suse man page for test_and_change_bit

TEST_AND_CHANGE_BIT(9)					     Basic C Library Functions					    TEST_AND_CHANGE_BIT(9)

NAME
       test_and_change_bit - Change a bit and return its old value

SYNOPSIS
       int test_and_change_bit(int nr, volatile unsigned long * addr);

ARGUMENTS
       nr
	   Bit to change

       addr
	   Address to count from

DESCRIPTION
       This operation is atomic and cannot be reordered. It also implies a memory barrier.

COPYRIGHT
Kernel Hackers Manual 2.6.					     July 2010						    TEST_AND_CHANGE_BIT(9)