1 files changed, 145 insertions, 0 deletions
diff --git a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/ThreadUtils.java b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/ThreadUtils.java
new file mode 100644
index 0000000000..00625800c9
--- /dev/null
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/ThreadUtils.java
@@ -0,0 +1,145 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.util;
+
+import android.os.Handler;
+import android.os.Looper;
+import android.util.Log;
+import org.mozilla.gecko.annotation.RobocopTarget;
+
+public final class ThreadUtils {
+  private static final String LOGTAG = "ThreadUtils";
+
+  /**
+   * Controls the action taken when a method like {@link
+   * ThreadUtils#assertOnUiThread(AssertBehavior)} detects a problem.
+   */
+  public enum AssertBehavior {
+    NONE,
+    THROW,
+  }
+
+  private static final Thread sUiThread = Looper.getMainLooper().getThread();
+  private static final Handler sUiHandler = new Handler(Looper.getMainLooper());
+
+  // Referenced directly from GeckoAppShell in highly performance-sensitive code (The extra
+  // function call of the getter was harming performance. (Bug 897123))
+  // Once Bug 709230 is resolved we should reconsider this as ProGuard should be able to optimise
+  // this out at compile time.
+  public static Handler sGeckoHandler;
+  public static volatile Thread sGeckoThread;
+
+  public static Thread getUiThread() {
+    return sUiThread;
+  }
+
+  public static Handler getUiHandler() {
+    return sUiHandler;
+  }
+
+  /**
+   * Runs the provided runnable on the UI thread. If this method is called on the UI thread the
+   * runnable will be executed synchronously.
+   *
+   * @param runnable the runnable to be executed.
+   */
+  public static void runOnUiThread(final Runnable runnable) {
+    // We're on the UI thread already, let's just run this
+    if (isOnUiThread()) {
+      runnable.run();
+      return;
+    }
+
+    postToUiThread(runnable);
+  }
+
+  public static void postToUiThread(final Runnable runnable) {
+    sUiHandler.post(runnable);
+  }
+
+  public static void postToUiThreadDelayed(final Runnable runnable, final long delayMillis) {
+    sUiHandler.postDelayed(runnable, delayMillis);
+  }
+
+  public static void removeUiThreadCallbacks(final Runnable runnable) {
+    sUiHandler.removeCallbacks(runnable);
+  }
+
+  public static Handler getBackgroundHandler() {
+    return GeckoBackgroundThread.getHandler();
+  }
+
+  public static void postToBackgroundThread(final Runnable runnable) {
+    GeckoBackgroundThread.post(runnable);
+  }
+
+  public static void assertOnUiThread(final AssertBehavior assertBehavior) {
+    assertOnThread(getUiThread(), assertBehavior);
+  }
+
+  public static void assertOnUiThread() {
+    assertOnThread(getUiThread(), AssertBehavior.THROW);
+  }
+
+  @RobocopTarget
+  public static void assertOnGeckoThread() {
+    assertOnThread(sGeckoThread, AssertBehavior.THROW);
+  }
+
+  public static void assertOnThread(final Thread expectedThread, final AssertBehavior behavior) {
+    assertOnThreadComparison(expectedThread, behavior, true);
+  }
+
+  private static void assertOnThreadComparison(
+      final Thread expectedThread, final AssertBehavior behavior, final boolean expected) {
+    final Thread currentThread = Thread.currentThread();
+    final long currentThreadId = currentThread.getId();
+    final long expectedThreadId = expectedThread.getId();
+
+    if ((currentThreadId == expectedThreadId) == expected) {
+      return;
+    }
+
+    final String message;
+    if (expected) {
+      message =
+          "Expected thread "
+              + expectedThreadId
+              + " (\""
+              + expectedThread.getName()
+              + "\"), but running on thread "
+              + currentThreadId
+              + " (\""
+              + currentThread.getName()
+              + "\")";
+    } else {
+      message =
+          "Expected anything but "
+              + expectedThreadId
+              + " (\""
+              + expectedThread.getName()
+              + "\"), but running there.";
+    }
+
+    final IllegalThreadStateException e = new IllegalThreadStateException(message);
+
+    switch (behavior) {
+      case THROW:
+        throw e;
+      default:
+        Log.e(LOGTAG, "Method called on wrong thread!", e);
+    }
+  }
+
+  public static boolean isOnUiThread() {
+    return isOnThread(getUiThread());
+  }
+
+  @RobocopTarget
+  public static boolean isOnThread(final Thread thread) {
+    return (Thread.currentThread().getId() == thread.getId());
+  }
+}