From 107ea4d84950e13be6b7291f506419b1839a0dda Mon Sep 17 00:00:00 2001
From: Andrey Kleshchev <117672381+akleshchev@users.noreply.github.com>
Date: Fri, 19 Dec 2025 13:18:41 +0200
Subject: #5084 Cover window's thread with watchdog

---
 indra/llwindow/llwindowwin32.cpp | 65 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 64 insertions(+), 1 deletion(-)

(limited to 'indra/llwindow/llwindowwin32.cpp')

diff --git a/indra/llwindow/llwindowwin32.cpp b/indra/llwindow/llwindowwin32.cpp
index f826a60ddd..9d05d7e5a4 100644
--- a/indra/llwindow/llwindowwin32.cpp
+++ b/indra/llwindow/llwindowwin32.cpp
@@ -49,6 +49,7 @@
 #include "llthreadsafequeue.h"
 #include "stringize.h"
 #include "llframetimer.h"
+#include "llwatchdog.h"
 
 // System includes
 #include <commdlg.h>
@@ -364,7 +365,8 @@ static LLMonitorInfo sMonitorInfo;
 // the containing class a friend.
 struct LLWindowWin32::LLWindowWin32Thread : public LL::ThreadPool
 {
-    static const int MAX_QUEUE_SIZE = 2048;
+    static constexpr int MAX_QUEUE_SIZE = 2048;
+    static constexpr F32 WINDOW_TIMEOUT_SEC = 90.f;
 
     LLThreadSafeQueue<MSG> mMessageQueue;
 
@@ -426,6 +428,50 @@ struct LLWindowWin32::LLWindowWin32Thread : public LL::ThreadPool
         PostMessage(windowHandle, WM_POST_FUNCTION_, wparam, LPARAM(ptr));
     }
 
+    // Call from main thread.
+    void initTimeout()
+    {
+        // post into thread's queue to avoid threading issues
+        post([this]()
+        {
+            if (!mWindowTimeout)
+            {
+                mWindowTimeout = std::make_unique<LLWatchdogTimeout>("mainloop");
+                // supposed to be executed within run(),
+                // so no point checking if thread is alive
+                resumeTimeout("TimeoutInit");
+            }
+        });
+    }
+private:
+    // These timeout related functions are strictly for the thread.
+    void resumeTimeout(std::string_view state)
+    {
+        if (mWindowTimeout)
+        {
+            mWindowTimeout->setTimeout(WINDOW_TIMEOUT_SEC);
+            mWindowTimeout->start(state);
+        }
+    }
+
+    void pauseTimeout()
+    {
+        if (mWindowTimeout)
+        {
+            mWindowTimeout->stop();
+        }
+    }
+
+    void pingTimeout(std::string_view state)
+    {
+        if (mWindowTimeout)
+        {
+            mWindowTimeout->setTimeout(WINDOW_TIMEOUT_SEC);
+            mWindowTimeout->ping(state);
+        }
+    }
+
+public:
     using FuncType = std::function<void()>;
     // call GetMessage() and pull enqueue messages for later processing
     HWND mWindowHandleThrd = NULL;
@@ -436,6 +482,8 @@ struct LLWindowWin32::LLWindowWin32Thread : public LL::ThreadPool
     bool mGLReady = false;
     bool mGotGLBuffer = false;
     LLAtomicBool mDeleteOnExit = false;
+private:
+    std::unique_ptr<LLWatchdogTimeout> mWindowTimeout;
 };
 
 
@@ -4595,6 +4643,11 @@ bool LLWindowWin32::getInputDevices(U32 device_type_filter,
     return false;
 }
 
+void LLWindowWin32::initWatchdog()
+{
+    mWindowThread->initTimeout();
+}
+
 F32 LLWindowWin32::getSystemUISize()
 {
     F32 scale_value = 1.f;
@@ -4732,6 +4785,8 @@ void LLWindowWin32::LLWindowWin32Thread::checkDXMem()
         return;
     }
 
+    pauseTimeout();
+
     IDXGIFactory4* p_factory = nullptr;
 
     HRESULT res = CreateDXGIFactory1(__uuidof(IDXGIFactory4), (void**)&p_factory);
@@ -4835,6 +4890,8 @@ void LLWindowWin32::LLWindowWin32Thread::checkDXMem()
     }
 
     mGotGLBuffer = true;
+
+    resumeTimeout("checkDXMem");
 }
 
 void LLWindowWin32::LLWindowWin32Thread::run()
@@ -4850,6 +4907,9 @@ void LLWindowWin32::LLWindowWin32Thread::run()
         timeBeginPeriod(llclamp((U32) 1, tc.wPeriodMin, tc.wPeriodMax));
     }
 
+    // Normally won't exist yet, but in case of re-init, make sure it's cleaned up
+    resumeTimeout("WindowThread");
+
     while (! getQueue().done())
     {
         LL_PROFILE_ZONE_SCOPED_CATEGORY_WIN32;
@@ -4859,6 +4919,7 @@ void LLWindowWin32::LLWindowWin32Thread::run()
 
         if (mWindowHandleThrd != 0)
         {
+            pingTimeout("messages");
             MSG msg;
             BOOL status;
             if (mhDCThrd == 0)
@@ -4886,6 +4947,7 @@ void LLWindowWin32::LLWindowWin32Thread::run()
 
         {
             LL_PROFILE_ZONE_NAMED_CATEGORY_WIN32("w32t - Function Queue");
+            pingTimeout("queue");
             logger.onChange("runPending()");
             //process any pending functions
             getQueue().runPending();
@@ -4900,6 +4962,7 @@ void LLWindowWin32::LLWindowWin32Thread::run()
 #endif
     }
 
+    pauseTimeout();
     destroyWindow();
 
     if (mDeleteOnExit)
-- 
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