Hold WakeLock while DreamService starts

Fixes a bug where DozeService would not properly initialize
because the CPU went to sleep before onDreamingStarted completed,
causing the pickup gesture to not work.

Change-Id: I85955a2b7d6bad5171accbc336117a9660b1b198
Fixes: 31044352

4 files changed, 151 insertions, 81 deletions

diff --git a/core/java/android/os/PowerManager.java b/core/java/android/os/PowerManager.java
index ce7a1243fe7a..1aed9b322816 100644
--- a/core/java/android/os/PowerManager.java
+++ b/core/java/android/os/PowerManager.java
@@ -1358,5 +1358,34 @@ public final class PowerManager {
                     + " held=" + mHeld + ", refCount=" + mCount + "}";
             }
         }
+
+        /**
+         * Wraps a Runnable such that this method immediately acquires the wake lock and then
+         * once the Runnable is done the wake lock is released.
+         *
+         * <p>Example:
+         *
+         * <pre>
+         * mHandler.post(mWakeLock.wrap(() -> {
+         *     // do things on handler, lock is held while we're waiting for this
+         *     // to get scheduled and until the runnable is done executing.
+         * });
+         * </pre>
+         *
+         * <p>Note: you must make sure that the Runnable eventually gets executed, otherwise you'll
+         *    leak the wakelock!
+         *
+         * @hide
+         */
+        public Runnable wrap(Runnable r) {
+            acquire();
+            return () -> {
+                try {
+                    r.run();
+                } finally {
+                    release();
+                }
+            };
+        }
     }
 }
diff --git a/core/java/android/service/dreams/DreamService.java b/core/java/android/service/dreams/DreamService.java
index 0557d138eb74..e958fbef563d 100644
--- a/core/java/android/service/dreams/DreamService.java
+++ b/core/java/android/service/dreams/DreamService.java
@@ -192,6 +192,9 @@ public class DreamService extends Service implements Window.Callback {
 
     private boolean mDebug = false;
 
+    private PowerManager.WakeLock mWakeLock;
+    private boolean mWakeLockAcquired;
+
     public DreamService() {
         mSandman = IDreamManager.Stub.asInterface(ServiceManager.getService(DREAM_SERVICE));
     }
@@ -786,6 +789,8 @@ public class DreamService extends Service implements Window.Callback {
     public void onCreate() {
         if (mDebug) Slog.v(TAG, "onCreate()");
         super.onCreate();
+        mWakeLock = getSystemService(PowerManager.class)
+                .newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "DreamService");
     }
 
     /**
@@ -825,9 +830,21 @@ public class DreamService extends Service implements Window.Callback {
     @Override
     public final IBinder onBind(Intent intent) {
         if (mDebug) Slog.v(TAG, "onBind() intent = " + intent);
+
+        // Need to stay awake until we dispatch onDreamingStarted. This is released either in
+        // attach() or onDestroy().
+        mWakeLock.acquire(5000);
+        mWakeLockAcquired = true;
         return new DreamServiceWrapper();
     }
 
+    private void releaseWakeLockIfNeeded() {
+        if (mWakeLockAcquired) {
+            mWakeLock.release();
+            mWakeLockAcquired = false;
+        }
+    }
+
     /**
      * Stops the dream and detaches from the window.
      * <p>
@@ -904,6 +921,8 @@ public class DreamService extends Service implements Window.Callback {
         detach();
 
         super.onDestroy();
+
+        releaseWakeLockIfNeeded(); // for acquire in onBind()
     }
 
     // end public api
@@ -944,83 +963,88 @@ public class DreamService extends Service implements Window.Callback {
      * @param windowToken A window token that will allow a window to be created in the correct layer.
      */
     private final void attach(IBinder windowToken, boolean canDoze) {
-        if (mWindowToken != null) {
-            Slog.e(TAG, "attach() called when already attached with token=" + mWindowToken);
-            return;
-        }
-        if (mFinished || mWaking) {
-            Slog.w(TAG, "attach() called after dream already finished");
-            try {
-                mSandman.finishSelf(windowToken, true /*immediate*/);
-            } catch (RemoteException ex) {
-                // system server died
+        try {
+            if (mWindowToken != null) {
+                Slog.e(TAG, "attach() called when already attached with token=" + mWindowToken);
+                return;
+            }
+            if (mFinished || mWaking) {
+                Slog.w(TAG, "attach() called after dream already finished");
+                try {
+                    mSandman.finishSelf(windowToken, true /*immediate*/);
+                } catch (RemoteException ex) {
+                    // system server died
+                }
+                return;
             }
-            return;
-        }
-
-        mWindowToken = windowToken;
-        mCanDoze = canDoze;
-        if (mWindowless && !mCanDoze) {
-            throw new IllegalStateException("Only doze dreams can be windowless");
-        }
-        if (!mWindowless) {
-            mWindow = new PhoneWindow(this);
-            mWindow.setCallback(this);
-            mWindow.requestFeature(Window.FEATURE_NO_TITLE);
-            mWindow.setBackgroundDrawable(new ColorDrawable(0xFF000000));
-            mWindow.setFormat(PixelFormat.OPAQUE);
-
-            if (mDebug) Slog.v(TAG, String.format("Attaching window token: %s to window of type %s",
-                    windowToken, WindowManager.LayoutParams.TYPE_DREAM));
 
-            WindowManager.LayoutParams lp = mWindow.getAttributes();
-            lp.type = WindowManager.LayoutParams.TYPE_DREAM;
-            lp.token = windowToken;
-            lp.windowAnimations = com.android.internal.R.style.Animation_Dream;
-            lp.flags |= ( WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN
-                        | WindowManager.LayoutParams.FLAG_LAYOUT_INSET_DECOR
-                        | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
-                        | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
-                        | WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON
-                        | (mFullscreen ? WindowManager.LayoutParams.FLAG_FULLSCREEN : 0)
-                        | (mScreenBright ? WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON : 0)
-                        );
-            mWindow.setAttributes(lp);
-            // Workaround: Currently low-profile and in-window system bar backgrounds don't go
-            // along well. Dreams usually don't need such bars anyways, so disable them by default.
-            mWindow.clearFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
-            mWindow.setWindowManager(null, windowToken, "dream", true);
+            mWindowToken = windowToken;
+            mCanDoze = canDoze;
+            if (mWindowless && !mCanDoze) {
+                throw new IllegalStateException("Only doze dreams can be windowless");
+            }
+            if (!mWindowless) {
+                mWindow = new PhoneWindow(this);
+                mWindow.setCallback(this);
+                mWindow.requestFeature(Window.FEATURE_NO_TITLE);
+                mWindow.setBackgroundDrawable(new ColorDrawable(0xFF000000));
+                mWindow.setFormat(PixelFormat.OPAQUE);
+
+                if (mDebug) {
+                    Slog.v(TAG, String.format("Attaching window token: %s to window of type %s",
+                            windowToken, WindowManager.LayoutParams.TYPE_DREAM));
+                }
 
-            applySystemUiVisibilityFlags(
-                    (mLowProfile ? View.SYSTEM_UI_FLAG_LOW_PROFILE : 0),
-                    View.SYSTEM_UI_FLAG_LOW_PROFILE);
+                WindowManager.LayoutParams lp = mWindow.getAttributes();
+                lp.type = WindowManager.LayoutParams.TYPE_DREAM;
+                lp.token = windowToken;
+                lp.windowAnimations = com.android.internal.R.style.Animation_Dream;
+                lp.flags |= (WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN
+                            | WindowManager.LayoutParams.FLAG_LAYOUT_INSET_DECOR
+                            | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
+                            | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
+                            | WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON
+                            | (mFullscreen ? WindowManager.LayoutParams.FLAG_FULLSCREEN : 0)
+                            | (mScreenBright ? WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON : 0)
+                            );
+                mWindow.setAttributes(lp);
+                // Workaround: Currently low-profile and in-window system bar backgrounds don't go
+                // along well. Dreams usually don't need such bars anyways, so disable them by default.
+                mWindow.clearFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
+                mWindow.setWindowManager(null, windowToken, "dream", true);
+
+                applySystemUiVisibilityFlags(
+                        (mLowProfile ? View.SYSTEM_UI_FLAG_LOW_PROFILE : 0),
+                        View.SYSTEM_UI_FLAG_LOW_PROFILE);
 
-            try {
-                getWindowManager().addView(mWindow.getDecorView(), mWindow.getAttributes());
-            } catch (WindowManager.BadTokenException ex) {
-                // This can happen because the dream manager service will remove the token
-                // immediately without necessarily waiting for the dream to start.
-                // We should receive a finish message soon.
-                Slog.i(TAG, "attach() called after window token already removed, dream will "
-                        + "finish soon");
-                mWindow = null;
-                return;
+                try {
+                    getWindowManager().addView(mWindow.getDecorView(), mWindow.getAttributes());
+                } catch (WindowManager.BadTokenException ex) {
+                    // This can happen because the dream manager service will remove the token
+                    // immediately without necessarily waiting for the dream to start.
+                    // We should receive a finish message soon.
+                    Slog.i(TAG, "attach() called after window token already removed, dream will "
+                            + "finish soon");
+                    mWindow = null;
+                    return;
+                }
             }
-        }
-        // We need to defer calling onDreamingStarted until after onWindowAttached,
-        // which is posted to the handler by addView, so we post onDreamingStarted
-        // to the handler also.  Need to watch out here in case detach occurs before
-        // this callback is invoked.
-        mHandler.post(new Runnable() {
-            @Override
-            public void run() {
+            // We need to defer calling onDreamingStarted until after onWindowAttached,
+            // which is posted to the handler by addView, so we post onDreamingStarted
+            // to the handler also.  Need to watch out here in case detach occurs before
+            // this callback is invoked.
+            mHandler.post(mWakeLock.wrap(() -> {
                 if (mWindow != null || mWindowless) {
-                    if (mDebug) Slog.v(TAG, "Calling onDreamingStarted()");
+                    if (mDebug) {
+                        Slog.v(TAG, "Calling onDreamingStarted()");
+                    }
                     mStarted = true;
                     onDreamingStarted();
                 }
-            }
-        });
+            }));
+        } finally {
+            releaseWakeLockIfNeeded(); // for acquire in onBind
+        }
     }
 
     private boolean getWindowFlagValue(int flag, boolean defaultValue) {
diff --git a/services/core/java/com/android/server/dreams/DreamController.java b/services/core/java/com/android/server/dreams/DreamController.java
index a63399656bab..9fa93f4b8a6c 100644
--- a/services/core/java/com/android/server/dreams/DreamController.java
+++ b/services/core/java/com/android/server/dreams/DreamController.java
@@ -26,6 +26,7 @@ import android.content.ServiceConnection;
 import android.os.Binder;
 import android.os.Handler;
 import android.os.IBinder;
+import android.os.PowerManager;
 import android.os.RemoteException;
 import android.os.IBinder.DeathRecipient;
 import android.os.SystemClock;
@@ -116,19 +117,19 @@ final class DreamController {
     }
 
     public void startDream(Binder token, ComponentName name,
-            boolean isTest, boolean canDoze, int userId) {
+            boolean isTest, boolean canDoze, int userId, PowerManager.WakeLock wakeLock) {
         stopDream(true /*immediate*/);
 
         Trace.traceBegin(Trace.TRACE_TAG_POWER, "startDream");
         try {
-            // Close the notification shade. Don't need to send to all, but better to be explicit.
+            // Close the notification shade. No need to send to all, but better to be explicit.
             mContext.sendBroadcastAsUser(mCloseNotificationShadeIntent, UserHandle.ALL);
 
             Slog.i(TAG, "Starting dream: name=" + name
                     + ", isTest=" + isTest + ", canDoze=" + canDoze
                     + ", userId=" + userId);
 
-            mCurrentDream = new DreamRecord(token, name, isTest, canDoze, userId);
+            mCurrentDream = new DreamRecord(token, name, isTest, canDoze, userId, wakeLock);
 
             mDreamStartTime = SystemClock.elapsedRealtime();
             MetricsLogger.visible(mContext,
@@ -230,6 +231,7 @@ final class DreamController {
             if (oldDream.mBound) {
                 mContext.unbindService(oldDream);
             }
+            oldDream.releaseWakeLockIfNeeded();
 
             try {
                 mIWindowManager.removeWindowToken(oldDream.mToken);
@@ -280,6 +282,7 @@ final class DreamController {
         public final boolean mCanDoze;
         public final int mUserId;
 
+        public PowerManager.WakeLock mWakeLock;
         public boolean mBound;
         public boolean mConnected;
         public IDreamService mService;
@@ -288,12 +291,17 @@ final class DreamController {
         public boolean mWakingGently;
 
         public DreamRecord(Binder token, ComponentName name,
-                boolean isTest, boolean canDoze, int userId) {
+                boolean isTest, boolean canDoze, int userId, PowerManager.WakeLock wakeLock) {
             mToken = token;
             mName = name;
             mIsTest = isTest;
             mCanDoze = canDoze;
             mUserId  = userId;
+            mWakeLock = wakeLock;
+            // Hold the lock while we're waiting for the service to connect. Released either when
+            // DreamService connects (and is then responsible for keeping the device awake) or
+            // dreaming stops.
+            mWakeLock.acquire();
         }
 
         // May be called on any thread.
@@ -316,14 +324,25 @@ final class DreamController {
             mHandler.post(new Runnable() {
                 @Override
                 public void run() {
-                    mConnected = true;
-                    if (mCurrentDream == DreamRecord.this && mService == null) {
-                        attach(IDreamService.Stub.asInterface(service));
+                    try {
+                        mConnected = true;
+                        if (mCurrentDream == DreamRecord.this && mService == null) {
+                            attach(IDreamService.Stub.asInterface(service));
+                        }
+                    } finally {
+                        releaseWakeLockIfNeeded();
                     }
                 }
             });
         }
 
+        private void releaseWakeLockIfNeeded() {
+            if (mWakeLock != null) {
+                mWakeLock.release();
+                mWakeLock = null;
+            }
+        }
+
         // May be called on any thread.
         @Override
         public void onServiceDisconnected(ComponentName name) {
diff --git a/services/core/java/com/android/server/dreams/DreamManagerService.java b/services/core/java/com/android/server/dreams/DreamManagerService.java
index a783fa25ed45..20bccf19f131 100644
--- a/services/core/java/com/android/server/dreams/DreamManagerService.java
+++ b/services/core/java/com/android/server/dreams/DreamManagerService.java
@@ -370,12 +370,10 @@ public final class DreamManagerService extends SystemService {
         mCurrentDreamCanDoze = canDoze;
         mCurrentDreamUserId = userId;
 
-        mHandler.post(new Runnable() {
-            @Override
-            public void run() {
-                mController.startDream(newToken, name, isTest, canDoze, userId);
-            }
-        });
+        PowerManager.WakeLock wakeLock = mPowerManager
+                .newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "startDream");
+        mHandler.post(wakeLock.wrap(
+                () -> mController.startDream(newToken, name, isTest, canDoze, userId, wakeLock)));
     }
 
     private void stopDreamLocked(final boolean immediate) {