feat: netpoll exception implement net.Error interface (#300)

Author: joway

connection_errors.go

@@ -16,6 +16,7 @@ package netpoll
 
 import (
 	"fmt"
+	"net"
 	"syscall"
 )
 
@@ -51,6 +52,10 @@ func Exception(err error, suffix string) error {
 	return &exception{no: no, suffix: suffix}
 }
 
+var (
+	_ net.Error = (*exception)(nil)
+)
+
 type exception struct {
 	no     syscall.Errno
 	suffix string
@@ -88,6 +93,21 @@ func (e *exception) Unwrap() error {
 	return e.no
 }
 
+func (e *exception) Timeout() bool {
+	switch e.no {
+	case ErrDialTimeout, ErrReadTimeout, ErrWriteTimeout:
+		return true
+	}
+	if e.no.Timeout() {
+		return true
+	}
+	return false
+}
+
+func (e *exception) Temporary() bool {
+	return e.no.Temporary()
+}
+
 // Errors defined in netpoll
 var errnos = [...]string{
 	ErrnoMask & ErrConnClosed:     "connection has been closed",