commit ac87c8df2780cb12c74942ec8a473718c76cb5b7
author Tommi <tommi@webrtc.org> Thu Mar 16 21:17:38 2023
committer WebRTC LUCI CQ <webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu Mar 16 23:22:15 2023
tree b29415b2f6117275699d9e543e3726abe0198e23
parent c4edef7c738bf224a22b9a70532acd4e658cf4ab

Temporary fix to guard against sctp_data_channels_ being modified.

Following https://webrtc-review.googlesource.com/c/src/+/297100
it seems that sctp_data_channels_ gets modified while we're iterating
through it. This temporary fix creates a copy of the array and iterates
through the copy instead of sctp_data_channels_. A follow-up CL (or CLs)
will provide more clarity, testing and regression guards.

Bug: webrtc:15004
Change-Id: I0cb5dfb6829d36b51328875c8c9cfa392ff393a7
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/297981
Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39584}

pc/data_channel_controller.cc

diff --git a/pc/data_channel_controller.cc b/pc/data_channel_controller.cc
index ca50c34..5ff3b1c 100644
--- a/pc/data_channel_controller.cc
+++ b/pc/data_channel_controller.cc
@@ -100,7 +100,8 @@
         RTC_DCHECK_RUN_ON(signaling_thread());
         // TODO(bugs.webrtc.org/11547): The data being received should be
         // delivered on the network thread.
-        for (const auto& channel : sctp_data_channels_) {
+        auto copy = sctp_data_channels_;
+        for (const auto& channel : copy) {
           if (channel->id() == channel_id)
             channel->OnDataReceived(type, buffer);
         }
@@ -113,7 +114,8 @@
       SafeTask(signaling_safety_.flag(), [this, channel_id] {
         RTC_DCHECK_RUN_ON(signaling_thread());
         // TODO(bugs.webrtc.org/11547): Should run on the network thread.
-        for (const auto& channel : sctp_data_channels_) {
+        auto copy = sctp_data_channels_;
+        for (const auto& channel : copy) {
           if (channel->id() == channel_id)
             channel->OnClosingProcedureStartedRemotely();
         }
@@ -147,7 +149,8 @@
   signaling_thread()->PostTask(SafeTask(signaling_safety_.flag(), [this] {
     RTC_DCHECK_RUN_ON(signaling_thread());
     data_channel_transport_ready_to_send_ = true;
-    for (const auto& channel : sctp_data_channels_)
+    auto copy = sctp_data_channels_;
+    for (const auto& channel : copy)
       channel->OnTransportReady(true);
   }));
 }
@@ -408,7 +411,8 @@
   RTC_DCHECK_RUN_ON(network_thread());
   signaling_thread()->PostTask(SafeTask(signaling_safety_.flag(), [this] {
     RTC_DCHECK_RUN_ON(signaling_thread());
-    for (const auto& channel : sctp_data_channels_) {
+    auto copy = sctp_data_channels_;
+    for (const auto& channel : copy) {
       channel->OnTransportChannelCreated();
     }
   }));