commit ff5b158f69bf453cf1fdedd175a09482c65f2bf2
author Dianne Hackborn <hackbod@google.com> Thu Apr 12 17:24:07 2012 -0700
committer Dianne Hackborn <hackbod@google.com> Thu Apr 12 17:26:55 2012 -0700
tree d9eb803d3a4a88814757434a8c8ec6c6ffb67cf3
parent b0398f59aae2c72161ea20339efaa950a788c375

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

services/java/com/android/server/am/ActivityManagerService.java

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 @@
     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 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 @@
         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 @@
                 }
             }
         }
-        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