Re: 3.3.0: Possible regression in cygwin DLL (Win10); fixed in snapshot

[Takashi Yano <takashi.yano@nifty.ne.jp>]

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On Thu, 11 Nov 2021 11:11:10 -0500
Ken Brown wrote:
> On 11/10/2021 4:32 PM, Ken Brown wrote:
> > On 11/10/2021 3:35 PM, Corinna Vinschen wrote:
> >> On Nov 10 22:30, Takashi Yano wrote:
> >>> Thanks. I have just pushed the experimental patch to topic/pipe.
> >>> Please try. If something wrong, please point it out.
> >>
> >> Great, I'll have a look.  Ken, you're looking as well, right?
> > 
> > Yes.  It looks good on a first read-through.  I want to look again and do some 
> > testing.  One minor thing I noticed is that fhandler_pipe::raw_read could be 
> > cleaned up a little more: There are still references to STATUS_THREAD_SIGNALED 
> > and STATUS_THREAD_CANCELED, which can't occur any more.
> 
> It still looks good after a second read.  I'll try using it in my normal Cygwin 
> install to make sure no problems come up.
> 
> I've pushed a cleanup patch removing STATUS_THREAD_SIGNALED and 
> STATUS_THREAD_CANCELED, as well as a patch documenting the new behavior of the 
> pipe_byte option.

I have just rebased topic/pipe to current master.

I also would like to propose patch attached for topic/pipe.
Please have a look.

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>

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From 544292f81d8914b8510f39fe07d2b05cd4e99828 Mon Sep 17 00:00:00 2001
From: "U-EXPRESS5800-S70\\yano" <takashi.yano@nifty.ne.jp>
Date: Tue, 16 Nov 2021 20:59:09 +0900
Subject: [PATCH] Cygwin: pipe: Suppress unnecessary set_pipe_non_blocking()
 call.

- Call set_pipe_non_blocking(false) only if the pipe will be really
  inherited to non-cygwin process.
- Set blocking mode properly when cygwin process is executed from non-
  cygwin process.
---
 winsup/cygwin/dtable.cc | 3 +++
 winsup/cygwin/spawn.cc  | 9 ++++++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/winsup/cygwin/dtable.cc b/winsup/cygwin/dtable.cc
index d57cbb355..e54db4446 100644
--- a/winsup/cygwin/dtable.cc
+++ b/winsup/cygwin/dtable.cc
@@ -410,6 +410,9 @@ dtable::init_std_file_from_handle (int fd, HANDLE handle)
 	{
 	  fhandler_pipe *fhp = (fhandler_pipe *) fh;
 	  fhp->set_pipe_buf_size ();
+	  /* Set read pipe always to nonblocking */
+	  fhp->set_pipe_non_blocking (fhp->get_device () == FH_PIPER ?
+				      true : fhp->is_nonblocking ());
 	}
 
       if (!fh->open_setup (openflags))
diff --git a/winsup/cygwin/spawn.cc b/winsup/cygwin/spawn.cc
index 6b2026776..e160fa3bb 100644
--- a/winsup/cygwin/spawn.cc
+++ b/winsup/cygwin/spawn.cc
@@ -648,8 +648,9 @@ child_info_spawn::worker (const char *prog_arg, const char *const *argv,
 
       if (!iscygwin ())
 	{
+	  int fd;
 	  cfd.rewind ();
-	  while (cfd.next () >= 0)
+	  while ((fd = cfd.next ()) >= 0)
 	    if (cfd->get_major () == DEV_PTYS_MAJOR)
 	      {
 		fhandler_pty_slave *ptys =
@@ -657,13 +658,15 @@ child_info_spawn::worker (const char *prog_arg, const char *const *argv,
 		ptys->create_invisible_console ();
 		ptys->setup_locale ();
 	      }
-	    else if (cfd->get_dev () == FH_PIPEW)
+	    else if (cfd->get_dev () == FH_PIPEW
+		     && (fd == (in__stdout < 0 ? 1 : in__stdout) || fd == 2))
 	      {
 		fhandler_pipe *pipe = (fhandler_pipe *)(fhandler_base *) cfd;
 		pipe->close_query_handle ();
 		pipe->set_pipe_non_blocking (false);
 	      }
-	    else if (cfd->get_dev () == FH_PIPER)
+	    else if (cfd->get_dev () == FH_PIPER
+		     && fd == (in__stdin < 0 ? 0 : in__stdin))
 	      {
 		fhandler_pipe *pipe = (fhandler_pipe *)(fhandler_base *) cfd;
 		pipe->set_pipe_non_blocking (false);
-- 
2.33.0