Add logging for AuthSession cancellation path

Also updates outdated documentation in
BiometricService#authenticateInternal

Bug: 190987014
Test: Builds
Change-Id: I8b32cfcfc0dd1ea1d27cf81737796a06dc2509ae

services/core/java/com/android/server/biometrics/AuthSession.java

@@ -366,10 +366,9 @@ public final class AuthSession implements IBinder.DeathRecipient {
         // sending the final error callback to the application.
         for (BiometricSensor sensor : mPreAuthInfo.eligibleSensors) {
             try {
-                if (filter.apply(sensor)) {
-                    if (DEBUG) {
-                        Slog.v(TAG, "Canceling sensor: " + sensor.id);
-                    }
+                final boolean shouldCancel = filter.apply(sensor);
+                Slog.d(TAG, "sensorId: " + sensor.id + ", shouldCancel: " + shouldCancel);
+                if (shouldCancel) {
                     sensor.goToStateCancelling(mToken, mOpPackageName);
                 }
             } catch (RemoteException e) {

services/core/java/com/android/server/biometrics/BiometricService.java

@@ -1369,11 +1369,11 @@ public class BiometricService extends SystemService {
     /**
      * handleAuthenticate() (above) which is called from BiometricPrompt determines which
      * modality/modalities to start authenticating with. authenticateInternal() should only be
-     * used for:
-     * 1) Preparing <Biometric>Services for authentication when BiometricPrompt#authenticate is,
-     * invoked, shortly after which BiometricPrompt is shown and authentication starts
-     * 2) Preparing <Biometric>Services for authentication when BiometricPrompt is already shown
-     * and the user has pressed "try again"
+     * used for preparing <Biometric>Services for authentication when BiometricPrompt#authenticate
+     * is invoked, shortly after which BiometricPrompt is shown and authentication starts.
+     *
+     * Note that this path is NOT invoked when the BiometricPrompt "Try again" button is pressed.
+     * In that case, see {@link #handleOnTryAgainPressed()}.
      */
     private void authenticateInternal(IBinder token, long operationId, int userId,
             IBiometricServiceReceiver receiver, String opPackageName, PromptInfo promptInfo,

services/core/java/com/android/server/biometrics/PreAuthInfo.java

@@ -408,22 +408,22 @@ class PreAuthInfo {
     public String toString() {
         StringBuilder string = new StringBuilder(
                 "BiometricRequested: " + mBiometricRequested
-                        + "\nStrengthRequested: " + mBiometricStrengthRequested
-                        + "\nCredentialRequested: " + credentialRequested);
-        string.append("\nEligible:{");
+                        + ", StrengthRequested: " + mBiometricStrengthRequested
+                        + ", CredentialRequested: " + credentialRequested);
+        string.append(", Eligible:{");
         for (BiometricSensor sensor: eligibleSensors) {
             string.append(sensor.id).append(" ");
         }
         string.append("}");
 
-        string.append("\nIneligible:{");
+        string.append(", Ineligible:{");
         for (Pair<BiometricSensor, Integer> ineligible : ineligibleSensors) {
             string.append(ineligible.first).append(":").append(ineligible.second).append(" ");
         }
         string.append("}");
 
-        string.append("\nCredentialAvailable: ").append(credentialAvailable);
-        string.append("\n");
+        string.append(", CredentialAvailable: ").append(credentialAvailable);
+        string.append(", ");
         return string.toString();
     }
 }

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

@@ -569,6 +569,9 @@ public class BiometricScheduler {
         final boolean isCorrectClient = isAuthenticationOrDetectionOperation(mCurrentOperation);
         final boolean tokenMatches = mCurrentOperation.mClientMonitor.getToken() == token;
 
+        Slog.d(getTag(), "cancelAuthenticationOrDetection, isCorrectClient: " + isCorrectClient
+                + ", tokenMatches: " + tokenMatches);
+
         if (isCorrectClient && tokenMatches) {
             Slog.d(getTag(), "Cancelling: " + mCurrentOperation);
             cancelInternal(mCurrentOperation);

services/core/java/com/android/server/biometrics/sensors/fingerprint/FingerprintService.java

@@ -498,6 +498,8 @@ public class FingerprintService extends SystemService {
 
             Utils.checkPermission(getContext(), MANAGE_BIOMETRIC);
 
+            Slog.d(TAG, "cancelAuthenticationFromService, sensorId: " + sensorId);
+
             final ServiceProvider provider = getProviderForSensor(sensorId);
             if (provider == null) {
                 Slog.w(TAG, "Null provider for cancelAuthenticationFromService");

services/core/java/com/android/server/biometrics/sensors/fingerprint/hidl/Fingerprint21.java

@@ -632,6 +632,7 @@ public class Fingerprint21 implements IHwBinder.DeathRecipient, ServiceProvider
 
     @Override
     public void cancelAuthentication(int sensorId, @NonNull IBinder token) {
+        Slog.d(TAG, "cancelAuthentication, sensorId: " + sensorId);
         mHandler.post(() -> mScheduler.cancelAuthenticationOrDetection(token));
     }