Keep activities stopped while the lock screen is up.

Tell the activity manager when the lock screen is shown, so it
can keep itself (mostly) in sleep mode during this time, having
the foreground actvities remain in their stopped state.

Change-Id: I71c86d3298f23a98014d7ae36fd540c9df9a64e6

1 files changed, 64 insertions, 11 deletions

diff --git a/services/java/com/android/server/am/ActivityManagerService.java b/services/java/com/android/server/am/ActivityManagerService.java
index 0c2e6ac..e37adc7 100644
--- a/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java
@@ -697,6 +697,16 @@ public final class ActivityManagerService extends ActivityManagerNative
     boolean mSleeping = false;
 
     /**
+     * State of external calls telling us if the device is asleep.
+     */
+    boolean mWentToSleep = false;
+
+    /**
+     * State of external call telling us if the lock screen is shown.
+     */
+    boolean mLockScreenShown = false;
+
+    /**
      * Set if we are shutting down the system, similar to sleeping.
      */
     boolean mShuttingDown = false;
@@ -6656,17 +6666,26 @@ public final class ActivityManagerService extends ActivityManagerNative
     }
 
     public void goingToSleep() {
+        if (checkCallingPermission(android.Manifest.permission.DEVICE_POWER)
+                != PackageManager.PERMISSION_GRANTED) {
+            throw new SecurityException("Requires permission "
+                    + android.Manifest.permission.DEVICE_POWER);
+        }
+
         synchronized(this) {
-            mSleeping = true;
+            mWentToSleep = true;
             mWindowManager.setEventDispatching(false);
 
-            mMainStack.stopIfSleepingLocked();
+            if (!mSleeping) {
+                mSleeping = true;
+                mMainStack.stopIfSleepingLocked();
 
-            // Initialize the wake times of all processes.
-            checkExcessivePowerUsageLocked(false);
-            mHandler.removeMessages(CHECK_EXCESSIVE_WAKE_LOCKS_MSG);
-            Message nmsg = mHandler.obtainMessage(CHECK_EXCESSIVE_WAKE_LOCKS_MSG);
-            mHandler.sendMessageDelayed(nmsg, POWER_CHECK_DELAY);
+                // Initialize the wake times of all processes.
+                checkExcessivePowerUsageLocked(false);
+                mHandler.removeMessages(CHECK_EXCESSIVE_WAKE_LOCKS_MSG);
+                Message nmsg = mHandler.obtainMessage(CHECK_EXCESSIVE_WAKE_LOCKS_MSG);
+                mHandler.sendMessageDelayed(nmsg, POWER_CHECK_DELAY);
+            }
         }
     }
 
@@ -6726,12 +6745,40 @@ public final class ActivityManagerService extends ActivityManagerNative
         Binder.restoreCallingIdentity(origId);
     }
 
+    private void comeOutOfSleepIfNeededLocked() {
+        if (!mWentToSleep && !mLockScreenShown) {
+            if (mSleeping) {
+                mSleeping = false;
+                mMainStack.awakeFromSleepingLocked();
+                mMainStack.resumeTopActivityLocked(null);
+            }
+        }
+    }
+
     public void wakingUp() {
+        if (checkCallingPermission(android.Manifest.permission.DEVICE_POWER)
+                != PackageManager.PERMISSION_GRANTED) {
+            throw new SecurityException("Requires permission "
+                    + android.Manifest.permission.DEVICE_POWER);
+        }
+
         synchronized(this) {
+            mWentToSleep = false;
             mWindowManager.setEventDispatching(true);
-            mSleeping = false;
-            mMainStack.awakeFromSleepingLocked();
-            mMainStack.resumeTopActivityLocked(null);
+            comeOutOfSleepIfNeededLocked();
+        }
+    }
+
+    public void setLockScreenShown(boolean shown) {
+        if (checkCallingPermission(android.Manifest.permission.DEVICE_POWER)
+                != PackageManager.PERMISSION_GRANTED) {
+            throw new SecurityException("Requires permission "
+                    + android.Manifest.permission.DEVICE_POWER);
+        }
+
+        synchronized(this) {
+            mLockScreenShown = shown;
+            comeOutOfSleepIfNeededLocked();
         }
     }
 
@@ -8815,7 +8862,13 @@ public final class ActivityManagerService extends ActivityManagerNative
                 }
             }
         }
-        pw.println("  mSleeping=" + mSleeping + " mShuttingDown=" + mShuttingDown);
+        if (mSleeping || mWentToSleep || mLockScreenShown) {
+            pw.println("  mSleeping=" + mSleeping + " mWentToSleep=" + mWentToSleep
+                    + " mLockScreenShown " + mLockScreenShown);
+        }
+        if (mShuttingDown) {
+            pw.println("  mShuttingDown=" + mShuttingDown);
+        }
         if (mDebugApp != null || mOrigDebugApp != null || mDebugTransient
                 || mOrigWaitForDebugger) {
             pw.println("  mDebugApp=" + mDebugApp + "/orig=" + mOrigDebugApp