net: fix accept/connect deadline handling
Ensure that accept/connect respect deadline,
even if the operation can be executed w/o blocking.
Note this changes external behavior, but it makes
it consistent with read/write.
Factor out deadline check into pollServer.PrepareRead/Write,
in preparation for edge triggered pollServer.
Ensure that pollServer.WaitRead/Write are not called concurrently
by adding rio/wio locks around connect/accept.
R=golang-dev, mikioh.mikioh, bradfitz, iant
CC=golang-dev
https://golang.org/cl/7436048
diff --git a/src/pkg/net/fd_unix.go b/src/pkg/net/fd_unix.go
index 0540df8..d7a83b6 100644
--- a/src/pkg/net/fd_unix.go
+++ b/src/pkg/net/fd_unix.go
@@ -234,6 +234,20 @@
}
}
+func (s *pollServer) PrepareRead(fd *netFD) error {
+ if fd.rdeadline.expired() {
+ return errTimeout
+ }
+ return nil
+}
+
+func (s *pollServer) PrepareWrite(fd *netFD) error {
+ if fd.wdeadline.expired() {
+ return errTimeout
+ }
+ return nil
+}
+
func (s *pollServer) WaitRead(fd *netFD) error {
err := s.AddFD(fd, 'r')
if err == nil {
@@ -331,6 +345,11 @@
}
func (fd *netFD) connect(ra syscall.Sockaddr) error {
+ fd.wio.Lock()
+ defer fd.wio.Unlock()
+ if err := fd.pollServer.PrepareWrite(fd); err != nil {
+ return err
+ }
err := syscall.Connect(fd.sysfd, ra)
if err == syscall.EINPROGRESS {
if err = fd.pollServer.WaitWrite(fd); err != nil {
@@ -425,11 +444,10 @@
return 0, err
}
defer fd.decref()
+ if err := fd.pollServer.PrepareRead(fd); err != nil {
+ return 0, &OpError{"read", fd.net, fd.raddr, err}
+ }
for {
- if fd.rdeadline.expired() {
- err = errTimeout
- break
- }
n, err = syscall.Read(int(fd.sysfd), p)
if err != nil {
n = 0
@@ -455,11 +473,10 @@
return 0, nil, err
}
defer fd.decref()
+ if err := fd.pollServer.PrepareRead(fd); err != nil {
+ return 0, nil, &OpError{"read", fd.net, fd.laddr, err}
+ }
for {
- if fd.rdeadline.expired() {
- err = errTimeout
- break
- }
n, sa, err = syscall.Recvfrom(fd.sysfd, p, 0)
if err != nil {
n = 0
@@ -485,11 +502,10 @@
return 0, 0, 0, nil, err
}
defer fd.decref()
+ if err := fd.pollServer.PrepareRead(fd); err != nil {
+ return 0, 0, 0, nil, &OpError{"read", fd.net, fd.laddr, err}
+ }
for {
- if fd.rdeadline.expired() {
- 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
@@ -522,11 +538,10 @@
return 0, err
}
defer fd.decref()
+ if err := fd.pollServer.PrepareWrite(fd); err != nil {
+ return 0, &OpError{"write", fd.net, fd.raddr, err}
+ }
for {
- if fd.wdeadline.expired() {
- err = errTimeout
- break
- }
var n int
n, err = syscall.Write(int(fd.sysfd), p[nn:])
if n > 0 {
@@ -562,11 +577,10 @@
return 0, err
}
defer fd.decref()
+ if err := fd.pollServer.PrepareWrite(fd); err != nil {
+ return 0, &OpError{"write", fd.net, fd.raddr, err}
+ }
for {
- if fd.wdeadline.expired() {
- err = errTimeout
- break
- }
err = syscall.Sendto(fd.sysfd, p, 0, sa)
if err == syscall.EAGAIN {
if err = fd.pollServer.WaitWrite(fd); err == nil {
@@ -590,11 +604,10 @@
return 0, 0, err
}
defer fd.decref()
+ if err := fd.pollServer.PrepareWrite(fd); err != nil {
+ return 0, 0, &OpError{"write", fd.net, fd.raddr, err}
+ }
for {
- if fd.wdeadline.expired() {
- err = errTimeout
- break
- }
err = syscall.Sendmsg(fd.sysfd, p, oob, sa, 0)
if err == syscall.EAGAIN {
if err = fd.pollServer.WaitWrite(fd); err == nil {
@@ -613,6 +626,8 @@
}
func (fd *netFD) accept(toAddr func(syscall.Sockaddr) Addr) (netfd *netFD, err error) {
+ fd.rio.Lock()
+ defer fd.rio.Unlock()
if err := fd.incref(false); err != nil {
return nil, err
}
@@ -620,6 +635,9 @@
var s int
var rsa syscall.Sockaddr
+ if err = fd.pollServer.PrepareRead(fd); err != nil {
+ return nil, &OpError{"accept", fd.net, fd.laddr, err}
+ }
for {
s, rsa, err = accept(fd.sysfd)
if err != nil {
