redis/internal/pool/conn_check.go

49 lines
845 B
Go

// +build linux darwin dragonfly freebsd netbsd openbsd solaris illumos
package pool
import (
"errors"
"io"
"net"
"syscall"
"time"
)
var errUnexpectedRead = errors.New("unexpected read from socket")
func connCheck(conn net.Conn) error {
// Reset previous timeout.
_ = conn.SetDeadline(time.Time{})
sysConn, ok := conn.(syscall.Conn)
if !ok {
return nil
}
rawConn, err := sysConn.SyscallConn()
if err != nil {
return err
}
var sysErr error
err = rawConn.Read(func(fd uintptr) bool {
var buf [1]byte
n, err := syscall.Read(int(fd), buf[:])
switch {
case n == 0 && err == nil:
sysErr = io.EOF
case n > 0:
sysErr = errUnexpectedRead
case err == syscall.EAGAIN || err == syscall.EWOULDBLOCK:
sysErr = nil
default:
sysErr = err
}
return true
})
if err != nil {
return err
}
return sysErr
}