android 8.0 Fingerprint 指纹识别震动解析

先从息屏或者按power键指纹监听开始分析

1.当灭屏后会从PhoneWindowManager.java执行startedGoingToSleep()方法：

 // Called on the PowerManager's Notifier thread.
    @Override
    public void startedGoingToSleep(int why) {
        if (DEBUG_WAKEUP) Slog.i(TAG, "Started going to sleep... (why=" + why + ")");

        mGoingToSleep = true;
        mRequestedOrGoingToSleep = true;

        if (mKeyguardDelegate != null) {
            mKeyguardDelegate.onStartedGoingToSleep(why);
        }
    }

2.然后KeyguardServiceDelegate.java-->onStartedGoingToSleep()

public void onStartedGoingToSleep(int why) {
        if (mKeyguardService != null) {
            mKeyguardService.onStartedGoingToSleep(why);
        }
        mKeyguardState.offReason = why;
        mKeyguardState.interactiveState = INTERACTIVE_STATE_GOING_TO_SLEEP;
  }

3.在从KeyguardServiceWrapper.java -->onStartedGoingToSleep()

@Override
    public void onStartedGoingToSleep(int reason) {
        try {
            mService.onStartedGoingToSleep(reason);
        } catch (RemoteException e) {
            Slog.w(TAG , "Remote Exception", e);
        }
    }

4.mService的实例对象为IKeyguardService，而KeyguardService.java搭建了IKeyguardService.Stub()桥梁，可以直接通信，且实现了onStartedGoingToSleep().

@Override // Binder interface
 public void onStartedGoingToSleep(int reason) {
            checkPermission();
            mKeyguardViewMediator.onStartedGoingToSleep(reason);
            mKeyguardLifecyclesDispatcher.dispatch(
                    KeyguardLifecyclesDispatcher.STARTED_GOING_TO_SLEEP);
    }

5.KeyguardViewMediator.java-->onStartedGoingToSleep()

  public void onStartedGoingToSleep(int why) {
        ...
        KeyguardUpdateMonitor.getInstance(mContext).dispatchStartedGoingToSleep(why);
        notifyStartedGoingToSleep();
    }

6.发送MSG_STARTED_GOING_TO_SLEEP消息，处理handleStartedGoingToSleep()方法，即：KeyguardUpdateMonitor.java-->dispatchStartedGoingToSleep()

  public void dispatchStartedGoingToSleep(int why) {
        mHandler.sendMessage(mHandler.obtainMessage(MSG_STARTED_GOING_TO_SLEEP, why, 0));
    }

7.处理handleStartedGoingToSleep方法：KeyguardUpdateMonitor.java-->handleStartedGoingToSleep()

 protected void handleStartedGoingToSleep(int arg1) {
        clearFingerprintRecognized();
        final int count = mCallbacks.size();
        for (int i = 0; i < count; i++) {
            KeyguardUpdateMonitorCallback cb = mCallbacks.get(i).get();
            if (cb != null) {
                cb.onStartedGoingToSleep(arg1);
            }
        }
        mGoingToSleep = true;
        updateFingerprintListeningState();//这行代码就是停止监听，还是开始监听指纹的，里面有判断
    }

8.KeyguardUpdateMonitor.java-->updateFingerprintListeningState()

private void updateFingerprintListeningState() {
        // If this message exists, we should not authenticate again until this message is
        // consumed by the handler
        if (mHandler.hasMessages(MSG_FINGERPRINT_AUTHENTICATION_CONTINUE)) {
            return;
        }
        mHandler.removeCallbacks(mRetryFingerprintAuthentication);
        boolean shouldListenForFingerprint = shouldListenForFingerprint();
        if (mFingerprintRunningState == FINGERPRINT_STATE_RUNNING && !shouldListenForFingerprint) {
            stopListeningForFingerprint();//停止监听
        } else if (mFingerprintRunningState != FINGERPRINT_STATE_RUNNING
                && shouldListenForFingerprint) {
            startListeningForFingerprint();//开始监听，一般监听会走这
        }
    }

9.KeyguardUpdateMonitor.java-->startListeningForFingerprint()

private void startListeningForFingerprint() {
        if (mFingerprintRunningState == FINGERPRINT_STATE_CANCELLING) {
            setFingerprintRunningState(FINGERPRINT_STATE_CANCELLING_RESTARTING);
            return;
        }
        if (DEBUG) Log.v(TAG, "startListeningForFingerprint()");
        int userId = ActivityManager.getCurrentUser();
        if (isUnlockWithFingerprintPossible(userId)) {
            if (mFingerprintCancelSignal != null) {
                mFingerprintCancelSignal.cancel();
            }
            mFingerprintCancelSignal = new CancellationSignal();
            mFpm.authenticate(null, mFingerprintCancelSignal, 0, mAuthenticationCallback, null, userId);
            setFingerprintRunningState(FINGERPRINT_STATE_RUNNING);
        }
    }

10.mAuthenticationCallback是FingerprintManager.java的一个回调接口，当指纹有状态反馈上层是时会触发

private FingerprintManager.AuthenticationCallback mAuthenticationCallback
            = new AuthenticationCallback() {

        @Override
        public void onAuthenticationFailed() {
            handleFingerprintAuthFailed();
        };

        @Override
        public void onAuthenticationSucceeded(AuthenticationResult result) {
            Trace.beginSection("KeyguardUpdateMonitor#onAuthenticationSucceeded");
            handleFingerprintAuthenticated(result.getUserId());
            Trace.endSection();
        }

        @Override
        public void onAuthenticationHelp(int helpMsgId, CharSequence helpString) {
            handleFingerprintHelp(helpMsgId, helpString.toString());
        }

        @Override
        public void onAuthenticationError(int errMsgId, CharSequence errString) {
            handleFingerprintError(errMsgId, errString.toString());
        }

        @Override
        public void onAuthenticationAcquired(int acquireInfo) {
            handleFingerprintAcquired(acquireInfo);
        }
    };

11.进入到FingerprintManager.java方法authenticate：FingerprintManager.java-->authenticate()

 @RequiresPermission(USE_FINGERPRINT)
    public void authenticate(@Nullable CryptoObject crypto, @Nullable CancellationSignal cancel,
            int flags, @NonNull AuthenticationCallback callback, Handler handler, int userId) {
        if (callback == null) {
            throw new IllegalArgumentException("Must supply an authentication callback");
        }

        if (cancel != null) {
            if (cancel.isCanceled()) {
                Log.w(TAG, "authentication already canceled");
                return;
            } else {
                cancel.setOnCancelListener(new OnAuthenticationCancelListener(crypto));
            }
        }

        if (mService != null) try {
            useHandler(handler);
            mAuthenticationCallback = callback;
            mCryptoObject = crypto;
            long sessionId = crypto != null ? crypto.getOpId() : 0;
            mService.authenticate(mToken, sessionId, userId, mServiceReceiver, flags,
                    mContext.getOpPackageName()); //mServiceReceiver这个广播很重要，接收从底层反馈的有关指纹的一些状态
        } catch (RemoteException e) {
            Log.w(TAG, "Remote exception while authenticating: ", e);
            if (callback != null) {
                // Though this may not be a hardware issue, it will cause apps to give up or try
                // again later.
                callback.onAuthenticationError(FINGERPRINT_ERROR_HW_UNAVAILABLE,
                        getErrorString(FINGERPRINT_ERROR_HW_UNAVAILABLE, 0 /* vendorCode */));
            }
        }
    }

 12.FingerprintService.java-->authenticate()

@Override // Binder call
        public void authenticate(final IBinder token, final long opId, final int groupId,
                final IFingerprintServiceReceiver receiver, final int flags,
                final String opPackageName) {
            final int callingUid = Binder.getCallingUid();
            final int callingPid = Binder.getCallingPid();
            final int callingUserId = UserHandle.getCallingUserId();
            final boolean restricted = isRestricted();

            if (!canUseFingerprint(opPackageName, true /* foregroundOnly */, callingUid, callingPid,
                    callingUserId)) {
                if (DEBUG) Slog.v(TAG, "authenticate(): reject " + opPackageName);
                return;
            }

            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    MetricsLogger.histogram(mContext, "fingerprint_token", opId != 0L ? 1 : 0);

                    // Get performance stats object for this user.
                    HashMap pmap
                            = (opId == 0) ? mPerformanceMap : mCryptoPerformanceMap;
                    PerformanceStats stats = pmap.get(mCurrentUserId);
                    if (stats == null) {
                        stats = new PerformanceStats();
                        pmap.put(mCurrentUserId, stats);
                    }
                    mPerformanceStats = stats;

                    startAuthentication(token, opId, callingUserId, groupId, receiver,
                            flags, restricted, opPackageName);
                }
            });
        }

13.FingerprintService.java-->startAuthentication()

private void startAuthentication(IBinder token, long opId, int callingUserId, int groupId,
                IFingerprintServiceReceiver receiver, int flags, boolean restricted,
                String opPackageName) {
        updateActiveGroup(groupId, opPackageName);

        if (DEBUG) Slog.v(TAG, "startAuthentication(" + opPackageName + ")");

        AuthenticationClient client = new AuthenticationClient(getContext(), mHalDeviceId, token,
                receiver, mCurrentUserId, groupId, opId, restricted, opPackageName) {
            @Override
            public int handleFailedAttempt() {
                mFailedAttempts++;
                mTimedLockoutCleared = false;
                final int lockoutMode = getLockoutMode();
                if (lockoutMode == AuthenticationClient.LOCKOUT_PERMANENT) {
                    mPerformanceStats.permanentLockout++;
                } else if (lockoutMode == AuthenticationClient.LOCKOUT_TIMED) {
                    mPerformanceStats.lockout++;
                }

                // Failing multiple times will continue to push out the lockout time
                if (lockoutMode != AuthenticationClient.LOCKOUT_NONE) {
                    scheduleLockoutReset();
                    return lockoutMode;
                }
                return AuthenticationClient.LOCKOUT_NONE;
            }

            @Override
            public void resetFailedAttempts() {
                FingerprintService.this.resetFailedAttempts(true /* clearAttemptCounter */);
            }

            @Override
            public void notifyUserActivity() {
                FingerprintService.this.userActivity();
            }

            @Override
            public IBiometricsFingerprint getFingerprintDaemon() {
                return FingerprintService.this.getFingerprintDaemon();
            }
        };

        int lockoutMode = getLockoutMode();
        if (lockoutMode != AuthenticationClient.LOCKOUT_NONE) {
            Slog.v(TAG, "In lockout mode(" + lockoutMode +
                    ") ; disallowing authentication");
            int errorCode = lockoutMode == AuthenticationClient.LOCKOUT_TIMED ?
                    FingerprintManager.FINGERPRINT_ERROR_LOCKOUT :
                    FingerprintManager.FINGERPRINT_ERROR_LOCKOUT_PERMANENT;
            if (!client.onError(errorCode, 0 /* vendorCode */)) {
                Slog.w(TAG, "Cannot send permanent lockout message to client");
            }
            return;
        }
        startClient(client, true /* initiatedByClient */);
    }

14.开始监听：FingerprintService.java-->startClient()

private void startClient(ClientMonitor newClient, boolean initiatedByClient) {
        ClientMonitor currentClient = mCurrentClient;
        if (currentClient != null) {
            if (DEBUG) Slog.v(TAG, "request stop current client " + currentClient.getOwnerString());
            if (currentClient instanceof InternalEnumerateClient ||
                    currentClient instanceof InternalRemovalClient) {
                // This condition means we're currently running internal diagnostics to
                // remove extra fingerprints in the hardware and/or the software
                // TODO: design an escape hatch in case client never finishes
            }
            else {
                currentClient.stop(initiatedByClient);
            }
            mPendingClient = newClient;
            mHandler.removeCallbacks(mResetClientState);
            mHandler.postDelayed(mResetClientState, CANCEL_TIMEOUT_LIMIT);
        } else if (newClient != null) {
            mCurrentClient = newClient;
            if (DEBUG) Slog.v(TAG, "starting client "
                    + newClient.getClass().getSuperclass().getSimpleName()
                    + "(" + newClient.getOwnerString() + ")"
                    + ", initiatedByClient = " + initiatedByClient + ")");
            notifyClientActiveCallbacks(true);

            newClient.start();//开始监听指纹状态
        }
    }

15.AuthenticationClient.java-->start()

/**
     * Start authentication
     */
    @Override
    public int start() {
        IBiometricsFingerprint daemon = getFingerprintDaemon();
        if (daemon == null) {
            Slog.w(TAG, "start authentication: no fingerprint HAL!");
            return ERROR_ESRCH;
        }
        try {
            final int result = daemon.authenticate(mOpId, getGroupId());//这行代码是跟底层打交道的，当把指纹的一些参数传给底层，底层处理后返回一个状态，result=0表示处理完成，开始监听
            if (result != 0) {
                Slog.w(TAG, "startAuthentication failed, result=" + result);
                MetricsLogger.histogram(getContext(), "fingeprintd_auth_start_error", result);
                onError(FingerprintManager.FINGERPRINT_ERROR_HW_UNAVAILABLE, 0 /* vendorCode */);
                return result;
            }
            if (DEBUG) Slog.w(TAG, "client " + getOwnerString() + " is authenticating...");
        } catch (RemoteException e) {
            Slog.e(TAG, "startAuthentication failed", e);
            return ERROR_ESRCH;
        }
        return 0; // success
    }

16.灭屏时开始监听的流程完成，当有指纹解锁时，会执行

AuthenticationClient.java-->onAuthenticated()

@Override
    public boolean onAuthenticated(int fingerId, int groupId) {
        boolean result = false;
        boolean authenticated = fingerId != 0;

        IFingerprintServiceReceiver receiver = getReceiver();
        if (receiver != null) {
            try {
                MetricsLogger.action(getContext(), MetricsEvent.ACTION_FINGERPRINT_AUTH,
                        authenticated);
                if (!authenticated) {
                    receiver.onAuthenticationFailed(getHalDeviceId());
                } else {
                    if (DEBUG) {
                        Slog.v(TAG, "onAuthenticated(owner=" + getOwnerString()
                                + ", id=" + fingerId + ", gp=" + groupId + ")");
                    }
                    Fingerprint fp = !getIsRestricted()
                            ? new Fingerprint("" /* TODO */, groupId, fingerId, getHalDeviceId())
                            : null;
                    receiver.onAuthenticationSucceeded(getHalDeviceId(), fp, getTargetUserId());
                }
            } catch (RemoteException e) {
                Slog.w(TAG, "Failed to notify Authenticated:", e);
                result = true; // client failed
            }
        } else {
            result = true; // client not listening
        }
        if (!authenticated) {
            if (receiver != null) {
                vibrateError();
            }
            // allow system-defined limit of number of attempts before giving up
            int lockoutMode =  handleFailedAttempt();
            if (lockoutMode != LOCKOUT_NONE) {
                try {
                    Slog.w(TAG, "Forcing lockout (fp driver code should do this!), mode(" +
                            lockoutMode + ")");
                    stop(false);
                    int errorCode = lockoutMode == LOCKOUT_TIMED ?
                            FingerprintManager.FINGERPRINT_ERROR_LOCKOUT :
                            FingerprintManager.FINGERPRINT_ERROR_LOCKOUT_PERMANENT;
                    receiver.onError(getHalDeviceId(), FingerprintManager.FINGERPRINT_ERROR_FORCING_LOCKOUT, 0 /* vendorCode */);//Add By [email protected] 2018/1/20 Defect:5880186
                    receiver.onError(getHalDeviceId(), errorCode, 0 /* vendorCode */);
                } catch (RemoteException e) {
                    Slog.w(TAG, "Failed to notify lockout:", e);
                }
            }
            result |= lockoutMode != LOCKOUT_NONE; // in a lockout mode
        } else {
            if (receiver != null) {
                vibrateSuccess();
            }
            result |= true; // we have a valid fingerprint, done
            resetFailedAttempts();
        }
        return result;
    }

当解锁成功，会执行 vibrateSuccess();，解锁失败会执行vibrateError();