blob: 43a94f17f3658f64cbff0b43a6395643393773d7 [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 "base/memory/scoped_refptr.h"
#include "base/single_thread_task_runner.h"
#include "build/build_config.h"
#include "content/common/content_export.h"
#include "content/public/browser/browser_thread.h"
#if defined(OS_POSIX)
#include "base/files/file_descriptor_watcher_posix.h"
#include "base/optional.h"
namespace content {
class BrowserMainLoop;
class BrowserProcessSubThread;
class TestBrowserThread;
// BrowserThreadImpl is a scoped object which maps a SingleThreadTaskRunner to a
// BrowserThread::ID. On ~BrowserThreadImpl() that ID enters a SHUTDOWN state
// (in which BrowserThread::IsThreadInitialized() returns false) but the mapping
// isn't undone to avoid shutdown races (the task runner is free to stop
// accepting tasks by then however).
// Very few users should use this directly. To mock BrowserThreads, tests should
// use TestBrowserThreadBundle instead.
class CONTENT_EXPORT BrowserThreadImpl : public BrowserThread {
// Returns the thread name for |identifier|.
static const char* GetThreadName(BrowserThread::ID identifier);
// Resets globals for |identifier|. Used in tests to clear global state that
// would otherwise leak to the next test. Globals are not otherwise fully
// cleaned up in ~BrowserThreadImpl() as there are subtle differences between
// UNINITIALIZED and SHUTDOWN state (e.g. globals.task_runners are kept around
// on shutdown). Must be called after ~BrowserThreadImpl() for the given
// |identifier|.
static void ResetGlobalsForTesting(BrowserThread::ID identifier);
// Exposed for BrowserTaskExecutor. Other code should use
// base::CreateSingleThreadTaskRunnerWithTraits({BrowserThread::UI/IO}).
using BrowserThread::GetTaskRunnerForThread;
// Restrict instantiation to BrowserProcessSubThread as it performs important
// initialization that shouldn't be bypassed (except by BrowserMainLoop for
// the main thread).
friend class BrowserProcessSubThread;
friend class BrowserMainLoop;
// TestBrowserThread is also allowed to construct this when instantiating fake
// threads.
friend class TestBrowserThread;
// Binds |identifier| to |task_runner| for the browser_thread.h API. This
// needs to happen on the main thread before //content and embedders are
// kicked off and enabled to invoke the BrowserThread API from other threads.
BrowserThreadImpl(BrowserThread::ID identifier,
scoped_refptr<base::SingleThreadTaskRunner> task_runner);
// The identifier of this thread. Only one thread can exist with a given
// identifier at a given time.
ID identifier_;
#if defined(OS_POSIX)
// Allows usage of the FileDescriptorWatcher API on the UI thread.
base::Optional<base::FileDescriptorWatcher> file_descriptor_watcher_;
} // namespace content