Add null check to a11y interrupt.

am: 74f9e1b867

Change-Id: I51bcf42327f30a0c6b1dc7666a5c057d44eec98c

core/java/android/view/accessibility/AccessibilityManager.java

@@ -353,7 +353,18 @@ public final class AccessibilityManager {
                 return;
             }
             if (!mIsEnabled) {
-                throw new IllegalStateException("Accessibility off. Did you forget to check that?");
+                Looper myLooper = Looper.myLooper();
+                if (myLooper == Looper.getMainLooper()) {
+                    throw new IllegalStateException(
+                            "Accessibility off. Did you forget to check that?");
+                } else {
+                    // If we're not running on the thread with the main looper, it's possible for
+                    // the state of accessibility to change between checking isEnabled and
+                    // calling this method. So just log the error rather than throwing the
+                    // exception.
+                    Log.e(LOG_TAG, "Interrupt called with accessibility disabled");
+                    return;
+                }
             }
             userId = mUserId;
         }

services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java

@@ -538,7 +538,7 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub {
 
     @Override
     public void interrupt(int userId) {
-        CopyOnWriteArrayList<Service> services;
+        List<IAccessibilityServiceClient> interfacesToInterrupt;
         synchronized (mLock) {
             // We treat calls from a profile as if made by its parent as profiles
             // share the accessibility state of the parent. The call below
@@ -549,15 +549,24 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub {
             if (resolvedUserId != mCurrentUserId) {
                 return;
             }
-            services = getUserStateLocked(resolvedUserId).mBoundServices;
+            List<Service> services = getUserStateLocked(resolvedUserId).mBoundServices;
+            int numServices = services.size();
+            interfacesToInterrupt = new ArrayList<>(numServices);
+            for (int i = 0; i < numServices; i++) {
+                Service service = services.get(i);
+                IBinder a11yServiceBinder = service.mService;
+                IAccessibilityServiceClient a11yServiceInterface = service.mServiceInterface;
+                if ((a11yServiceBinder != null) && (a11yServiceInterface != null)) {
+                    interfacesToInterrupt.add(a11yServiceInterface);
+                }
+            }
         }
-        for (int i = 0, count = services.size(); i < count; i++) {
+        for (int i = 0, count = interfacesToInterrupt.size(); i < count; i++) {
-            Service service = services.get(i);
             try {
-                service.mServiceInterface.onInterrupt();
+                interfacesToInterrupt.get(i).onInterrupt();
             } catch (RemoteException re) {
-                Slog.e(LOG_TAG, "Error during sending interrupt request to "
+                Slog.e(LOG_TAG, "Error sending interrupt request to "
-                    + service.mService, re);
+                        + interfacesToInterrupt.get(i), re);
             }
         }
     }