From 1ed5a32fd1a33771f12f0eb3329727a3425ed2f3 Mon Sep 17 00:00:00 2001
From: pajlada <rasmus.karlsson@pajlada.com>
Date: Sun, 20 Jul 2025 12:13:41 +0200
Subject: [PATCH] fix: eventsub stopped flag join (#6136)

---
 CHANGELOG.md                                 |  1 +
 src/providers/twitch/eventsub/Controller.cpp | 25 ++++++++++++++------
 src/providers/twitch/eventsub/Controller.hpp |  2 ++
 3 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index bcc9e9be..ca00fef3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -63,6 +63,7 @@
 - Dev: Refactored `Notebook`-related enums into their own file. (#6220)
 - Dev: Refactored `SettingWidget::dropdown` for string enums to the source file. (#6293)
 - Dev: Don't try to save emote popup bounds if we're quitting. (#6292)
+- Dev: Only carefully join EventSub controller thread. (#6136)
 - Dev: Remove `ChannelPageView::addCheckbox`. (#6305)
 - Dev: Remove `ChannelPageView::addIntInput`. (#6306)
 - Dev: Implemented customizable display names for enums. (#6238)
diff --git a/src/providers/twitch/eventsub/Controller.cpp b/src/providers/twitch/eventsub/Controller.cpp
index 91f140e4..f0774b46 100644
--- a/src/providers/twitch/eventsub/Controller.cpp
+++ b/src/providers/twitch/eventsub/Controller.cpp
@@ -40,6 +40,8 @@ const auto &LOG = chatterinoTwitchEventSub;
 
 namespace chatterino::eventsub {
 
+using namespace std::literals::chrono_literals;
+
 class QLogProxy : public lib::Logger
 {
 public:
@@ -79,6 +81,11 @@ Controller::Controller()
     std::tie(this->eventSubHost, this->eventSubPort, this->eventSubPath) =
         getEventSubHost();
     this->thread = std::make_unique<std::thread>([this] {
+        // make sure we set in any case, even exceptions
+        auto guard = qScopeGuard([&] {
+            this->stoppedFlag.set();
+        });
+
         this->ioContext.run();
     });
     renameThread(*this->thread, "C2EventSub");
@@ -111,16 +118,20 @@ Controller::~Controller()
 
     this->work.reset();
 
-    if (this->thread->joinable())
+    if (!this->thread->joinable())
     {
-        this->thread->join();
-    }
-    else
-    {
-        qCWarning(LOG) << "Thread not joinable";
+        qCInfo(LOG) << "Controller dtor end (not joinable)";
+        return;
     }
 
-    qCInfo(LOG) << "Controller dtor end";
+    if (this->stoppedFlag.waitFor(250ms))
+    {
+        this->thread->join();
+        qCInfo(LOG) << "Controller dtor end (joined)";
+        return;
+    }
+
+    qCWarning(LOG) << "Controller dtor end (stopped flag didn't stop)";
 }
 
 void Controller::removeRef(const SubscriptionRequest &request)
diff --git a/src/providers/twitch/eventsub/Controller.hpp b/src/providers/twitch/eventsub/Controller.hpp
index 0b878610..123a0afa 100644
--- a/src/providers/twitch/eventsub/Controller.hpp
+++ b/src/providers/twitch/eventsub/Controller.hpp
@@ -5,6 +5,7 @@
 #include "twitch-eventsub-ws/logger.hpp"
 #include "twitch-eventsub-ws/session.hpp"
 #include "util/ExponentialBackoff.hpp"
+#include "util/OnceFlag.hpp"
 #include "util/ThreadGuard.hpp"
 
 #include <boost/asio/executor_work_guard.hpp>
@@ -149,6 +150,7 @@ private:
     std::unordered_map<SubscriptionRequest, Subscription> subscriptions;
 
     std::atomic<bool> quitting = false;
+    OnceFlag stoppedFlag;
 };
 
 class DummyController : public IController