ipc/mscom/ApartmentRegion.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_mscom_ApartmentRegion_h
   8 #define mozilla_mscom_ApartmentRegion_h
   9
  10 #include "mozilla/Assertions.h"
  11 #include "mozilla/Attributes.h"
  12 #include "mozilla/mscom/COMWrappers.h"
  13
  14 namespace mozilla::mscom {
  15
  16 // This runtime-dynamic apartment class is used in ProcessRuntime.cpp, to
  17 // initialize the process's main thread. Do not use it in new contexts if at all
  18 // possible; instead, prefer ApartmentRegionT, below.
  19 //
  20 // For backwards compatibility, this class does not yet automatically disable
  21 // OLE1/DDE, although there is believed to be no code relying on it.
  22 //
  23 // (TODO: phase out all uses of CoInitialize without `COINIT_DISABLE_OLE1DDE`?)
  24 class MOZ_NON_TEMPORARY_CLASS ApartmentRegion final {
  25  public:
  26   /**
  27    * This constructor is to be used when we want to instantiate the object but
  28    * we do not yet know which type of apartment we want. Call Init() to
  29    * complete initialization.
  30    */
  31   constexpr ApartmentRegion() : mInitResult(CO_E_NOTINITIALIZED) {}
  32
  33   explicit ApartmentRegion(COINIT aAptType)
  34       : mInitResult(wrapped::CoInitializeEx(nullptr, aAptType)) {
  35     // If this fires then we're probably mixing apartments on the same thread
  36     MOZ_ASSERT(IsValid());
  37   }
  38
  39   ~ApartmentRegion() {
  40     if (IsValid()) {
  41       wrapped::CoUninitialize();
  42     }
  43   }
  44
  45   explicit operator bool() const { return IsValid(); }
  46
  47   bool IsValidOutermost() const { return mInitResult == S_OK; }
  48
  49   bool IsValid() const { return SUCCEEDED(mInitResult); }
  50
  51   bool Init(COINIT aAptType) {
  52     MOZ_ASSERT(mInitResult == CO_E_NOTINITIALIZED);
  53     mInitResult = wrapped::CoInitializeEx(nullptr, aAptType);
  54     MOZ_ASSERT(IsValid());
  55     return IsValid();
  56   }
  57
  58   HRESULT GetHResult() const { return mInitResult; }
  59
  60   ApartmentRegion(const ApartmentRegion&) = delete;
  61   ApartmentRegion& operator=(const ApartmentRegion&) = delete;
  62   ApartmentRegion(ApartmentRegion&&) = delete;
  63   ApartmentRegion& operator=(ApartmentRegion&&) = delete;
  64
  65  private:
  66   HRESULT mInitResult;
  67 };
  68
  69 template <COINIT AptType, bool UseOLE1 = false>
  70 class MOZ_NON_TEMPORARY_CLASS ApartmentRegionT final {
  71   static COINIT ActualType() {
  72     static_assert(
  73         !((AptType & COINIT_DISABLE_OLE1DDE) == 0 && UseOLE1),
  74         "only one of `UseOLE1` and `COINIT_DISABLE_OLE1DDE` permitted");
  75     if (UseOLE1) return AptType;
  76     return static_cast<COINIT>(AptType | COINIT_DISABLE_OLE1DDE);
  77   }
  78
  79  public:
  80   ApartmentRegionT() : mAptRgn(ActualType()) {}
  81
  82   ~ApartmentRegionT() = default;
  83
  84   explicit operator bool() const { return mAptRgn.IsValid(); }
  85
  86   bool IsValidOutermost() const { return mAptRgn.IsValidOutermost(); }
  87
  88   bool IsValid() const { return mAptRgn.IsValid(); }
  89
  90   HRESULT GetHResult() const { return mAptRgn.GetHResult(); }
  91
  92   ApartmentRegionT(const ApartmentRegionT&) = delete;
  93   ApartmentRegionT& operator=(const ApartmentRegionT&) = delete;
  94   ApartmentRegionT(ApartmentRegionT&&) = delete;
  95   ApartmentRegionT& operator=(ApartmentRegionT&&) = delete;
  96
  97  private:
  98   ApartmentRegion mAptRgn;
  99 };
 100
 101 using STARegion = ApartmentRegionT<COINIT_APARTMENTTHREADED>;
 102 using MTARegion = ApartmentRegionT<COINIT_MULTITHREADED>;
 103
 104 }  // namespace mozilla::mscom
 105
 106 #endif  // mozilla_mscom_ApartmentRegion_h