Fix MidiDevice.MidiConnection lifecycle

Update device server's MidiDeviceStatus when a connection is made to one of its output ports.

After connecting an input port to an output port using MidiDevice.connectPorts(),
do not call IMidiDeviceServer.closePort() until MidiDevice.MidiConnection.close() is called.

While I was in there, added missing CloseGuard support to the MidiDevice.MidiConnection class.

This fixes a problem resulting in UsbMidiDevice closing the device's ALSA driver too soon.

Bug: 21850709

Change-Id: I0c120f76b42eec8a143161e46dba73fbec5e4f31

media/java/android/media/midi/MidiDevice.java

@@ -50,21 +50,43 @@ public final class MidiDevice implements Closeable {
      * Close this object to terminate the connection.
      */
     public class MidiConnection implements Closeable {
-        private final IBinder mToken;
-        private final MidiInputPort mInputPort;
+        private final IMidiDeviceServer mInputPortDeviceServer;
+        private final IBinder mInputPortToken;
+        private final IBinder mOutputPortToken;
+        private final CloseGuard mGuard = CloseGuard.get();
+        private boolean mIsClosed;
 
-        MidiConnection(IBinder token, MidiInputPort inputPort) {
-            mToken = token;
-            mInputPort = inputPort;
+        MidiConnection(IBinder outputPortToken, MidiInputPort inputPort) {
+            mInputPortDeviceServer = inputPort.getDeviceServer();
+            mInputPortToken = inputPort.getToken();
+            mOutputPortToken = outputPortToken;
+            mGuard.open("close");
         }
 
         @Override
         public void close() throws IOException {
+            synchronized (mGuard) {
+                if (mIsClosed) return;
+                mGuard.close();
+                try {
+                    // close input port
+                    mInputPortDeviceServer.closePort(mInputPortToken);
+                    // close output port
+                    mDeviceServer.closePort(mOutputPortToken);
+                } catch (RemoteException e) {
+                    Log.e(TAG, "RemoteException in MidiConnection.close");
+                }
+                mIsClosed = true;
+            }
+        }
+
+        @Override
+        protected void finalize() throws Throwable {
             try {
-                mDeviceServer.closePort(mToken);
-                IoUtils.closeQuietly(mInputPort);
-            } catch (RemoteException e) {
-                Log.e(TAG, "RemoteException in MidiConnection.close");
+                mGuard.warnIfOpen();
+                close();
+            } finally {
+                super.finalize();
             }
         }
     }

media/java/android/media/midi/MidiDeviceServer.java

@@ -257,7 +257,14 @@ public final class MidiDeviceServer implements Closeable {
         public void connectPorts(IBinder token, ParcelFileDescriptor pfd,
                 int outputPortNumber) {
             MidiInputPort inputPort = new MidiInputPort(pfd, outputPortNumber);
-            mOutputPortDispatchers[outputPortNumber].getSender().connect(inputPort);
+            MidiDispatcher dispatcher = mOutputPortDispatchers[outputPortNumber];
+            synchronized (dispatcher) {
+                dispatcher.getSender().connect(inputPort);
+                int openCount = dispatcher.getReceiverCount();
+                mOutputPortOpenCount[outputPortNumber] = openCount;
+                updateDeviceStatus();
+            }
+
             mInputPorts.add(inputPort);
             OutputPortClient client = new OutputPortClient(token, inputPort);
             synchronized (mPortClients) {

media/java/android/media/midi/MidiInputPort.java

@@ -103,17 +103,33 @@ public final class MidiInputPort extends MidiReceiver implements Closeable {
 
     // used by MidiDevice.connectInputPort() to connect our socket directly to another device
     /* package */ ParcelFileDescriptor claimFileDescriptor() {
-        synchronized (mBuffer) {
-            ParcelFileDescriptor pfd = mParcelFileDescriptor;
-            if (pfd != null) {
+        synchronized (mGuard) {
+            ParcelFileDescriptor pfd;
+            synchronized (mBuffer) {
+                pfd = mParcelFileDescriptor;
+                if (pfd == null) return null;
                 IoUtils.closeQuietly(mOutputStream);
                 mParcelFileDescriptor = null;
                 mOutputStream = null;
             }
+
+            // Set mIsClosed = true so we will not call mDeviceServer.closePort() in close().
+            // MidiDevice.MidiConnection.close() will do the cleanup instead.
+            mIsClosed = true;
             return pfd;
         }
     }
 
+    // used by MidiDevice.MidiConnection to close this port after the connection is closed
+    /* package */ IBinder getToken() {
+        return mToken;
+    }
+
+    // used by MidiDevice.MidiConnection to close this port after the connection is closed
+    /* package */ IMidiDeviceServer getDeviceServer() {
+        return mDeviceServer;
+    }
+
     @Override
     public void close() throws IOException {
         synchronized (mGuard) {