naiveproxy/base/win/com_init_util.cc
2018-02-02 05:49:39 -05:00

82 lines
2.1 KiB
C++

// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/win/com_init_util.h"
#include <windows.h>
#include <winternl.h>
namespace base {
namespace win {
#if DCHECK_IS_ON()
namespace {
const char kComNotInitialized[] = "COM is not initialized on this thread.";
// Derived from combase.dll.
struct OleTlsData {
enum ApartmentFlags {
LOGICAL_THREAD_REGISTERED = 0x2,
STA = 0x80,
MTA = 0x140,
};
void* thread_base;
void* sm_allocator;
DWORD apartment_id;
DWORD apartment_flags;
// There are many more fields than this, but for our purposes, we only care
// about |apartment_flags|. Correctly declaring the previous types allows this
// to work between x86 and x64 builds.
};
OleTlsData* GetOleTlsData() {
TEB* teb = NtCurrentTeb();
return reinterpret_cast<OleTlsData*>(teb->ReservedForOle);
}
ComApartmentType GetComApartmentTypeForThread() {
OleTlsData* ole_tls_data = GetOleTlsData();
if (!ole_tls_data)
return ComApartmentType::NONE;
if (ole_tls_data->apartment_flags & OleTlsData::ApartmentFlags::STA)
return ComApartmentType::STA;
if ((ole_tls_data->apartment_flags & OleTlsData::ApartmentFlags::MTA) ==
OleTlsData::ApartmentFlags::MTA) {
return ComApartmentType::MTA;
}
return ComApartmentType::NONE;
}
} // namespace
void AssertComInitialized(const char* message) {
if (GetComApartmentTypeForThread() != ComApartmentType::NONE)
return;
// COM worker threads don't always set up the apartment, but they do perform
// some thread registration, so we allow those.
OleTlsData* ole_tls_data = GetOleTlsData();
if (ole_tls_data && (ole_tls_data->apartment_flags &
OleTlsData::ApartmentFlags::LOGICAL_THREAD_REGISTERED)) {
return;
}
NOTREACHED() << (message ? message : kComNotInitialized);
}
void AssertComApartmentType(ComApartmentType apartment_type) {
DCHECK_EQ(apartment_type, GetComApartmentTypeForThread());
}
#endif // DCHECK_IS_ON()
} // namespace win
} // namespace base