diff --git a/core/java/android/view/inputmethod/IInputMethodSessionInvoker.java b/core/java/android/view/inputmethod/IInputMethodSessionInvoker.java
index 1fbe2d4a0a3a0..db597e118f2ca 100644
--- a/core/java/android/view/inputmethod/IInputMethodSessionInvoker.java
+++ b/core/java/android/view/inputmethod/IInputMethodSessionInvoker.java
@@ -20,10 +20,14 @@ import android.annotation.AnyThread;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.graphics.Rect;
+import android.os.Binder;
 import android.os.Bundle;
+import android.os.Handler;
+import android.os.HandlerThread;
 import android.os.RemoteException;
 import android.util.Log;
 
+import com.android.internal.annotations.GuardedBy;
 import com.android.internal.inputmethod.IInputMethodSession;
 import com.android.internal.inputmethod.IRemoteInputConnection;
 
@@ -42,8 +46,25 @@ final class IInputMethodSessionInvoker {
     @NonNull
     private final IInputMethodSession mSession;
 
-    private IInputMethodSessionInvoker(@NonNull IInputMethodSession inputMethodSession) {
+    /**
+     * An optional {@link Handler} to dispatch {@link IInputMethodSession} method invocations to
+     * a background thread to emulate async (one-way) {@link Binder} call.
+     *
+     * {@code null} if {@code Binder.isProxy(mSession)} is {@code true}.
+     */
+    @Nullable
+    private final Handler mCustomHandler;
+
+    private static final Object sAsyncBinderEmulationHandlerLock = new Object();
+
+    @GuardedBy("sAsyncBinderEmulationHandlerLock")
+    @Nullable
+    private static Handler sAsyncBinderEmulationHandler;
+
+    private IInputMethodSessionInvoker(@NonNull IInputMethodSession inputMethodSession,
+            @Nullable Handler customHandler) {
         mSession = inputMethodSession;
+        mCustomHandler = customHandler;
     }
 
     /**
@@ -56,12 +77,37 @@ final class IInputMethodSessionInvoker {
     @Nullable
     public static IInputMethodSessionInvoker createOrNull(
             @NonNull IInputMethodSession inputMethodSession) {
-        return inputMethodSession != null ? new IInputMethodSessionInvoker(inputMethodSession)
-                : null;
+
+        final Handler customHandler;
+        if (inputMethodSession != null && !Binder.isProxy(inputMethodSession)) {
+            synchronized (sAsyncBinderEmulationHandlerLock) {
+                if (sAsyncBinderEmulationHandler == null) {
+                    final HandlerThread thread = new HandlerThread("IMM.binder-emu");
+                    thread.start();
+                    // Use an async handler instead of Handler#getThreadHandler().
+                    sAsyncBinderEmulationHandler = Handler.createAsync(thread.getLooper());
+                }
+                customHandler = sAsyncBinderEmulationHandler;
+            }
+        } else {
+            customHandler = null;
+        }
+
+        return inputMethodSession != null
+                ? new IInputMethodSessionInvoker(inputMethodSession, customHandler) : null;
     }
 
     @AnyThread
     void finishInput() {
+        if (mCustomHandler == null) {
+            finishInputInternal();
+        } else {
+            mCustomHandler.post(this::finishInputInternal);
+        }
+    }
+
+    @AnyThread
+    private void finishInputInternal() {
         try {
             mSession.finishInput();
         } catch (RemoteException e) {
@@ -71,6 +117,15 @@ final class IInputMethodSessionInvoker {
 
     @AnyThread
     void updateCursorAnchorInfo(CursorAnchorInfo cursorAnchorInfo) {
+        if (mCustomHandler == null) {
+            updateCursorAnchorInfoInternal(cursorAnchorInfo);
+        } else {
+            mCustomHandler.post(() -> updateCursorAnchorInfoInternal(cursorAnchorInfo));
+        }
+    }
+
+    @AnyThread
+    private void updateCursorAnchorInfoInternal(CursorAnchorInfo cursorAnchorInfo) {
         try {
             mSession.updateCursorAnchorInfo(cursorAnchorInfo);
         } catch (RemoteException e) {
@@ -80,6 +135,15 @@ final class IInputMethodSessionInvoker {
 
     @AnyThread
     void displayCompletions(CompletionInfo[] completions) {
+        if (mCustomHandler == null) {
+            displayCompletionsInternal(completions);
+        } else {
+            mCustomHandler.post(() -> displayCompletionsInternal(completions));
+        }
+    }
+
+    @AnyThread
+    void displayCompletionsInternal(CompletionInfo[] completions) {
         try {
             mSession.displayCompletions(completions);
         } catch (RemoteException e) {
@@ -89,6 +153,15 @@ final class IInputMethodSessionInvoker {
 
     @AnyThread
     void updateExtractedText(int token, ExtractedText text) {
+        if (mCustomHandler == null) {
+            updateExtractedTextInternal(token, text);
+        } else {
+            mCustomHandler.post(() -> updateExtractedTextInternal(token, text));
+        }
+    }
+
+    @AnyThread
+    private void updateExtractedTextInternal(int token, ExtractedText text) {
         try {
             mSession.updateExtractedText(token, text);
         } catch (RemoteException e) {
@@ -98,6 +171,15 @@ final class IInputMethodSessionInvoker {
 
     @AnyThread
     void appPrivateCommand(String action, Bundle data) {
+        if (mCustomHandler == null) {
+            appPrivateCommandInternal(action, data);
+        } else {
+            mCustomHandler.post(() -> appPrivateCommandInternal(action, data));
+        }
+    }
+
+    @AnyThread
+    private void appPrivateCommandInternal(String action, Bundle data) {
         try {
             mSession.appPrivateCommand(action, data);
         } catch (RemoteException e) {
@@ -107,6 +189,15 @@ final class IInputMethodSessionInvoker {
 
     @AnyThread
     void viewClicked(boolean focusChanged) {
+        if (mCustomHandler == null) {
+            viewClickedInternal(focusChanged);
+        } else {
+            mCustomHandler.post(() -> viewClickedInternal(focusChanged));
+        }
+    }
+
+    @AnyThread
+    private void viewClickedInternal(boolean focusChanged) {
         try {
             mSession.viewClicked(focusChanged);
         } catch (RemoteException e) {
@@ -116,6 +207,15 @@ final class IInputMethodSessionInvoker {
 
     @AnyThread
     void updateCursor(Rect newCursor) {
+        if (mCustomHandler == null) {
+            updateCursorInternal(newCursor);
+        } else {
+            mCustomHandler.post(() -> updateCursorInternal(newCursor));
+        }
+    }
+
+    @AnyThread
+    private void updateCursorInternal(Rect newCursor) {
         try {
             mSession.updateCursor(newCursor);
         } catch (RemoteException e) {
@@ -126,6 +226,18 @@ final class IInputMethodSessionInvoker {
     @AnyThread
     void updateSelection(int oldSelStart, int oldSelEnd, int selStart, int selEnd,
             int candidatesStart, int candidatesEnd) {
+        if (mCustomHandler == null) {
+            updateSelectionInternal(
+                    oldSelStart, oldSelEnd, selStart, selEnd, candidatesStart, candidatesEnd);
+        } else {
+            mCustomHandler.post(() -> updateSelectionInternal(
+                    oldSelStart, oldSelEnd, selStart, selEnd, candidatesStart, candidatesEnd));
+        }
+    }
+
+    @AnyThread
+    private void updateSelectionInternal(int oldSelStart, int oldSelEnd, int selStart, int selEnd,
+            int candidatesStart, int candidatesEnd) {
         try {
             mSession.updateSelection(
                     oldSelStart, oldSelEnd, selStart, selEnd, candidatesStart, candidatesEnd);
@@ -137,6 +249,17 @@ final class IInputMethodSessionInvoker {
     @AnyThread
     void invalidateInput(EditorInfo editorInfo, IRemoteInputConnection inputConnection,
             int sessionId) {
+        if (mCustomHandler == null) {
+            invalidateInputInternal(editorInfo, inputConnection, sessionId);
+        } else {
+            mCustomHandler.post(() -> invalidateInputInternal(editorInfo, inputConnection,
+                    sessionId));
+        }
+    }
+
+    @AnyThread
+    private void invalidateInputInternal(EditorInfo editorInfo,
+            IRemoteInputConnection inputConnection, int sessionId) {
         try {
             mSession.invalidateInput(editorInfo, inputConnection, sessionId);
         } catch (RemoteException e) {