1 files changed, 69 insertions, 0 deletions
diff --git a/mobile/android/services/src/main/java/org/mozilla/gecko/sync/DelayedWorkTracker.java b/mobile/android/services/src/main/java/org/mozilla/gecko/sync/DelayedWorkTracker.java
new file mode 100644
index 000000000..ddcb5411c
--- /dev/null
+++ b/mobile/android/services/src/main/java/org/mozilla/gecko/sync/DelayedWorkTracker.java
@@ -0,0 +1,69 @@
+/* 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.sync;
+
+import org.mozilla.gecko.background.common.log.Logger;
+
+/**
+ * A little class to allow us to maintain a count of extant
+ * things (in our case, callbacks that need to fire), and
+ * some work that we want done when that count hits 0.
+ *
+ * @author rnewman
+ *
+ */
+public class DelayedWorkTracker {
+  private static final String LOG_TAG = "DelayedWorkTracker";
+  protected Runnable workItem = null;
+  protected int outstandingCount = 0;
+
+  public int incrementOutstanding() {
+    Logger.trace(LOG_TAG, "Incrementing outstanding.");
+    synchronized(this) {
+      return ++outstandingCount;
+    }
+  }
+  public int decrementOutstanding() {
+    Logger.trace(LOG_TAG, "Decrementing outstanding.");
+    Runnable job = null;
+    int count;
+    synchronized(this) {
+      if ((count = --outstandingCount) == 0 &&
+          workItem != null) {
+        job = workItem;
+        workItem = null;
+      } else {
+        return count;
+      }
+    }
+    job.run();
+    // In case it's changed.
+    return getOutstandingOperations();
+  }
+  public int getOutstandingOperations() {
+    synchronized(this) {
+      return outstandingCount;
+    }
+  }
+  public void delayWorkItem(Runnable item) {
+    Logger.trace(LOG_TAG, "delayWorkItem.");
+    boolean runnableNow = false;
+    synchronized(this) {
+      Logger.trace(LOG_TAG, "outstandingCount: " + outstandingCount);
+      if (outstandingCount == 0) {
+        runnableNow = true;
+      } else {
+        if (workItem != null) {
+          throw new IllegalStateException("Work item already set!");
+        }
+        workItem = item;
+      }
+    }
+    if (runnableNow) {
+      Logger.trace(LOG_TAG, "Running item now.");
+      item.run();
+    }
+  }
+}
+\ No newline at end of file