--- /dev/null
+// Copyright 2004 Adam Megacz, see the COPYING file for licensing [GPL]
+package org.ibex.util;
+
+import java.io.IOException;
+
+import org.ibex.js.*;
+import org.ibex.util.*;
+import org.ibex.graphics.*;
+import org.ibex.plat.*;
+
+/** Implements cooperative multitasking */
+public class Scheduler {
+
+ // Public API Exposed to org.ibex /////////////////////////////////////////////////
+
+ private static Scheduler singleton;
+ public static void add(Task t) { Log.debug(Scheduler.class, "scheduling " + t); Scheduler.runnable.append(t); }
+ public static void init() { if (singleton == null) (singleton = Platform.getScheduler()).run(); }
+
+ private static Task current = null;
+
+ private static volatile boolean rendering = false;
+ private static volatile boolean again = false;
+
+ /** synchronizd so that we can safely call it from an event-delivery thread, in-context */
+ public static void renderAll() {
+ if (rendering) { again = true; return; }
+ synchronized(Scheduler.class) {
+ try {
+ rendering = true;
+ do {
+ // FEATURE: this could be cleaner
+ again = false;
+ for(int i=0; i<Surface.allSurfaces.size(); i++) {
+ Surface s = ((Surface)Surface.allSurfaces.elementAt(i));
+ do { s.render(); } while(s.abort);
+ }
+ } while(again);
+ } finally {
+ rendering = false;
+ }
+ }
+ }
+
+
+
+ // API which must be supported by subclasses /////////////////////////////////////
+
+ /**
+ * 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(); }
+ public Scheduler() { }
+
+
+ // Default Implementation //////////////////////////////////////////////////////
+
+ protected static Queue runnable = new Queue(50);
+ public void defaultRun() {
+ while(true) {
+ current = (Task)runnable.remove(true);
+ try {
+ // FIXME hideous
+ synchronized(this) {
+ for(int i=0; i<Surface.allSurfaces.size(); i++) {
+ Surface s = (Surface)Surface.allSurfaces.elementAt(i);
+ if (current instanceof JS) {
+ s._mousex = Integer.MAX_VALUE;
+ s._mousey = Integer.MAX_VALUE;
+ } else {
+ s._mousex = s.mousex;
+ s._mousey = s.mousey;
+ }
+ }
+ Log.debug(Scheduler.class, "performing " + current);
+ current.perform();
+ }
+ renderAll();
+ } catch (JSExn e) {
+ Log.info(Scheduler.class, "a JavaScript thread spawned with ibex.thread() threw an exception:");
+ Log.info(Scheduler.class,e);
+ } catch (Exception e) {
+ Log.info(Scheduler.class, "a Task threw an exception which was caught by the scheduler:");
+ Log.info(Scheduler.class, e);
+ } catch (Throwable t) {
+ t.printStackTrace();
+ }
+ // if an Error is thrown it will cause the engine to quit
+ }
+ }
+}