1// Copyright 2015 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package net
6
7import (
8	"runtime"
9	"syscall"
10	"time"
11)
12
13func setKeepAlivePeriod(fd *netFD, d time.Duration) error {
14	// The kernel expects milliseconds so round to next highest
15	// millisecond.
16	msecs := int(roundDurationUp(d, time.Millisecond))
17
18	// Normally we'd do
19	//	syscall.SetsockoptInt(fd.sysfd, syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, secs)
20	// here, but we can't because Solaris does not have TCP_KEEPINTVL.
21	// Solaris has TCP_KEEPALIVE_ABORT_THRESHOLD, but it's not the same
22	// thing, it refers to the total time until aborting (not between
23	// probes), and it uses an exponential backoff algorithm instead of
24	// waiting the same time between probes. We can't hope for the best
25	// and do it anyway, like on Darwin, because Solaris might eventually
26	// allocate a constant with a different meaning for the value of
27	// TCP_KEEPINTVL on illumos.
28
29	err := fd.pfd.SetsockoptInt(syscall.IPPROTO_TCP, syscall.TCP_KEEPALIVE_THRESHOLD, msecs)
30	runtime.KeepAlive(fd)
31	return wrapSyscallError("setsockopt", err)
32}
33