optimise: smart control graceful shutdown wait time

netpoll_config.go

@@ -17,14 +17,12 @@ package netpoll
 import (
 	"context"
 	"io"
-	"time"
 )
 
 // global config
 var (
-	defaultLinkBufferSize                = pagesize
-	defaultGracefulShutdownCheckInterval = time.Second
-	featureAlwaysNoCopyRead              = false
+	defaultLinkBufferSize   = pagesize
+	featureAlwaysNoCopyRead = false
 )
 
 // Config expose some tuning parameters to control the internal behaviors of netpoll.

netpoll_server.go

@@ -63,27 +63,33 @@ func (s *server) Close(ctx context.Context) error {
 	s.operator.Control(PollDetach)
 	s.ln.Close()
 
-	var ticker = time.NewTicker(defaultGracefulShutdownCheckInterval)
-	defer ticker.Stop()
-	var hasConn bool
 	for {
-		hasConn = false
+		activeConn := 0
 		s.connections.Range(func(key, value interface{}) bool {
 			var conn, ok = value.(gracefulExit)
 			if !ok || conn.isIdle() {
 				value.(Connection).Close()
+			} else {
+				activeConn++
 			}
-			hasConn = true
 			return true
 		})
-		if !hasConn { // all connections have been closed
+		if activeConn == 0 { // all connections have been closed
 			return nil
 		}
 
+		// smart control graceful shutdown check internal
+		// we should wait for more time if there are more active connections
+		waitTime := time.Millisecond * time.Duration(activeConn)
+		if waitTime > time.Second { // max wait time is 1000 ms
+			waitTime = time.Millisecond * 1000
+		} else if waitTime < time.Millisecond*10 { // min wait time is 50 ms
+			waitTime = time.Millisecond * 50
+		}
 		select {
 		case <-ctx.Done():
 			return ctx.Err()
-		case <-ticker.C:
+		case <-time.After(waitTime):
 			continue
 		}
 	}

netpoll_unix_test.go

@@ -64,15 +64,6 @@ func Assert(t *testing.T, cond bool, val ...interface{}) {
 	}
 }
 
-func TestMain(m *testing.M) {
-	// defaultGracefulShutdownCheckInterval will affect shutdown function running time,
-	// so for speed up tests, we change it to 10ms here
-	oldGracefulShutdownCheckInterval := defaultGracefulShutdownCheckInterval
-	defaultGracefulShutdownCheckInterval = time.Millisecond * 10
-	m.Run()
-	defaultGracefulShutdownCheckInterval = oldGracefulShutdownCheckInterval
-}
-
 var testPort int32 = 10000
 
 // getTestAddress return a unique port for every tests, so all tests will not share a same listerner

poll_test.go

@@ -90,7 +90,7 @@ func TestPollMod(t *testing.T) {
 		runtime.Gosched()
 	}
 	r, w, h = atomic.LoadInt32(&rn), atomic.LoadInt32(&wn), atomic.LoadInt32(&hn)
-	Assert(t, r == 0 && w == 1 && h == 0, r, w, h)
+	Assert(t, r == 0 && w >= 1 && h == 0, r, w, h)
 
 	err = p.Control(rop, PollR2RW) // trigger write
 	MustNil(t, err)