Thead safe linked_ptr

[kmakaron11]

Hello, recently I found very nice linked_ptr imlementation:http://
groups.google.com/group/comp.lang.c++/browse_thread/thread/
790fc30ab1e5d3ad/6f8a15c3033d4852?
lnk=gst&q=linked_ptr#6f8a15c3033d4852
, which unforunaltely is not thread safe. Is there similar thread-safe
smart pointer classes?
I have in mind to use it like an object pool, where each object will
be used in another thread.
If the reference to that object is unique(), then it can be used. If
not, the object is already in use, until the reference in other thread
it is deleted.

Thanks.