Mojo: Move waiting APIs to public library

mojo/edk/system/wait_set_dispatcher.h

-// Copyright 2015 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_EDK_SYSTEM_WAIT_SET_DISPATCHER_H_
-#define MOJO_EDK_SYSTEM_WAIT_SET_DISPATCHER_H_
-
-#include <stdint.h>
-
-#include <deque>
-#include <memory>
-#include <unordered_map>
-#include <utility>
-
-#include "base/macros.h"
-#include "base/synchronization/lock.h"
-#include "mojo/edk/system/awakable_list.h"
-#include "mojo/edk/system/dispatcher.h"
-#include "mojo/edk/system/system_impl_export.h"
-
-namespace mojo {
-namespace edk {
-
-class MOJO_SYSTEM_IMPL_EXPORT WaitSetDispatcher : public Dispatcher {
- public:
-  WaitSetDispatcher();
-
-  // Dispatcher:
-  Type GetType() const override;
-  MojoResult Close() override;
-  MojoResult AddWaitingDispatcher(const scoped_refptr<Dispatcher>& dispatcher,
-                                  MojoHandleSignals signals,
-                                  uintptr_t context) override;
-  MojoResult RemoveWaitingDispatcher(
-      const scoped_refptr<Dispatcher>& dispatcher) override;
-  MojoResult GetReadyDispatchers(uint32_t* count,
-                                 DispatcherVector* dispatchers,
-                                 MojoResult* results,
-                                 uintptr_t* contexts) override;
-  HandleSignalsState GetHandleSignalsState() const override;
-  MojoResult AddAwakable(Awakable* awakable,
-                         MojoHandleSignals signals,
-                         uintptr_t context,
-                         HandleSignalsState* signals_state) override;
-  void RemoveAwakable(Awakable* awakable,
-                      HandleSignalsState* signals_state) override;
-  bool BeginTransit() override;
-
- private:
-  // Internal implementation of Awakable.
-  class Waiter;
-
-  struct WaitState {
-    WaitState();
-    WaitState(const WaitState& other);
-    ~WaitState();
-
-    scoped_refptr<Dispatcher> dispatcher;
-    MojoHandleSignals signals;
-    uintptr_t context;
-  };
-
-  ~WaitSetDispatcher() override;
-
-  HandleSignalsState GetHandleSignalsStateNoLock() const;
-
-  // Signal that the dispatcher indexed by |context| has been woken up with
-  // |result| and is now ready.
-  void WakeDispatcher(MojoResult result, uintptr_t context);
-
-  // Guards |is_closed_|, |waiting_dispatchers_|, and |waiter_|.
-  //
-  // TODO: Consider removing this.
-  mutable base::Lock lock_;
-  bool is_closed_ = false;
-
-  // Map of dispatchers being waited on. Key is a Dispatcher* casted to a
-  // uintptr_t, and should be treated as an opaque value and not casted back.
-  std::unordered_map<uintptr_t, WaitState> waiting_dispatchers_;
-
-  // Separate lock that can be locked without locking |lock_|.
-  mutable base::Lock awoken_lock_;
-  // List of dispatchers that have been woken up. Any dispatcher in this queue
-  // will NOT currently be waited on.
-  std::deque<std::pair<uintptr_t, MojoResult>> awoken_queue_;
-  // List of dispatchers that have been woken up and retrieved.
-  std::deque<uintptr_t> processed_dispatchers_;
-
-  // Separate lock that can be locked without locking |lock_|.
-  base::Lock awakable_lock_;
-  // List of dispatchers being waited on.
-  AwakableList awakable_list_;
-
-  // Waiter used to wait on dispatchers.
-  std::unique_ptr<Waiter> waiter_;
-
-  DISALLOW_COPY_AND_ASSIGN(WaitSetDispatcher);
-};
-
-}  // namespace edk
-}  // namespace mojo
-
-#endif  // MOJO_EDK_SYSTEM_WAIT_SET_DISPATCHER_H_