server/server.go
crusader 3a437b10a4 ing
2017-11-07 11:57:26 +09:00

143 lines
2.4 KiB
Go

package server
import (
"fmt"
"net"
"sync"
"sync/atomic"
"time"
"git.loafle.net/commons_go/logging"
)
type Server interface {
Start() error
Stop()
Serve() error
}
func New(sh ServerHandler) Server {
s := &server{
sh: sh,
}
return s
}
type server struct {
sh ServerHandler
listener net.Listener
Stats ServerStats
stopChan chan struct{}
stopWg sync.WaitGroup
}
func (s *server) Start() error {
if nil == s.sh {
panic("Server: server handler must be specified.")
}
s.sh.Validate()
if s.stopChan != nil {
panic("Server: server is already running. Stop it before starting it again")
}
var err error
if s.listener, err = s.sh.Listen(); nil != err {
return err
}
s.stopChan = make(chan struct{})
s.sh.OnStart()
s.stopWg.Add(1)
go handleServer(s)
return nil
}
func (s *server) Stop() {
if s.stopChan == nil {
panic("Server: server must be started before stopping it")
}
close(s.stopChan)
s.stopWg.Wait()
s.stopChan = nil
s.sh.OnStop()
}
func (s *server) Serve() error {
if err := s.Start(); err != nil {
return err
}
s.stopWg.Wait()
return nil
}
func handleServer(s *server) {
defer s.stopWg.Done()
var conn net.Conn
var err error
var stopping atomic.Value
for {
acceptChan := make(chan struct{})
go func() {
if conn, err = s.listener.Accept(); err != nil {
if stopping.Load() == nil {
logging.Logger.Error(fmt.Sprintf("Server: Cannot accept new connection: [%s]", err))
}
} else {
conn, err = s.sh.OnAccept(conn)
}
close(acceptChan)
}()
select {
case <-s.stopChan:
stopping.Store(true)
s.listener.Close()
<-acceptChan
return
case <-acceptChan:
s.Stats.incAcceptCalls()
}
if err != nil {
s.Stats.incAcceptErrors()
select {
case <-s.stopChan:
return
case <-time.After(time.Second):
}
continue
}
s.stopWg.Add(1)
go handleConnection(s, conn)
}
}
func handleConnection(s *server, conn net.Conn) {
defer s.stopWg.Done()
logging.Logger.Debug(fmt.Sprintf("Server: Client[%s] is connected.", conn.RemoteAddr()))
clientStopChan := make(chan struct{})
handleDoneChan := make(chan struct{})
go s.sh.Handle(conn, clientStopChan, handleDoneChan)
select {
case <-s.stopChan:
close(clientStopChan)
conn.Close()
<-handleDoneChan
case <-handleDoneChan:
close(clientStopChan)
conn.Close()
logging.Logger.Debug(fmt.Sprintf("Server: Client[%s] is disconnected.", conn.RemoteAddr()))
}
}