Wireframe scheduler implementation

chrome/android/java/src/org/chromium/chrome/browser/offlinepages/BackgroundTask.java

Index: chrome/android/java/src/org/chromium/chrome/browser/offlinepages/BackgroundTask.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/BackgroundTask.java b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/BackgroundTask.java
new file mode 100644
index 0000000000000000000000000000000000000000..2d95a4f9c1a5bff9da94b7425c9d6bb5d7bc9e95
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/BackgroundTask.java
@@ -0,0 +1,64 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.offlinepages;
+
+import android.content.Context;
+import android.os.Bundle;
+
+import org.chromium.base.Log;
+import org.chromium.base.ThreadUtils;
+
+import java.util.concurrent.CountDownLatch;
+
+/**
+ * Handles servicing of background offlining requests coming via the GcmNetworkManager.
+ */
+public class BackgroundTask implements BackgroundSchedulerBridge.ProcessingDoneCallback {
+    private static final String TAG = "BackgroundTask";
+    /**
+     * Triggers processing of background offlining requests.  This is called when
+     * system conditions are appropriate for background offlining, typically from the
+     * GcmTaskService onRunTask() method.  In response, we will start the
+     * task processing by passing the call along to the C++ RequestCoordinator.
+     *
+     * @returns true for success
+     */
+    public boolean processBackgroundRequests(Context context, Bundle bundle) {
+        mProcessingDoneLatch = new CountDownLatch(1);
+        // GCM Network Manager promises to call us on a fresh thread, not the UI thread.
+        assert (!ThreadUtils.runningOnUiThread());

[dougarnett, 2016/05/24 16:27:58]

Will assert as ChromeBackgroundService is currently written

[dewittj, 2016/05/24 16:56:19]

also nit: this should be the first line of the function

[Pete Williamson, 2016/05/24 18:49:31]

Noted, I'll discuss the resolution with you (possibly rewriting
ChromeBackgroundService for our needs).

[Pete Williamson, 2016/05/24 18:49:31]

Done.

+
+        // TODO(petewil): Decode the TriggerConditions from the bundle.
+
+        // Pass the activation on to the bridge to the C++ RequestCoordinator.
+        BackgroundSchedulerBridge.startProcessing(context, this);
+
+        // Gather UMA data to measure how often the user's machine is amenable to background
+        // loading when we wake to do a task.
+        OfflinePageUtils.recordWakeupUMA(context);
+
+        // Wait for callback async completion before returning.  This is important so
+        // we don't start the next GCM task until we are done with this one.  It also
+        // rate limits our pre-render calls, and holds the wake lock for us.
+        try {
+            // TODO(petewil): Add a timeout here in case pre-rendering hangs.
+            mProcessingDoneLatch.await();

[dewittj, 2016/05/24 16:56:19]

why not just use the two-argument await with a timeout instead of adding a TODO

[Pete Williamson, 2016/05/24 18:49:31]

Done.

+        } catch (InterruptedException e) {
+            Log.w(TAG, "IncomingTask interrupted, returning to GcmNetworkManager");
+            return false;
+        }
+        return true;
+    }
+
+    /**
+     * Callback function which indicates completion of background work.
+     * @param result - TODO(petewil): What is this for again?  What does true mean?
+     */
+    public void onProcessingDone(boolean result) {
+        mProcessingDoneLatch.countDown();
+    }
+
+    private CountDownLatch mProcessingDoneLatch;
+}