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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /xpcom/base/nsWeakReference.cpp | |
parent | Initial commit. (diff) | |
download | firefox-upstream/124.0.1.tar.xz firefox-upstream/124.0.1.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'xpcom/base/nsWeakReference.cpp')
-rw-r--r-- | xpcom/base/nsWeakReference.cpp | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/xpcom/base/nsWeakReference.cpp b/xpcom/base/nsWeakReference.cpp new file mode 100644 index 0000000000..958ef08451 --- /dev/null +++ b/xpcom/base/nsWeakReference.cpp @@ -0,0 +1,151 @@ +/* -*- 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/. */ + +// nsWeakReference.cpp + +#include "mozilla/Attributes.h" + +#include "nsWeakReference.h" +#include "nsCOMPtr.h" +#include "nsDebug.h" + +class nsWeakReference final : public nsIWeakReference { + public: + // nsISupports... + NS_DECL_ISUPPORTS + + // nsIWeakReference... + NS_DECL_NSIWEAKREFERENCE + + private: + friend class nsSupportsWeakReference; + + explicit nsWeakReference(nsSupportsWeakReference* aReferent) + : nsIWeakReference(aReferent) + // ...I can only be constructed by an |nsSupportsWeakReference| + {} + + ~nsWeakReference() + // ...I will only be destroyed by calling |delete| myself. + { + MOZ_WEAKREF_ASSERT_OWNINGTHREAD; + if (mObject) { + static_cast<nsSupportsWeakReference*>(mObject)->NoticeProxyDestruction(); + } + } + + void NoticeReferentDestruction() + // ...called (only) by an |nsSupportsWeakReference| from _its_ dtor. + { + MOZ_WEAKREF_ASSERT_OWNINGTHREAD; + mObject = nullptr; + } +}; + +nsresult nsQueryReferent::operator()(const nsIID& aIID, void** aAnswer) const { + nsresult status; + if (mWeakPtr) { + if (NS_FAILED(status = mWeakPtr->QueryReferent(aIID, aAnswer))) { + *aAnswer = 0; + } + } else { + status = NS_ERROR_NULL_POINTER; + } + + if (mErrorPtr) { + *mErrorPtr = status; + } + return status; +} + +nsIWeakReference* NS_GetWeakReference(nsISupportsWeakReference* aInstancePtr, + nsresult* aErrorPtr) { + nsresult status; + + nsIWeakReference* result = nullptr; + + if (aInstancePtr) { + status = aInstancePtr->GetWeakReference(&result); + } else { + status = NS_ERROR_NULL_POINTER; + } + + if (aErrorPtr) { + *aErrorPtr = status; + } + + return result; +} + +nsIWeakReference* // or else |already_AddRefed<nsIWeakReference>| +NS_GetWeakReference(nsISupports* aInstancePtr, nsresult* aErrorPtr) { + nsresult status; + + nsIWeakReference* result = nullptr; + + if (aInstancePtr) { + nsCOMPtr<nsISupportsWeakReference> factoryPtr = + do_QueryInterface(aInstancePtr, &status); + if (factoryPtr) { + status = factoryPtr->GetWeakReference(&result); + } + // else, |status| has already been set by |do_QueryInterface| + } else { + status = NS_ERROR_NULL_POINTER; + } + + if (aErrorPtr) { + *aErrorPtr = status; + } + return result; +} + +nsresult nsSupportsWeakReference::GetWeakReference( + nsIWeakReference** aInstancePtr) { + if (!aInstancePtr) { + return NS_ERROR_NULL_POINTER; + } + + if (!mProxy) { + mProxy = new nsWeakReference(this); + } else { + MOZ_WEAKREF_ASSERT_OWNINGTHREAD_DELEGATED(mProxy); + } + RefPtr<nsWeakReference> rval = mProxy; + rval.forget(aInstancePtr); + + return NS_OK; +} + +NS_IMPL_ISUPPORTS(nsWeakReference, nsIWeakReference) + +NS_IMETHODIMP +nsWeakReference::QueryReferentFromScript(const nsIID& aIID, + void** aInstancePtr) { + return QueryReferent(aIID, aInstancePtr); +} + +nsresult nsIWeakReference::QueryReferent(const nsIID& aIID, + void** aInstancePtr) { + MOZ_WEAKREF_ASSERT_OWNINGTHREAD; + + if (!mObject) { + return NS_ERROR_NULL_POINTER; + } + + return mObject->QueryInterface(aIID, aInstancePtr); +} + +size_t nsWeakReference::SizeOfOnlyThis(mozilla::MallocSizeOf aMallocSizeOf) { + return aMallocSizeOf(this); +} + +void nsSupportsWeakReference::ClearWeakReferences() { + if (mProxy) { + mProxy->NoticeReferentDestruction(); + mProxy = nullptr; + } +} |