Make delays depending on available processors

Currently we use a fixed delay for a given job priority, depending on
the number of jobs running and other factors this can considerably delay
some actions and make eclipse feel laggy.

This now makes these values dependent on the number of CPUs installed in
the machine, as we can assume more CPUs can do the work better in
parallel without additional sleep delays.

Author: laeubi

runtime/bundles/org.eclipse.core.jobs/src/org/eclipse/core/internal/jobs/JobManager.java

@@ -78,6 +78,19 @@
  */
 public class JobManager implements IJobManager, DebugOptionsListener {
 
+
+	private static final int CORES = Runtime.getRuntime().availableProcessors();
+
+	private static final long DELAY_PRIORITY_INTERACTIVE = 0;
+
+	private static final long DELAY_PRIORITY_DECORATE = 1000 / CORES;
+
+	private static final long DELAY_PRIORITY_BUILD = 500 / CORES;
+
+	private static final long DELAY_PRIORITY_LONG = 100 / CORES;
+
+	private static final long DELAY_PRIORITY_SHORT = 50 / CORES;
+
 	private static final int NANOS_IN_MS = 1_000_000;
 
 	/**
@@ -618,18 +631,17 @@ public ISchedulingRule currentRule() {
 	 * tolerate waiting.
 	 */
 	private long delayFor(int priority) {
-		//these values may need to be tweaked based on machine speed
 		switch (priority) {
 			case Job.INTERACTIVE :
-				return 0L;
+				return DELAY_PRIORITY_INTERACTIVE;
 			case Job.SHORT :
-				return 50L;
+				return DELAY_PRIORITY_SHORT;
 			case Job.LONG :
-				return 100L;
+				return DELAY_PRIORITY_LONG;
 			case Job.BUILD :
-				return 500L;
+				return DELAY_PRIORITY_BUILD;
 			case Job.DECORATE :
-				return 1000L;
+				return DELAY_PRIORITY_DECORATE;
 			default :
 				Assert.isTrue(false, "Job has invalid priority: " + priority); //$NON-NLS-1$
 				return 0;