Re: libstdc++ debugging, was:Re: Heads up: Several thousand g++ andlibstdc++ test failures on sparc[64]

[Andreas Tobler <toa at pop dot agri dot ch>]

Pétur Runólfsson wrote:


> 1) The problem also shows up on i386-pc-solaris2.9
> http://gcc.gnu.org/ml/gcc-testresults/2003-10/msg00348.html
> so it's a Solaris problem, not a Sparc problem.

Aha, wasn't aware of.
> 2) The testcases testsuite/thread/pthread*.cc are not failing.
> This of course doesn't mean they are succeeding, but it's a strong
> hint. These testcases contain:
> // { dg-options "-D_GLIBCXX_ASSERT -pthreads" { target *-*-solaris* } }
> so it seems that compiling with -pthreads fixes the problem.
>
> My current theory is that __gthread_active_p() is for some reason
> returning true when it should return false on Solaris. This should
> be easy to check.

Hm, still not that easy to check, tried the thing below :)
I don't seem to be able to set breakpoints in this code, sigh.
> If this is the case, then there are two options for fixing the
> bug.
>
> 1) Fix gthr on Solaris.
>
> 2) Change use of __gthread_active_p() and __gthread_once() from:

[snip]

> that is, the "else" is removed, everything else is as before.

Bingo, did that and now it seems much better.
Wow!!!

> So long as __gthread_active_p() always returns true when thread
> support is enabled (and this seems to be the case since the
> pthread*.cc test cases succeed), this should be threadsafe.

I do a sync and rebuild the libstdc++ now. Afterwards I run the suite again.

Thanks again!


Regards,
Andreas