Provided by: linux-doc-2.6.15_2.6.15-23.39_all bug

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.