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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /xpcom/glue/nsIWeakReferenceUtils.h
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'xpcom/glue/nsIWeakReferenceUtils.h')
-rw-r--r--xpcom/glue/nsIWeakReferenceUtils.h102
1 files changed, 102 insertions, 0 deletions
diff --git a/xpcom/glue/nsIWeakReferenceUtils.h b/xpcom/glue/nsIWeakReferenceUtils.h
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+++ b/xpcom/glue/nsIWeakReferenceUtils.h
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+/* -*- 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/. */
+
+#ifndef nsIWeakReferenceUtils_h__
+#define nsIWeakReferenceUtils_h__
+
+#include "nsCOMPtr.h"
+#include "nsIWeakReference.h"
+
+typedef nsCOMPtr<nsIWeakReference> nsWeakPtr;
+
+/**
+ *
+ */
+
+// a type-safe shortcut for calling the |QueryReferent()| member function
+// T must inherit from nsIWeakReference, but the cast may be ambiguous.
+template<class T, class DestinationType>
+inline nsresult
+CallQueryReferent(T* aSource, DestinationType** aDestination)
+{
+ NS_PRECONDITION(aSource, "null parameter");
+ NS_PRECONDITION(aDestination, "null parameter");
+
+ return aSource->QueryReferent(NS_GET_TEMPLATE_IID(DestinationType),
+ reinterpret_cast<void**>(aDestination));
+}
+
+
+class MOZ_STACK_CLASS nsQueryReferent final : public nsCOMPtr_helper
+{
+public:
+ nsQueryReferent(nsIWeakReference* aWeakPtr, nsresult* aError)
+ : mWeakPtr(aWeakPtr)
+ , mErrorPtr(aError)
+ {
+ }
+
+ virtual nsresult NS_FASTCALL operator()(const nsIID& aIID, void**) const
+ override;
+
+private:
+ nsIWeakReference* MOZ_NON_OWNING_REF mWeakPtr;
+ nsresult* mErrorPtr;
+};
+
+inline const nsQueryReferent
+do_QueryReferent(nsIWeakReference* aRawPtr, nsresult* aError = 0)
+{
+ return nsQueryReferent(aRawPtr, aError);
+}
+
+
+/**
+ * Deprecated, use |do_GetWeakReference| instead.
+ */
+extern nsIWeakReference* NS_GetWeakReference(nsISupports*,
+ nsresult* aResult = 0);
+
+/**
+ * |do_GetWeakReference| is a convenience function that bundles up all the work needed
+ * to get a weak reference to an arbitrary object, i.e., the |QueryInterface|, test, and
+ * call through to |GetWeakReference|, and put it into your |nsCOMPtr|.
+ * It is specifically designed to cooperate with |nsCOMPtr| (or |nsWeakPtr|) like so:
+ * |nsWeakPtr myWeakPtr = do_GetWeakReference(aPtr);|.
+ */
+inline already_AddRefed<nsIWeakReference>
+do_GetWeakReference(nsISupports* aRawPtr, nsresult* aError = 0)
+{
+ return dont_AddRef(NS_GetWeakReference(aRawPtr, aError));
+}
+
+inline void
+do_GetWeakReference(nsIWeakReference* aRawPtr, nsresult* aError = 0)
+{
+ // This signature exists solely to _stop_ you from doing a bad thing.
+ // Saying |do_GetWeakReference()| on a weak reference itself,
+ // is very likely to be a programmer error.
+}
+
+template<class T>
+inline void
+do_GetWeakReference(already_AddRefed<T>&)
+{
+ // This signature exists solely to _stop_ you from doing the bad thing.
+ // Saying |do_GetWeakReference()| on a pointer that is not otherwise owned by
+ // someone else is an automatic leak. See <http://bugzilla.mozilla.org/show_bug.cgi?id=8221>.
+}
+
+template<class T>
+inline void
+do_GetWeakReference(already_AddRefed<T>&, nsresult*)
+{
+ // This signature exists solely to _stop_ you from doing the bad thing.
+ // Saying |do_GetWeakReference()| on a pointer that is not otherwise owned by
+ // someone else is an automatic leak. See <http://bugzilla.mozilla.org/show_bug.cgi?id=8221>.
+}
+
+#endif