libthr shared locks

[Simon J. Gerraty]

Julian Elischer <julian at freebsd.org> wrote:
> > ABI variant.  But since userspace tends to use the pthread objects in
> > the layouts of the library objects, this causes serious ABI issues
> > when mixing libraries built against different default versions of
> > libthr.
> 
> which is one reason I think symbol versioning is over-rated..

symbol versioning works fine - provided you have opaque structs.

> just make a new library version.

as previously noted, this rarely solves anything since to avoid problems
you need to bump the major version of all shared libs, and you cannot do
that for 3rd party code you don't even know exists.