[Lldb-commits] [lldb] [lldb] Adjust MainLoop on Win32 to work with mingw (PR #163419)

[John Harrison via lldb-commits]

https://github.com/ashgti created https://github.com/llvm/llvm-project/pull/163419

This adjusts the monitor tear down to only call CancelIoEx a single time, which should cancel all IO operations in the monitoring thread, instead of calling it in a loop.

This removes the `m_monitor_thread.native_handle()` call that returns a different type on windows/mingw compiles with pthreads enabled and should fix #162801.

>From b33aaee0f71b5efd55dedfcae7c7bbea0c58d642 Mon Sep 17 00:00:00 2001
From: John Harrison <harjohn at google.com>
Date: Tue, 14 Oct 2025 09:20:34 -0700
Subject: [PATCH] [lldb] Adjust MainLoop on Win32 to work with mingw

This adjusts the monitor tear down to only call CancelIoEx a single time, which should cancel all IO operations in the monitoring thread, instead of calling it in a loop.

This removes the `m_monitor_thread.native_handle()` call that returns a different type on windows/mingw compiles with pthreads enabled and should fix #162801.
---
 lldb/source/Host/windows/MainLoopWindows.cpp | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/lldb/source/Host/windows/MainLoopWindows.cpp b/lldb/source/Host/windows/MainLoopWindows.cpp
index c0b10797e506a..9b7df10258bcd 100644
--- a/lldb/source/Host/windows/MainLoopWindows.cpp
+++ b/lldb/source/Host/windows/MainLoopWindows.cpp
@@ -55,11 +55,7 @@ class PipeEvent : public MainLoopWindows::IOEvent {
     if (m_monitor_thread.joinable()) {
       m_stopped = true;
       SetEvent(m_ready);
-      // Keep trying to cancel ReadFile() until the thread exits.
-      do {
-        CancelIoEx(m_handle, /*lpOverlapped=*/NULL);
-      } while (WaitForSingleObject(m_monitor_thread.native_handle(), 1) ==
-               WAIT_TIMEOUT);
+      CancelIoEx(m_handle, /*lpOverlapped=*/NULL);
       m_monitor_thread.join();
     }
     CloseHandle(m_event);