diff options
Diffstat (limited to 'libgo/go/internal/poll/fd_windows.go')
| -rw-r--r-- | libgo/go/internal/poll/fd_windows.go | 873 |
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") +} |