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// Copyright 2016 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.
#ifndef MOJO_CORE_WATCHER_SET_H_
#define MOJO_CORE_WATCHER_SET_H_
#include "base/containers/flat_map.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/optional.h"
#include "mojo/core/handle_signals_state.h"
#include "mojo/core/watcher_dispatcher.h"
namespace mojo {
namespace core {
// A WatcherSet maintains a set of references to WatcherDispatchers to be
// notified when a handle changes state.
//
// Dispatchers which may be watched by a watcher should own a WatcherSet and
// notify it of all relevant state changes.
class WatcherSet {
public:
// |owner| is the Dispatcher who owns this WatcherSet.
explicit WatcherSet(Dispatcher* owner);
~WatcherSet();
// Notifies all watchers of the handle's current signals state.
void NotifyState(const HandleSignalsState& state);
// Notifies all watchers that this handle has been closed.
void NotifyClosed();
// Adds a new watcher+context.
MojoResult Add(const scoped_refptr<WatcherDispatcher>& watcher,
uintptr_t context,
const HandleSignalsState& current_state);
// Removes a watcher+context.
MojoResult Remove(WatcherDispatcher* watcher, uintptr_t context);
private:
using ContextSet = std::set<uintptr_t>;
struct Entry {
Entry(const scoped_refptr<WatcherDispatcher>& dispatcher);
Entry(Entry&& other);
~Entry();
Entry& operator=(Entry&& other);
scoped_refptr<WatcherDispatcher> dispatcher;
ContextSet contexts;
private:
DISALLOW_COPY_AND_ASSIGN(Entry);
};
Dispatcher* const owner_;
base::flat_map<WatcherDispatcher*, Entry> watchers_;
base::Optional<HandleSignalsState> last_known_state_;
DISALLOW_COPY_AND_ASSIGN(WatcherSet);
};
} // namespace core
} // namespace mojo
#endif // MOJO_CORE_WATCHER_SET_H_