Name

__test_and_set_bit — Set a bit and return its old value

Synopsis

int __test_and_set_bit (int  nr,
 volatile void *  addr);

Arguments

nr

Bit to set

addr

Address to count from

Description

This operation is non-atomic and can be reordered. If two examples of this operation race, one can appear to succeed but actually fail. You must protect multiple accesses with a lock.