Merge "[AppsFilter] read sysprop only when it's changed"

services/core/java/com/android/server/pm/AppsFilterBase.java

@@ -28,7 +28,6 @@ import android.content.pm.SigningDetails;
 import android.os.Binder;
 import android.os.Handler;
 import android.os.Process;
-import android.os.SystemProperties;
 import android.os.Trace;
 import android.os.UserHandle;
 import android.text.TextUtils;
@@ -199,6 +198,7 @@ public abstract class AppsFilterBase implements AppsFilterSnapshot {
     protected SnapshotCache<WatchedSparseBooleanMatrix> mShouldFilterCacheSnapshot;
 
     protected volatile boolean mCacheReady = false;
+    protected volatile boolean mCacheEnabled = true;
 
     protected static final boolean CACHE_VALID = true;
     protected static final boolean CACHE_INVALID = false;
@@ -342,8 +342,7 @@ public abstract class AppsFilterBase implements AppsFilterSnapshot {
                       && !isImplicitlyQueryable(callingAppId, targetPkgSetting.getAppId());
             }
             // use cache
-            if (mCacheReady && SystemProperties.getBoolean("debug.pm.use_app_filter_cache",
-                    true)) {
+            if (mCacheReady && mCacheEnabled) {
                 if (!shouldFilterApplicationUsingCache(callingUid,
                         targetPkgSetting.getAppId(),
                         userId)) {

services/core/java/com/android/server/pm/AppsFilterImpl.java

@@ -36,6 +36,7 @@ import android.content.pm.PackageManagerInternal;
 import android.content.pm.SigningDetails;
 import android.content.pm.UserInfo;
 import android.os.Handler;
+import android.os.SystemProperties;
 import android.os.Trace;
 import android.os.UserHandle;
 import android.provider.DeviceConfig;
@@ -223,6 +224,12 @@ public final class AppsFilterImpl extends AppsFilterLocked implements Watchable,
                 return new AppsFilterSnapshotImpl(AppsFilterImpl.this);
             }
         };
+        readCacheEnabledSysProp();
+        SystemProperties.addChangeCallback(this::readCacheEnabledSysProp);
+    }
+
+    private void readCacheEnabledSysProp() {
+        mCacheEnabled = SystemProperties.getBoolean("debug.pm.use_app_filter_cache", true);
     }
 
     /**

services/core/java/com/android/server/pm/AppsFilterSnapshotImpl.java

@@ -74,6 +74,7 @@ public final class AppsFilterSnapshotImpl extends AppsFilterBase {
             // cache is not ready, use an empty cache for the snapshot
             mShouldFilterCache = new WatchedSparseBooleanMatrix();
         }
+        mCacheEnabled = orig.mCacheEnabled;
         mShouldFilterCacheSnapshot = new SnapshotCache.Sealed<>();
 
         mBackgroundHandler = null;