Summary: due to the fact that each two-process entry and exit sec-
tion of Peterson's algorithm requires fewer remote op-
erations outside of busy-waiting loops than does ours.
Thisgives rise tothe followingopen question: howmany
remote operations outside of busy-waiting loops are re-
quired in two-process read/write algorithms based on
We end the paper with a few observations concerning
the time complexity of concurrent algorithms. A natu-
ral approach to measuring the time complexity of such
an algorithm would be to simply count the number of
operations. However, a straightforward application of
such an approach does not provide any insight into the
behavior of mutual exclusion algorithms under heavy
contention. Inparticular, in anyalgorithminwhich pro-
cesses busy-wait, the number of operations needed for
one process to get to its critical section is unbounded.
In order to serve as a measure of time complexity, a
measure should be both intuitive and easy to compute.
In sequential programming, the usual measure of time