Speculate epoll results
Speculate epoll results

In many cases, we can guess the result of an epoll_wait() before it happens:
 - if a read() or write() consumes the entire buffer, a following call
   will likely succeed (and if it doesn't, it likely won't)
 - after an accept() completes, a write() will likely succeed

Speculatively add these events to events_known; if we mispredict and
fail with EAGAIN, all we need to do is retry.

kjniemi/seastar,norcimo5/seastar,dwdm/scylla,kjniemi/scylla,rentongzhang/scylla,glommer/scylla,scylladb/scylla,scylladb/scylla,kjniemi/scylla,tempbottle/scylla,justintung/scylla,printedheart/seastar,syuu1228/seastar,kjniemi/scylla,scylladb/scylla-seastar,dreamsxin/seastar,koolhazz/seastar,scylladb/scylla,chunshengster/seastar,hongliangzhao/seastar,bowlofstew/scylla,bowlofstew/seastar,victorbriz/scylla,linearregression/scylla,capturePointer/scylla,raphaelsc/scylla,leejir/seastar,xtao/seastar,stamhe/seastar,duarten/scylla,avikivity/scylla,asias/scylla,victorbriz/scylla,scylladb/seastar,acbellini/scylla,kjniemi/seastar,avikivity/seastar,stamhe/seastar,flashbuckets/seastar,slivne/seastar,dreamsxin/seastar,ducthangho/imdb,rluta/scylla,justintung/scylla,jonathanleang/seastar,joerg84/seastar,linearregression/seastar,respu/scylla,duarten/scylla,raphaelsc/seastar,cloudius-systems/seastar,sjperkins/seastar,flashbuckets/seastar,printedheart/seastar,chunshengster/seastar,avikivity/scylla,acbellini/scylla,tempbottle/seastar,avikivity/seastar,aruanruan/scylla,dreamsxin/seastar,gwicke/scylla,wildinto/seastar,aruanruan/scylla,aruanruan/scylla,linearregression/scylla,gwicke/scylla,wildinto/seastar,stamhe/scylla,linearregression/seastar,shaunstanislaus/scylla,bzero/seastar,leejir/seastar,eklitzke/scylla,kangkot/scylla,tempbottle/seastar,capturePointer/scylla,wildinto/seastar,kangkot/scylla,phonkee/scylla,guiquanz/scylla,phonkee/scylla,sjperkins/seastar,rluta/scylla,flashbuckets/seastar,tempbottle/scylla,scylladb/seastar,wildinto/scylla,respu/scylla,xtao/seastar,joerg84/seastar,mixja/seastar,capturePointer/scylla,avikivity/scylla,sjperkins/seastar,stamhe/seastar,shyamalschandra/seastar,linearregression/seastar,cloudius-systems/seastar,syuu1228/seastar,eklitzke/scylla,dwdm/scylla,acbellini/seastar,acbellini/seastar,glommer/scylla,dwdm/seastar,acbellini/seastar,kangkot/scylla,asias/scylla,scylladb/scylla-seastar,senseb/scylla,respu/scylla,linearregression/scylla,joerg84/seastar,wildinto/scylla,glommer/scylla,bzero/seastar,anzihenry/seastar,shyamalschandra/seastar,jonathanleang/seastar,raphaelsc/scylla,eklitzke/scylla,hongliangzhao/seastar,rentongzhang/scylla,scylladb/scylla,koolhazz/seastar,bowlofstew/seastar,duarten/scylla,stamhe/scylla,mixja/seastar,syuu1228/seastar,koolhazz/seastar,leejir/seastar,asias/scylla,norcimo5/seastar,bowlofstew/scylla,ducthangho/imdb,dwdm/seastar,cloudius-systems/seastar,anzihenry/seastar,justintung/scylla,xtao/seastar,shyamalschandra/seastar,norcimo5/seastar,senseb/scylla,bowlofstew/seastar,shaunstanislaus/scylla,guiquanz/scylla,printedheart/seastar,stamhe/scylla,tempbottle/seastar,scylladb/scylla-seastar,anzihenry/seastar,dwdm/seastar,bowlofstew/scylla,senseb/scylla,avikivity/seastar,rentongzhang/scylla,guiquanz/scylla,acbellini/scylla,victorbriz/scylla,tempbottle/scylla,wildinto/scylla,raphaelsc/scylla,gwicke/scylla,hongliangzhao/seastar,slivne/seastar,scylladb/seastar,dwdm/scylla,phonkee/scylla,mixja/seastar,raphaelsc/seastar,chunshengster/seastar,rluta/scylla,ducthangho/imdb,raphaelsc/seastar,kjniemi/seastar,slivne/seastar,jonathanleang/seastar,bzero/seastar,shaunstanislaus/scylla