Commit 5b425cc3 authored by Dave Cheney's avatar Dave Cheney

undo CL 6855110 / 869253ef7009

64bit atomics are broken on 32bit systems. This is issue 599.

linux/arm builders all broke with this change, I am concerned that the other 32bit builders are silently impacted.

««« original CL description
net: fix data races on deadline vars

Fixes #4434.

R=mikioh.mikioh, bradfitz, dvyukov, alex.brainman
CC=golang-dev
https://golang.org/cl/6855110
»»»

R=rsc, mikioh.mikioh, dvyukov, minux.ma
CC=golang-dev
https://golang.org/cl/6852105
parent be0d84e3
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build darwin freebsd linux netbsd openbsd windows
package net
import (
"testing"
"time"
)
var deadlineSetTimeTests = []struct {
input time.Time
expected int64
}{
{time.Time{}, 0},
{time.Date(2009, 11, 10, 23, 00, 00, 00, time.UTC), 1257894000000000000}, // 2009-11-10 23:00:00 +0000 UTC
}
func TestDeadlineSetTime(t *testing.T) {
for _, tt := range deadlineSetTimeTests {
var d deadline
d.setTime(tt.input)
actual := d.value()
expected := int64(0)
if !tt.input.IsZero() {
expected = tt.input.UnixNano()
}
if actual != expected {
t.Errorf("set/value failed: expected %v, actual %v", expected, actual)
}
}
}
var deadlineExpiredTests = []struct {
deadline time.Time
expired bool
}{
// note, times are relative to the start of the test run, not
// the start of TestDeadlineExpired
{time.Now().Add(5 * time.Minute), false},
{time.Now().Add(-5 * time.Minute), true},
{time.Time{}, false}, // no deadline set
}
func TestDeadlineExpired(t *testing.T) {
for _, tt := range deadlineExpiredTests {
var d deadline
d.set(tt.deadline.UnixNano())
expired := d.expired()
if expired != tt.expired {
t.Errorf("expire failed: expected %v, actual %v", tt.expired, expired)
}
}
}
......@@ -11,7 +11,6 @@ import (
"os"
"runtime"
"sync"
"sync/atomic"
"syscall"
"time"
)
......@@ -38,11 +37,11 @@ type netFD struct {
laddr Addr
raddr Addr
// serialize access to Read and Write methods
rio, wio sync.Mutex
// read and write deadlines
rdeadline, wdeadline deadline
// owned by client
rdeadline int64
rio sync.Mutex
wdeadline int64
wio sync.Mutex
// owned by fd wait server
ncr, ncw int
......@@ -51,31 +50,6 @@ type netFD struct {
pollServer *pollServer
}
// deadline is an atomically-accessed number of nanoseconds since 1970
// or 0, if no deadline is set.
type deadline int64
func (d *deadline) expired() bool {
t := d.value()
return t > 0 && time.Now().UnixNano() >= t
}
func (d *deadline) value() int64 {
return atomic.LoadInt64((*int64)(d))
}
func (d *deadline) set(v int64) {
atomic.StoreInt64((*int64)(d), v)
}
func (d *deadline) setTime(t time.Time) {
if t.IsZero() {
d.set(0)
} else {
d.set(t.UnixNano())
}
}
// A pollServer helps FDs determine when to retry a non-blocking
// read or write after they get EAGAIN. When an FD needs to wait,
// call s.WaitRead() or s.WaitWrite() to pass the request to the poll server.
......@@ -108,11 +82,11 @@ func (s *pollServer) AddFD(fd *netFD, mode int) error {
key := intfd << 1
if mode == 'r' {
fd.ncr++
t = fd.rdeadline.value()
t = fd.rdeadline
} else {
fd.ncw++
key++
t = fd.wdeadline.value()
t = fd.wdeadline
}
s.pending[key] = fd
doWakeup := false
......@@ -179,8 +153,12 @@ func (s *pollServer) WakeFD(fd *netFD, mode int, err error) {
}
}
func (s *pollServer) Now() int64 {
return time.Now().UnixNano()
}
func (s *pollServer) CheckDeadlines() {
now := time.Now().UnixNano()
now := s.Now()
// TODO(rsc): This will need to be handled more efficiently,
// probably with a heap indexed by wakeup time.
......@@ -194,9 +172,9 @@ func (s *pollServer) CheckDeadlines() {
mode = 'w'
}
if mode == 'r' {
t = fd.rdeadline.value()
t = fd.rdeadline
} else {
t = fd.wdeadline.value()
t = fd.wdeadline
}
if t > 0 {
if t <= now {
......@@ -220,15 +198,15 @@ func (s *pollServer) Run() {
s.Lock()
defer s.Unlock()
for {
var timeout int64 // nsec to wait for or 0 for none
if s.deadline > 0 {
timeout = s.deadline - time.Now().UnixNano()
if timeout <= 0 {
var t = s.deadline
if t > 0 {
t = t - s.Now()
if t <= 0 {
s.CheckDeadlines()
continue
}
}
fd, mode, err := s.poll.WaitFD(s, timeout)
fd, mode, err := s.poll.WaitFD(s, t)
if err != nil {
print("pollServer WaitFD: ", err.Error(), "\n")
return
......@@ -439,10 +417,12 @@ func (fd *netFD) Read(p []byte) (n int, err error) {
}
defer fd.decref()
for {
if fd.rdeadline.expired() {
if fd.rdeadline > 0 {
if time.Now().UnixNano() >= fd.rdeadline {
err = errTimeout
break
}
}
n, err = syscall.Read(int(fd.sysfd), p)
if err != nil {
n = 0
......@@ -469,10 +449,12 @@ func (fd *netFD) ReadFrom(p []byte) (n int, sa syscall.Sockaddr, err error) {
}
defer fd.decref()
for {
if fd.rdeadline.expired() {
if fd.rdeadline > 0 {
if time.Now().UnixNano() >= fd.rdeadline {
err = errTimeout
break
}
}
n, sa, err = syscall.Recvfrom(fd.sysfd, p, 0)
if err != nil {
n = 0
......@@ -499,13 +481,15 @@ func (fd *netFD) ReadMsg(p []byte, oob []byte) (n, oobn, flags int, sa syscall.S
}
defer fd.decref()
for {
if fd.rdeadline.expired() {
if fd.rdeadline > 0 {
if time.Now().UnixNano() >= fd.rdeadline {
err = errTimeout
break
}
}
n, oobn, flags, sa, err = syscall.Recvmsg(fd.sysfd, p, oob, 0)
if err != nil {
// TODO(dfc) should n and oobn be set to 0
// TODO(dfc) should n and oobn be set to nil
if err == syscall.EAGAIN {
if err = fd.pollServer.WaitRead(fd); err == nil {
continue
......@@ -528,18 +512,22 @@ func chkReadErr(n int, err error, fd *netFD) error {
return err
}
func (fd *netFD) Write(p []byte) (nn int, err error) {
func (fd *netFD) Write(p []byte) (int, error) {
fd.wio.Lock()
defer fd.wio.Unlock()
if err := fd.incref(false); err != nil {
return 0, err
}
defer fd.decref()
var err error
nn := 0
for {
if fd.wdeadline.expired() {
if fd.wdeadline > 0 {
if time.Now().UnixNano() >= fd.wdeadline {
err = errTimeout
break
}
}
var n int
n, err = syscall.Write(int(fd.sysfd), p[nn:])
if n > 0 {
......@@ -576,10 +564,12 @@ func (fd *netFD) WriteTo(p []byte, sa syscall.Sockaddr) (n int, err error) {
}
defer fd.decref()
for {
if fd.wdeadline.expired() {
if fd.wdeadline > 0 {
if time.Now().UnixNano() >= fd.wdeadline {
err = errTimeout
break
}
}
err = syscall.Sendto(fd.sysfd, p, 0, sa)
if err == syscall.EAGAIN {
if err = fd.pollServer.WaitWrite(fd); err == nil {
......@@ -604,10 +594,12 @@ func (fd *netFD) WriteMsg(p []byte, oob []byte, sa syscall.Sockaddr) (n int, oob
}
defer fd.decref()
for {
if fd.wdeadline.expired() {
if fd.wdeadline > 0 {
if time.Now().UnixNano() >= fd.wdeadline {
err = errTimeout
break
}
}
err = syscall.Sendmsg(fd.sysfd, p, oob, sa, 0)
if err == syscall.EAGAIN {
if err = fd.pollServer.WaitWrite(fd); err == nil {
......
......@@ -285,39 +285,11 @@ type netFD struct {
errnoc [2]chan error // read/write submit or cancel operation errors
closec chan bool // used by Close to cancel pending IO
// serialize access to Read and Write methods
rio, wio sync.Mutex
// read and write deadlines
rdeadline, wdeadline deadline
}
// deadline is a number of nanoseconds since 1970 or 0, if no deadline is set.
// For compatability, deadline has the same method set as fd_unix.go, but
// does not use atomic operations as it is not known if data races exist on
// these values.
// TODO(dfc,brainman) when we get a windows race builder, revisit this.
type deadline int64
func (d *deadline) expired() bool {
t := d.value()
return t > 0 && time.Now().UnixNano() >= t
}
func (d *deadline) value() int64 {
return int64(*d)
}
func (d *deadline) set(v int64) {
*d = deadline(v)
}
func (d *deadline) setTime(t time.Time) {
if t.IsZero() {
d.set(0)
} else {
d.set(t.UnixNano())
}
// owned by client
rdeadline int64
rio sync.Mutex
wdeadline int64
wio sync.Mutex
}
func allocFD(fd syscall.Handle, family, sotype int, net string) *netFD {
......@@ -450,7 +422,7 @@ func (fd *netFD) Read(buf []byte) (int, error) {
defer fd.rio.Unlock()
var o readOp
o.Init(fd, buf, 'r')
n, err := iosrv.ExecIO(&o, fd.rdeadline.value())
n, err := iosrv.ExecIO(&o, fd.rdeadline)
if err == nil && n == 0 {
err = io.EOF
}
......@@ -487,7 +459,7 @@ func (fd *netFD) ReadFrom(buf []byte) (n int, sa syscall.Sockaddr, err error) {
var o readFromOp
o.Init(fd, buf, 'r')
o.rsan = int32(unsafe.Sizeof(o.rsa))
n, err = iosrv.ExecIO(&o, fd.rdeadline.value())
n, err = iosrv.ExecIO(&o, fd.rdeadline)
if err != nil {
return 0, nil, err
}
......@@ -519,7 +491,7 @@ func (fd *netFD) Write(buf []byte) (int, error) {
defer fd.wio.Unlock()
var o writeOp
o.Init(fd, buf, 'w')
return iosrv.ExecIO(&o, fd.wdeadline.value())
return iosrv.ExecIO(&o, fd.wdeadline)
}
// WriteTo to network.
......@@ -551,7 +523,7 @@ func (fd *netFD) WriteTo(buf []byte, sa syscall.Sockaddr) (int, error) {
var o writeToOp
o.Init(fd, buf, 'w')
o.sa = sa
return iosrv.ExecIO(&o, fd.wdeadline.value())
return iosrv.ExecIO(&o, fd.wdeadline)
}
// Accept new network connections.
......@@ -600,7 +572,7 @@ func (fd *netFD) accept(toAddr func(syscall.Sockaddr) Addr) (*netFD, error) {
var o acceptOp
o.Init(fd, 'r')
o.newsock = s
_, err = iosrv.ExecIO(&o, fd.rdeadline.value())
_, err = iosrv.ExecIO(&o, fd.rdeadline)
if err != nil {
closesocket(s)
return nil, err
......
......@@ -82,7 +82,7 @@ func sendFile(c *netFD, r io.Reader) (written int64, err error, handled bool) {
if n == 0 && err1 == nil {
break
}
if err1 == syscall.EAGAIN {
if err1 == syscall.EAGAIN && c.wdeadline >= 0 {
if err1 = c.pollServer.WaitWrite(c); err1 == nil {
continue
}
......
......@@ -58,7 +58,7 @@ func sendFile(c *netFD, r io.Reader) (written int64, err error, handled bool) {
if n == 0 && err1 == nil {
break
}
if err1 == syscall.EAGAIN {
if err1 == syscall.EAGAIN && c.wdeadline >= 0 {
if err1 = c.pollServer.WaitWrite(c); err1 == nil {
continue
}
......
......@@ -57,14 +57,16 @@ func socket(net string, f, t, p int, ipv6only bool, ulsa, ursa syscall.Sockaddr,
}
if ursa != nil {
fd.wdeadline.setTime(deadline)
if !deadline.IsZero() {
fd.wdeadline = deadline.UnixNano()
}
if err = fd.connect(ursa); err != nil {
closesocket(s)
fd.Close()
return nil, err
}
fd.isConnected = true
fd.wdeadline.set(0)
fd.wdeadline = 0
}
lsa, _ := syscall.Getsockname(s)
......
......@@ -119,22 +119,29 @@ func setWriteBuffer(fd *netFD, bytes int) error {
return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(fd.sysfd, syscall.SOL_SOCKET, syscall.SO_SNDBUF, bytes))
}
// TODO(dfc) these unused error returns could be removed
func setReadDeadline(fd *netFD, t time.Time) error {
fd.rdeadline.setTime(t)
if t.IsZero() {
fd.rdeadline = 0
} else {
fd.rdeadline = t.UnixNano()
}
return nil
}
func setWriteDeadline(fd *netFD, t time.Time) error {
fd.wdeadline.setTime(t)
if t.IsZero() {
fd.wdeadline = 0
} else {
fd.wdeadline = t.UnixNano()
}
return nil
}
func setDeadline(fd *netFD, t time.Time) error {
setReadDeadline(fd, t)
setWriteDeadline(fd, t)
return nil
if err := setReadDeadline(fd, t); err != nil {
return err
}
return setWriteDeadline(fd, t)
}
func setKeepAlive(fd *netFD, keepalive bool) error {
......
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