io func return n==0

net_io.go

@@ -3,26 +3,26 @@ package netpoll
 import "syscall"
 
 // return value:
-// - n: n < 0 but err == nil, retry syscall
+// - n: n == 0 but err == nil, retry syscall
 // - err: if not nil, connection should be closed.
 func ioread(fd int, bs [][]byte, ivs []syscall.Iovec) (n int, err error) {
 	n, err = readv(fd, bs, ivs)
 	if n == 0 && err == nil { // means EOF
-		return -1, Exception(ErrEOF, "")
+		return 0, Exception(ErrEOF, "")
 	}
 	if err == syscall.EINTR || err == syscall.EAGAIN {
-		return -1, nil
+		return 0, nil
 	}
 	return n, err
 }
 
 // return value:
-// - n: n < 0 but err == nil, retry syscall
+// - n: n == 0 but err == nil, retry syscall
 // - err: if not nil, connection should be closed.
 func iosend(fd int, bs [][]byte, ivs []syscall.Iovec, zerocopy bool) (n int, err error) {
 	n, err = sendmsg(fd, bs, ivs, zerocopy)
 	if err == syscall.EAGAIN {
-		return -1, nil
+		return 0, nil
 	}
 	return n, err
 }