[PATCH] Cygwin: pipe: Restore non-blocking mode which was reset for non-cygwin app.

[Takashi Yano]

On Mon, 11 Mar 2024 20:42:37 +0900
Takashi Yano wrote:
> On Mon, 11 Mar 2024 11:47:32 +0100
> Corinna Vinschen wrote:
> > Hi Takashi,
> > 
> > On Mar 10 19:31, Takashi Yano wrote:
> > > @@ -590,6 +591,10 @@ child_info_spawn::worker (const char *prog_arg, const char *const *argv,
> > >  	      {
> > >  		fhandler_pipe *pipe = (fhandler_pipe *)(fhandler_base *) cfd;
> > >  		pipe->set_pipe_non_blocking (false);
> > > +		pipew_duped = (fhandler_pipe *)
> > > +			ccalloc (HEAP_FHANDLER, 1, sizeof (fhandler_pipe));
> > > +		pipew_duped = new (pipew_duped) fhandler_pipe;
> > > +		pipe->dup (pipew_duped, 0);
> > >  		if (pipe->request_close_query_hdl ())
> > >  		  need_send_sig = true;
> > >  	      }
> > 
> > The code setting up pipes and the dummy_tty is sufficiently complex,
> > so that I wonder if it shouldn't have
> > 
> > - its own methods and
> > - comments to describe why this stuff is necessary.
> > 
> > What about adding two methods, kind of like (the names are only
> > suggestion, albeit bad ones):
> > 
> >   child_info_spawn::noncygwin_child_pre_fork()
> > 
> > to keep the above stuff together (plus comments) and
> > 
> >   child_info_spawn::noncygwin_child_post_fork()
> > 
> > for the below code?
> > 
> > > @@ -597,6 +602,10 @@ child_info_spawn::worker (const char *prog_arg, const char *const *argv,
> > >  	      {
> > >  		fhandler_pipe *pipe = (fhandler_pipe *)(fhandler_base *) cfd;
> > >  		pipe->set_pipe_non_blocking (false);
> > > +		piper_duped = (fhandler_pipe *)
> > > +			ccalloc (HEAP_FHANDLER, 1, sizeof (fhandler_pipe));
> > > +		piper_duped = new (piper_duped) fhandler_pipe;
> > > +		pipe->dup (piper_duped, 0);
> > >  	      }
> > >  
> > >  	  if (need_send_sig)
> > > @@ -905,6 +914,19 @@ child_info_spawn::worker (const char *prog_arg, const char *const *argv,
> > >  	      term_spawn_worker.cleanup ();
> > >  	      term_spawn_worker.close_handle_set ();
> > >  	    }
> > > +	  if (pipew_duped)
> > > +	    {
> > > +	      bool is_nonblocking = pipew_duped->is_nonblocking ();
> > > +	      pipew_duped->set_pipe_non_blocking (is_nonblocking);
> > 
> > Is that really right?  You're asking pipew_duped for its
> > nonblocking flag and then set pipew_duped to the same value...?
> > 
> > > +	      pipew_duped->close ();
> > > +	      cfree (pipew_duped);
> > > +	    }
> 
> Thanks for the reviewing and advice. I'll work for v2 patch. Please wait a while.

I have reconsider what is essential. Then, just setting read pipe to non-blocking
mode for cygwin apps is enough when it starts.

Please review v2 patch attached.

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