chromium/third_party/ipcz/src/ipcz/router.h

// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef IPCZ_SRC_IPCZ_ROUTER_H_
#define IPCZ_SRC_IPCZ_ROUTER_H_

#include <cstdint>
#include <utility>

#include "ipcz/fragment_ref.h"
#include "ipcz/ipcz.h"
#include "ipcz/parcel_queue.h"
#include "ipcz/pending_transaction_set.h"
#include "ipcz/route_edge.h"
#include "ipcz/router_descriptor.h"
#include "ipcz/router_link.h"
#include "ipcz/sequence_number.h"
#include "ipcz/sublink_id.h"
#include "ipcz/trap_set.h"
#include "third_party/abseil-cpp/absl/base/thread_annotations.h"
#include "third_party/abseil-cpp/absl/synchronization/mutex.h"
#include "util/ref_counted.h"

namespace ipcz {

class NodeLink;
class RemoteRouterLink;
struct RouterLinkState;
class TrapEventDispatcher;

// The Router is the main primitive responsible for routing parcels between ipcz
// portals. This class is thread-safe.
//
// Before a Router can participate in any actual routing, it must have an
// outward link to another Router (see SetOutwardLink()). To establish a locally
// connected pair of Routers, pass both to LocalRouterLink::Create() and pass
// each returned link to the coresponding router:
//
//     Router::Pair routers = {MakeRefCounted<Router>(),
//                             MakeRefCounted<Router>()};
//     RouterLink::Pair links =
//         LocalRouterLink::CreatePair(LinkType::kCentral, routers);
//     routers.first->SetOutwardLink(std::move(links.first));
//     routers.second->SetOutwardLink(std::move(links.second));
//
// Each ipcz portal handle directly controls a terminal Router along its route,
// and all routes stabilize to eventually consist of only two interconnected
// terminal Routers. When a portal moves, its side of the route is extended by
// creating a new terminal Router at the portal's new location. The previous
// terminal Router remains as a proxying hop to be phased out eventually.
class Router : public APIObjectImpl<Router, APIObject::kPortal> { … };

}  // namespace ipcz

#endif  // IPCZ_SRC_IPCZ_ROUTER_H_