Previously, the sig thread ran in THREAD_PRIORITY_HIGHEST priority. This causes a critical delay in the signal handling in the main thread if too many signals are received rapidly and the CPU is very busy. In this case, most of the CPU time is allocated to the sig thread, so the main thread cannot have a chance of handling signals. With this patch, to avoid such a situation, the priority of the sig thread is set to THREAD_PRIORITY_NORMAL priority.
Addresses: https://cygwin.com/pipermail/cygwin/2024-November/256744.html Fixes: 53ad6f1394aa ("(cygthread::cygthread): Use three only arguments for detached threads, and start the thread via QueueUserAPC/async_create.") Reported-by: Christian Franke <christian.fra...@t-online.de> Reviewed-by: Corinna Vinschen <cori...@vinschen.de> Signed-off-by: Takashi Yano <takashi.y...@nifty.ne.jp> --- winsup/cygwin/sigproc.cc | 1 + 1 file changed, 1 insertion(+) diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc index 730259484..4c557f048 100644 --- a/winsup/cygwin/sigproc.cc +++ b/winsup/cygwin/sigproc.cc @@ -1333,6 +1333,7 @@ wait_sig (VOID *) hntdll = GetModuleHandle ("ntdll.dll"); + SetThreadPriority (GetCurrentThread (), THREAD_PRIORITY_NORMAL); for (;;) { DWORD nb; -- 2.45.1
