Depends on D19752. Ref T13210. If resources take a long time to reclaim/destroy (normally, more than 15 seconds) a single new lease may update several times during the reclaim/destroy process and end up reclaiming multiple resources.

Instead: after a lease triggers a reclaim, prevent it from triggering another reclaim as long as the resource it is reclaiming hasn't finished its reclaim/destroy cycle. Basically, each lease only gets to destroy one resource at a time.

• Added a sleep(120) to destroyResource() to simulate a long reclaim/destroy cycle.
• Allocated A, A, A working copies. Leased a B working copy.
• Before patch: saw "B" lease destroy all three "A" working copies after ~0, ~15, and ~30 seconds, then build a new "B" resource after ~120 seconds (when the first reclaim/destroy finished).
• After patch: saw "B" lease destroy one "A" working copy after ~0 seconds, then wait patiently until it finished up, then build a new "B" resource.