forked from mirrors/gecko-dev
de10571c3c
Previously, we only did this when IsCallerExternalProcess() returned false. There are three reasons for changing this: 1. There seem to be cases where IsCallerExternalProcess() returns true even when marshaling for a COM query in the MTA. 2. After bug 1627084, we pre-build a11y handler payloads on the main thread for bulk fetch calls. That will marshal interceptors. However, IsCallerExternalProcess() can't work in that case because it's not running on the thread on which the COM call is being handled. 3. If MSHLFLAGS_NOPING is used, Release calls from remote clients are never sent to the server. So, as soon as we use NOPING for our parent process, we're already going to leak references, even if we don't use NOPING for external callers. Put another way, as soon as we use NOPING for one caller, we may as well use it for all callers because COM pinging will never release the object anyway. Differential Revision: https://phabricator.services.mozilla.com/D84778
66 lines
2.6 KiB
C++
66 lines
2.6 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=8 sts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef mozilla_mscom_FastMarshaler_h
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#define mozilla_mscom_FastMarshaler_h
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#include "mozilla/Atomics.h"
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#include "mozilla/mscom/Aggregation.h"
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#include "mozilla/RefPtr.h"
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#include <objidl.h>
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namespace mozilla {
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namespace mscom {
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/**
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* COM ping functionality is enabled by default and is designed to free strong
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* references held by defunct client processes. However, this incurs a
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* significant performance penalty in a11y code due to large numbers of remote
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* objects being created and destroyed within a short period of time. Thus, we
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* turn off pings to improve performance.
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* ACHTUNG! When COM pings are disabled, Release calls from remote clients are
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* never sent to the server! If you use this marshaler, you *must* explicitly
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* disconnect clients using CoDisconnectObject when the object is no longer
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* relevant. Otherwise, references to the object will never be released, causing
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* a leak.
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*/
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class FastMarshaler final : public IMarshal {
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public:
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static HRESULT Create(IUnknown* aOuter, IUnknown** aOutMarshalerUnk);
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// IMarshal
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STDMETHODIMP GetUnmarshalClass(REFIID riid, void* pv, DWORD dwDestContext,
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void* pvDestContext, DWORD mshlflags,
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CLSID* pCid) override;
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STDMETHODIMP GetMarshalSizeMax(REFIID riid, void* pv, DWORD dwDestContext,
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void* pvDestContext, DWORD mshlflags,
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DWORD* pSize) override;
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STDMETHODIMP MarshalInterface(IStream* pStm, REFIID riid, void* pv,
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DWORD dwDestContext, void* pvDestContext,
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DWORD mshlflags) override;
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STDMETHODIMP UnmarshalInterface(IStream* pStm, REFIID riid,
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void** ppv) override;
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STDMETHODIMP ReleaseMarshalData(IStream* pStm) override;
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STDMETHODIMP DisconnectObject(DWORD dwReserved) override;
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private:
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FastMarshaler(IUnknown* aOuter, HRESULT* aResult);
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~FastMarshaler() = default;
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static DWORD GetMarshalFlags(DWORD aDestContext, DWORD aMshlFlags);
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Atomic<ULONG> mRefCnt;
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IUnknown* mOuter;
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RefPtr<IUnknown> mStdMarshalUnk;
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IMarshal* mStdMarshalWeak;
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DECLARE_AGGREGATABLE(FastMarshaler);
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};
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} // namespace mscom
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} // namespace mozilla
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#endif // mozilla_mscom_FastMarshaler_h
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