tree b8e75877a0e5489838477bea1fff0bd647ae0e58
parent 776960024585b907acc4abc3c59aef605941bb75
author Ilya Tokar <tokarip@google.com> 1581714177 -0500
committer Ilya Tokar <tokarip@google.com> 1581714177 -0500

Avoid a division in NonBlockingThreadPool::Steal.

Looking at profiles we spend ~10-20% of Steal on simply computing
random % size. We can reduce random 32-bit int into [0, size) range with
a single multiplication and shift. This transformation is described in
https://lemire.me/blog/2016/06/27/a-fast-alternative-to-the-modulo-reduction/