Re: (ITS#8638) Recursive mutex in libldap_r

[hyc@symas.com]

ondra@mistotebe.net wrote:
>> IMO using recursive mutexes means your code is broken. We introduced these for
>> accesslog.c but in fact we could avoid them at zero cost. Also I don't see the
>> relevance of libevent to this discussion. We use our own event mechanism and
>> it is more efficient than libevent.
> 
> libevent is a dependency for the load balancer that I intend to propose
> for integration into the project after all the relevant dependencies
> have come in.
> 
> There is a new version of this patch that provides an implementation on
> each platform or defers to the existing one (as per each platform's
> documentation). Untested except on POSIX and most of them seem pretty
> arcane anyway.
> 
> ftp://ftp.openldap.org/incoming/Ondrej-Kuznik-20170918-ITS8638-libldap_r-recursive-mutex.patch
> 
It looks like glibc still doesn't define PTHREAD_MUTEX_RECURSIVE by default, 
it requires compiling with either -D_GNU_SOURCE or -D_XOPEN_SOURCE. The 
feature itself appears to be part of UNIX98. It's likely that all pthread 
implementations available today support it, but it still seems a bit iffy.

-- 
   -- Howard Chu
   CTO, Symas Corp.           http://www.symas.com
   Director, Highland Sun     http://highlandsun.com/hyc/
   Chief Architect, OpenLDAP  http://www.openldap.org/project/