 the thread-unsafe version if a second processor is available.
The execution time for two clients with thread local allocation time is
only 1.4 times the sequential execution time for a single thread in a
thread-unsafe environment, even though it involves twice the client work.
That represents close to a
factor of 2 improvement over the 2 client case with the old collector.
The old collector clearly
still suffered from some contention overhead, in spite of the fact that the
locking scheme had been fairly we