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Re: [PATCH] Unbuffer stdout and stderr on windows
- From: Yao Qi <yao at codesourcery dot com>
- To: Pedro Alves <palves at redhat dot com>
- Cc: <gdb-patches at sourceware dot org>, <brobecker at adacore dot com>, Eli Zaretskii <eliz at gnu dot org>
- Date: Fri, 16 Aug 2013 20:33:56 +0800
- Subject: Re: [PATCH] Unbuffer stdout and stderr on windows
- References: <51EE23F8 dot 1070905 at codesourcery dot com> <83wqohw4ee dot fsf at gnu dot org> <20130729192559 dot GA5348 at ednor dot casa dot cgf dot cx> <83d2q1xiyv dot fsf at gnu dot org> <51F6C7B2 dot 3020400 at redhat dot com> <20130731034045 dot GA5565 at ednor dot casa dot cgf dot cx> <20130812211105 dot GA11128 at adacore dot com> <8361v9piop dot fsf at gnu dot org> <20130815173618 dot GA6955 at ednor dot casa dot cgf dot cx> <83eh9uonlg dot fsf at gnu dot org> <20130815175940 dot GD6955 at ednor dot casa dot cgf dot cx> <520E1109 dot 7000304 at redhat dot com>
On 08/16/2013 07:46 PM, Pedro Alves wrote:
However, the Windows runtime, in its infinite wisdom, makes stderr
fully buffered if connected to a pipe.
So all this makes me very much question the desire to detect
if a native Win32 GDB is running under Cygwin.
IMO, stderr should_always_ be forced to unbuffered.
From this long discussion, people agree that stderr should be unbuffered.
I can't really imagine that leaving stdout fully buffered to
ever be good (which the cygwin detection seems to want to preserve),
even for frontends, given GDB is an interactive program, and even
MI is text/line based.
So I think the "in cygwin" detection is really not necessary
or desirable, and this patch should go back to its original form:
However, we didn't have an agreement on what to set for stdout. As you
posted above, on Win32, stdout can be either full buffered or
non-buffered. If we change stdout to non-buffered, there are two
concerns, 1) GDB will slow down, 2) cause troubles to front-end, like Emacs.
Is it useful to reduce the concerns by measuring the slow down and
testing patched GDB under Emacs?
--
Yao (éå)