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

NAME

       test_and_clear_bit - Clear a bit and return its old value

SYNOPSIS

       int test_and_clear_bit  (int nr, volatile unsigned long * addr);

ARGUMENTS

       nr     Bit to clear

       addr   Address to count from

DESCRIPTION

       This   operation   is  atomic  and  cannot  be  reordered.  It  can  be
       reorderdered on other architectures other than x86. It also  implies  a
       memory barrier.