chromium/base/files/file_descriptor_watcher_posix.h

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_FILES_FILE_DESCRIPTOR_WATCHER_POSIX_H_
#define BASE_FILES_FILE_DESCRIPTOR_WATCHER_POSIX_H_

#include <memory>

#include "base/auto_reset.h"
#include "base/base_export.h"
#include "base/dcheck_is_on.h"
#include "base/functional/callback.h"
#include "base/memory/raw_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/message_loop/message_pump_for_io.h"
#include "base/sequence_checker.h"
#include "base/synchronization/waitable_event.h"
#include "base/task/single_thread_task_runner.h"

namespace base {

class SingleThreadTaskRunner;

// The FileDescriptorWatcher API allows callbacks to be invoked when file
// descriptors are readable or writable without blocking.
//
// To enable this API in unit tests, use a TaskEnvironment with
// MainThreadType::IO.
//
// Note: Prefer FileDescriptorWatcher to MessageLoopForIO::WatchFileDescriptor()
// for non-critical IO. FileDescriptorWatcher works on threads/sequences without
// MessagePumps but involves going through the task queue after being notified
// by the OS (a desirablable property for non-critical IO that shouldn't preempt
// the main queue).
class BASE_EXPORT FileDescriptorWatcher { … };

}  // namespace base

#endif  // BASE_FILES_FILE_DESCRIPTOR_WATCHER_POSIX_H_