1 files changed, 77 insertions, 0 deletions
diff --git a/netwerk/base/AutoClose.h b/netwerk/base/AutoClose.h
new file mode 100644
index 000000000..43ab27133
--- /dev/null
+++ b/netwerk/base/AutoClose.h
@@ -0,0 +1,77 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=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/. */
+
+#ifndef mozilla_net_AutoClose_h
+#define mozilla_net_AutoClose_h
+
+#include "nsCOMPtr.h"
+#include "mozilla/Mutex.h"
+
+namespace mozilla { namespace net {
+
+// Like an nsAutoPtr for XPCOM streams (e.g. nsIAsyncInputStream) and other
+// refcounted classes that need to have the Close() method called explicitly
+// before they are destroyed.
+template <typename T>
+class AutoClose
+{
+public:
+  AutoClose() : mMutex("net::AutoClose.mMutex") { }
+  ~AutoClose(){
+    CloseAndRelease();
+  }
+
+  explicit operator bool()
+  {
+    MutexAutoLock lock(mMutex);
+    return mPtr;
+  }
+
+  already_AddRefed<T> forget()
+  {
+    MutexAutoLock lock(mMutex);
+    return mPtr.forget();
+  }
+
+  void takeOver(nsCOMPtr<T> & rhs)
+  {
+    already_AddRefed<T> other = rhs.forget();
+    TakeOverInternal(&other);
+  }
+
+  void CloseAndRelease()
+  {
+    TakeOverInternal(nullptr);
+  }
+
+private:
+  void TakeOverInternal(already_AddRefed<T> *aOther)
+  {
+    nsCOMPtr<T> ptr;
+    {
+      MutexAutoLock lock(mMutex);
+      ptr.swap(mPtr);
+      if (aOther) {
+        mPtr = *aOther;
+      }
+    }
+
+    if (ptr) {
+      ptr->Close();
+    }
+  }
+
+  void operator=(const AutoClose<T> &) = delete;
+  AutoClose(const AutoClose<T> &) = delete;
+
+  nsCOMPtr<T> mPtr;
+  Mutex mMutex;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif // mozilla_net_AutoClose_h