[PATCH] Cygwin: pipe: Suppress unnecessary set_pipe_non_blocking() call.

[Takashi Yano]

- Call set_pipe_non_blocking(false) only if the pipe will be really
  inherited to non-cygwin process.
---
 winsup/cygwin/spawn.cc | 9 ++---
 1 file changed, 6 insertions(+), 3 deletions(-)

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

Re: [PATCH] Cygwin: pipe: Suppress unnecessary set_pipe_non_blocking() call.

[Ken Brown]

On 11/17/2021 3:08 AM, Takashi Yano wrote:

- Call set_pipe_non_blocking(false) only if the pipe will be really
   inherited to non-cygwin process.


LGTM, but Corinna should probably take a quick look too, since I'm not very 
familiar with this part of the code.


Ken

Re: [PATCH] Cygwin: pipe: Suppress unnecessary set_pipe_non_blocking() call.

[Corinna Vinschen]

On Nov 17 10:09, Ken Brown wrote:
> On 11/17/2021 3:08 AM, Takashi Yano wrote:
> > - Call set_pipe_non_blocking(false) only if the pipe will be really
> >inherited to non-cygwin process.
> 
> LGTM, but Corinna should probably take a quick look too, since I'm not very
> familiar with this part of the code.

Looks right to me.


Corinna