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Diffstat (limited to 'libgo/go/internal/poll/fd_windows.go')
-rw-r--r--libgo/go/internal/poll/fd_windows.go873
1 files changed, 873 insertions, 0 deletions
diff --git a/libgo/go/internal/poll/fd_windows.go b/libgo/go/internal/poll/fd_windows.go
new file mode 100644
index 00000000000..655f9348c62
--- /dev/null
+++ b/libgo/go/internal/poll/fd_windows.go
@@ -0,0 +1,873 @@
+// Copyright 2017 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.
+
+package poll
+
+import (
+ "errors"
+ "internal/race"
+ "io"
+ "runtime"
+ "sync"
+ "syscall"
+ "unicode/utf16"
+ "unicode/utf8"
+ "unsafe"
+)
+
+var (
+ initErr error
+ ioSync uint64
+)
+
+// CancelIo Windows API cancels all outstanding IO for a particular
+// socket on current thread. To overcome that limitation, we run
+// special goroutine, locked to OS single thread, that both starts
+// and cancels IO. It means, there are 2 unavoidable thread switches
+// for every IO.
+// Some newer versions of Windows has new CancelIoEx API, that does
+// not have that limitation and can be used from any thread. This
+// package uses CancelIoEx API, if present, otherwise it fallback
+// to CancelIo.
+
+var (
+ canCancelIO bool // determines if CancelIoEx API is present
+ skipSyncNotif bool
+ hasLoadSetFileCompletionNotificationModes bool
+)
+
+func init() {
+ var d syscall.WSAData
+ e := syscall.WSAStartup(uint32(0x202), &d)
+ if e != nil {
+ initErr = e
+ }
+ canCancelIO = syscall.LoadCancelIoEx() == nil
+ hasLoadSetFileCompletionNotificationModes = syscall.LoadSetFileCompletionNotificationModes() == nil
+ if hasLoadSetFileCompletionNotificationModes {
+ // It's not safe to use FILE_SKIP_COMPLETION_PORT_ON_SUCCESS if non IFS providers are installed:
+ // http://support.microsoft.com/kb/2568167
+ skipSyncNotif = true
+ protos := [2]int32{syscall.IPPROTO_TCP, 0}
+ var buf [32]syscall.WSAProtocolInfo
+ len := uint32(unsafe.Sizeof(buf))
+ n, err := syscall.WSAEnumProtocols(&protos[0], &buf[0], &len)
+ if err != nil {
+ skipSyncNotif = false
+ } else {
+ for i := int32(0); i < n; i++ {
+ if buf[i].ServiceFlags1&syscall.XP1_IFS_HANDLES == 0 {
+ skipSyncNotif = false
+ break
+ }
+ }
+ }
+ }
+}
+
+// operation contains superset of data necessary to perform all async IO.
+type operation struct {
+ // Used by IOCP interface, it must be first field
+ // of the struct, as our code rely on it.
+ o syscall.Overlapped
+
+ // fields used by runtime.netpoll
+ runtimeCtx uintptr
+ mode int32
+ errno int32
+ qty uint32
+
+ // fields used only by net package
+ fd *FD
+ errc chan error
+ buf syscall.WSABuf
+ sa syscall.Sockaddr
+ rsa *syscall.RawSockaddrAny
+ rsan int32
+ handle syscall.Handle
+ flags uint32
+ bufs []syscall.WSABuf
+}
+
+func (o *operation) InitBuf(buf []byte) {
+ o.buf.Len = uint32(len(buf))
+ o.buf.Buf = nil
+ if len(buf) != 0 {
+ o.buf.Buf = &buf[0]
+ }
+}
+
+func (o *operation) InitBufs(buf *[][]byte) {
+ if o.bufs == nil {
+ o.bufs = make([]syscall.WSABuf, 0, len(*buf))
+ } else {
+ o.bufs = o.bufs[:0]
+ }
+ for _, b := range *buf {
+ var p *byte
+ if len(b) > 0 {
+ p = &b[0]
+ }
+ o.bufs = append(o.bufs, syscall.WSABuf{Len: uint32(len(b)), Buf: p})
+ }
+}
+
+// ClearBufs clears all pointers to Buffers parameter captured
+// by InitBufs, so it can be released by garbage collector.
+func (o *operation) ClearBufs() {
+ for i := range o.bufs {
+ o.bufs[i].Buf = nil
+ }
+ o.bufs = o.bufs[:0]
+}
+
+// ioSrv executes net IO requests.
+type ioSrv struct {
+ req chan ioSrvReq
+}
+
+type ioSrvReq struct {
+ o *operation
+ submit func(o *operation) error // if nil, cancel the operation
+}
+
+// ProcessRemoteIO will execute submit IO requests on behalf
+// of other goroutines, all on a single os thread, so it can
+// cancel them later. Results of all operations will be sent
+// back to their requesters via channel supplied in request.
+// It is used only when the CancelIoEx API is unavailable.
+func (s *ioSrv) ProcessRemoteIO() {
+ runtime.LockOSThread()
+ defer runtime.UnlockOSThread()
+ for r := range s.req {
+ if r.submit != nil {
+ r.o.errc <- r.submit(r.o)
+ } else {
+ r.o.errc <- syscall.CancelIo(r.o.fd.Sysfd)
+ }
+ }
+}
+
+// ExecIO executes a single IO operation o. It submits and cancels
+// IO in the current thread for systems where Windows CancelIoEx API
+// is available. Alternatively, it passes the request onto
+// runtime netpoll and waits for completion or cancels request.
+func (s *ioSrv) ExecIO(o *operation, submit func(o *operation) error) (int, error) {
+ if o.fd.pd.runtimeCtx == 0 {
+ return 0, errors.New("internal error: polling on unsupported descriptor type")
+ }
+
+ if !canCancelIO {
+ onceStartServer.Do(startServer)
+ }
+
+ fd := o.fd
+ // Notify runtime netpoll about starting IO.
+ err := fd.pd.prepare(int(o.mode), fd.isFile)
+ if err != nil {
+ return 0, err
+ }
+ // Start IO.
+ if canCancelIO {
+ err = submit(o)
+ } else {
+ // Send request to a special dedicated thread,
+ // so it can stop the IO with CancelIO later.
+ s.req <- ioSrvReq{o, submit}
+ err = <-o.errc
+ }
+ switch err {
+ case nil:
+ // IO completed immediately
+ if o.fd.skipSyncNotif {
+ // No completion message will follow, so return immediately.
+ return int(o.qty), nil
+ }
+ // Need to get our completion message anyway.
+ case syscall.ERROR_IO_PENDING:
+ // IO started, and we have to wait for its completion.
+ err = nil
+ default:
+ return 0, err
+ }
+ // Wait for our request to complete.
+ err = fd.pd.wait(int(o.mode), fd.isFile)
+ if err == nil {
+ // All is good. Extract our IO results and return.
+ if o.errno != 0 {
+ err = syscall.Errno(o.errno)
+ return 0, err
+ }
+ return int(o.qty), nil
+ }
+ // IO is interrupted by "close" or "timeout"
+ netpollErr := err
+ switch netpollErr {
+ case ErrNetClosing, ErrFileClosing, ErrTimeout:
+ // will deal with those.
+ default:
+ panic("unexpected runtime.netpoll error: " + netpollErr.Error())
+ }
+ // Cancel our request.
+ if canCancelIO {
+ err := syscall.CancelIoEx(fd.Sysfd, &o.o)
+ // Assuming ERROR_NOT_FOUND is returned, if IO is completed.
+ if err != nil && err != syscall.ERROR_NOT_FOUND {
+ // TODO(brainman): maybe do something else, but panic.
+ panic(err)
+ }
+ } else {
+ s.req <- ioSrvReq{o, nil}
+ <-o.errc
+ }
+ // Wait for cancelation to complete.
+ fd.pd.waitCanceled(int(o.mode))
+ if o.errno != 0 {
+ err = syscall.Errno(o.errno)
+ if err == syscall.ERROR_OPERATION_ABORTED { // IO Canceled
+ err = netpollErr
+ }
+ return 0, err
+ }
+ // We issued a cancelation request. But, it seems, IO operation succeeded
+ // before the cancelation request run. We need to treat the IO operation as
+ // succeeded (the bytes are actually sent/recv from network).
+ return int(o.qty), nil
+}
+
+// Start helper goroutines.
+var rsrv, wsrv ioSrv
+var onceStartServer sync.Once
+
+func startServer() {
+ // This is called, once, when only the CancelIo API is available.
+ // Start two special goroutines, both locked to an OS thread,
+ // that start and cancel IO requests.
+ // One will process read requests, while the other will do writes.
+ rsrv.req = make(chan ioSrvReq)
+ go rsrv.ProcessRemoteIO()
+ wsrv.req = make(chan ioSrvReq)
+ go wsrv.ProcessRemoteIO()
+}
+
+// FD is a file descriptor. The net and os packages embed this type in
+// a larger type representing a network connection or OS file.
+type FD struct {
+ // Lock sysfd and serialize access to Read and Write methods.
+ fdmu fdMutex
+
+ // System file descriptor. Immutable until Close.
+ Sysfd syscall.Handle
+
+ // Read operation.
+ rop operation
+ // Write operation.
+ wop operation
+
+ // I/O poller.
+ pd pollDesc
+
+ // Used to implement pread/pwrite.
+ l sync.Mutex
+
+ // For console I/O.
+ isConsole bool
+ lastbits []byte // first few bytes of the last incomplete rune in last write
+ readuint16 []uint16 // buffer to hold uint16s obtained with ReadConsole
+ readbyte []byte // buffer to hold decoding of readuint16 from utf16 to utf8
+ readbyteOffset int // readbyte[readOffset:] is yet to be consumed with file.Read
+
+ skipSyncNotif bool
+
+ // Whether this is a streaming descriptor, as opposed to a
+ // packet-based descriptor like a UDP socket.
+ IsStream bool
+
+ // Whether a zero byte read indicates EOF. This is false for a
+ // message based socket connection.
+ ZeroReadIsEOF bool
+
+ // Whether this is a normal file.
+ isFile bool
+
+ // Whether this is a directory.
+ isDir bool
+}
+
+// Init initializes the FD. The Sysfd field should already be set.
+// This can be called multiple times on a single FD.
+// The net argument is a network name from the net package (e.g., "tcp"),
+// or "file" or "console" or "dir".
+func (fd *FD) Init(net string) (string, error) {
+ if initErr != nil {
+ return "", initErr
+ }
+
+ switch net {
+ case "file":
+ fd.isFile = true
+ case "console":
+ fd.isConsole = true
+ case "dir":
+ fd.isDir = true
+ case "tcp", "tcp4", "tcp6":
+ case "udp", "udp4", "udp6":
+ case "ip", "ip4", "ip6":
+ case "unix", "unixgram", "unixpacket":
+ default:
+ return "", errors.New("internal error: unknown network type " + net)
+ }
+
+ if !fd.isFile && !fd.isConsole && !fd.isDir {
+ // Only call init for a network socket.
+ // This means that we don't add files to the runtime poller.
+ // Adding files to the runtime poller can confuse matters
+ // if the user is doing their own overlapped I/O.
+ // See issue #21172.
+ //
+ // In general the code below avoids calling the ExecIO
+ // method for non-network sockets. If some method does
+ // somehow call ExecIO, then ExecIO, and therefore the
+ // calling method, will return an error, because
+ // fd.pd.runtimeCtx will be 0.
+ if err := fd.pd.init(fd); err != nil {
+ return "", err
+ }
+ }
+ if hasLoadSetFileCompletionNotificationModes {
+ // We do not use events, so we can skip them always.
+ flags := uint8(syscall.FILE_SKIP_SET_EVENT_ON_HANDLE)
+ // It's not safe to skip completion notifications for UDP:
+ // http://blogs.technet.com/b/winserverperformance/archive/2008/06/26/designing-applications-for-high-performance-part-iii.aspx
+ if skipSyncNotif && (net == "tcp" || net == "file") {
+ flags |= syscall.FILE_SKIP_COMPLETION_PORT_ON_SUCCESS
+ }
+ err := syscall.SetFileCompletionNotificationModes(fd.Sysfd, flags)
+ if err == nil && flags&syscall.FILE_SKIP_COMPLETION_PORT_ON_SUCCESS != 0 {
+ fd.skipSyncNotif = true
+ }
+ }
+ // Disable SIO_UDP_CONNRESET behavior.
+ // http://support.microsoft.com/kb/263823
+ switch net {
+ case "udp", "udp4", "udp6":
+ ret := uint32(0)
+ flag := uint32(0)
+ size := uint32(unsafe.Sizeof(flag))
+ err := syscall.WSAIoctl(fd.Sysfd, syscall.SIO_UDP_CONNRESET, (*byte)(unsafe.Pointer(&flag)), size, nil, 0, &ret, nil, 0)
+ if err != nil {
+ return "wsaioctl", err
+ }
+ }
+ fd.rop.mode = 'r'
+ fd.wop.mode = 'w'
+ fd.rop.fd = fd
+ fd.wop.fd = fd
+ fd.rop.runtimeCtx = fd.pd.runtimeCtx
+ fd.wop.runtimeCtx = fd.pd.runtimeCtx
+ if !canCancelIO {
+ fd.rop.errc = make(chan error)
+ fd.wop.errc = make(chan error)
+ }
+ return "", nil
+}
+
+func (fd *FD) destroy() error {
+ if fd.Sysfd == syscall.InvalidHandle {
+ return syscall.EINVAL
+ }
+ // Poller may want to unregister fd in readiness notification mechanism,
+ // so this must be executed before fd.CloseFunc.
+ fd.pd.close()
+ var err error
+ if fd.isFile || fd.isConsole {
+ err = syscall.CloseHandle(fd.Sysfd)
+ } else if fd.isDir {
+ err = syscall.FindClose(fd.Sysfd)
+ } else {
+ // The net package uses the CloseFunc variable for testing.
+ err = CloseFunc(fd.Sysfd)
+ }
+ fd.Sysfd = syscall.InvalidHandle
+ return err
+}
+
+// Close closes the FD. The underlying file descriptor is closed by
+// the destroy method when there are no remaining references.
+func (fd *FD) Close() error {
+ if !fd.fdmu.increfAndClose() {
+ return errClosing(fd.isFile)
+ }
+ // unblock pending reader and writer
+ fd.pd.evict()
+ return fd.decref()
+}
+
+// Shutdown wraps the shutdown network call.
+func (fd *FD) Shutdown(how int) error {
+ if err := fd.incref(); err != nil {
+ return err
+ }
+ defer fd.decref()
+ return syscall.Shutdown(fd.Sysfd, how)
+}
+
+// Read implements io.Reader.
+func (fd *FD) Read(buf []byte) (int, error) {
+ if err := fd.readLock(); err != nil {
+ return 0, err
+ }
+ defer fd.readUnlock()
+
+ var n int
+ var err error
+ if fd.isFile || fd.isDir || fd.isConsole {
+ fd.l.Lock()
+ defer fd.l.Unlock()
+ if fd.isConsole {
+ n, err = fd.readConsole(buf)
+ } else {
+ n, err = syscall.Read(fd.Sysfd, buf)
+ }
+ if err != nil {
+ n = 0
+ }
+ } else {
+ o := &fd.rop
+ o.InitBuf(buf)
+ n, err = rsrv.ExecIO(o, func(o *operation) error {
+ return syscall.WSARecv(o.fd.Sysfd, &o.buf, 1, &o.qty, &o.flags, &o.o, nil)
+ })
+ if race.Enabled {
+ race.Acquire(unsafe.Pointer(&ioSync))
+ }
+ }
+ if len(buf) != 0 {
+ err = fd.eofError(n, err)
+ }
+ return n, err
+}
+
+var ReadConsole = syscall.ReadConsole // changed for testing
+
+// readConsole reads utf16 characters from console File,
+// encodes them into utf8 and stores them in buffer b.
+// It returns the number of utf8 bytes read and an error, if any.
+func (fd *FD) readConsole(b []byte) (int, error) {
+ if len(b) == 0 {
+ return 0, nil
+ }
+
+ if fd.readuint16 == nil {
+ // Note: syscall.ReadConsole fails for very large buffers.
+ // The limit is somewhere around (but not exactly) 16384.
+ // Stay well below.
+ fd.readuint16 = make([]uint16, 0, 10000)
+ fd.readbyte = make([]byte, 0, 4*cap(fd.readuint16))
+ }
+
+ for fd.readbyteOffset >= len(fd.readbyte) {
+ n := cap(fd.readuint16) - len(fd.readuint16)
+ if n > len(b) {
+ n = len(b)
+ }
+ var nw uint32
+ err := ReadConsole(fd.Sysfd, &fd.readuint16[:len(fd.readuint16)+1][len(fd.readuint16)], uint32(n), &nw, nil)
+ if err != nil {
+ return 0, err
+ }
+ uint16s := fd.readuint16[:len(fd.readuint16)+int(nw)]
+ fd.readuint16 = fd.readuint16[:0]
+ buf := fd.readbyte[:0]
+ for i := 0; i < len(uint16s); i++ {
+ r := rune(uint16s[i])
+ if utf16.IsSurrogate(r) {
+ if i+1 == len(uint16s) {
+ if nw > 0 {
+ // Save half surrogate pair for next time.
+ fd.readuint16 = fd.readuint16[:1]
+ fd.readuint16[0] = uint16(r)
+ break
+ }
+ r = utf8.RuneError
+ } else {
+ r = utf16.DecodeRune(r, rune(uint16s[i+1]))
+ if r != utf8.RuneError {
+ i++
+ }
+ }
+ }
+ n := utf8.EncodeRune(buf[len(buf):cap(buf)], r)
+ buf = buf[:len(buf)+n]
+ }
+ fd.readbyte = buf
+ fd.readbyteOffset = 0
+ if nw == 0 {
+ break
+ }
+ }
+
+ src := fd.readbyte[fd.readbyteOffset:]
+ var i int
+ for i = 0; i < len(src) && i < len(b); i++ {
+ x := src[i]
+ if x == 0x1A { // Ctrl-Z
+ if i == 0 {
+ fd.readbyteOffset++
+ }
+ break
+ }
+ b[i] = x
+ }
+ fd.readbyteOffset += i
+ return i, nil
+}
+
+// Pread emulates the Unix pread system call.
+func (fd *FD) Pread(b []byte, off int64) (int, error) {
+ // Call incref, not readLock, because since pread specifies the
+ // offset it is independent from other reads.
+ if err := fd.incref(); err != nil {
+ return 0, err
+ }
+ defer fd.decref()
+
+ fd.l.Lock()
+ defer fd.l.Unlock()
+ curoffset, e := syscall.Seek(fd.Sysfd, 0, io.SeekCurrent)
+ if e != nil {
+ return 0, e
+ }
+ defer syscall.Seek(fd.Sysfd, curoffset, io.SeekStart)
+ o := syscall.Overlapped{
+ OffsetHigh: uint32(off >> 32),
+ Offset: uint32(off),
+ }
+ var done uint32
+ e = syscall.ReadFile(fd.Sysfd, b, &done, &o)
+ if e != nil {
+ done = 0
+ if e == syscall.ERROR_HANDLE_EOF {
+ e = io.EOF
+ }
+ }
+ if len(b) != 0 {
+ e = fd.eofError(int(done), e)
+ }
+ return int(done), e
+}
+
+// ReadFrom wraps the recvfrom network call.
+func (fd *FD) ReadFrom(buf []byte) (int, syscall.Sockaddr, error) {
+ if len(buf) == 0 {
+ return 0, nil, nil
+ }
+ if err := fd.readLock(); err != nil {
+ return 0, nil, err
+ }
+ defer fd.readUnlock()
+ o := &fd.rop
+ o.InitBuf(buf)
+ n, err := rsrv.ExecIO(o, func(o *operation) error {
+ if o.rsa == nil {
+ o.rsa = new(syscall.RawSockaddrAny)
+ }
+ o.rsan = int32(unsafe.Sizeof(*o.rsa))
+ return syscall.WSARecvFrom(o.fd.Sysfd, &o.buf, 1, &o.qty, &o.flags, o.rsa, &o.rsan, &o.o, nil)
+ })
+ err = fd.eofError(n, err)
+ if err != nil {
+ return n, nil, err
+ }
+ sa, _ := o.rsa.Sockaddr()
+ return n, sa, nil
+}
+
+// Write implements io.Writer.
+func (fd *FD) Write(buf []byte) (int, error) {
+ if err := fd.writeLock(); err != nil {
+ return 0, err
+ }
+ defer fd.writeUnlock()
+
+ var n int
+ var err error
+ if fd.isFile || fd.isDir || fd.isConsole {
+ fd.l.Lock()
+ defer fd.l.Unlock()
+ if fd.isConsole {
+ n, err = fd.writeConsole(buf)
+ } else {
+ n, err = syscall.Write(fd.Sysfd, buf)
+ }
+ if err != nil {
+ n = 0
+ }
+ } else {
+ if race.Enabled {
+ race.ReleaseMerge(unsafe.Pointer(&ioSync))
+ }
+ o := &fd.wop
+ o.InitBuf(buf)
+ n, err = wsrv.ExecIO(o, func(o *operation) error {
+ return syscall.WSASend(o.fd.Sysfd, &o.buf, 1, &o.qty, 0, &o.o, nil)
+ })
+ }
+ return n, err
+}
+
+// writeConsole writes len(b) bytes to the console File.
+// It returns the number of bytes written and an error, if any.
+func (fd *FD) writeConsole(b []byte) (int, error) {
+ n := len(b)
+ runes := make([]rune, 0, 256)
+ if len(fd.lastbits) > 0 {
+ b = append(fd.lastbits, b...)
+ fd.lastbits = nil
+
+ }
+ for len(b) >= utf8.UTFMax || utf8.FullRune(b) {
+ r, l := utf8.DecodeRune(b)
+ runes = append(runes, r)
+ b = b[l:]
+ }
+ if len(b) > 0 {
+ fd.lastbits = make([]byte, len(b))
+ copy(fd.lastbits, b)
+ }
+ // syscall.WriteConsole seems to fail, if given large buffer.
+ // So limit the buffer to 16000 characters. This number was
+ // discovered by experimenting with syscall.WriteConsole.
+ const maxWrite = 16000
+ for len(runes) > 0 {
+ m := len(runes)
+ if m > maxWrite {
+ m = maxWrite
+ }
+ chunk := runes[:m]
+ runes = runes[m:]
+ uint16s := utf16.Encode(chunk)
+ for len(uint16s) > 0 {
+ var written uint32
+ err := syscall.WriteConsole(fd.Sysfd, &uint16s[0], uint32(len(uint16s)), &written, nil)
+ if err != nil {
+ return 0, err
+ }
+ uint16s = uint16s[written:]
+ }
+ }
+ return n, nil
+}
+
+// Pwrite emulates the Unix pwrite system call.
+func (fd *FD) Pwrite(b []byte, off int64) (int, error) {
+ // Call incref, not writeLock, because since pwrite specifies the
+ // offset it is independent from other writes.
+ if err := fd.incref(); err != nil {
+ return 0, err
+ }
+ defer fd.decref()
+
+ fd.l.Lock()
+ defer fd.l.Unlock()
+ curoffset, e := syscall.Seek(fd.Sysfd, 0, io.SeekCurrent)
+ if e != nil {
+ return 0, e
+ }
+ defer syscall.Seek(fd.Sysfd, curoffset, io.SeekStart)
+ o := syscall.Overlapped{
+ OffsetHigh: uint32(off >> 32),
+ Offset: uint32(off),
+ }
+ var done uint32
+ e = syscall.WriteFile(fd.Sysfd, b, &done, &o)
+ if e != nil {
+ return 0, e
+ }
+ return int(done), nil
+}
+
+// Writev emulates the Unix writev system call.
+func (fd *FD) Writev(buf *[][]byte) (int64, error) {
+ if len(*buf) == 0 {
+ return 0, nil
+ }
+ if err := fd.writeLock(); err != nil {
+ return 0, err
+ }
+ defer fd.writeUnlock()
+ if race.Enabled {
+ race.ReleaseMerge(unsafe.Pointer(&ioSync))
+ }
+ o := &fd.wop
+ o.InitBufs(buf)
+ n, err := wsrv.ExecIO(o, func(o *operation) error {
+ return syscall.WSASend(o.fd.Sysfd, &o.bufs[0], uint32(len(o.bufs)), &o.qty, 0, &o.o, nil)
+ })
+ o.ClearBufs()
+ TestHookDidWritev(n)
+ consume(buf, int64(n))
+ return int64(n), err
+}
+
+// WriteTo wraps the sendto network call.
+func (fd *FD) WriteTo(buf []byte, sa syscall.Sockaddr) (int, error) {
+ if len(buf) == 0 {
+ return 0, nil
+ }
+ if err := fd.writeLock(); err != nil {
+ return 0, err
+ }
+ defer fd.writeUnlock()
+ o := &fd.wop
+ o.InitBuf(buf)
+ o.sa = sa
+ n, err := wsrv.ExecIO(o, func(o *operation) error {
+ return syscall.WSASendto(o.fd.Sysfd, &o.buf, 1, &o.qty, 0, o.sa, &o.o, nil)
+ })
+ return n, err
+}
+
+// Call ConnectEx. This doesn't need any locking, since it is only
+// called when the descriptor is first created. This is here rather
+// than in the net package so that it can use fd.wop.
+func (fd *FD) ConnectEx(ra syscall.Sockaddr) error {
+ o := &fd.wop
+ o.sa = ra
+ _, err := wsrv.ExecIO(o, func(o *operation) error {
+ return ConnectExFunc(o.fd.Sysfd, o.sa, nil, 0, nil, &o.o)
+ })
+ return err
+}
+
+func (fd *FD) acceptOne(s syscall.Handle, rawsa []syscall.RawSockaddrAny, o *operation) (string, error) {
+ // Submit accept request.
+ o.handle = s
+ o.rsan = int32(unsafe.Sizeof(rawsa[0]))
+ _, err := rsrv.ExecIO(o, func(o *operation) error {
+ return AcceptFunc(o.fd.Sysfd, o.handle, (*byte)(unsafe.Pointer(&rawsa[0])), 0, uint32(o.rsan), uint32(o.rsan), &o.qty, &o.o)
+ })
+ if err != nil {
+ CloseFunc(s)
+ return "acceptex", err
+ }
+
+ // Inherit properties of the listening socket.
+ err = syscall.Setsockopt(s, syscall.SOL_SOCKET, syscall.SO_UPDATE_ACCEPT_CONTEXT, (*byte)(unsafe.Pointer(&fd.Sysfd)), int32(unsafe.Sizeof(fd.Sysfd)))
+ if err != nil {
+ CloseFunc(s)
+ return "setsockopt", err
+ }
+
+ return "", nil
+}
+
+// Accept handles accepting a socket. The sysSocket parameter is used
+// to allocate the net socket.
+func (fd *FD) Accept(sysSocket func() (syscall.Handle, error)) (syscall.Handle, []syscall.RawSockaddrAny, uint32, string, error) {
+ if err := fd.readLock(); err != nil {
+ return syscall.InvalidHandle, nil, 0, "", err
+ }
+ defer fd.readUnlock()
+
+ o := &fd.rop
+ var rawsa [2]syscall.RawSockaddrAny
+ for {
+ s, err := sysSocket()
+ if err != nil {
+ return syscall.InvalidHandle, nil, 0, "", err
+ }
+
+ errcall, err := fd.acceptOne(s, rawsa[:], o)
+ if err == nil {
+ return s, rawsa[:], uint32(o.rsan), "", nil
+ }
+
+ // Sometimes we see WSAECONNRESET and ERROR_NETNAME_DELETED is
+ // returned here. These happen if connection reset is received
+ // before AcceptEx could complete. These errors relate to new
+ // connection, not to AcceptEx, so ignore broken connection and
+ // try AcceptEx again for more connections.
+ errno, ok := err.(syscall.Errno)
+ if !ok {
+ return syscall.InvalidHandle, nil, 0, errcall, err
+ }
+ switch errno {
+ case syscall.ERROR_NETNAME_DELETED, syscall.WSAECONNRESET:
+ // ignore these and try again
+ default:
+ return syscall.InvalidHandle, nil, 0, errcall, err
+ }
+ }
+}
+
+// Seek wraps syscall.Seek.
+func (fd *FD) Seek(offset int64, whence int) (int64, error) {
+ if err := fd.incref(); err != nil {
+ return 0, err
+ }
+ defer fd.decref()
+
+ fd.l.Lock()
+ defer fd.l.Unlock()
+
+ return syscall.Seek(fd.Sysfd, offset, whence)
+}
+
+// FindNextFile wraps syscall.FindNextFile.
+func (fd *FD) FindNextFile(data *syscall.Win32finddata) error {
+ if err := fd.incref(); err != nil {
+ return err
+ }
+ defer fd.decref()
+ return syscall.FindNextFile(fd.Sysfd, data)
+}
+
+// Fchdir wraps syscall.Fchdir.
+func (fd *FD) Fchdir() error {
+ if err := fd.incref(); err != nil {
+ return err
+ }
+ defer fd.decref()
+ return syscall.Fchdir(fd.Sysfd)
+}
+
+// GetFileType wraps syscall.GetFileType.
+func (fd *FD) GetFileType() (uint32, error) {
+ if err := fd.incref(); err != nil {
+ return 0, err
+ }
+ defer fd.decref()
+ return syscall.GetFileType(fd.Sysfd)
+}
+
+// GetFileInformationByHandle wraps GetFileInformationByHandle.
+func (fd *FD) GetFileInformationByHandle(data *syscall.ByHandleFileInformation) error {
+ if err := fd.incref(); err != nil {
+ return err
+ }
+ defer fd.decref()
+ return syscall.GetFileInformationByHandle(fd.Sysfd, data)
+}
+
+// RawControl invokes the user-defined function f for a non-IO
+// operation.
+func (fd *FD) RawControl(f func(uintptr)) error {
+ if err := fd.incref(); err != nil {
+ return err
+ }
+ defer fd.decref()
+ f(uintptr(fd.Sysfd))
+ return nil
+}
+
+// RawRead invokes the user-defined function f for a read operation.
+func (fd *FD) RawRead(f func(uintptr) bool) error {
+ return errors.New("not implemented")
+}
+
+// RawWrite invokes the user-defined function f for a write operation.
+func (fd *FD) RawWrite(f func(uintptr) bool) error {
+ return errors.New("not implemented")
+}