gecko-dev/ipc/mscom/ActivationContext.cpp

/* -*- 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/. */

#include "mozilla/mscom/ActivationContext.h"

#include "mozilla/Assertions.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/mscom/Utils.h"

namespace mozilla {
namespace mscom {

ActivationContext::ActivationContext(WORD aResourceId)
    : ActivationContext(reinterpret_cast<HMODULE>(GetContainingModuleHandle()),
                        aResourceId) {}

ActivationContext::ActivationContext(HMODULE aLoadFromModule, WORD aResourceId)
    : mActCtx(INVALID_HANDLE_VALUE) {
  ACTCTX actCtx = {sizeof(actCtx)};
  actCtx.dwFlags = ACTCTX_FLAG_RESOURCE_NAME_VALID | ACTCTX_FLAG_HMODULE_VALID;
  actCtx.lpResourceName = MAKEINTRESOURCE(aResourceId);
  actCtx.hModule = aLoadFromModule;

  Init(actCtx);
}

void ActivationContext::Init(ACTCTX& aActCtx) {
  MOZ_ASSERT(mActCtx == INVALID_HANDLE_VALUE);
  mActCtx = ::CreateActCtx(&aActCtx);
  MOZ_ASSERT(mActCtx != INVALID_HANDLE_VALUE);
}

void ActivationContext::AddRef() {
  if (mActCtx == INVALID_HANDLE_VALUE) {
    return;
  }
  ::AddRefActCtx(mActCtx);
}

ActivationContext::ActivationContext(ActivationContext&& aOther)
    : mActCtx(aOther.mActCtx) {
  aOther.mActCtx = INVALID_HANDLE_VALUE;
}

ActivationContext& ActivationContext::operator=(ActivationContext&& aOther) {
  Release();

  mActCtx = aOther.mActCtx;
  aOther.mActCtx = INVALID_HANDLE_VALUE;
  return *this;
}

ActivationContext::ActivationContext(const ActivationContext& aOther)
    : mActCtx(aOther.mActCtx) {
  AddRef();
}

ActivationContext& ActivationContext::operator=(
    const ActivationContext& aOther) {
  Release();
  mActCtx = aOther.mActCtx;
  AddRef();
  return *this;
}

void ActivationContext::Release() {
  if (mActCtx == INVALID_HANDLE_VALUE) {
    return;
  }
  ::ReleaseActCtx(mActCtx);
  mActCtx = INVALID_HANDLE_VALUE;
}

ActivationContext::~ActivationContext() { Release(); }

#if defined(MOZILLA_INTERNAL_API)

/* static */ Result<uintptr_t, HRESULT> ActivationContext::GetCurrent() {
  HANDLE actCtx;
  if (!::GetCurrentActCtx(&actCtx)) {
    return Result<uintptr_t, HRESULT>(HRESULT_FROM_WIN32(::GetLastError()));
  }

  return reinterpret_cast<uintptr_t>(actCtx);
}

/* static */
HRESULT ActivationContext::GetCurrentManifestPath(nsAString& aOutManifestPath) {
  aOutManifestPath.Truncate();

  SIZE_T bytesNeeded;
  BOOL ok = ::QueryActCtxW(QUERY_ACTCTX_FLAG_USE_ACTIVE_ACTCTX, nullptr,
                           nullptr, ActivationContextDetailedInformation,
                           nullptr, 0, &bytesNeeded);
  if (!ok) {
    DWORD err = ::GetLastError();
    if (err != ERROR_INSUFFICIENT_BUFFER) {
      return HRESULT_FROM_WIN32(err);
    }
  }

  auto ctxBuf = MakeUnique<BYTE[]>(bytesNeeded);

  ok = ::QueryActCtxW(QUERY_ACTCTX_FLAG_USE_ACTIVE_ACTCTX, nullptr, nullptr,
                      ActivationContextDetailedInformation, ctxBuf.get(),
                      bytesNeeded, nullptr);
  if (!ok) {
    return HRESULT_FROM_WIN32(::GetLastError());
  }

  auto ctxInfo =
      reinterpret_cast<ACTIVATION_CONTEXT_DETAILED_INFORMATION*>(ctxBuf.get());

  // assemblyIndex is 1-based, and we want the last index, so we can just copy
  // ctxInfo->ulAssemblyCount directly.
  DWORD assemblyIndex = ctxInfo->ulAssemblyCount;
  ok = ::QueryActCtxW(
      QUERY_ACTCTX_FLAG_USE_ACTIVE_ACTCTX, nullptr, &assemblyIndex,
      AssemblyDetailedInformationInActivationContext, nullptr, 0, &bytesNeeded);
  if (!ok) {
    DWORD err = ::GetLastError();
    if (err != ERROR_INSUFFICIENT_BUFFER) {
      return HRESULT_FROM_WIN32(err);
    }
  }

  auto assemblyBuf = MakeUnique<BYTE[]>(bytesNeeded);

  ok = ::QueryActCtxW(QUERY_ACTCTX_FLAG_USE_ACTIVE_ACTCTX, nullptr,
                      &assemblyIndex,
                      AssemblyDetailedInformationInActivationContext,
                      assemblyBuf.get(), bytesNeeded, &bytesNeeded);
  if (!ok) {
    return HRESULT_FROM_WIN32(::GetLastError());
  }

  auto assemblyInfo =
      reinterpret_cast<ACTIVATION_CONTEXT_ASSEMBLY_DETAILED_INFORMATION*>(
          assemblyBuf.get());
  aOutManifestPath = nsDependentString(
      assemblyInfo->lpAssemblyManifestPath,
      (assemblyInfo->ulManifestPathLength + 1) / sizeof(wchar_t));

  return S_OK;
}

#endif  // defined(MOZILLA_INTERNAL_API)

ActivationContextRegion::ActivationContextRegion() : mActCookie(0) {}

ActivationContextRegion::ActivationContextRegion(
    const ActivationContext& aActCtx)
    : mActCtx(aActCtx), mActCookie(0) {
  Activate();
}

ActivationContextRegion& ActivationContextRegion::operator=(
    const ActivationContext& aActCtx) {
  Deactivate();
  mActCtx = aActCtx;
  Activate();
  return *this;
}

ActivationContextRegion::ActivationContextRegion(ActivationContext&& aActCtx)
    : mActCtx(std::move(aActCtx)), mActCookie(0) {
  Activate();
}

ActivationContextRegion& ActivationContextRegion::operator=(
    ActivationContext&& aActCtx) {
  Deactivate();
  mActCtx = std::move(aActCtx);
  Activate();
  return *this;
}

ActivationContextRegion::ActivationContextRegion(ActivationContextRegion&& aRgn)
    : mActCtx(std::move(aRgn.mActCtx)), mActCookie(aRgn.mActCookie) {
  aRgn.mActCookie = 0;
}

ActivationContextRegion& ActivationContextRegion::operator=(
    ActivationContextRegion&& aRgn) {
  Deactivate();
  mActCtx = std::move(aRgn.mActCtx);
  mActCookie = aRgn.mActCookie;
  aRgn.mActCookie = 0;
  return *this;
}

void ActivationContextRegion::Activate() {
  if (mActCtx.mActCtx == INVALID_HANDLE_VALUE) {
    return;
  }

#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
  BOOL activated =
#endif
      ::ActivateActCtx(mActCtx.mActCtx, &mActCookie);
  MOZ_DIAGNOSTIC_ASSERT(activated);
}

bool ActivationContextRegion::Deactivate() {
  if (!mActCookie) {
    return true;
  }

  BOOL deactivated = ::DeactivateActCtx(0, mActCookie);
  MOZ_DIAGNOSTIC_ASSERT(deactivated);
  if (deactivated) {
    mActCookie = 0;
  }

  return !!deactivated;
}

ActivationContextRegion::~ActivationContextRegion() { Deactivate(); }

}  // namespace mscom
}  // namespace mozilla