use wait()/get() instead of while(!f.isReady()) { ... }
use wait()/get() instead of while(!f.isReady()) { ... }

Summary: as above. nice redness. couple of comments inline though

Test Plan: contbuild

Reviewed By: hans@fb.com

Subscribers: trunkagent, zeus-diffs@, cold-storage-diffs@, targeting-diff-backend@, apollo-diffs@, micha, folly-diffs@, jsedgwick

FB internal diff: D1787776

Tasks: 5940008

Signature: t1:1787776:1421776843:13772348538a0af27ceb5a363b818ece0cdfffc6

chjp2046/folly,nickhen/folly,zhiweicai/folly,leolujuyi/folly,gavioto/folly,upsoft/folly,juniway/folly,CJstar/folly,colemancda/folly,raphaelamorim/folly,mqeizi/folly,gavioto/folly,doctaweeks/folly,PPC64/folly,xzmagic/folly,doctaweeks/folly,constantine001/folly,renyinew/folly,tempbottle/folly,loversInJapan/folly,colemancda/folly,reddit/folly,PoisonBOx/folly,project-zerus/folly,Eagle-X/folly,cole14/folly,clearlylin/folly,raphaelamorim/folly,arg0/folly,fw1121/folly,theiver9827/folly,Orvid/folly,brunomorishita/folly,bobegir/folly,charsyam/folly,arg0/folly,facebook/folly,loverszhaokai/folly,romange/folly,upsoft/folly,facebook/folly,bsampath/folly,PPC64/folly,bobegir/folly,tomhughes/folly,stonegithubs/folly,xzmagic/folly,yangjin-unique/folly,Eagle-X/folly,chjp2046/folly,CJstar/folly,SeanRBurton/folly,zhiweicai/folly,gaoyingie/folly,bikong2/folly,wildinto/folly,Hincoin/folly,bowlofstew/folly,sakishum/folly,colemancda/folly,clearlinux/folly,facebook/folly,KSreeHarsha/folly,facebook/folly,floxard/folly,tempbottle/folly,brunomorishita/folly,upsoft/folly,clearlinux/folly,bsampath/folly,Eagle-X/folly,clearlylin/folly,kernelim/folly,CJstar/folly,cppfool/folly,facebook/folly,brunomorishita/folly,hongliangzhao/folly,SeanRBurton/folly,Hincoin/folly,PPC64/folly,sakishum/folly,bobegir/folly,alexst07/folly,Eagle-X/folly,sonnyhu/folly,loverszhaokai/folly,Hincoin/folly,zhiweicai/folly,bowlofstew/folly,mqeizi/folly,clearlinux/folly,guker/folly,project-zerus/folly,sakishum/folly,Hincoin/folly,ykarlsbrun/folly,wildinto/folly,renyinew/folly,KSreeHarsha/folly,Orvid/folly,ykarlsbrun/folly,CJstar/folly,SeanRBurton/folly,SammyK/folly,xzmagic/folly,tomhughes/folly,kernelim/folly,tempbottle/folly,tempbottle/folly,wildinto/folly,theiver9827/folly,reddit/folly,wildinto/folly,lifei/folly,reddit/folly,leolujuyi/folly,chjp2046/folly,raphaelamorim/folly,cole14/folly,stonegithubs/folly,gavioto/folly,xzmagic/folly,rklabs/folly,PoisonBOx/folly,shaobz/folly,kernelim/folly,sakishum/folly,colemancda/folly,doctaweeks/folly,SammyK/folly,bowlofstew/folly,clearlylin/folly,juniway/folly,sonnyhu/folly,mqeizi/folly,arg0/folly,fw1121/folly,doctaweeks/folly,cppfool/folly,rklabs/folly,constantine001/folly,shaobz/folly,zhiweicai/folly,yangjin-unique/folly,ykarlsbrun/folly,stonegithubs/folly,yangjin-unique/folly,hongliangzhao/folly,Orvid/folly,fw1121/folly,gavioto/folly,bikong2/folly,bowlofstew/folly,clearlinux/folly,constantine001/folly,juniway/folly,yangjin-unique/folly,bobegir/folly,gaoyingie/folly,alexst07/folly,upsoft/folly,lifei/folly,loverszhaokai/folly,loverszhaokai/folly,hongliangzhao/folly,floxard/folly,SammyK/folly,alexst07/folly,arg0/folly,lifei/folly,SeanRBurton/folly,PPC64/folly,PoisonBOx/folly,bsampath/folly,alexst07/folly,KSreeHarsha/folly,romange/folly,CJstar/folly,bobegir/folly,xzmagic/folly,lifei/folly,loversInJapan/folly,charsyam/folly,bikong2/folly,loversInJapan/folly,KSreeHarsha/folly,bowlofstew/folly,KSreeHarsha/folly,loverszhaokai/folly,gaoyingie/folly,tomhughes/folly,floxard/folly,chjp2046/folly,project-zerus/folly,sakishum/folly,tomhughes/folly,cole14/folly,loversInJapan/folly,project-zerus/folly,Eagle-X/folly,clearlinux/folly,gaoyingie/folly,bikong2/folly,bsampath/folly,hongliangzhao/folly,charsyam/folly,raphaelamorim/folly,theiver9827/folly,lifei/folly,gaoyingie/folly,gavioto/folly,fw1121/folly,Orvid/folly,arg0/folly,clearlylin/folly,romange/folly,chjp2046/folly,clearlylin/folly,upsoft/folly,loversInJapan/folly,guker/folly,theiver9827/folly,romange/folly,rklabs/folly,cole14/folly,brunomorishita/folly,fw1121/folly,leolujuyi/folly,sonnyhu/folly,doctaweeks/folly,theiver9827/folly,floxard/folly,cppfool/folly,shaobz/folly,PoisonBOx/folly,romange/folly,ykarlsbrun/folly,cole14/folly,nickhen/folly,tempbottle/folly,shaobz/folly,brunomorishita/folly,renyinew/folly,Orvid/folly,PoisonBOx/folly,raphaelamorim/folly,leolujuyi/folly,nickhen/folly,SammyK/folly,zhiweicai/folly,mqeizi/folly,constantine001/folly,bikong2/folly,SeanRBurton/folly,Hincoin/folly,juniway/folly,sonnyhu/folly,wildinto/folly,nickhen/folly,guker/folly,constantine001/folly,nickhen/folly,cppfool/folly,rklabs/folly,colemancda/folly,floxard/folly,stonegithubs/folly,bsampath/folly,tomhughes/folly,renyinew/folly,reddit/folly,kernelim/folly,charsyam/folly,sonnyhu/folly,stonegithubs/folly,alexst07/folly,yangjin-unique/folly,kernelim/folly,project-zerus/folly,renyinew/folly,ykarlsbrun/folly,guker/folly,SammyK/folly,PPC64/folly,mqeizi/folly,guker/folly,cppfool/folly,shaobz/folly,rklabs/folly,juniway/folly,leolujuyi/folly,reddit/folly,hongliangzhao/folly