The commit a22a0ad7c4f0 was not exactly the correct thing. Even with the patch, some hangs still happen. This patch overrides the previous commit to fix these hangs.
Addresses: https://cygwin.com/pipermail/cygwin/2024-December/256954.html Addresses: https://cygwin.com/pipermail/cygwin/2024-December/256987.html Fixes: d243e51ef1d3 ("Cygwin: signal: Fix deadlock between main thread and sig thread") Fixes: a22a0ad7c4f0 ("Cygwin: signal: Do not handle signal when __SIGFLUSHFAST is sent") Reported-by: Daisuke Fujimura <booleanla...@gmail.com> Reported-by: Jeremy Drake <cyg...@jdrake.com> Reviewed-by: Signed-off-by: Takashi Yano <takashi.y...@nifty.ne.jp> --- winsup/cygwin/sigproc.cc | 33 +++++++++++++++++++++++++++------ 1 file changed, 27 insertions(+), 6 deletions(-) diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc index ba7818a68..4dcdd94de 100644 --- a/winsup/cygwin/sigproc.cc +++ b/winsup/cygwin/sigproc.cc @@ -751,8 +751,19 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls) res = WriteFile (sendsig, leader, packsize, &nb, NULL); if (!res || packsize == nb) break; - if (cygwait (NULL, 10, cw_sig_eintr) == WAIT_SIGNALED) - _my_tls.call_signal_handler (); + if (pack.si.si_signo == __SIGFLUSHFAST) + Sleep (10); + else /* Handle signals */ + do + { + DWORD rc = WaitForSingleObject (_my_tls.get_signal_arrived (), 10); + if (rc == WAIT_OBJECT_0) + { + _my_tls.call_signal_handler (); + continue; + } + } + while (false); res = 0; } @@ -785,7 +796,20 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls) if (wait_for_completion) { sigproc_printf ("Waiting for pack.wakeup %p", pack.wakeup); - rc = cygwait (pack.wakeup, WSSC); + if (pack.si.si_signo == __SIGFLUSHFAST) + rc = WaitForSingleObject (pack.wakeup, WSSC); + else /* Handle signals */ + do + { + HANDLE w[2] = {pack.wakeup, _my_tls.get_signal_arrived ()}; + rc = WaitForMultipleObjects (2, w, FALSE, WSSC); + if (rc == WAIT_OBJECT_0 + 1) /* signal arrived */ + { + _my_tls.call_signal_handler (); + continue; + } + } + while (false); ForceCloseHandle (pack.wakeup); } else @@ -806,9 +830,6 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls) rc = -1; } - if (wait_for_completion && si.si_signo != __SIGFLUSHFAST) - _my_tls.call_signal_handler (); - out: if (communing && rc) { -- 2.45.1
