1 /* 2 * Copyright 2018 The WebRTC Project Authors. All rights reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef P2P_BASE_REGATHERING_CONTROLLER_H_ 12 #define P2P_BASE_REGATHERING_CONTROLLER_H_ 13 14 #include <memory> 15 16 #include "api/task_queue/pending_task_safety_flag.h" 17 #include "p2p/base/ice_transport_internal.h" 18 #include "p2p/base/port_allocator.h" 19 #include "rtc_base/thread.h" 20 21 namespace webrtc { 22 23 // Controls regathering of candidates for the ICE transport passed into it, 24 // reacting to signals like SignalWritableState, SignalNetworkRouteChange, etc., 25 // using methods like GetStats to get additional information, and calling 26 // methods like RegatherOnFailedNetworks on the PortAllocatorSession when 27 // regathering is desired. 28 // 29 // "Regathering" is defined as gathering additional candidates within a single 30 // ICE generation (or in other words, PortAllocatorSession), and is possible 31 // when "continual gathering" is enabled. This may allow connectivity to be 32 // maintained and/or restored without a full ICE restart. 33 // 34 // Regathering will only begin after PortAllocationSession is set via 35 // set_allocator_session. This should be called any time the "active" 36 // PortAllocatorSession is changed (in other words, when an ICE restart occurs), 37 // so that candidates are gathered for the "current" ICE generation. 38 // 39 // All methods of BasicRegatheringController should be called on the same 40 // thread as the one passed to the constructor, and this thread should be the 41 // same one where PortAllocatorSession runs, which is also identical to the 42 // network thread of the ICE transport, as given by 43 // P2PTransportChannel::thread(). 44 class BasicRegatheringController : public sigslot::has_slots<> { 45 public: 46 struct Config { 47 int regather_on_failed_networks_interval = 48 cricket::REGATHER_ON_FAILED_NETWORKS_INTERVAL; 49 }; 50 51 BasicRegatheringController() = delete; 52 BasicRegatheringController(const Config& config, 53 cricket::IceTransportInternal* ice_transport, 54 rtc::Thread* thread); 55 ~BasicRegatheringController() override; 56 // TODO(qingsi): Remove this method after implementing a new signal in 57 // P2PTransportChannel and reacting to that signal for the initial schedules 58 // of regathering. 59 void Start(); set_allocator_session(cricket::PortAllocatorSession * allocator_session)60 void set_allocator_session(cricket::PortAllocatorSession* allocator_session) { 61 allocator_session_ = allocator_session; 62 } 63 // Setting a different config of the regathering interval range on all 64 // networks cancels and reschedules the recurring schedules, if any, of 65 // regathering on all networks. The same applies to the change of the 66 // regathering interval on the failed networks. This rescheduling behavior is 67 // seperately defined for the two config parameters. 68 void SetConfig(const Config& config); 69 70 private: 71 // TODO(qingsi): Implement the following methods and use methods from the ICE 72 // transport like GetStats to get additional information for the decision 73 // making in regathering. OnIceTransportStateChanged(cricket::IceTransportInternal *)74 void OnIceTransportStateChanged(cricket::IceTransportInternal*) {} OnIceTransportWritableState(rtc::PacketTransportInternal *)75 void OnIceTransportWritableState(rtc::PacketTransportInternal*) {} OnIceTransportReceivingState(rtc::PacketTransportInternal *)76 void OnIceTransportReceivingState(rtc::PacketTransportInternal*) {} OnIceTransportNetworkRouteChanged(absl::optional<rtc::NetworkRoute>)77 void OnIceTransportNetworkRouteChanged(absl::optional<rtc::NetworkRoute>) {} 78 // Schedules delayed and repeated regathering of local candidates on failed 79 // networks, where the delay in milliseconds is given by the config. Each 80 // repetition is separated by the same delay. When scheduled, all previous 81 // schedules are canceled. 82 void ScheduleRecurringRegatheringOnFailedNetworks(); 83 // Cancels regathering scheduled by ScheduleRecurringRegatheringOnAllNetworks. 84 void CancelScheduledRecurringRegatheringOnAllNetworks(); 85 86 // We use a flag to be able to cancel pending regathering operations when 87 // the object goes out of scope or the config changes. 88 std::unique_ptr<ScopedTaskSafety> pending_regathering_; 89 Config config_; 90 cricket::IceTransportInternal* ice_transport_; 91 cricket::PortAllocatorSession* allocator_session_ = nullptr; 92 rtc::Thread* const thread_; 93 }; 94 95 } // namespace webrtc 96 97 #endif // P2P_BASE_REGATHERING_CONTROLLER_H_ 98