Re: [boost] [thread] best practice to lock multiple mutexes

Howard Hinnant <hinnant <at> twcny.rr.com> writes:

template <class L1, class L2> void lock(L1& l1, L2& l2) { while (true) { { unique_lock<L1> __u1(l1); if (l2.try_lock()) { __u1.release(); break; } } std::this_thread::yield();

snipped rest of multi-lock code.

3. The yields are absolutely necessary to get the high performance mentioned in the previous note.

I find this comment intriguing. Is this always the case, or does it depend on the specifics of how a mutex is implemented on a given platform? Anthony