poll([{fd=4, events=POLLIN}], 1, -1
)    = 1 ([{fd=4, revents=POLLIN}])
epoll_wait(4, [{EPOLLIN, {u32=17909760, u64=17909760}}], 128, 0) = 1
accept4(3, {sa_family=AF_INET, sin_port=htons(34846), sin_addr=inet_addr("127.0.0.1")}, [28->16], SOCK_CLOEXEC|SOCK_NONBLOCK) = 7
setsockopt(7, SOL_TCP, TCP_NODELAY, [1], 4) = 0
epoll_ctl(4, EPOLL_CTL_ADD, 7, {EPOLLIN|EPOLLPRI|EPOLLOUT|EPOLLET, {u32=17946880, u64=17946880}}) = 0
accept4(3, 0x7ffd0c13e8d0, [28], SOCK_CLOEXEC|SOCK_NONBLOCK) = -1 EAGAIN (Resource temporarily unavailable)
close(6)                                = 0
poll([{fd=4, events=POLLIN}], 1, -1)    = 1 ([{fd=4, revents=POLLIN}])
epoll_wait(4, [{EPOLLIN|EPOLLOUT, {u32=17946880, u64=17946880}}], 128, 0) = 1
recvfrom(7, "GET /api HTTP/1.1\r\nHost: 127.0.0.1:5555\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Vers"..., 16384, 0, NULL, NULL) = 215
sendmsg(7, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nSec-WebSocket-Protocol: x-afb-ws-json1\r\nSec-We"..., iov_len=206}, {iov_base=NULL, iov_len=0}], msg_iovlen=2, msg_controllen=0, msg_flags=0}, MSG_NOSIGNAL) = 206
epoll_ctl(4, EPOLL_CTL_DEL, 7, NULL)    = 0
poll([{fd=4, events=POLLIN}], 1, -1