From acc7fa67549cd8f29a5b0f70eb9c8187df97f504 Mon Sep 17 00:00:00 2001
From: Ken Sanislo <ken@intherack.com>
Date: Sun, 26 Jul 2026 22:47:18 +0000
Subject: [PATCH] Invoke resource manager callbacks outside the callback mutex

---
 ResourceManager.cpp                | 20 ++++++++++++++++----
 qt/OpenRGBDialog/OpenRGBDialog.cpp |  8 ++++++++
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/ResourceManager.cpp b/ResourceManager.cpp
index 0366ce14f..83fa7aaaa 100644
--- a/ResourceManager.cpp
+++ b/ResourceManager.cpp
@@ -811,15 +811,27 @@ void ResourceManager::SignalResourceManagerUpdate(unsigned int update_reason)
         server->SignalResourceManagerUpdate(update_reason);
     }
 
+    /*-----------------------------------------------------*\
+    | Snapshot the callback list, then invoke unlocked. A   |
+    | blocking callback must not hold the mutex: the GUI's  |
+    | blocking device list callback waits forever once the  |
+    | event loop has exited at shutdown, and a held mutex   |
+    | then deadlocks the unregister in the dialog           |
+    | destructor. A callback may still fire once after its  |
+    | unregister returns.                                   |
+    \*-----------------------------------------------------*/
     ResourceManagerCallbackMutex.lock();
 
-    for(std::size_t callback_idx = 0; callback_idx < ResourceManagerCallbacks.size(); callback_idx++)
-    {
-        ResourceManagerCallbacks[callback_idx](ResourceManagerCallbackArgs[callback_idx], update_reason);
-    }
+    std::vector<ResourceManagerCallback>    callbacks       = ResourceManagerCallbacks;
+    std::vector<void *>                     callback_args   = ResourceManagerCallbackArgs;
 
     ResourceManagerCallbackMutex.unlock();
 
+    for(std::size_t callback_idx = 0; callback_idx < callbacks.size(); callback_idx++)
+    {
+        callbacks[callback_idx](callback_args[callback_idx], update_reason);
+    }
+
     LOG_TRACE("[%s] ResourceManager update signalled: %d", RESOURCEMANAGER, update_reason);
 }
 
diff --git a/qt/OpenRGBDialog/OpenRGBDialog.cpp b/qt/OpenRGBDialog/OpenRGBDialog.cpp
index ab19e8200..910dd8bb0 100644
--- a/qt/OpenRGBDialog/OpenRGBDialog.cpp
+++ b/qt/OpenRGBDialog/OpenRGBDialog.cpp
@@ -577,6 +577,14 @@ void OpenRGBDialog::closeEvent(QCloseEvent *event)
     }
     else
     {
+        /*-------------------------------------------------*\
+        | Stop receiving resource manager callbacks before  |
+        | the event loop dies: plugin teardown signals from |
+        | worker threads would post blocking calls no loop  |
+        | will ever service.                                |
+        \*-------------------------------------------------*/
+        ResourceManager::get()->UnregisterResourceManagerCallback(OpenRGBDialogResourceManagerCallback, this);
+
         plugin_manager->UnloadPlugins();
 
         if(ResourceManager::get()->GetProfileManager()->LoadAutoProfileExit())