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| __TEST_AND_SET_BIT(9) | Basic C Library Functions | __TEST_AND_SET_BIT(9) |
NAME¶
__test_and_set_bit - Set a bit and return its old value
SYNOPSIS¶
bool __test_and_set_bit(long nr, volatile unsigned long * addr);
ARGUMENTS¶
long nr
Bit to set
volatile unsigned long * 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.
COPYRIGHT¶
| June 2017 | Kernel Hackers Manual 4.11 |