From bd4a6002256b5644e1c57f7d42dac37775c8fc2e Mon Sep 17 00:00:00 2001
From: Yi Jiang <eejiang@google.com>
Date: Thu, 29 Apr 2021 15:47:02 -0700
Subject: [PATCH] Adds expirations for remote callbacks

Right now there is no timeout/expiration in the remote service. In cases
that the implementer of Rotation Resolver Service doesn't call back
and the pending callback blocks the following requests, we should
add an expiration of the pending callback in the remote service.

Bug: 186674250
Test: Manually tested the feature

Change-Id: I82f08155243e2205a2c95ae39c71c3118e9249ec
---
 .../rotationresolver/RotationResolverService.java  | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/core/java/android/service/rotationresolver/RotationResolverService.java b/core/java/android/service/rotationresolver/RotationResolverService.java
index 0932901edf506..8278ded4b18b3 100644
--- a/core/java/android/service/rotationresolver/RotationResolverService.java
+++ b/core/java/android/service/rotationresolver/RotationResolverService.java
@@ -31,6 +31,7 @@ import android.os.IBinder;
 import android.os.ICancellationSignal;
 import android.os.Looper;
 import android.os.RemoteException;
+import android.os.SystemClock;
 import android.view.Surface;
 
 import java.lang.annotation.Retention;
@@ -136,12 +137,16 @@ public abstract class RotationResolverService extends Service {
     @MainThread
     private void resolveRotation(IRotationResolverCallback callback,
             RotationResolutionRequest request, ICancellationSignal transport) {
+        // If there is a valid, uncancelled pending callback running in process, the new rotation
+        // resolution request will be rejected immediately with a failure result.
         if (mPendingCallback != null
-                && (mCancellationSignal == null || !mCancellationSignal.isCanceled())) {
+                && (mCancellationSignal == null || !mCancellationSignal.isCanceled())
+                && (SystemClock.uptimeMillis() < mPendingCallback.mExpirationTime)) {
             reportFailures(callback, ROTATION_RESULT_FAILURE_PREEMPTED);
             return;
         }
-        mPendingCallback = new RotationResolverCallbackWrapper(callback, this);
+        mPendingCallback = new RotationResolverCallbackWrapper(callback, this,
+                SystemClock.uptimeMillis() + request.getTimeoutMillis());
         mCancellationSignal = CancellationSignal.fromTransport(transport);
 
         onResolveRotation(request, mCancellationSignal, mPendingCallback);
@@ -224,12 +229,15 @@ public abstract class RotationResolverService extends Service {
         @NonNull
         private final Handler mHandler;
 
+        private final long mExpirationTime;
+
         private RotationResolverCallbackWrapper(
                 @NonNull android.service.rotationresolver.IRotationResolverCallback callback,
-                RotationResolverService service) {
+                RotationResolverService service, long expirationTime) {
             mCallback = callback;
             mService = service;
             mHandler = service.mMainThreadHandler;
+            mExpirationTime = expirationTime;
             Objects.requireNonNull(mHandler);
         }