Overhead of pthread mutexes?

Question

I\'m trying to make a C++ API (for Linux and Solaris) thread-safe, so that its functions can be called from different threads without breaking internal data structures. In m

Answer 1

For member variable access, you should use read/write locks, which have slightly less overhead and allow multiple concurrent reads without blocking.

In many cases you can use atomic builtins, if your compiler provides them (if you are using gcc or icc __sync_fetch*() and the like), but they are notouriously hard to handle correctly.

If you can guarantee the access being atomic (for example on x86 an dword read or write is always atomic, if it is aligned, but not a read-modify-write), you can often avoid locks at all and use volatile instead, but this is non portable and requires knowledge of the hardware.