Make fibers tests more robust
Make fibers tests more robust

Summary: This version works with ASAN.

Test Plan: ran test with ASAN enabled and disabled

Reviewed By: meyering@fb.com

Subscribers: alikhtarov

FB internal diff: D1570107

Tasks: 5192045

synecdoche/mcrouter,tempbottle/mcrouter,tempbottle/mcrouter,leitao/mcrouter,apinski-cavium/mcrouter,leitao/mcrouter,glensc/mcrouter,is00hcw/mcrouter,seem-sky/mcrouter,easyfmxu/mcrouter,apinski-cavium/mcrouter,seem-sky/mcrouter,reddit/mcrouter,tempbottle/mcrouter,facebook/mcrouter,nvaller/mcrouter,seem-sky/mcrouter,glensc/mcrouter,is00hcw/mcrouter,synecdoche/mcrouter,reddit/mcrouter,tempbottle/mcrouter,zhlong73/mcrouter,easyfmxu/mcrouter,reddit/mcrouter,facebook/mcrouter,evertrue/mcrouter,zhlong73/mcrouter,apinski-cavium/mcrouter,is00hcw/mcrouter,yqzhang/mcrouter,glensc/mcrouter,leitao/mcrouter,synecdoche/mcrouter,zhlong73/mcrouter,evertrue/mcrouter,yqzhang/mcrouter,reddit/mcrouter,yqzhang/mcrouter,zhlong73/mcrouter,facebook/mcrouter,apinski-cavium/mcrouter,easyfmxu/mcrouter,facebook/mcrouter,is00hcw/mcrouter,glensc/mcrouter,seem-sky/mcrouter,leitao/mcrouter,synecdoche/mcrouter,nvaller/mcrouter,easyfmxu/mcrouter,evertrue/mcrouter,nvaller/mcrouter,nvaller/mcrouter,yqzhang/mcrouter,evertrue/mcrouter