STATUS;
			}
			/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.ui.progress.WorkbenchJob#shouldRun()
			 */
			public boolean shouldRun() {
				
				if (preBuildTime > 0
						&& System.currentTimeMillis() - preBuildTime < TIME_OUT)
					return false;
				
				preBuildTime = -1;
				
				return IDEWorkbenchPlugin.getDefault().getBundle().getState() == Bundle.ACTIVE;