commit 6f170a05dc27b0add7d9f351585b96e644382b1c
author Harald Alvestrand <hta@webrtc.org> Mon Apr 22 10:22:08 2024
committer WebRTC LUCI CQ <webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com> Mon Apr 22 12:29:56 2024
tree c5dbc5c19e4751249aeecdd02b70a296a990e709
parent 5bd0a32859ab476c0fe2cde25c07ad7544491dcc

Convert P2PtransportChannel.GatheringState to CallbackList

Earlier attempts have shown that this signal is multiply listened to.

Bug: webrtc:11943
Change-Id: I382df9a554925d214872d788c5d7a36f2f7c7b7e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/348661
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42139}

p2p/base/ice_transport_internal.h

diff --git a/p2p/base/ice_transport_internal.h b/p2p/base/ice_transport_internal.h
index 38b6bfe..32e913d 100644
--- a/p2p/base/ice_transport_internal.h
+++ b/p2p/base/ice_transport_internal.h
@@ -306,10 +306,14 @@
 
   // Signal Exposed for backwards compatibility.
   sigslot::signal1<IceTransportInternal*> SignalGatheringState;
-  void SetGatheringStateCallback(
+  void AddGatheringStateCallback(
+      const void* removal_tag,
       absl::AnyInvocable<void(IceTransportInternal*)> callback) {
-    RTC_DCHECK(!gathering_state_callback_);
-    gathering_state_callback_ = std::move(callback);
+    gathering_state_callback_list_.AddReceiver(removal_tag,
+                                               std::move(callback));
+  }
+  void RemoveGatheringStateCallback(const void* removal_tag) {
+    gathering_state_callback_list_.RemoveReceivers(removal_tag);
   }
 
   // Handles sending and receiving of candidates.
@@ -393,7 +397,7 @@
   webrtc::CallbackList<IceTransportInternal*, const StunDictionaryWriter&>
       dictionary_writer_synced_callback_list_;
 
-  absl::AnyInvocable<void(IceTransportInternal*)> gathering_state_callback_;
+  webrtc::CallbackList<IceTransportInternal*> gathering_state_callback_list_;
 
   absl::AnyInvocable<void(IceTransportInternal*, const IceCandidateErrorEvent&)>
       candidate_error_callback_;
@@ -407,9 +411,7 @@
  private:
   // TODO(bugs.webrtc.org/11943): remove when removing Signal
   void SignalGatheringStateFired(IceTransportInternal* transport) {
-    if (gathering_state_callback_) {
-      gathering_state_callback_(transport);
-    }
+    gathering_state_callback_list_.Send(transport);
   }
 };
 

pc/jsep_transport_controller.cc

diff --git a/pc/jsep_transport_controller.cc b/pc/jsep_transport_controller.cc
index dae7060..7152826 100644
--- a/pc/jsep_transport_controller.cc
+++ b/pc/jsep_transport_controller.cc
@@ -439,8 +439,8 @@
       this, &JsepTransportController::OnTransportWritableState_n);
   dtls->SignalReceivingState.connect(
       this, &JsepTransportController::OnTransportReceivingState_n);
-  dtls->ice_transport()->SetGatheringStateCallback(
-      [this](cricket::IceTransportInternal* transport) {
+  dtls->ice_transport()->AddGatheringStateCallback(
+      this, [this](cricket::IceTransportInternal* transport) {
         RTC_DCHECK_RUN_ON(network_thread_);
         OnTransportGatheringState_n(transport);
       });