Boost C++ Application Development Cookbook - Second Edition

Fast access to common resource using atomics

In the previous recipe, we saw how to safely access a common resource from different threads. But in that recipe, we were doing two system calls (in locking and unlocking mutex) to just get the value from an integer:

{   // Critical section begin.    boost::lock_guard<boost::mutex> lock(i_mutex);     i_snapshot = ++ shared_i; }   // Critical section end.

This looks lame and slow! Can we make the code from the previous recipe better?