1 files changed, 75 insertions, 0 deletions
diff --git a/image/ShutdownTracker.cpp b/image/ShutdownTracker.cpp
new file mode 100644
index 000000000..c52c0b79e
--- /dev/null
+++ b/image/ShutdownTracker.cpp
@@ -0,0 +1,75 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#include "ShutdownTracker.h"
+
+#include "mozilla/Services.h"
+#include "nsIObserver.h"
+#include "nsIObserverService.h"
+
+namespace mozilla {
+namespace image {
+
+class ShutdownTrackerImpl;
+
+///////////////////////////////////////////////////////////////////////////////
+// Static Data
+///////////////////////////////////////////////////////////////////////////////
+
+// Whether we've observed shutdown starting yet.
+static bool sShutdownHasStarted = false;
+
+
+///////////////////////////////////////////////////////////////////////////////
+// Implementation
+///////////////////////////////////////////////////////////////////////////////
+
+struct ShutdownObserver : public nsIObserver
+{
+  NS_DECL_ISUPPORTS
+
+  NS_IMETHOD Observe(nsISupports*, const char* aTopic, const char16_t*) override
+  {
+    if (strcmp(aTopic, "xpcom-will-shutdown") != 0) {
+      return NS_OK;
+    }
+
+    nsCOMPtr<nsIObserverService> os = services::GetObserverService();
+    if (os) {
+      os->RemoveObserver(this, "xpcom-will-shutdown");
+    }
+
+    sShutdownHasStarted = true;
+    return NS_OK;
+  }
+
+private:
+  virtual ~ShutdownObserver() { }
+};
+
+NS_IMPL_ISUPPORTS(ShutdownObserver, nsIObserver)
+
+
+///////////////////////////////////////////////////////////////////////////////
+// Public API
+///////////////////////////////////////////////////////////////////////////////
+
+/* static */ void
+ShutdownTracker::Initialize()
+{
+  nsCOMPtr<nsIObserverService> os = services::GetObserverService();
+  if (os) {
+    os->AddObserver(new ShutdownObserver, "xpcom-will-shutdown", false);
+  }
+}
+
+/* static */ bool
+ShutdownTracker::ShutdownHasStarted()
+{
+  return sShutdownHasStarted;
+}
+
+} // namespace image
+} // namespace mozilla