I wrote:
The primitives supplied by g++ were not enough to support sp_counted_base (although this is going to change in 4.2, I think).
It seems that 4.1 supports the atomics as well, http://gcc.gnu.org/onlinedocs/gcc-4.1.1/gcc/Atomic-Builtins.html so we'll be able to take advantage of them for 1.35 for all g++ targets. Jerry Lawson wrote:
Thanks for the response. I will patch my boost with those files.
Just for my education, however, I'd like to understand what was missing from the gcc primitives that you needed for the sp_counted_base required implementation?
shared_ptr requires a "compare and swap" operation (__sync_(bool|val)_compare_and_swap in the page above) in addition to atomic increment/decrement, and libstdc++ doesn't provide one.
Furthermore, should it be okay for me to continue to use atomic_count_gcc.hpp's pre-increment and post-increment overloaded operators as the implementation for my specialization of intrusive_ptr_add_ref(T*) and intrusive_ptr_add_release(T*) free functions?
You should be OK. I don't remember any reports of a problem with atomic_count_gcc.