io: fix for race conditions in keepalivewriter
io: fix for race conditions in keepalivewriter

tuxmonteiro/tsuru,cgvarela/tsuru,tsuru/tsuru,kgrvamsi/tsuru,ggarnier/tsuru,guilhermebr/tsuru,cgvarela/tsuru,firebitsbr/tsuru,gwmoura/tsuru,hugoantunes/tsuru,RichardKnop/tsuru,hcxiong/tsuru,hcxiong/tsuru,cezarsa/tsuru,Endika/tsuru,jblancett/tsuru,mderaldo/tsuru,4eek/tsuru,ggarnier/tsuru,tuxmonteiro/tsuru,cgvarela/tsuru,gciotta/tsuru,cezarsa/tsuru,guilhermebr/tsuru,tuxmonteiro/tsuru,Endika/tsuru,4eek/tsuru,cezarsa/tsuru,guilhermebr/tsuru,mderaldo/tsuru,Endika/tsuru,ArxdSilva/tsuru,ArxdSilva/tsuru,RichardKnop/tsuru,4eek/tsuru,kgrvamsi/tsuru,ArxdSilva/tsuru,cezarsa/tsuru,gciotta/tsuru,jblancett/tsuru,ggarnier/tsuru,firebitsbr/tsuru,jblancett/tsuru,guilhermebr/tsuru,gwmoura/tsuru,tsuru/tsuru,hugoantunes/tsuru,kgrvamsi/tsuru,tsuru/tsuru,gciotta/tsuru,RichardKnop/tsuru,ArxdSilva/tsuru,gwmoura/tsuru,hcxiong/tsuru,tsuru/tsuru,firebitsbr/tsuru,ggarnier/tsuru,mderaldo/tsuru