From 3a74630f7542c12f58f1a23d696b6b5f647b70d4 Mon Sep 17 00:00:00 2001 From: Corinna Vinschen Date: Mon, 23 Mar 2020 13:08:32 +0100 Subject: [PATCH] Cygwin: serial: select: fix WaitCommEvent request - make sure event object is reset - set read_ready to true if WaitCommEvent returns success - improve debugging Signed-off-by: Corinna Vinschen --- winsup/cygwin/select.cc | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/winsup/cygwin/select.cc b/winsup/cygwin/select.cc index e11f5850a..07e0d82fb 100644 --- a/winsup/cygwin/select.cc +++ b/winsup/cygwin/select.cc @@ -1457,7 +1457,7 @@ peek_serial (select_record *s, bool) if (!ClearCommError (h, &io_err, &st)) { - debug_printf ("ClearCommError %E"); + select_printf ("ClearCommError %E"); goto err; } if (st.cbInQue) @@ -1493,6 +1493,7 @@ serial_read_cleanup (select_record *s, select_stuff *stuff) } } +static int verify_serial (select_record *me, fd_set *rfds, fd_set *wfds, fd_set *efds) { return peek_serial (me, true); @@ -1513,9 +1514,16 @@ fhandler_serial::select_read (select_stuff *ss) See: http://cygwin.com/ml/cygwin/2009-01/msg00667.html */ SetCommMask (get_handle_cyg (), 0); SetCommMask (get_handle_cyg (), EV_RXCHAR); - if (!WaitCommEvent (get_handle_cyg (), &event, &io_status) - && GetLastError () == ERROR_IO_PENDING) - s->h = io_status.hEvent; + ResetEvent (io_status.hEvent); + if (!WaitCommEvent (get_handle_cyg (), &event, &io_status)) + { + if (GetLastError () == ERROR_IO_PENDING) + s->h = io_status.hEvent; + else + select_printf ("WaitCommEvent %E"); + } + else + s->read_ready = true; return s; }