linux.conf.au, January 2003
      PRINCIPLES: Race Conditions

Problems:
Shared address space: all using the same global & static variables.
Other functions can interrupt at any time
Maybe more than one CPU (SMP)

We need ways to protect data from simultaneous access.
We call these multiple accesses at the same time "Race Conditions"
                foo.c:
                 	/* Increment i by 1 */
                 	i++;

                foo.s:
                 	lwz 9,0(3)		# Load contents of R3 + 0 into R9
                 	addi 9,9,1		# Add one to R9
                 	stw 9,0(3)		# Put contents of R9 back into R3 + 0