Send last received message to recipient
Eliminate race condition of a message being sent prior
to the callback being registered.
Bug: 144163031
Test: Unit tests pass
Change-Id: Ic58154dda962e1eff463cacf1fe12e138c853d3f
diff --git a/connected-device-lib/src/com/android/car/connecteddevice/ConnectedDeviceManager.java b/connected-device-lib/src/com/android/car/connecteddevice/ConnectedDeviceManager.java
index c4e392e..0f57de2 100644
--- a/connected-device-lib/src/com/android/car/connecteddevice/ConnectedDeviceManager.java
+++ b/connected-device-lib/src/com/android/car/connecteddevice/ConnectedDeviceManager.java
@@ -93,6 +93,10 @@
private final Map<String, InternalConnectedDevice> mConnectedDevices =
new ConcurrentHashMap<>();
+ // recipientId -> (deviceId -> message bytes)
+ private final Map<UUID, Map<String, byte[]>> mRecipientMissedMessages =
+ new ConcurrentHashMap<>();
+
// Recipient ids that received multiple callback registrations indicate that the recipient id
// has been compromised. Another party now has access the messages intended for that recipient.
// As a safeguard, that recipient id will be added to this list and blocked from further
@@ -313,6 +317,12 @@
ThreadSafeCallbacks<DeviceCallback> newCallbacks = new ThreadSafeCallbacks<>();
newCallbacks.add(callback, executor);
recipientCallbacks.put(recipientId, newCallbacks);
+
+ byte[] message = popMissedMessage(recipientId, device.getDeviceId());
+ if (message != null) {
+ newCallbacks.invoke(deviceCallback ->
+ deviceCallback.onMessageReceived(device, message));
+ }
}
private void notifyOfBlacklisting(@NonNull ConnectedDevice device, @NonNull UUID recipientId,
@@ -323,6 +333,32 @@
callback.onDeviceError(device, DEVICE_ERROR_INSECURE_RECIPIENT_ID_DETECTED));
}
+ private void saveMissedMessage(@NonNull String deviceId, @NonNull UUID recipientId,
+ @NonNull byte[] message) {
+ // Store last message in case recipient registers callbacks in the future.
+ mRecipientMissedMessages.putIfAbsent(recipientId, new HashMap<>());
+ mRecipientMissedMessages.get(recipientId).putIfAbsent(deviceId, message);
+ }
+
+ /**
+ * Remove the last message sent for this device prior to a {@link DeviceCallback} being
+ * registered.
+ *
+ * @param recipientId Recipient's id
+ * @param deviceId Device id
+ * @return The last missed {@code byte[]} of the message, or {@code null} if no messages were
+ * missed.
+ */
+ @Nullable
+ private byte[] popMissedMessage(@NonNull UUID recipientId, @NonNull String deviceId) {
+ Map<String, byte[]> missedMessages = mRecipientMissedMessages.get(recipientId);
+ if (missedMessages == null) {
+ return null;
+ }
+
+ return missedMessages.remove(deviceId);
+ }
+
/**
* Unregister callback from device events.
*
@@ -509,14 +545,17 @@
+ "recipient " + message.getRecipient() + ".");
return;
}
+ UUID recipientId = message.getRecipient();
Map<UUID, ThreadSafeCallbacks<DeviceCallback>> deviceCallbacks =
mDeviceCallbacks.get(deviceId);
if (deviceCallbacks == null) {
+ saveMissedMessage(deviceId, recipientId, message.getMessage());
return;
}
ThreadSafeCallbacks<DeviceCallback> recipientCallbacks =
- deviceCallbacks.get(message.getRecipient());
+ deviceCallbacks.get(recipientId);
if (recipientCallbacks == null) {
+ saveMissedMessage(deviceId, recipientId, message.getMessage());
return;
}
diff --git a/connected-device-lib/tests/unit/src/com/android/car/connecteddevice/ConnectedDeviceManagerTest.java b/connected-device-lib/tests/unit/src/com/android/car/connecteddevice/ConnectedDeviceManagerTest.java
index 20520ef..f8a546e 100644
--- a/connected-device-lib/tests/unit/src/com/android/car/connecteddevice/ConnectedDeviceManagerTest.java
+++ b/connected-device-lib/tests/unit/src/com/android/car/connecteddevice/ConnectedDeviceManagerTest.java
@@ -423,6 +423,58 @@
assertThat(tryAcquire(semaphore)).isFalse();
}
+ @Test
+ public void registerDeviceCallback_sendsMissedMessageAfterRegistration()
+ throws InterruptedException {
+ Semaphore semaphore = new Semaphore(0);
+ connectNewDevice(mMockCentralManager);
+ ConnectedDevice connectedDevice =
+ mConnectedDeviceManager.getActiveUserConnectedDevices().get(0);
+ byte[] payload = ByteUtils.randomBytes(10);
+ DeviceMessage message = new DeviceMessage(mRecipientId, false, payload);
+ mConnectedDeviceManager.onMessageReceived(connectedDevice.getDeviceId(), message);
+ DeviceCallback deviceCallback = createDeviceCallback(semaphore);
+ mConnectedDeviceManager.registerDeviceCallback(connectedDevice, mRecipientId,
+ deviceCallback, mCallbackExecutor);
+ assertThat(tryAcquire(semaphore)).isTrue();
+ verify(deviceCallback).onMessageReceived(connectedDevice, payload);
+ }
+
+ @Test
+ public void registerDeviceCallback_doesNotSendMissedMessageForDifferentRecipient()
+ throws InterruptedException {
+ Semaphore semaphore = new Semaphore(0);
+ connectNewDevice(mMockCentralManager);
+ ConnectedDevice connectedDevice =
+ mConnectedDeviceManager.getActiveUserConnectedDevices().get(0);
+ byte[] payload = ByteUtils.randomBytes(10);
+ DeviceMessage message = new DeviceMessage(UUID.randomUUID(), false, payload);
+ mConnectedDeviceManager.onMessageReceived(connectedDevice.getDeviceId(), message);
+ DeviceCallback deviceCallback = createDeviceCallback(semaphore);
+ mConnectedDeviceManager.registerDeviceCallback(connectedDevice, mRecipientId,
+ deviceCallback, mCallbackExecutor);
+ assertThat(tryAcquire(semaphore)).isFalse();
+ }
+
+ @Test
+ public void registerDeviceCallback_doesNotSendMissedMessageForDifferentDevice()
+ throws InterruptedException {
+ Semaphore semaphore = new Semaphore(0);
+ connectNewDevice(mMockCentralManager);
+ connectNewDevice(mMockCentralManager);
+ List<ConnectedDevice> connectedDevices =
+ mConnectedDeviceManager.getActiveUserConnectedDevices();
+ ConnectedDevice connectedDevice = connectedDevices.get(0);
+ ConnectedDevice otherDevice = connectedDevices.get(1);
+ byte[] payload = ByteUtils.randomBytes(10);
+ DeviceMessage message = new DeviceMessage(mRecipientId, false, payload);
+ mConnectedDeviceManager.onMessageReceived(otherDevice.getDeviceId(), message);
+ DeviceCallback deviceCallback = createDeviceCallback(semaphore);
+ mConnectedDeviceManager.registerDeviceCallback(connectedDevice, mRecipientId,
+ deviceCallback, mCallbackExecutor);
+ assertThat(tryAcquire(semaphore)).isFalse();
+ }
+
private boolean tryAcquire(Semaphore semaphore) throws InterruptedException {
return semaphore.tryAcquire(100, TimeUnit.MILLISECONDS);
}
