1 files changed, 78 insertions, 0 deletions
diff --git a/ipc/mscom/EnsureMTA.cpp b/ipc/mscom/EnsureMTA.cpp
new file mode 100644
index 000000000..f4bc911e9
--- /dev/null
+++ b/ipc/mscom/EnsureMTA.cpp
@@ -0,0 +1,78 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "mozilla/mscom/EnsureMTA.h"
+
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/StaticPtr.h"
+#include "nsThreadUtils.h"
+
+#include "private/pprthred.h"
+
+namespace {
+
+class EnterMTARunnable : public mozilla::Runnable
+{
+public:
+  NS_IMETHOD Run() override
+  {
+    mozilla::DebugOnly<HRESULT> hr = ::CoInitializeEx(nullptr,
+                                                      COINIT_MULTITHREADED);
+    MOZ_ASSERT(SUCCEEDED(hr));
+    return NS_OK;
+  }
+};
+
+class BackgroundMTAData
+{
+public:
+  BackgroundMTAData()
+  {
+    nsCOMPtr<nsIRunnable> runnable = new EnterMTARunnable();
+    nsresult rv = NS_NewNamedThread("COM MTA",
+                                    getter_AddRefs(mThread), runnable);
+    NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "NS_NewNamedThread failed");
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+  }
+
+  ~BackgroundMTAData()
+  {
+    if (mThread) {
+      mThread->Dispatch(NS_NewRunnableFunction(&::CoUninitialize),
+                        NS_DISPATCH_NORMAL);
+      mThread->Shutdown();
+    }
+  }
+
+  nsCOMPtr<nsIThread> GetThread() const
+  {
+    return mThread;
+  }
+
+private:
+  nsCOMPtr<nsIThread> mThread;
+};
+
+} // anonymous namespace
+
+static mozilla::StaticAutoPtr<BackgroundMTAData> sMTAData;
+
+namespace mozilla {
+namespace mscom {
+
+/* static */ nsCOMPtr<nsIThread>
+EnsureMTA::GetMTAThread()
+{
+  if (!sMTAData) {
+    sMTAData = new BackgroundMTAData();
+    ClearOnShutdown(&sMTAData, ShutdownPhase::ShutdownThreads);
+  }
+  return sMTAData->GetThread();
+}
+
+} // namespace mscom
+} // namespace mozilla
+