Re: parallel make and I/O of child processes

[Stefano Lattarini]

Hi Eric.  Thanks for the quick review.

On Monday 24 January 2011, Eric Blake wrote:
> [dropping automake-patches]
> 
> On 01/24/2011 03:38 PM, Stefano Lattarini wrote:
> > Hello autoconfers and automakers.
> > 
> > In both FreeBSD and NetBSD make, when "parallel mode" is used (e.g., with
> > `make -j2'), the stdout and stderr of child processes get connected to
> > pipes[1][2].  Similarly, in Solaris 10 dmake, the stdout and stderr of
> > child processes get connected to temporary files[3].
> 
> Odd, but a definite thing to be aware of.
> 
> > Subject: [PATCH] docs: another parallel make issue
> > 
> > * doc/autoconf.texi (Parallel Make): Document that some make
> > implementations, when run in parallel mode, connect stdout and
> > stderr of child processes to pipes or temporary files.
> > ---
> >  ChangeLog         |    7 +++++++
> >  doc/autoconf.texi |   37 ++++++++++++++++++++++++++++++++++++-
> >  2 files changed, 43 insertions(+), 1 deletions(-)
> 
> ACK with nits fixed (do you have push rights yet, or do I need to help
> out with this one?)
>
I don't have push rights yet, nor have I asked for them until now because
the number of patches I've contributed to autoconf is really small anyway.
But if you think that conceding me push rights might be useful to relieve
you and other developers of extra work in the future (even if just a bit),
I'm in; just contact me off-list (or on-list if you deem that appropriate)
for the details.  Thanks.

> > +++ b/doc/autoconf.texi
> > @@ -19475,7 +19475,42 @@ sh
> >  @cindex Parallel @command{make}
> >  
> >  Support for parallel execution in @command{make} implementation varies.
> > -Generally, using GNU make is your best bet.  When NetBSD
> > +Generally, using GNU make is your best bet.
> > +
> > +Some make implementations (among them, FreeBSD @command{make}, NetBSD
> > address@hidden, and Solaris @command{dmake}), when invoked with a
> > address@hidden@var{N}} option, connect the standard output and standard
> > +error of all their children processes to pipes or temporary regular
> 
> s/children/child/ - when using "child" as an adjective, you use the
> singular form.
>
Hmpf, silly mistake.  And I've even got that right in the ChangeLog
entry!  Sorry for the noise.

> > +files.  This can lead to slightly but subtly different semantics in
> > +the behaviour of the spawned processes.  For example, even if the
> 
> s/behaviour/behavior/ - favor US spelling in GNU manuals
> 
OK (even if I'll have a hard time remembering that "behavior" is not a
typo ;-)

Thanks,
  Stefano