Atomically adds val to the integer pointed to by atomic. It returns the value of *atomic just before the addition took place. Also acts as a memory barrier. Since 2.4
a pointer to an integer
the value to add to *atomic
the value of *atomic before the addition.
See Implementation
Atomically adds val to the integer pointed to by atomic. It returns the value of *atomic just before the addition took place. Also acts as a memory barrier. Since 2.4