Re: [PATCH v4 3/3] parallel-tests: allow each test to have multiple results

[Stefano Lattarini]

On Tuesday 21 June 2011, Ralf Wildenhues wrote:
> * Stefano Lattarini wrote on Mon, Jun 20, 2011 at 10:58:05PM CEST:
> > On Monday 20 June 2011, Ralf Wildenhues wrote:
> > > For example the parallel BSD makes tend to reuse shells for running
> > > the recipe commands;
> > >
> > But only for the commands in the same recipe, right?
> 
> I think not.
>
This example seems to show otherwise, luckily:

  $ cat Makefile
  all: a b c d
  a b c d:
        @exec echo seen-$@
        @echo unseen-$@
  $ make -j4
  --- a ---
  --- b ---
  --- c ---
  --- d ---
  --- a ---
  seen-a
  --- b ---
  seen-b
  --- c ---
  seen-c
  --- d ---
  seen-d

Tested on NetBSD 5.1 with system make, and on Debian with netbsd-make
and freebsd-make.

And in fact, quoting the Autoconf manual:

 `` Support for parallel execution in make implementation varies.
    Generally, using GNU make is your best bet. When NetBSD make
    is invoked with -jN, it will reuse the same shell for multiple
    commands *within one recipe*. ''

(emphasis added by me above)

> > > I'm not so sure they like if their shells go away with exec.
> > >
> > In this case, not a problem I think, since the invocation of the
> > testsuite driver is the last command in the recipe.
> 
> Well, they should cope with it anyway, and use a new shell if the old
> one is gone.
>
Agreed.  Still, as shown above, in this case that bug-like feature
shouldn't come to bite us.

Regards,
  Stefano