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Hardware solutions: special machine instructions
nNormally, access to
a memory location excludes other access
to that same location
nExtension: designers
have proposed machines instructions
that perform 2 actions atomically (indivisible) on the
same memory location (ex: reading and
testing)
nThe execution of such an instruction is mutually exclusive (even with multiple CPUs)
nThey can be used simply to provide mutual exclusion but need more complex algorithms for satisfying the 3 requirements of the CS problem