__sync_lock_test_and_set
Purpose
This function atomically assigns the value of __v to the variable that __p points to.
An acquire memory barrier is created when this function is invoked.
Prototype
T __sync_lock_test_and_set (T* __p, U __v, ...);
Parameters
- __p
- The pointer of the variable that is to be set.
- __v
- The value to set to the variable that __p points to.
Return value
The function returns the initial value of the variable that __p points to.
