Mercurial > hg > pulseaudio

changeset 45:c3802b8ed541

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
fixed the deadlock which occurred when adding multiple listeners during the open() call of the PulseAudioMixer
author Omair Majid <omajid@redhat.com>
date Wed, 06 Aug 2008 14:55:15 -0400
parents 4a01f1203d48
children 2331da2e5f6a
files .hgignore src/org/classpath/icedtea/pulseaudio/EventLoop.java src/org/classpath/icedtea/pulseaudio/PulseAudioMixer.java
diffstat 3 files changed, 64 insertions(+), 50 deletions(-) [+]
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/.hgignore	Wed Aug 06 14:55:15 2008 -0400
@@ -0,0 +1,8 @@
+# use glob syntax.
+syntax: glob
+
+*.class
+*.o
+*~
+org_classpath_icedtea_*.h
+*.log
--- a/src/org/classpath/icedtea/pulseaudio/EventLoop.java	Wed Aug 06 14:08:52 2008 -0400
+++ b/src/org/classpath/icedtea/pulseaudio/EventLoop.java	Wed Aug 06 14:55:15 2008 -0400
@@ -45,8 +45,8 @@
 import org.classpath.icedtea.pulseaudio.ContextEvent.Type;
 
 /*
- * any methods that can obstruct the behaviour of pa_mainloop
- * should run synchronized
+ * any methods that can obstruct the behaviour of pa_mainloop should run
+ * synchronized
  * 
  * 
  */
@@ -68,7 +68,7 @@
 	private String serverString;
 
 	private int status;
-	//	private boolean eventLoopIsRunning = false;
+	// private boolean eventLoopIsRunning = false;
 
 	public Semaphore finished = new Semaphore(0);
 
@@ -214,25 +214,16 @@
 	private void fireEvent(final ContextEvent e) {
 		System.out.println(this.getClass().getName() + "firing event: "
 				+ e.getType().toString());
-		Thread th = new Thread(new Runnable() {
+		System.out.println("notifying listeners");
 
-			@Override
-			public void run() {
-				System.out.println("notifying listeners");
-				
-				synchronized (contextListeners) {
-					System.out.println(contextListeners.size());
-					for (ContextListener listener : contextListeners) {
-						listener.update(e);
-						System.out.println("updating listeners");
-					}
-				}
+		synchronized (contextListeners) {
+			System.out.println(contextListeners.size());
+			for (ContextListener listener : contextListeners) {
+				listener.update(e);
+				System.out.println("updating listeners");
 			}
-
-		});
+		}
 
-		th.start();
-		
 	}
 
 	public void setVolume(long streamPointer, int volume) {
--- a/src/org/classpath/icedtea/pulseaudio/PulseAudioMixer.java	Wed Aug 06 14:08:52 2008 -0400
+++ b/src/org/classpath/icedtea/pulseaudio/PulseAudioMixer.java	Wed Aug 06 14:55:15 2008 -0400
@@ -308,12 +308,38 @@
 		eventLoop.setAppName(appName);
 		eventLoop.setServer(host);
 
+		
+		ContextListener eventListener = new ContextListener() {
+
+			@Override
+			public void update(ContextEvent e) {
+				System.out.println("General listener was notified");
+				System.out.println("  eventType: " + e.getType());
+				if (e.getType() == ContextEvent.Type.READY) {
+					System.out.println("firing event ready..");
+					fireEvent(new LineEvent(PulseAudioMixer.this,
+							LineEvent.Type.OPEN, AudioSystem.NOT_SPECIFIED));
+					System.out.println("done");
+				} else if (e.getType() == ContextEvent.Type.FAILED
+						|| e.getType() == ContextEvent.Type.TERMINATED) {
+					fireEvent(new LineEvent(PulseAudioMixer.this,
+							LineEvent.Type.CLOSE, AudioSystem.NOT_SPECIFIED));
+				}
+				System.out.println("general listener returning");
+			}
+
+		};
+
+		eventLoop.addContextListener(eventListener);
+		
+		
 		final Semaphore ready = new Semaphore(0);
 
 		ContextListener initListener = new ContextListener() {
 
 			@Override
 			public void update(ContextEvent e) {
+				System.out.println("specific listener notifed");
 				System.out.println(this.getClass().getName()
 						+ ": Event detected " + e.getType().toString());
 				if (e.getType() == ContextEvent.Type.READY
@@ -322,6 +348,7 @@
 					ready.release();
 					System.out.println("realeasing semaphore ready");
 				}
+				System.out.println("specific listener returning");
 			}
 
 		};
@@ -355,48 +382,36 @@
 		}
 
 		System.out.println(this.getClass().getName() + ": ready");
-		
+
 		this.isOpen = true;
 
-//		ContextListener eventListener = new ContextListener() {
-//
-//			@Override
-//			public void update(ContextEvent e) {
-//				if (e.getType() == ContextEvent.Type.READY) {
-//
-//					fireEvent(new LineEvent(PulseAudioMixer.this,
-//							LineEvent.Type.OPEN, AudioSystem.NOT_SPECIFIED));
-//				} else if (e.getType() == ContextEvent.Type.FAILED
-//						|| e.getType() == ContextEvent.Type.TERMINATED) {
-//					fireEvent(new LineEvent(PulseAudioMixer.this,
-//							LineEvent.Type.CLOSE, AudioSystem.NOT_SPECIFIED));
-//				}
-//
-//			}
-//
-//		};
 
-//		eventLoop.addContextListener(eventListener);
 
 	}
 
 	@Override
-	synchronized public void removeLineListener(LineListener listener) {
+	public void removeLineListener(LineListener listener) {
 		lineListeners.remove(listener);
 	}
 
-	synchronized private void fireEvent(final LineEvent e) {
-		Thread th = new Thread(new Runnable() {
-			@Override
-			public void run() {
-				synchronized (lineListeners) {
-					for (LineListener lineListener : lineListeners) {
-						lineListener.update(e);
-					}
-				}
+	/*
+	 * Should this method be synchronized? I had a few reasons, but i forgot them
+	 * Pros:
+	 *  - Thread safety?
+	 * 
+	 * Cons:
+	 *  - eventListeners are run from other threads, if those then call fireEvent 
+	 *    while a method is waiting on a listener, this synchronized block wont 
+	 *    be entered: deadlock!
+	 * 
+	 */
+	private void fireEvent(final LineEvent e) {
+		System.out.println(this.getClass().getName() + "fireEvent(): firing event");
+		synchronized (lineListeners) {
+			for (LineListener lineListener : lineListeners) {
+				lineListener.update(e);
 			}
-		});
-		th.start();
+		}
 	}
 
 	public static void main(String[] args) throws Exception {