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// Copyright 2018 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef BASE_MESSAGE_PUMP_IO_STARBOARD_H_
#define BASE_MESSAGE_PUMP_IO_STARBOARD_H_
#include "base/compiler_specific.h"
#include "base/memory/weak_ptr.h"
#include "base/message_loop/message_pump.h"
#include "base/observer_list.h"
#include "base/threading/thread_checker.h"
#include "base/time/time.h"
#include "starboard/common/socket.h"
#include "starboard/socket_waiter.h"
namespace base {
// Class to monitor sockets and issue callbacks when sockets are ready for I/O.
class BASE_EXPORT MessagePumpIOStarboard : public MessagePump {
public:
class IOObserver : public CheckedObserver {
public:
IOObserver() {}
virtual ~IOObserver() {}
// An IOObserver is an object that receives IO notifications from the
// MessagePump.
//
// NOTE: An IOObserver should not do much work, it should return extremely
// quickly!
virtual void WillProcessIOEvent() = 0;
virtual void DidProcessIOEvent() = 0;
};
// Used with WatchFileDescriptor to asynchronously monitor the I/O readiness
// of a file descriptor.
class Watcher {
public:
// These methods are called from MessageLoop::Run when a socket can be
// interacted with without blocking.
virtual void OnSocketReadyToRead(SbSocket socket) {}
virtual void OnSocketReadyToWrite(SbSocket socket) {}
protected:
virtual ~Watcher() {}
};
// Object returned by WatchSocket to manage further watching.
class SocketWatcher {
public:
SocketWatcher();
~SocketWatcher(); // Implicitly calls StopWatchingSocket.
// NOTE: These methods aren't called StartWatching()/StopWatching() to avoid
// confusion with the win32 ObjectWatcher class.
// Stops watching the socket, always safe to call. No-op if there's nothing
// to do.
bool StopWatchingSocket();
bool persistent() const { return persistent_; }
private:
friend class MessagePumpIOStarboard;
friend class MessagePumpIOStarboardTest;
// Called by MessagePumpIOStarboard.
void Init(SbSocket socket, bool persistent);
SbSocket Release();
int interests() const { return interests_; }
void set_interests(int interests) { interests_ = interests; }
void set_pump(MessagePumpIOStarboard* pump) { pump_ = pump; }
MessagePumpIOStarboard* pump() const { return pump_; }
void set_watcher(Watcher* watcher) { watcher_ = watcher; }
void OnSocketReadyToRead(SbSocket socket, MessagePumpIOStarboard* pump);
void OnSocketReadyToWrite(SbSocket socket, MessagePumpIOStarboard* pump);
int interests_;
SbSocket socket_;
bool persistent_;
MessagePumpIOStarboard* pump_;
Watcher* watcher_;
base::WeakPtrFactory<SocketWatcher> weak_factory_;
DISALLOW_COPY_AND_ASSIGN(SocketWatcher);
};
enum Mode {
WATCH_READ = 1 << 0,
WATCH_WRITE = 1 << 1,
WATCH_READ_WRITE = WATCH_READ | WATCH_WRITE
};
MessagePumpIOStarboard();
// Have the current thread's message loop watch for a a situation in which
// reading/writing to the socket can be performed without blocking. Callers
// must provide a preallocated SocketWatcher object which can later be used to
// manage the lifetime of this event. If a SocketWatcher is passed in which
// is already attached to a socket, then the effect is cumulative i.e. after
// the call |controller| will watch both the previous event and the new one.
// If an error occurs while calling this method in a cumulative fashion, the
// event previously attached to |controller| is aborted. Returns true on
// success. Must be called on the same thread the message_pump is running on.
bool Watch(SbSocket socket,
bool persistent,
int mode,
SocketWatcher* controller,
Watcher* delegate);
// Stops watching the socket.
bool StopWatching(SbSocket socket);
void AddIOObserver(IOObserver* obs);
void RemoveIOObserver(IOObserver* obs);
// MessagePump methods:
virtual void Run(Delegate* delegate) override;
virtual void Quit() override;
virtual void ScheduleWork() override;
virtual void ScheduleDelayedWork(const TimeTicks& delayed_work_time) override;
protected:
virtual ~MessagePumpIOStarboard();
private:
friend class MessagePumpIOStarboardTest;
void WillProcessIOEvent();
void DidProcessIOEvent();
// Called by SbSocketWaiter to tell us a registered socket can be read and/or
// written to.
static void OnSocketWaiterNotification(SbSocketWaiter waiter,
SbSocket socket,
void* context,
int ready_interests);
// This flag is set to false when Run should return.
bool keep_running_;
// This flag is set when inside Run.
bool in_run_;
// This flag is set if the Socket Waiter has processed I/O events.
bool processed_io_events_;
// The time at which we should call DoDelayedWork.
TimeTicks delayed_work_time_;
// Starboard socket waiter dispatcher. Waits for all sockets registered with
// it, and sends readiness callbacks when a socket is ready for I/O.
SbSocketWaiter waiter_;
ObserverList<IOObserver> io_observers_;
THREAD_CHECKER(watch_socket_caller_checker_);
DISALLOW_COPY_AND_ASSIGN(MessagePumpIOStarboard);
};
using MessagePumpForIO = MessagePumpIOStarboard;
} // namespace base
#endif // BASE_MESSAGE_PUMP_IO_STARBOARD_H_