Use input transport for communications between app and IME.

The input method manager service now supplies an input channel for
communication while creating an IME session on behalf of the
application.

This change significanly reduces the overhead of IME event dispatch
by using a standard input channel to send input events rather than
using binder.  This results in fewer thread context switches
and fewer object allocations.

What's more, the IME may perform additional batching of the motion
events that it receives which may help it catch up if it is
getting behind while processing them.

Bug: 7984576
Bug: 8473020
Change-Id: Ibe26311edd0060cdcae80194f1753482e635786f

1 files changed, 39 insertions, 13 deletions

diff --git a/core/java/android/inputmethodservice/IInputMethodWrapper.java b/core/java/android/inputmethodservice/IInputMethodWrapper.java
index 0d981be..9306373 100644
--- a/core/java/android/inputmethodservice/IInputMethodWrapper.java
+++ b/core/java/android/inputmethodservice/IInputMethodWrapper.java
@@ -32,6 +32,7 @@ import android.os.Message;
 import android.os.RemoteException;
 import android.os.ResultReceiver;
 import android.util.Log;
+import android.view.InputChannel;
 import android.view.inputmethod.EditorInfo;
 import android.view.inputmethod.InputBinding;
 import android.view.inputmethod.InputConnection;
@@ -53,7 +54,6 @@ import java.util.concurrent.TimeUnit;
 class IInputMethodWrapper extends IInputMethod.Stub
         implements HandlerCaller.Callback {
     private static final String TAG = "InputMethodWrapper";
-    private static final boolean DEBUG = false;
 
     private static final int DO_DUMP = 1;
     private static final int DO_ATTACH_TOKEN = 10;
@@ -78,20 +78,29 @@ class IInputMethodWrapper extends IInputMethod.Stub
     }
     
     // NOTE: we should have a cache of these.
-    static class InputMethodSessionCallbackWrapper implements InputMethod.SessionCallback {
+    static final class InputMethodSessionCallbackWrapper implements InputMethod.SessionCallback {
         final Context mContext;
+        final InputChannel mChannel;
         final IInputSessionCallback mCb;
-        InputMethodSessionCallbackWrapper(Context context, IInputSessionCallback cb) {
+
+        InputMethodSessionCallbackWrapper(Context context, InputChannel channel,
+                IInputSessionCallback cb) {
             mContext = context;
+            mChannel = channel;
             mCb = cb;
         }
+
+        @Override
         public void sessionCreated(InputMethodSession session) {
             try {
                 if (session != null) {
                     IInputMethodSessionWrapper wrap =
-                            new IInputMethodSessionWrapper(mContext, session);
+                            new IInputMethodSessionWrapper(mContext, session, mChannel);
                     mCb.sessionCreated(wrap);
                 } else {
+                    if (mChannel != null) {
+                        mChannel.dispose();
+                    }
                     mCb.sessionCreated(null);
                 }
             } catch (RemoteException e) {
@@ -112,6 +121,7 @@ class IInputMethodWrapper extends IInputMethod.Stub
         return mInputMethod.get();
     }
 
+    @Override
     public void executeMessage(Message msg) {
         InputMethod inputMethod = mInputMethod.get();
         // Need a valid reference to the inputMethod for everything except a dump.
@@ -174,8 +184,11 @@ class IInputMethodWrapper extends IInputMethod.Stub
                 return;
             }
             case DO_CREATE_SESSION: {
+                SomeArgs args = (SomeArgs)msg.obj;
                 inputMethod.createSession(new InputMethodSessionCallbackWrapper(
-                        mCaller.mContext, (IInputSessionCallback)msg.obj));
+                        mCaller.mContext, (InputChannel)args.arg1,
+                        (IInputSessionCallback)args.arg2));
+                args.recycle();
                 return;
             }
             case DO_SET_SESSION_ENABLED:
@@ -197,8 +210,9 @@ class IInputMethodWrapper extends IInputMethod.Stub
         }
         Log.w(TAG, "Unhandled message code: " + msg.what);
     }
-    
-    @Override protected void dump(FileDescriptor fd, PrintWriter fout, String[] args) {
+
+    @Override
+    protected void dump(FileDescriptor fd, PrintWriter fout, String[] args) {
         AbstractInputMethodService target = mTarget.get();
         if (target == null) {
             return;
@@ -224,10 +238,12 @@ class IInputMethodWrapper extends IInputMethod.Stub
         }
     }
 
+    @Override
     public void attachToken(IBinder token) {
         mCaller.executeOrSendMessage(mCaller.obtainMessageO(DO_ATTACH_TOKEN, token));
     }
-    
+
+    @Override
     public void bindInput(InputBinding binding) {
         InputConnection ic = new InputConnectionWrapper(
                 IInputContext.Stub.asInterface(binding.getConnectionToken()));
@@ -235,24 +251,30 @@ class IInputMethodWrapper extends IInputMethod.Stub
         mCaller.executeOrSendMessage(mCaller.obtainMessageO(DO_SET_INPUT_CONTEXT, nu));
     }
 
+    @Override
     public void unbindInput() {
         mCaller.executeOrSendMessage(mCaller.obtainMessage(DO_UNSET_INPUT_CONTEXT));
     }
 
+    @Override
     public void startInput(IInputContext inputContext, EditorInfo attribute) {
         mCaller.executeOrSendMessage(mCaller.obtainMessageOO(DO_START_INPUT,
                 inputContext, attribute));
     }
 
+    @Override
     public void restartInput(IInputContext inputContext, EditorInfo attribute) {
         mCaller.executeOrSendMessage(mCaller.obtainMessageOO(DO_RESTART_INPUT,
                 inputContext, attribute));
     }
 
-    public void createSession(IInputSessionCallback callback) {
-        mCaller.executeOrSendMessage(mCaller.obtainMessageO(DO_CREATE_SESSION, callback));
+    @Override
+    public void createSession(InputChannel channel, IInputSessionCallback callback) {
+        mCaller.executeOrSendMessage(mCaller.obtainMessageOO(DO_CREATE_SESSION,
+                channel, callback));
     }
 
+    @Override
     public void setSessionEnabled(IInputMethodSession session, boolean enabled) {
         try {
             InputMethodSession ls = ((IInputMethodSessionWrapper)
@@ -263,7 +285,8 @@ class IInputMethodWrapper extends IInputMethod.Stub
             Log.w(TAG, "Incoming session not of correct type: " + session, e);
         }
     }
-    
+
+    @Override
     public void revokeSession(IInputMethodSession session) {
         try {
             InputMethodSession ls = ((IInputMethodSessionWrapper)
@@ -273,17 +296,20 @@ class IInputMethodWrapper extends IInputMethod.Stub
             Log.w(TAG, "Incoming session not of correct type: " + session, e);
         }
     }
-    
+
+    @Override
     public void showSoftInput(int flags, ResultReceiver resultReceiver) {
         mCaller.executeOrSendMessage(mCaller.obtainMessageIO(DO_SHOW_SOFT_INPUT,
                 flags, resultReceiver));
     }
-    
+
+    @Override
     public void hideSoftInput(int flags, ResultReceiver resultReceiver) {
         mCaller.executeOrSendMessage(mCaller.obtainMessageIO(DO_HIDE_SOFT_INPUT,
                 flags, resultReceiver));
     }
 
+    @Override
     public void changeInputMethodSubtype(InputMethodSubtype subtype) {
         mCaller.executeOrSendMessage(mCaller.obtainMessageO(DO_CHANGE_INPUTMETHOD_SUBTYPE,
                 subtype));