compatible with 0.6.2

README.md

@@ -34,6 +34,9 @@ socket = new Socket("ws://localhost") {
 
   @Override
   public void onclose() {}
+
+  @Override
+  public void onerror(Exception err) {}
 };
 socket.open();
 ```

src/main/java/com/github/nkzawa/engineio/client/Socket.java

@@ -106,8 +106,8 @@ public abstract class Socket extends Emitter {
     private List<String> transports;
     private List<String> upgrades;
     private Map<String, String> query;
-    private Queue<Packet> writeBuffer = new LinkedList<Packet>();
+    private LinkedList<Packet> writeBuffer = new LinkedList<Packet>();
-    private Queue<Runnable> callbackBuffer = new LinkedList<Runnable>();
+    private LinkedList<Runnable> callbackBuffer = new LinkedList<Runnable>();
     private Transport transport;
     private Future pingTimeoutTimer;
     private Future pingIntervalTimer;
@@ -461,7 +461,7 @@ public abstract class Socket extends Emitter {
     }
 
     /**
-     * Sends a ping packet
+     * Sends a ping packet.
      */
     public void ping() {
         EventThread.exec(new Runnable() {
@@ -473,7 +473,13 @@ public abstract class Socket extends Emitter {
     }
 
     private void onDrain() {
-        this.callbacks();
+        for (int i = 0; i < this.prevBufferLen; i++) {
+            Runnable callback = this.callbackBuffer.get(i);
+            if (callback != null) {
+                callback.run();
+            }
+        }
+
         for (int i = 0; i < this.prevBufferLen; i++) {
             this.writeBuffer.poll();
             this.callbackBuffer.poll();
@@ -487,16 +493,6 @@ public abstract class Socket extends Emitter {
         }
     }
 
-    private void callbacks() {
-        Iterator<Runnable> iter = this.callbackBuffer.iterator();
-        for (int i = 0; i < this.prevBufferLen && iter.hasNext(); i++) {
-            Runnable callback = iter.next();
-            if (callback != null) {
-                callback.run();
-            }
-        }
-    }
-
     private void flush() {
         if (this.readyState != ReadyState.CLOSED && this.transport.writable &&
                 !this.upgrading && this.writeBuffer.size() != 0) {
@@ -569,7 +565,6 @@ public abstract class Socket extends Emitter {
                     Socket.this.onClose("forced close");
                     logger.fine("socket closing - telling transport to close");
                     Socket.this.transport.close();
-                    Socket.this.transport.off();
                 }
 
             }
@@ -580,6 +575,7 @@ public abstract class Socket extends Emitter {
     private void onError(Exception err) {
         logger.fine(String.format("socket error %s", err));
         this.emit(EVENT_ERROR, err);
+        this.onerror(err);
         this.onClose("transport error", err);
     }
 
@@ -591,12 +587,15 @@ public abstract class Socket extends Emitter {
         if (this.readyState == ReadyState.OPENING || this.readyState == ReadyState.OPEN) {
             logger.fine(String.format("socket close with reason: %s", reason));
             final Socket self = this;
+
+            // clear timers
             if (this.pingIntervalTimer != null) {
                 this.pingIntervalTimer.cancel(true);
             }
             if (this.pingTimeoutTimer != null) {
                 this.pingTimeoutTimer.cancel(true);
             }
+
             EventThread.nextTick(new Runnable() {
                 @Override
                 public void run() {
@@ -604,13 +603,22 @@ public abstract class Socket extends Emitter {
                     self.callbackBuffer.clear();
                 }
             });
+
+            // ignore further transport communication
+            this.transport.off();
+
+            // set ready state
             ReadyState prev = this.readyState;
             this.readyState = ReadyState.CLOSED;
+
+            // clear session id
+            this.id = null;
+
+            // emit events
             if (prev == ReadyState.OPEN) {
                 this.emit(EVENT_CLOSE, reason, desc);
-            }
                 this.onclose();
-            this.id = null;
+            }
         }
     }
 
@@ -630,6 +638,7 @@ public abstract class Socket extends Emitter {
 
     public abstract void onclose();
 
+    public abstract void onerror(Exception err);
 
     public static class Options extends Transport.Options {
 

src/main/java/com/github/nkzawa/engineio/client/transports/Polling.java

@@ -128,8 +128,25 @@ abstract public class Polling extends Transport {
     }
 
     protected void doClose() {
-        logger.fine("sending close packet");
+        final Polling self = this;
-        this.send(new Packet[] {new Packet(Packet.CLOSE, null)});
+
+        Listener close = new Listener() {
+            @Override
+            public void call(Object... args) {
+                logger.fine("writing close packet");
+                self.write(new Packet[] {new Packet(Packet.CLOSE, null)});
+            }
+        };
+
+        if (this.readyState == ReadyState.OPEN) {
+            logger.fine("transport open - closing");
+            close.call();
+        } else {
+            // in case we're trying to close while
+            // handshaking is in progress (engine.io-client GH-164)
+            logger.fine("transport not open - deferring close");
+            this.once(EVENT_OPEN, close);
+        }
     }
 
     protected void write(Packet[] packets) {

src/test/java/com/github/nkzawa/engineio/client/ServerConnectionTest.java

@@ -105,6 +105,9 @@ public class ServerConnectionTest {
                 System.out.println("onclose:");
                 events.offer("onclose");
             }
+
+            @Override
+            public void onerror(Exception err) {}
         };
         socket.open();
 
@@ -132,6 +135,9 @@ public class ServerConnectionTest {
 
             @Override
             public void onclose() {}
+
+            @Override
+            public void onerror(Exception err) {}
         };
         socket.open();
 
@@ -151,6 +157,8 @@ public class ServerConnectionTest {
             public void onmessage(String data) {}
             @Override
             public void onclose() {}
+            @Override
+            public void onerror(Exception err) {}
         };
         socket.on(Socket.EVENT_HANDSHAKE, new Emitter.Listener() {
             @Override
@@ -186,6 +194,8 @@ public class ServerConnectionTest {
             public void onmessage(String data) {}
             @Override
             public void onclose() {}
+            @Override
+            public void onerror(Exception err) {}
         };
         socket.on(Socket.EVENT_UPGRADING, new Emitter.Listener() {
             @Override
@@ -237,6 +247,9 @@ public class ServerConnectionTest {
 
             @Override
             public void onclose() {}
+
+            @Override
+            public void onerror(Exception err) {}
         };
         socket.open();
 

src/test/java/com/github/nkzawa/engineio/client/SocketTest.java

@@ -28,6 +28,8 @@ public class SocketTest {
             public void onmessage(String data) {}
             @Override
             public void onclose() {}
+            @Override
+            public void onerror(Exception err) {}
         };
         List<String> upgrades = new ArrayList<String>() {{
             add(Polling.NAME);
@@ -51,6 +53,8 @@ public class SocketTest {
             public void onmessage(String data) {}
             @Override
             public void onclose() {}
+            @Override
+            public void onerror(Exception err) {}
         };
         final boolean[] closed = {false};