Atomically adds val to the value of atomic.
Think of this operation as an atomic version of { tmp = *atomic; *atomic += val; return tmp; }.
This call acts as a full compiler and hardware memory barrier.
Before version 2.30, this function did not return a value (but g_atomic_int_exchange_and_add() did, and had the same meaning).
a pointer to a gint or guint
the value to add
the value of atomic before the add, signed
2.4
Atomically adds val to the value of atomic.
Think of this operation as an atomic version of { tmp = *atomic; *atomic += val; return tmp; }.
This call acts as a full compiler and hardware memory barrier.
Before version 2.30, this function did not return a value (but g_atomic_int_exchange_and_add() did, and had the same meaning).