1__TEST_AND_SET_BIT(9) Basic C Library Functions __TEST_AND_SET_BIT(9)
2
3
4
6 __test_and_set_bit - Set a bit and return its old value
7
9 int __test_and_set_bit(int nr, volatile unsigned long * addr);
10
12 nr
13 Bit to set
14
15 addr
16 Address to count from
17
19 This operation is non-atomic and can be reordered. If two examples of
20 this operation race, one can appear to succeed but actually fail. You
21 must protect multiple accesses with a lock.
22
24Kernel Hackers Manual 2.6. November 2011 __TEST_AND_SET_BIT(9)