On 04.03.2015 13:50, Ivan Zhakov wrote: > On 4 March 2015 at 11:27, Branko Čibej <br...@wandisco.com> wrote: >> There was some discussion on #svn-dev recently about making the error >> location tracing (see libsvn_subr/error.c and svn_error__locate) >> thread-safe, by using platform- and compiler-specific flags for making >> the location variables thread-safe. >> >> It turns out that, since we now require APR 1.3+ which provides >> unmanaged pools, we can now safely do this by using APR's threadkey API. >> See: >> >> https://paste.apache.org/fG82 >> >> With this patch, all tests pass for on my Mac in parallel mode and the >> error stacks look sane. But, before committing the change, I'd like >> someone else to review the patch because it's just a wee bit tricky in >> places what with all the #ifdefs. >> > I was thinking about similar change, but as far I remember it's not > safe to use svn_atomic__init_once() in error.c, because > svn_atomic__init_once() uses svn_error_*() API. This may lead circular > initialization of svn_error_*() tracing infrastructure.
Nope. svn_atomic__init_once only begins using the svn_error_* functions after the init function has returned, at which point the tracing logic is initialized. Furthermore, I intentionally implemented this particular init function so that it never returns an error. Although, looking at the implementation of svn_atomic__init_once, we really shouldn't be optimizing the error case with all the #if APR_HAS_THREADS blocks. -- Brane
