Re: [PATCH] Use cygwin spawn functions

[Richard Henderson <rth at redhat dot com>]

On 10/11/2010 05:41 PM, Richard Henderson wrote:
> Emulating fork(2) on cygwin is a bit of a challenge; the hoop jumping is
> a regular circus act.  Worse, fork has a habit of failing on Windows 7 64-bit,
> as seen in the many "Bad address" and "Resource temporarily unavailable"
> errors during testing
> (e.g. http://gcc.gnu.org/ml/gcc-testresults/2010-10/msg00624.html).
> 
> Cygwin's own faq (sec 5.5) says that it's better to avoid using fork+exec
> when possible and use the spawn family of calls instead.

The previous attempt failed to close all of the descriptors within
the parent, which lead to collect2 holding an open input end of a
pipe, which of course meant that it would wait forever for end-of-data.

I'm currently running a full test cycle on i686-cygwin, but this has
passed a few LTO tests run by hand, which had been the path that lead
to the failure case described above.

Ok?


r~

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