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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/. */
#define INITGUID
#include "mozilla/mscom/WeakRef.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/Mutex.h"
#include "nsThreadUtils.h"
#include "nsWindowsHelpers.h"
#include "nsProxyRelease.h"
static void InitializeCS(CRITICAL_SECTION& aCS) {
DWORD flags = 0;
#if defined(RELEASE_OR_BETA)
flags |= CRITICAL_SECTION_NO_DEBUG_INFO;
#endif
InitializeCriticalSectionEx(&aCS, 4000, flags);
}
namespace mozilla {
namespace mscom {
namespace detail {
SharedRef::SharedRef(WeakReferenceSupport* aSupport) : mSupport(aSupport) {
::InitializeCS(mCS);
}
SharedRef::~SharedRef() { ::DeleteCriticalSection(&mCS); }
void SharedRef::Lock() { ::EnterCriticalSection(&mCS); }
void SharedRef::Unlock() { ::LeaveCriticalSection(&mCS); }
HRESULT
SharedRef::ToStrongRef(IWeakReferenceSource** aOutStrongReference) {
RefPtr<IWeakReferenceSource> strongRef;
{ // Scope for lock
AutoCriticalSection lock(&mCS);
if (!mSupport) {
return E_POINTER;
}
strongRef = mSupport;
}
strongRef.forget(aOutStrongReference);
return S_OK;
}
HRESULT
SharedRef::Resolve(REFIID aIid, void** aOutStrongReference) {
RefPtr<WeakReferenceSupport> strongRef;
{ // Scope for lock
AutoCriticalSection lock(&mCS);
if (!mSupport) {
return E_POINTER;
}
strongRef = mSupport;
}
return strongRef->QueryInterface(aIid, aOutStrongReference);
}
void SharedRef::Clear() {
AutoCriticalSection lock(&mCS);
mSupport = nullptr;
}
} // namespace detail
typedef mozilla::detail::BaseAutoLock<detail::SharedRef&> SharedRefAutoLock;
typedef mozilla::detail::BaseAutoUnlock<detail::SharedRef&> SharedRefAutoUnlock;
WeakReferenceSupport::WeakReferenceSupport(Flags aFlags)
: mRefCnt(0), mFlags(aFlags) {
mSharedRef = new detail::SharedRef(this);
}
HRESULT
WeakReferenceSupport::QueryInterface(REFIID riid, void** ppv) {
RefPtr<IUnknown> punk;
if (!ppv) {
return E_INVALIDARG;
}
*ppv = nullptr;
// Raise the refcount for stabilization purposes during aggregation
StabilizeRefCount stabilize(*this);
if (riid == IID_IUnknown || riid == IID_IWeakReferenceSource) {
punk = static_cast<IUnknown*>(this);
} else {
HRESULT hr = WeakRefQueryInterface(riid, getter_AddRefs(punk));
if (FAILED(hr)) {
return hr;
}
}
if (!punk) {
return E_NOINTERFACE;
}
punk.forget(ppv);
return S_OK;
}
WeakReferenceSupport::StabilizeRefCount::StabilizeRefCount(
WeakReferenceSupport& aObject)
: mObject(aObject) {
SharedRefAutoLock lock(*mObject.mSharedRef);
++mObject.mRefCnt;
}
WeakReferenceSupport::StabilizeRefCount::~StabilizeRefCount() {
// We directly access these fields instead of calling Release() because we
// want to adjust the ref count without the other side effects (such as
// deleting this if the count drops back to zero, which may happen during
// an initial QI during object creation).
SharedRefAutoLock lock(*mObject.mSharedRef);
--mObject.mRefCnt;
}
ULONG
WeakReferenceSupport::AddRef() {
SharedRefAutoLock lock(*mSharedRef);
ULONG result = ++mRefCnt;
NS_LOG_ADDREF(this, result, "mscom::WeakReferenceSupport", sizeof(*this));
return result;
}
ULONG
WeakReferenceSupport::Release() {
ULONG newRefCnt;
{ // Scope for lock
SharedRefAutoLock lock(*mSharedRef);
newRefCnt = --mRefCnt;
if (newRefCnt == 0) {
mSharedRef->Clear();
}
}
NS_LOG_RELEASE(this, newRefCnt, "mscom::WeakReferenceSupport");
if (newRefCnt == 0) {
if (mFlags != Flags::eDestroyOnMainThread || NS_IsMainThread()) {
delete this;
} else {
// We need to delete this object on the main thread, but we aren't on the
// main thread right now, so we send a reference to ourselves to the main
// thread to be re-released there.
RefPtr<WeakReferenceSupport> self = this;
NS_ReleaseOnMainThread("WeakReferenceSupport", self.forget());
}
}
return newRefCnt;
}
HRESULT
WeakReferenceSupport::GetWeakReference(IWeakReference** aOutWeakRef) {
if (!aOutWeakRef) {
return E_INVALIDARG;
}
RefPtr<WeakRef> weakRef = MakeAndAddRef<WeakRef>(mSharedRef);
return weakRef->QueryInterface(IID_IWeakReference, (void**)aOutWeakRef);
}
WeakRef::WeakRef(RefPtr<detail::SharedRef>& aSharedRef)
: mRefCnt(0), mSharedRef(aSharedRef) {
MOZ_ASSERT(aSharedRef);
}
HRESULT
WeakRef::QueryInterface(REFIID riid, void** ppv) {
IUnknown* punk = nullptr;
if (!ppv) {
return E_INVALIDARG;
}
if (riid == IID_IUnknown || riid == IID_IWeakReference) {
punk = static_cast<IUnknown*>(this);
}
*ppv = punk;
if (!punk) {
return E_NOINTERFACE;
}
punk->AddRef();
return S_OK;
}
ULONG
WeakRef::AddRef() {
ULONG result = ++mRefCnt;
NS_LOG_ADDREF(this, result, "mscom::WeakRef", sizeof(*this));
return result;
}
ULONG
WeakRef::Release() {
ULONG newRefCnt = --mRefCnt;
NS_LOG_RELEASE(this, newRefCnt, "mscom::WeakRef");
if (newRefCnt == 0) {
delete this;
}
return newRefCnt;
}
HRESULT
WeakRef::ToStrongRef(IWeakReferenceSource** aOutStrongReference) {
return mSharedRef->ToStrongRef(aOutStrongReference);
}
HRESULT
WeakRef::Resolve(REFIID aIid, void** aOutStrongReference) {
return mSharedRef->Resolve(aIid, aOutStrongReference);
}
} // namespace mscom
} // namespace mozilla
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