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From Stefan Teleman <stefan.tele...@gmail.com>
Subject Re: 4.2.2 release
Date Fri, 14 Aug 2009 19:27:56 GMT
On Fri, Aug 14, 2009 at 15:18, Martin Sebor<msebor@gmail.com> wrote:
> I think we should think about cutting a 4.2.2 release sometime this
> month. It's been embarrassingly long since 4.2.1. Farid (or anyone
> else), do you have anything that you'd like included in it?
>
> Martin

Hi.

Solaris 10 10/2008 SPARC has introduced a binary incompatible change
in the POSIX and Solaris threads implementation:

http://docs.sun.com/app/docs/doc/820-5245/chapter2-1000?a=view

<QUOTE>

Objects of type mutex_t and pthread_mutex_t must start at 8-byte
aligned addresses. Applications that do not satisfy this requirement
fail. The following error message is displayed:

*** _THREAD_ERROR_DETECTION: lock usage error detected ***
...
"mutex is misaligned"
OR:
"condvar is misaligned"

</QUOTE>

In reality, the run-time performance is much worse than the errata
above claims: misaligned mutexes or conditional variables cause the
program to spuriously SEGV in sometimes hard to reproduce ways [
Heisenbug ].

You can view full details of this bug/change here:

http://bugs.opensolaris.org/view_bug.do?bug_id=6729759

To make a long story short, Solaris Kernel Update 137111-01 introduced
an ABI incompatible implementation restriction, requiring that mutexes
and conditional variables must be 8-byte aligned. This restriction has
never been documented, nor has it ever been enforced, until Solaris 10
10/2008 [ Solaris Kernel Update 137111-01 ].

The consequence of this KU is that, the multi-threaded 32-bit SPARC
version of the Apache Standard C++ Library [ 4.2.1 ] will no longer
work, and will fail at run-time with seemingly unexplainable crashes [
the exact same build will work on Solaris versions prior to Kernel
Update 137111-01 ].

This problem is not specific to the Apache Standard C++ Library: it
will occur with any 32-bit SPARCV8 binaries which do not align mutexes
or conditional variables on an 8 byte boundary.

I have created a set of patches for the Apache Standard C++ Library,
Version 4.2.1, for this problem:

http://s247136804.onlinehome.us/stdcxx-upstream/4.2.1/

You can download the tarball with all the patches from the same URL:

http://s247136804.onlinehome.us/stdcxx-upstream/4.2.1/stdcxx-upstream-patches.tar.bz2

These patches force an 8-byte alignment for all objects which contain
a mutex or a conditional variable, and that only for SPARC. With these
patches, all the tests perform as expected.

The patch 22.locale.numpunct.cpp.43.diff is not related to the SPARCV8
ABI change -- it is simply an avoidance of a SEGV in case the variable
first_non_c == NULL [ Solaris sprintf(3C) SEGV's on NULL char*
arguments ].

--Stefan

-- 
Stefan Teleman
stefan.teleman@gmail.com

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