Changeset 766 in code

Timestamp:

Jan 19, 2022, 9:35:46 PM (3 years ago)

Author:

contact

Message:

Retry on temporary net.Listener failure

Instead of stopping to listen, retry on temporary failure. This
can happen when running out of FDs.

Closes: ​https://todo.sr.ht/~emersion/soju/183

Location:

trunk

Files:

• ident.go (modified) (1 diff)
• server.go (modified) (2 diffs)

trunk/ident.go

@@ -75 +75 @@
 
 func (s *Identd) Serve(ln net.Listener) error {
+        ln = &retryListener{Listener: ln}
+
         for {
                 conn, err := ln.Accept()

trunk/server.go

@@ -94 +94 @@
 }
 
+type retryListener struct {
+        net.Listener
+        Logger Logger
+
+        delay time.Duration
+}
+
+func (ln *retryListener) Accept() (net.Conn, error) {
+        for {
+                conn, err := ln.Listener.Accept()
+                if ne, ok := err.(net.Error); ok && ne.Temporary() {
+                        if ln.delay == 0 {
+                                ln.delay = 5 * time.Millisecond
+                        } else {
+                                ln.delay *= 2
+                        }
+                        if max := 1 * time.Second; ln.delay > max {
+                                ln.delay = max
+                        }
+                        if ln.Logger != nil {
+                                ln.Logger.Printf("accept error (retrying in %v): %v", ln.delay, err)
+                        }
+                        time.Sleep(ln.delay)
+                } else {
+                        ln.delay = 0
+                        return conn, err
+                }
+        }
+}
+
 type Config struct {
         Hostname        string
@@ -329 +359 @@
 
 func (s *Server) Serve(ln net.Listener) error {
+        ln = &retryListener{
+                Listener: ln,
+                Logger:   &prefixLogger{logger: s.Logger, prefix: fmt.Sprintf("listener %v: ", ln.Addr())},
+        }
+
         s.lock.Lock()
         s.listeners[ln] = struct{}{}