net: implement windows timeout

R=brainman, rsc
CC=golang-dev
https://golang.org/cl/1731047

src/pkg/net/fd_windows.go

@@ -6,14 +6,14 @@ package net
 
 import (
 	"os"
+	"runtime"
 	"sync"
 	"syscall"
+	"time"
 	"unsafe"
 	"runtime"
 )
 
-// BUG(brainman): The Windows implementation does not implement SetTimeout.
-
 // IO completion result parameters.
 type ioResult struct {
 	key   uint32
@@ -79,6 +79,8 @@ type ioPacket struct {
 
 	// Link to the io owner.
 	c chan *ioResult
+
+	w *syscall.WSABuf
 }
 
 func (s *pollServer) getCompletedIO() (ov *syscall.Overlapped, result *ioResult, err os.Error) {
@@ -126,6 +128,8 @@ func startServer() {
 		panic("Start pollServer: " + err.String() + "\n")
 	}
 	pollserver = p
+
+	go timeoutIO()
 }
 
 var initErr os.Error
@@ -143,8 +147,8 @@ func newFD(fd, family, proto int, net string, laddr, raddr Addr) (f *netFD, err
 		sysfd:  fd,
 		family: family,
 		proto:  proto,
-		cr:     make(chan *ioResult),
-		cw:     make(chan *ioResult),
+		cr:     make(chan *ioResult, 1),
+		cw:     make(chan *ioResult, 1),
 		net:    net,
 		laddr:  laddr,
 		raddr:  raddr,
@@ -199,6 +203,80 @@ func newWSABuf(p []byte) *syscall.WSABuf {
 	return &syscall.WSABuf{uint32(len(p)), p0}
 }
 
+func waitPacket(fd *netFD, pckt *ioPacket, mode int) (r *ioResult) {
+	var delta int64
+	if mode == 'r' {
+		delta = fd.rdeadline_delta
+	}
+	if mode == 'w' {
+		delta = fd.wdeadline_delta
+	}
+	if delta <= 0 {
+		return <-pckt.c
+	}
+
+	select {
+	case r = <-pckt.c:
+	case <-time.After(delta):
+		a := &arg{f: cancel, fd: fd, pckt: pckt, c: make(chan int)}
+		ioChan <- a
+		<-a.c
+		r = <-pckt.c
+		if r.errno == 995 { // IO Canceled
+			r.errno = syscall.EWOULDBLOCK
+		}
+	}
+	return r
+}
+
+const (
+	read = iota
+	readfrom
+	write
+	writeto
+	cancel
+)
+
+type arg struct {
+	f     int
+	fd    *netFD
+	pckt  *ioPacket
+	done  *uint32
+	flags *uint32
+	rsa   *syscall.RawSockaddrAny
+	size  *int32
+	sa    *syscall.Sockaddr
+	c     chan int
+}
+
+var ioChan chan *arg = make(chan *arg)
+
+func timeoutIO() {
+	// CancelIO only cancels all pending input and output (I/O) operations that are
+	// issued by the calling thread for the specified file, does not cancel I/O
+	// operations that other threads issue for a file handle. So we need do all timeout
+	// I/O in single OS thread.
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+	for {
+		o := <-ioChan
+		var e int
+		switch o.f {
+		case read:
+			e = syscall.WSARecv(uint32(o.fd.sysfd), o.pckt.w, 1, o.done, o.flags, &o.pckt.o, nil)
+		case readfrom:
+			e = syscall.WSARecvFrom(uint32(o.fd.sysfd), o.pckt.w, 1, o.done, o.flags, o.rsa, o.size, &o.pckt.o, nil)
+		case write:
+			e = syscall.WSASend(uint32(o.fd.sysfd), o.pckt.w, 1, o.done, uint32(0), &o.pckt.o, nil)
+		case writeto:
+			e = syscall.WSASendto(uint32(o.fd.sysfd), o.pckt.w, 1, o.done, 0, *o.sa, &o.pckt.o, nil)
+		case cancel:
+			_, e = syscall.CancelIo(uint32(o.fd.sysfd))
+		}
+		o.c <- e
+	}
+}
+
 func (fd *netFD) Read(p []byte) (n int, err os.Error) {
 	if fd == nil {
 		return 0, os.EINVAL
@@ -213,9 +291,17 @@ func (fd *netFD) Read(p []byte) (n int, err os.Error) {
 	// Submit receive request.
 	var pckt ioPacket
 	pckt.c = fd.cr
+	pckt.w = newWSABuf(p)
 	var done uint32
 	flags := uint32(0)
-	e := syscall.WSARecv(uint32(fd.sysfd), newWSABuf(p), 1, &done, &flags, &pckt.o, nil)
+	var e int
+	if fd.rdeadline_delta > 0 {
+		a := &arg{f: read, fd: fd, pckt: &pckt, done: &done, flags: &flags, c: make(chan int)}
+		ioChan <- a
+		e = <-a.c
+	} else {
+		e = syscall.WSARecv(uint32(fd.sysfd), pckt.w, 1, &done, &flags, &pckt.o, nil)
+	}
 	switch e {
 	case 0:
 		// IO completed immediately, but we need to get our completion message anyway.
@@ -225,7 +311,7 @@ func (fd *netFD) Read(p []byte) (n int, err os.Error) {
 		return 0, &OpError{"WSARecv", fd.net, fd.laddr, os.Errno(e)}
 	}
 	// Wait for our request to complete.
-	r := <-pckt.c
+	r := waitPacket(fd, &pckt, 'r')
 	if r.errno != 0 {
 		err = &OpError{"WSARecv", fd.net, fd.laddr, os.Errno(r.errno)}
 	}
@@ -253,11 +339,19 @@ func (fd *netFD) ReadFrom(p []byte) (n int, sa syscall.Sockaddr, err os.Error) {
 	// Submit receive request.
 	var pckt ioPacket
 	pckt.c = fd.cr
+	pckt.w = newWSABuf(p)
 	var done uint32
 	flags := uint32(0)
 	var rsa syscall.RawSockaddrAny
 	l := int32(unsafe.Sizeof(rsa))
-	e := syscall.WSARecvFrom(uint32(fd.sysfd), newWSABuf(p), 1, &done, &flags, &rsa, &l, &pckt.o, nil)
+	var e int
+	if fd.rdeadline_delta > 0 {
+		a := &arg{f: readfrom, fd: fd, pckt: &pckt, done: &done, flags: &flags, rsa: &rsa, size: &l, c: make(chan int)}
+		ioChan <- a
+		e = <-a.c
+	} else {
+		e = syscall.WSARecvFrom(uint32(fd.sysfd), pckt.w, 1, &done, &flags, &rsa, &l, &pckt.o, nil)
+	}
 	switch e {
 	case 0:
 		// IO completed immediately, but we need to get our completion message anyway.
@@ -267,7 +361,7 @@ func (fd *netFD) ReadFrom(p []byte) (n int, sa syscall.Sockaddr, err os.Error) {
 		return 0, nil, &OpError{"WSARecvFrom", fd.net, fd.laddr, os.Errno(e)}
 	}
 	// Wait for our request to complete.
-	r := <-pckt.c
+	r := waitPacket(fd, &pckt, 'r')
 	if r.errno != 0 {
 		err = &OpError{"WSARecvFrom", fd.net, fd.laddr, os.Errno(r.errno)}
 	}
@@ -290,8 +384,16 @@ func (fd *netFD) Write(p []byte) (n int, err os.Error) {
 	// Submit send request.
 	var pckt ioPacket
 	pckt.c = fd.cw
+	pckt.w = newWSABuf(p)
 	var done uint32
-	e := syscall.WSASend(uint32(fd.sysfd), newWSABuf(p), 1, &done, uint32(0), &pckt.o, nil)
+	var e int
+	if fd.wdeadline_delta > 0 {
+		a := &arg{f: write, fd: fd, pckt: &pckt, done: &done, c: make(chan int)}
+		ioChan <- a
+		e = <-a.c
+	} else {
+		e = syscall.WSASend(uint32(fd.sysfd), pckt.w, 1, &done, uint32(0), &pckt.o, nil)
+	}
 	switch e {
 	case 0:
 		// IO completed immediately, but we need to get our completion message anyway.
@@ -301,7 +403,7 @@ func (fd *netFD) Write(p []byte) (n int, err os.Error) {
 		return 0, &OpError{"WSASend", fd.net, fd.laddr, os.Errno(e)}
 	}
 	// Wait for our request to complete.
-	r := <-pckt.c
+	r := waitPacket(fd, &pckt, 'w')
 	if r.errno != 0 {
 		err = &OpError{"WSASend", fd.net, fd.laddr, os.Errno(r.errno)}
 	}
@@ -326,8 +428,16 @@ func (fd *netFD) WriteTo(p []byte, sa syscall.Sockaddr) (n int, err os.Error) {
 	// Submit send request.
 	var pckt ioPacket
 	pckt.c = fd.cw
+	pckt.w = newWSABuf(p)
 	var done uint32
-	e := syscall.WSASendto(uint32(fd.sysfd), newWSABuf(p), 1, &done, 0, sa, &pckt.o, nil)
+	var e int
+	if fd.wdeadline_delta > 0 {
+		a := &arg{f: writeto, fd: fd, pckt: &pckt, done: &done, sa: &sa, c: make(chan int)}
+		ioChan <- a
+		e = <-a.c
+	} else {
+		e = syscall.WSASendto(uint32(fd.sysfd), pckt.w, 1, &done, 0, sa, &pckt.o, nil)
+	}
 	switch e {
 	case 0:
 		// IO completed immediately, but we need to get our completion message anyway.
@@ -337,7 +447,7 @@ func (fd *netFD) WriteTo(p []byte, sa syscall.Sockaddr) (n int, err os.Error) {
 		return 0, &OpError{"WSASendTo", fd.net, fd.laddr, os.Errno(e)}
 	}
 	// Wait for our request to complete.
-	r := <-pckt.c
+	r := waitPacket(fd, &pckt, 'w')
 	if r.errno != 0 {
 		err = &OpError{"WSASendTo", fd.net, fd.laddr, os.Errno(r.errno)}
 	}
@@ -410,8 +520,8 @@ func (fd *netFD) accept(toAddr func(syscall.Sockaddr) Addr) (nfd *netFD, err os.
 		sysfd:  s,
 		family: fd.family,
 		proto:  fd.proto,
-		cr:     make(chan *ioResult),
-		cw:     make(chan *ioResult),
+		cr:     make(chan *ioResult, 1),
+		cw:     make(chan *ioResult, 1),
 		net:    fd.net,
 		laddr:  laddr,
 		raddr:  raddr,

src/pkg/net/timeout_test.go

@@ -8,14 +8,9 @@ import (
 	"os"
 	"testing"
 	"time"
-	"runtime"
 )
 
 func testTimeout(t *testing.T, network, addr string, readFrom bool) {
-	// Timeouts are not implemented on windows.
-	if runtime.GOOS == "windows" {
-		return
-	}
 	fd, err := Dial(network, "", addr)
 	if err != nil {
 		t.Errorf("dial %s %s failed: %v", network, addr, err)

src/pkg/syscall/syscall_windows.go

@@ -126,6 +126,7 @@ func getSysProcAddr(m uint32, pname string) uintptr {
 //sys	GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, errno int) [failretval==0xffffffff]
 //sys	CreateIoCompletionPort(filehandle int32, cphandle int32, key uint32, threadcnt uint32) (handle int32, errno int)
 //sys	GetQueuedCompletionStatus(cphandle int32, qty *uint32, key *uint32, overlapped **Overlapped, timeout uint32) (ok bool, errno int)
+//sys	CancelIo(s uint32) (ok bool, errno int)
 //sys	CreateProcess(appName *int16, commandLine *uint16, procSecurity *int16, threadSecurity *int16, inheritHandles bool, creationFlags uint32, env *uint16, currentDir *uint16, startupInfo *StartupInfo, outProcInfo *ProcessInformation)  (ok bool, errno int) = CreateProcessW
 //sys	GetStartupInfo(startupInfo *StartupInfo)  (ok bool, errno int) = GetStartupInfoW
 //sys	GetCurrentProcess() (pseudoHandle int32, errno int)

src/pkg/syscall/zsyscall_windows_386.go

@@ -43,6 +43,7 @@ var (
 	procGetTimeZoneInformation     = getSysProcAddr(modkernel32, "GetTimeZoneInformation")
 	procCreateIoCompletionPort     = getSysProcAddr(modkernel32, "CreateIoCompletionPort")
 	procGetQueuedCompletionStatus  = getSysProcAddr(modkernel32, "GetQueuedCompletionStatus")
+	procCancelIo                   = getSysProcAddr(modkernel32, "CancelIo")
 	procCreateProcessW             = getSysProcAddr(modkernel32, "CreateProcessW")
 	procGetStartupInfoW            = getSysProcAddr(modkernel32, "GetStartupInfoW")
 	procGetCurrentProcess          = getSysProcAddr(modkernel32, "GetCurrentProcess")
@@ -512,6 +513,21 @@ func GetQueuedCompletionStatus(cphandle int32, qty *uint32, key *uint32, overlap
 	return
 }
 
+func CancelIo(s uint32) (ok bool, errno int) {
+	r0, _, e1 := Syscall(procCancelIo, uintptr(s), 0, 0)
+	ok = bool(r0 != 0)
+	if !ok {
+		if e1 != 0 {
+			errno = int(e1)
+		} else {
+			errno = EINVAL
+		}
+	} else {
+		errno = 0
+	}
+	return
+}
+
 func CreateProcess(appName *int16, commandLine *uint16, procSecurity *int16, threadSecurity *int16, inheritHandles bool, creationFlags uint32, env *uint16, currentDir *uint16, startupInfo *StartupInfo, outProcInfo *ProcessInformation) (ok bool, errno int) {
 	var _p0 uint32
 	if inheritHandles {