2003/12/13 08:13:32

[org.ibex.core.git] / src / org / xwt / Scheduler.java

diff --git a/src/org/xwt/Scheduler.java b/src/org/xwt/Scheduler.java
index 1f57fe7..8a5cd32 100644 (file)
--- a/src/org/xwt/Scheduler.java
+++ b/src/org/xwt/Scheduler.java
@@ -11,20 +11,17 @@ public class Scheduler {
     // Public API Exposed to org.xwt /////////////////////////////////////////////////
 
     private static Scheduler singleton;
-    public static abstract class Task { public abstract void perform() throws Exception; }
+    public static interface Task { public abstract void perform() throws Exception; }
     public static void add(Task t) { singleton.runnable.append(t); }
-    public static void init() {
-        if (singleton != null) return;
-        singleton = Platform.getScheduler();
-        singleton.run();
-    }
-
+    public static void init() { if (singleton == null) (singleton = Platform.getScheduler()).run(); }
 
     // API which must be supported by subclasses /////////////////////////////////////
 
     /**
-     *  INVARIANT: all scheduler implementations MUST invoke Surface.renderAll() after performing a Task if no tasks remain
-     *  in the queue.  A scheduler may choose to invoke Surface.renderAll() more often than that if it so chooses.
+     *  SCHEDULER INVARIANT: all scheduler implementations MUST invoke
+     *  Surface.renderAll() after performing a Task if no tasks remain
+     *  in the queue.  A scheduler may choose to invoke
+     *  Surface.renderAll() more often than that if it so chooses.
      */
     public void run() { defaultRun(); }
     protected Scheduler() { }
@@ -39,12 +36,15 @@ public class Scheduler {
             try {
                 t.perform();
                 // FEATURE: be smarter about this
-                Surface.renderAll();
+                if (t != Surface.renderAll) add(Surface.renderAll);
             } catch (JSExn e) {
+                Log.log(Scheduler.class, "a JavaScript thread spawned with xwt.thread() threw an exception:");
                 Log.log(Scheduler.class, e.toString());
             } catch (Exception e) {
+                Log.log(Scheduler.class, "a Task threw an exception which was caught by the scheduler:");
                 Log.log(Scheduler.class, e);
             }
+            // if an Error is thrown it will cause the engine to quit
         }
     }
 }