poll

Documentation

Overview

Package poll supports non-blocking I/O on file descriptors with polling. This supports I/O operations that block only a goroutine, not a thread. This is used by the net and os packages. It uses a poller built into the runtime, with support from the runtime scheduler.

Index

• Variables
• func IsPollDescriptor(fd uintptr) bool
• func SendFile(fd *FD, src syscall.Handle, n int64) (written int64, err error)
• type DeadlineExceededError
  • func (e *DeadlineExceededError) Error() string
  • func (e *DeadlineExceededError) Temporary() bool
  • func (e *DeadlineExceededError) Timeout() bool
• type FD
  • func (fd *FD) Accept(sysSocket func() (syscall.Handle, error)) (syscall.Handle, []syscall.RawSockaddrAny, uint32, string, error)
  • func (fd *FD) Close() error
  • func (fd *FD) ConnectEx(ra syscall.Sockaddr) error
  • func (fd *FD) Copy() FD
  • func (fd *FD) Fchdir() error
  • func (fd *FD) Fchmod(mode uint32) error
  • func (fd *FD) Fchown(uid, gid int) error
  • func (fd *FD) Fsync() error
  • func (fd *FD) Ftruncate(size int64) error
  • func (fd *FD) GetFileInformationByHandle(data *syscall.ByHandleFileInformation) error
  • func (fd *FD) GetFileType() (uint32, error)
  • func (fd *FD) GetsockoptInt(level, name int) (int, error)
  • func (fd *FD) Init(net string, pollable bool) (string, error)
  • func (fd *FD) Pread(b []byte, off int64) (int, error)
  • func (fd *FD) Pwrite(buf []byte, off int64) (int, error)
  • func (fd *FD) RawControl(f func(uintptr)) error
  • func (fd *FD) RawRead(f func(uintptr) bool) error
  • func (fd *FD) RawWrite(f func(uintptr) bool) error
  • func (fd *FD) Read(buf []byte) (int, error)
  • func (fd *FD) ReadDir(buf []byte, cookie syscall.Dircookie) (int, error)
  • func (fd *FD) ReadDirent(buf []byte) (int, error)
  • func (fd *FD) ReadFrom(buf []byte) (int, syscall.Sockaddr, error)
  • func (fd *FD) ReadFromInet4(buf []byte, sa4 *syscall.SockaddrInet4) (int, error)
  • func (fd *FD) ReadFromInet6(buf []byte, sa6 *syscall.SockaddrInet6) (int, error)
  • func (fd *FD) ReadMsg(p []byte, oob []byte, flags int) (int, int, int, syscall.Sockaddr, error)
  • func (fd *FD) ReadMsgInet4(p []byte, oob []byte, flags int, sa4 *syscall.SockaddrInet4) (int, int, int, error)
  • func (fd *FD) ReadMsgInet6(p []byte, oob []byte, flags int, sa6 *syscall.SockaddrInet6) (int, int, int, error)
  • func (fd *FD) Seek(offset int64, whence int) (int64, error)
  • func (fd *FD) SetDeadline(t time.Time) error
  • func (fd *FD) SetReadDeadline(t time.Time) error
  • func (fd *FD) SetWriteDeadline(t time.Time) error
  • func (fd *FD) Setsockopt(level, optname int32, optval *byte, optlen int32) error
  • func (fd *FD) SetsockoptIPMreq(level, name int, mreq *syscall.IPMreq) error
  • func (fd *FD) SetsockoptIPv6Mreq(level, name int, mreq *syscall.IPv6Mreq) error
  • func (fd *FD) SetsockoptInet4Addr(level, name int, arg [4]byte) error
  • func (fd *FD) SetsockoptInt(level, name, arg int) error
  • func (fd *FD) SetsockoptLinger(level, name int, l *syscall.Linger) error
  • func (fd *FD) Shutdown(how int) error
  • func (fd *FD) WSAIoctl(iocc uint32, inbuf *byte, cbif uint32, outbuf *byte, cbob uint32, cbbr *uint32, ...) error
  • func (fd *FD) Write(buf []byte) (int, error)
  • func (fd *FD) WriteMsg(p []byte, oob []byte, sa syscall.Sockaddr) (int, int, error)
  • func (fd *FD) WriteMsgInet4(p []byte, oob []byte, sa *syscall.SockaddrInet4) (int, int, error)
  • func (fd *FD) WriteMsgInet6(p []byte, oob []byte, sa *syscall.SockaddrInet6) (int, int, error)
  • func (fd *FD) WriteTo(buf []byte, sa syscall.Sockaddr) (int, error)
  • func (fd *FD) WriteToInet4(buf []byte, sa4 *syscall.SockaddrInet4) (int, error)
  • func (fd *FD) WriteToInet6(buf []byte, sa6 *syscall.SockaddrInet6) (int, error)
  • func (fd *FD) Writev(buf *[][]byte) (int64, error)
• type SysFile

Variables

var AcceptFunc func(syscall.Handle, syscall.Handle, *byte, uint32, uint32, uint32, *uint32, *syscall.Overlapped) error = syscall.AcceptEx

AcceptFunc is used to hook the accept call.

var CloseFunc func(syscall.Handle) error = syscall.Closesocket

CloseFunc is used to hook the close call.

var ConnectExFunc func(syscall.Handle, syscall.Sockaddr, *byte, uint32, *uint32, *syscall.Overlapped) error = syscall.ConnectEx

ConnectExFunc is used to hook the ConnectEx call.

var ErrDeadlineExceeded error = &DeadlineExceededError{}

ErrDeadlineExceeded is returned for an expired deadline. This is exported by the os package as os.ErrDeadlineExceeded.

var ErrFileClosing = errors.New("use of closed file")

ErrFileClosing is returned when a file descriptor is used after it has been closed.

var ErrNetClosing = errNetClosing{}

ErrNetClosing is returned when a network descriptor is used after it has been closed.

var ErrNoDeadline = errors.New("file type does not support deadline")

ErrNoDeadline is returned when a request is made to set a deadline on a file type that does not use the poller.

var ErrNotPollable = errors.New("not pollable")

ErrNotPollable is returned when the file or socket is not suitable for event notification.

var ReadConsole = syscall.ReadConsole // changed for testing

var TestHookDidWritev = func(wrote int) {}

TestHookDidWritev is a hook for testing writev.

Functions

func IsPollDescriptor

func IsPollDescriptor(fd uintptr) bool

IsPollDescriptor reports whether fd is the descriptor being used by the poller. This is only used for testing.

func SendFile

func SendFile(fd *FD, src syscall.Handle, n int64) (written int64, err error)

SendFile wraps the TransmitFile call.

Types

type DeadlineExceededError

type DeadlineExceededError struct{}

DeadlineExceededError is returned for an expired deadline.

func (*DeadlineExceededError) Error

func (e *DeadlineExceededError) Error() string

Implement the net.Error interface. The string is "i/o timeout" because that is what was returned by earlier Go versions. Changing it may break programs that match on error strings.

func (*DeadlineExceededError) Temporary

func (e *DeadlineExceededError) Temporary() bool

func (*DeadlineExceededError) Timeout

func (e *DeadlineExceededError) Timeout() bool

type FD

type FD struct {

	// System file descriptor. Immutable until Close.
	Sysfd syscall.Handle

	// 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
	// contains filtered or unexported fields
}

FD is a file descriptor. The net and os packages embed this type in a larger type representing a network connection or OS file.

func (*FD) Accept

func (fd *FD) Accept(sysSocket func() (syscall.Handle, error)) (syscall.Handle, []syscall.RawSockaddrAny, uint32, string, error)

Accept handles accepting a socket. The sysSocket parameter is used to allocate the net socket.

func (*FD) Close

func (fd *FD) Close() error

Close closes the FD. The underlying file descriptor is closed by the destroy method when there are no remaining references.

func (*FD) ConnectEx

func (fd *FD) ConnectEx(ra syscall.Sockaddr) error

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) Copy

func (fd *FD) Copy() FD

Copy creates a copy of the FD.

The FD instance points to the same underlying file descriptor. The file descriptor isn't closed until all FD instances that refer to it have been closed/destroyed.

func (*FD) Fchdir

func (fd *FD) Fchdir() error

Fchdir wraps syscall.Fchdir.

func (*FD) Fchmod

func (fd *FD) Fchmod(mode uint32) error

Fchmod updates syscall.ByHandleFileInformation.Fileattributes when needed.

func (*FD) Fchown

func (fd *FD) Fchown(uid, gid int) error

Fchown wraps syscall.Fchown.

func (*FD) Fsync

func (fd *FD) Fsync() error

Fsync wraps syscall.Fsync.

func (*FD) Ftruncate

func (fd *FD) Ftruncate(size int64) error

Ftruncate wraps syscall.Ftruncate.

func (*FD) GetFileInformationByHandle

func (fd *FD) GetFileInformationByHandle(data *syscall.ByHandleFileInformation) error

GetFileInformationByHandle wraps GetFileInformationByHandle.

func (*FD) GetFileType

func (fd *FD) GetFileType() (uint32, error)

GetFileType wraps syscall.GetFileType.

func (*FD) GetsockoptInt

func (fd *FD) GetsockoptInt(level, name int) (int, error)

GetsockoptInt wraps the getsockopt network call with an int argument.

func (*FD) Init

func (fd *FD) Init(net string, pollable bool) (string, error)

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". Set pollable to true if fd should be managed by runtime netpoll.

func (*FD) Pread

func (fd *FD) Pread(b []byte, off int64) (int, error)

Pread emulates the Unix pread system call.

func (*FD) Pwrite

func (fd *FD) Pwrite(buf []byte, off int64) (int, error)

Pwrite emulates the Unix pwrite system call.

func (*FD) RawControl

func (fd *FD) RawControl(f func(uintptr)) error

RawControl invokes the user-defined function f for a non-IO operation.

func (*FD) RawRead

func (fd *FD) RawRead(f func(uintptr) bool) error

RawRead invokes the user-defined function f for a read operation.

func (*FD) RawWrite

func (fd *FD) RawWrite(f func(uintptr) bool) error

RawWrite invokes the user-defined function f for a write operation.

func (*FD) Read

func (fd *FD) Read(buf []byte) (int, error)

Read implements io.Reader.

func (*FD) ReadDir

func (fd *FD) ReadDir(buf []byte, cookie syscall.Dircookie) (int, error)

ReadDir wraps syscall.ReadDir. We treat this like an ordinary system call rather than a call that tries to fill the buffer.

func (*FD) ReadDirent

func (fd *FD) ReadDirent(buf []byte) (int, error)

func (*FD) ReadFrom

func (fd *FD) ReadFrom(buf []byte) (int, syscall.Sockaddr, error)

ReadFrom wraps the recvfrom network call.

func (*FD) ReadFromInet4

func (fd *FD) ReadFromInet4(buf []byte, sa4 *syscall.SockaddrInet4) (int, error)

ReadFromInet4 wraps the recvfrom network call for IPv4.

func (*FD) ReadFromInet6

func (fd *FD) ReadFromInet6(buf []byte, sa6 *syscall.SockaddrInet6) (int, error)

ReadFromInet6 wraps the recvfrom network call for IPv6.

func (*FD) ReadMsg

func (fd *FD) ReadMsg(p []byte, oob []byte, flags int) (int, int, int, syscall.Sockaddr, error)

ReadMsg wraps the WSARecvMsg network call.

func (*FD) ReadMsgInet4

func (fd *FD) ReadMsgInet4(p []byte, oob []byte, flags int, sa4 *syscall.SockaddrInet4) (int, int, int, error)

ReadMsgInet4 is ReadMsg, but specialized to return a syscall.SockaddrInet4.

func (*FD) ReadMsgInet6

func (fd *FD) ReadMsgInet6(p []byte, oob []byte, flags int, sa6 *syscall.SockaddrInet6) (int, int, int, error)

ReadMsgInet6 is ReadMsg, but specialized to return a syscall.SockaddrInet6.

func (*FD) Seek

func (fd *FD) Seek(offset int64, whence int) (int64, error)

Seek wraps syscall.Seek.

func (*FD) SetDeadline

func (fd *FD) SetDeadline(t time.Time) error

SetDeadline sets the read and write deadlines associated with fd.

func (*FD) SetReadDeadline

func (fd *FD) SetReadDeadline(t time.Time) error

SetReadDeadline sets the read deadline associated with fd.

func (*FD) SetWriteDeadline

func (fd *FD) SetWriteDeadline(t time.Time) error

SetWriteDeadline sets the write deadline associated with fd.

func (*FD) Setsockopt

func (fd *FD) Setsockopt(level, optname int32, optval *byte, optlen int32) error

Setsockopt wraps the setsockopt network call.

func (*FD) SetsockoptIPMreq

func (fd *FD) SetsockoptIPMreq(level, name int, mreq *syscall.IPMreq) error

SetsockoptIPMreq wraps the setsockopt network call with an IPMreq argument.

func (*FD) SetsockoptIPv6Mreq

func (fd *FD) SetsockoptIPv6Mreq(level, name int, mreq *syscall.IPv6Mreq) error

SetsockoptIPv6Mreq wraps the setsockopt network call with an IPv6Mreq argument.

func (*FD) SetsockoptInet4Addr

func (fd *FD) SetsockoptInet4Addr(level, name int, arg [4]byte) error

SetsockoptInet4Addr wraps the setsockopt network call with an IPv4 address.

func (*FD) SetsockoptInt

func (fd *FD) SetsockoptInt(level, name, arg int) error

SetsockoptInt wraps the setsockopt network call with an int argument.

func (*FD) SetsockoptLinger

func (fd *FD) SetsockoptLinger(level, name int, l *syscall.Linger) error

SetsockoptLinger wraps the setsockopt network call with a Linger argument.

func (*FD) Shutdown

func (fd *FD) Shutdown(how int) error

Shutdown wraps syscall.Shutdown.

func (*FD) WSAIoctl

func (fd *FD) WSAIoctl(iocc uint32, inbuf *byte, cbif uint32, outbuf *byte, cbob uint32, cbbr *uint32, overlapped *syscall.Overlapped, completionRoutine uintptr) error

WSAIoctl wraps the WSAIoctl network call.

func (*FD) Write

func (fd *FD) Write(buf []byte) (int, error)

Write implements io.Writer.

func (*FD) WriteMsg

func (fd *FD) WriteMsg(p []byte, oob []byte, sa syscall.Sockaddr) (int, int, error)

WriteMsg wraps the WSASendMsg network call.

func (*FD) WriteMsgInet4

func (fd *FD) WriteMsgInet4(p []byte, oob []byte, sa *syscall.SockaddrInet4) (int, int, error)

WriteMsgInet4 is WriteMsg specialized for syscall.SockaddrInet4.

func (*FD) WriteMsgInet6

func (fd *FD) WriteMsgInet6(p []byte, oob []byte, sa *syscall.SockaddrInet6) (int, int, error)

WriteMsgInet6 is WriteMsg specialized for syscall.SockaddrInet6.

func (*FD) WriteTo

func (fd *FD) WriteTo(buf []byte, sa syscall.Sockaddr) (int, error)

WriteTo wraps the sendto network call.

func (*FD) WriteToInet4

func (fd *FD) WriteToInet4(buf []byte, sa4 *syscall.SockaddrInet4) (int, error)

WriteToInet4 is WriteTo, specialized for syscall.SockaddrInet4.

func (*FD) WriteToInet6

func (fd *FD) WriteToInet6(buf []byte, sa6 *syscall.SockaddrInet6) (int, error)

WriteToInet6 is WriteTo, specialized for syscall.SockaddrInet6.

func (*FD) Writev

func (fd *FD) Writev(buf *[][]byte) (int64, error)

Writev emulates the Unix writev system call.

type SysFile

type SysFile struct {
	// RefCountPtr is a pointer to the reference count of Sysfd.
	//
	// WASI preview 1 lacks a dup(2) system call. When the os and net packages
	// need to share a file/socket, instead of duplicating the underlying file
	// descriptor, we instead provide a way to copy FD instances and manage the
	// underlying file descriptor with reference counting.
	RefCountPtr *int32

	// RefCount is the reference count of Sysfd. When a copy of an FD is made,
	// it points to the reference count of the original FD instance.
	RefCount int32

	// Cache for the file type, lazily initialized when Seek is called.
	Filetype uint32

	// If the file represents a directory, this field contains the current
	// readdir position. It is reset to zero if the program calls Seek(0, 0).
	Dircookie uint64

	// Absolute path of the file, as returned by syscall.PathOpen;
	// this is used by Fchdir to emulate setting the current directory
	// to an open file descriptor.
	Path string
}