blob: edc223865bada7e557da945fecc7a635c2ab1eff [file] [log] [blame]
// Copyright (c) 2012 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 <memory>
#include "base/macros.h"
#include "base/threading/thread.h"
#include "base/threading/thread_checker.h"
#include "build/build_config.h"
#include "content/common/content_export.h"
#include "content/public/browser/browser_thread.h"
#if defined(OS_WIN)
namespace base {
namespace win {
class ScopedCOMInitializer;
namespace content {
class NotificationService;
namespace content {
// ----------------------------------------------------------------------------
// A BrowserProcessSubThread is a physical thread backing a BrowserThread.
// Applications must initialize the COM library before they can call
// COM library functions other than CoGetMalloc and memory allocation
// functions, so this class initializes COM for those users.
class CONTENT_EXPORT BrowserProcessSubThread : public base::Thread {
// Constructs a BrowserProcessSubThread for |identifier|.
explicit BrowserProcessSubThread(BrowserThread::ID identifier);
~BrowserProcessSubThread() override;
// Registers this thread to represent |identifier_| in the browser_thread.h
// API. This thread must already be running when this is called. This can only
// be called once per BrowserProcessSubThread instance.
void RegisterAsBrowserThread();
// Ideally there wouldn't be a special blanket allowance to block the
// BrowserThreads in tests but TestBrowserThreadImpl previously bypassed
// BrowserProcessSubThread and hence wasn't subject to ThreadRestrictions...
// Flipping that around in favor of explicit scoped allowances would be
// preferable but a non-trivial amount of work. Can only be called before
// starting this BrowserProcessSubThread.
void AllowBlockingForTesting();
// Creates and starts the IO thread. It should not be promoted to
// BrowserThread::IO until BrowserMainLoop::CreateThreads().
static std::unique_ptr<BrowserProcessSubThread> CreateIOThread();
void Init() override;
void Run(base::RunLoop* run_loop) override;
void CleanUp() override;
// Second Init() phase that must happen on this thread but can only happen
// after it's promoted to a BrowserThread in |RegisterAsBrowserThread()|.
void CompleteInitializationOnBrowserThread();
// These methods merely forwards to Thread::Run() but are useful to identify
// which BrowserThread this represents in stack traces.
void UIThreadRun(base::RunLoop* run_loop);
void IOThreadRun(base::RunLoop* run_loop);
// This method encapsulates cleanup that needs to happen on the IO thread.
void IOThreadCleanUp();
const BrowserThread::ID identifier_;
// BrowserThreads are not allowed to do file I/O nor wait on synchronization
// primivives except when explicitly allowed in tests.
bool is_blocking_allowed_for_testing_ = false;
// The BrowserThread registration for this |identifier_|, initialized in
// RegisterAsBrowserThread().
std::unique_ptr<BrowserThreadImpl> browser_thread_;
#if defined (OS_WIN)
std::unique_ptr<base::win::ScopedCOMInitializer> com_initializer_;
// Each specialized thread has its own notification service.
std::unique_ptr<NotificationService> notification_service_;
} // namespace content