Make scheduler robust to duplicate finish calls

Mis-implemented clients may invoke onClientFinished more than once.
The scheduler should be robust to this, and assume that the first
onClientFinished is the one that matters.

Test: atest BiometricSchedulerTest

Bug: 161325267
Change-Id: Ifc64fd4732d2abe03738dda270feeb29bb818bcf

services/core/java/com/android/server/biometrics/sensors/BiometricScheduler.java

@@ -194,19 +194,19 @@ public class BiometricScheduler {
                     return;
                 }
 
+                if (clientMonitor != mCurrentOperation.clientMonitor) {
+                    Slog.e(getTag(), "[Ignoring Finish] " + clientMonitor + " does not match"
+                            + " current: " + mCurrentOperation.clientMonitor);
+                    return;
+                }
+
+                Slog.d(getTag(), "[Finishing] " + clientMonitor + ", success: " + success);
                 mCurrentOperation.state = Operation.STATE_FINISHED;
 
                 if (mCurrentOperation.clientFinishCallback != null) {
                     mCurrentOperation.clientFinishCallback.onClientFinished(clientMonitor, success);
                 }
 
-                if (clientMonitor != mCurrentOperation.clientMonitor) {
-                    throw new IllegalStateException("Mismatched operation, "
-                            + " current: " + mCurrentOperation.clientMonitor
-                            + " received: " + clientMonitor);
-                }
-
-                Slog.d(getTag(), "[Finished] " + clientMonitor + ", success: " + success);
                 if (mGestureAvailabilityDispatcher != null) {
                     mGestureAvailabilityDispatcher.markSensorActive(
                             mCurrentOperation.clientMonitor.getSensorId(), false /* active */);

services/tests/servicestests/src/com/android/server/biometrics/sensors/BiometricSchedulerTest.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.biometrics.sensors;
+
+import android.content.Context;
+import android.os.IBinder;
+import android.platform.test.annotations.Presubmit;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.test.InstrumentationRegistry;
+import androidx.test.filters.SmallTest;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+@Presubmit
+@SmallTest
+public class BiometricSchedulerTest {
+
+    private static final String TAG = "BiometricSchedulerTest";
+
+    private BiometricScheduler mScheduler;
+
+    @Mock
+    private Context mContext;
+    @Mock
+    private ClientMonitor.LazyDaemon<Object> mLazyDaemon;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mScheduler = new BiometricScheduler(TAG, null /* gestureAvailabilityTracker */);
+    }
+
+    @Test
+    public void testClientDuplicateFinish_ignoredBySchedulerAndDoesNotCrash() {
+        final ClientMonitor<Object> client1 = new TestClientMonitor(mContext, mLazyDaemon);
+        final ClientMonitor<Object> client2 = new TestClientMonitor(mContext, mLazyDaemon);
+        mScheduler.scheduleClientMonitor(client1);
+        mScheduler.scheduleClientMonitor(client2);
+
+        client1.mFinishCallback.onClientFinished(client1, true /* success */);
+        client1.mFinishCallback.onClientFinished(client1, true /* success */);
+    }
+
+    private static class TestClientMonitor extends ClientMonitor<Object> {
+
+        public TestClientMonitor(@NonNull Context context, @NonNull LazyDaemon<Object> lazyDaemon) {
+            super(context, lazyDaemon, null /* token */, null /* listener */, 0 /* userId */,
+                    TAG, 0 /* cookie */, 0 /* sensorId */, 0 /* statsModality */,
+                    0 /* statsAction */, 0 /* statsClient */);
+        }
+
+        @Override
+        public void unableToStart() {
+
+        }
+
+        @Override
+        protected void startHalOperation() {
+
+        }
+    }
+}