Adding some utility methods for thread verification

Change-Id: I3fb6a1b860bba8a6efe413dd2698f972dc3e2506

src/com/android/launcher3/Utilities.java

@@ -47,7 +47,6 @@ import android.graphics.drawable.PaintDrawable;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.PowerManager;
-import android.os.Process;
 import android.text.Spannable;
 import android.text.SpannableString;
 import android.text.TextUtils;
@@ -62,7 +61,6 @@ import android.widget.Toast;
 
 import com.android.launcher3.compat.UserHandleCompat;
 import com.android.launcher3.config.FeatureFlags;
-import com.android.launcher3.config.ProviderConfig;
 import com.android.launcher3.util.IconNormalizer;
 
 import java.io.ByteArrayOutputStream;
@@ -728,13 +726,6 @@ public final class Utilities {
                 (res.getConfiguration().getLayoutDirection() == View.LAYOUT_DIRECTION_RTL);
     }
 
-    public static void assertWorkerThread() {
-        if (ProviderConfig.IS_DOGFOOD_BUILD &&
-                (LauncherModel.sWorkerThread.getThreadId() != Process.myTid())) {
-            throw new IllegalStateException();
-        }
-    }
-
     /**
      * Returns true if the intent is a valid launch intent for a launcher activity of an app.
      * This is used to identify shortcuts which are different from the ones exposed by the

src/com/android/launcher3/WidgetPreviewLoader.java

@@ -33,6 +33,7 @@ import com.android.launcher3.compat.UserHandleCompat;
 import com.android.launcher3.compat.UserManagerCompat;
 import com.android.launcher3.model.WidgetItem;
 import com.android.launcher3.util.ComponentKey;
+import com.android.launcher3.util.Preconditions;
 import com.android.launcher3.util.SQLiteCacheHelper;
 import com.android.launcher3.util.Thunk;
 import com.android.launcher3.widget.WidgetCell;
@@ -169,7 +170,7 @@ public class WidgetPreviewLoader {
      * This ensures that we remove entries for packages which changed while the launcher was dead.
      */
     public void removeObsoletePreviews(ArrayList<? extends ComponentKey> list) {
-        Utilities.assertWorkerThread();
+        Preconditions.assertWorkerThread();
 
         LongSparseArray<HashSet<String>> validPackages = new LongSparseArray<>();
 

src/com/android/launcher3/model/WidgetsModel.java

@@ -16,10 +16,10 @@ import com.android.launcher3.InvariantDeviceProfile;
 import com.android.launcher3.ItemInfo;
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.LauncherAppWidgetProviderInfo;
-import com.android.launcher3.Utilities;
 import com.android.launcher3.compat.AlphabeticIndexCompat;
 import com.android.launcher3.compat.AppWidgetManagerCompat;
 import com.android.launcher3.config.ProviderConfig;
+import com.android.launcher3.util.Preconditions;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -101,7 +101,7 @@ public class WidgetsModel {
     }
 
     public WidgetsModel updateAndClone(Context context) {
-        Utilities.assertWorkerThread();
+        Preconditions.assertWorkerThread();
 
         try {
             final ArrayList<WidgetItem> widgetsAndShortcuts = new ArrayList<>();

src/com/android/launcher3/util/Preconditions.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3.util;
+
+import android.os.Looper;
+
+import com.android.launcher3.LauncherModel;
+import com.android.launcher3.config.ProviderConfig;
+
+/**
+ * A set of utility methods for thread verification.
+ */
+public class Preconditions {
+
+    public static void assertWorkerThread() {
+        if (ProviderConfig.IS_DOGFOOD_BUILD && !isSameLooper(LauncherModel.getWorkerLooper())) {
+            throw new IllegalStateException();
+        }
+    }
+
+    public static void assertUIThread() {
+        if (ProviderConfig.IS_DOGFOOD_BUILD && !isSameLooper(Looper.getMainLooper())) {
+            throw new IllegalStateException();
+        }
+    }
+
+    public static void assertNonUiThread() {
+        if (ProviderConfig.IS_DOGFOOD_BUILD && isSameLooper(Looper.getMainLooper())) {
+            throw new IllegalStateException();
+        }
+    }
+
+    private static boolean isSameLooper(Looper looper) {
+        return Looper.myLooper() == looper;
+    }
+}