Stream->Fountain, move Scheduler to Platform, HashMap->Hash

[org.ibex.core.git] / src / org / ibex / plat / Platform.java

diff --git a/src/org/ibex/plat/Platform.java b/src/org/ibex/plat/Platform.java
index 321a80d..389caa4 100644 (file)
--- a/src/org/ibex/plat/Platform.java
+++ b/src/org/ibex/plat/Platform.java
@@ -293,6 +293,91 @@ public abstract class Platform {
             return p;
         }
     }
+
+    /** Implements cooperative multitasking */
+    public static class Scheduler {
+
+    // Public API Exposed to org.ibex /////////////////////////////////////////////////
+
+    private static Scheduler singleton;
+    public static void add(Callable t) { Log.debug(Scheduler.class, "scheduling " + t); Scheduler.runnable.append(t); }
+    public static void init() { if (singleton == null) (singleton = Platform.getScheduler()).run(); }
+
+    private static Callable 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 Callable 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 = (Callable)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.run(null);
+                    }
+                    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 Callable 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
+            }
+        }
+    }
 }