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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 mozilla_mscom_FastMarshaler_h
#define mozilla_mscom_FastMarshaler_h
#include "mozilla/Atomics.h"
#include "mozilla/mscom/Aggregation.h"
#include "mozilla/RefPtr.h"
#include <objidl.h>
namespace mozilla {
namespace mscom {
/**
* COM ping functionality is enabled by default and is designed to free strong
* references held by defunct client processes. However, this incurs a
* significant performance penalty in a11y code due to large numbers of remote
* objects being created and destroyed within a short period of time. Thus, we
* turn off pings to improve performance.
* ACHTUNG! When COM pings are disabled, Release calls from remote clients are
* never sent to the server! If you use this marshaler, you *must* explicitly
* disconnect clients using CoDisconnectObject when the object is no longer
* relevant. Otherwise, references to the object will never be released, causing
* a leak.
*/
class FastMarshaler final : public IMarshal {
public:
static HRESULT Create(IUnknown* aOuter, IUnknown** aOutMarshalerUnk);
// IMarshal
STDMETHODIMP GetUnmarshalClass(REFIID riid, void* pv, DWORD dwDestContext,
void* pvDestContext, DWORD mshlflags,
CLSID* pCid) override;
STDMETHODIMP GetMarshalSizeMax(REFIID riid, void* pv, DWORD dwDestContext,
void* pvDestContext, DWORD mshlflags,
DWORD* pSize) override;
STDMETHODIMP MarshalInterface(IStream* pStm, REFIID riid, void* pv,
DWORD dwDestContext, void* pvDestContext,
DWORD mshlflags) override;
STDMETHODIMP UnmarshalInterface(IStream* pStm, REFIID riid,
void** ppv) override;
STDMETHODIMP ReleaseMarshalData(IStream* pStm) override;
STDMETHODIMP DisconnectObject(DWORD dwReserved) override;
private:
FastMarshaler(IUnknown* aOuter, HRESULT* aResult);
~FastMarshaler() = default;
static DWORD GetMarshalFlags(DWORD aDestContext, DWORD aMshlFlags);
Atomic<ULONG> mRefCnt;
IUnknown* mOuter;
RefPtr<IUnknown> mStdMarshalUnk;
IMarshal* mStdMarshalWeak;
DECLARE_AGGREGATABLE(FastMarshaler);
};
} // namespace mscom
} // namespace mozilla
#endif // mozilla_mscom_FastMarshaler_h
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