Libatomic provides arch-independant API for the low-level atomic implementation. Library supports x86 (both i386 and x86_64), PPC64, Sparc64 (v9 and higher) and with modern gcc (version higher than 4.1.0) and its __sync extensions all its supported platforms.

Library exports platform-dependant atomic_t type and number of API to work with, namely

void atomic_set(atomic_t *a, int val)
int atomic_add(atomic_t *a, int val);
int atomic_sub(atomic_t *a, int val);
int atomic_inc(atomic_t *a);
int atomic_dec(atomic_t *a);
int atomic_dec_and_test(atomic_t *a);

All functions perform atomic operation and return new value of the atomic counter. atomic_dec_and_test() returns true if after decrement counter reached zero.

Library configuration automatically performs architecture detection and selection for the proper low-level atomic implementation. It is easily extensible with new platform-dependant code (both inline and usual asm or C if needed).

Source code is available in git tree or archive.