package poll

import "internal/poll"

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 DupCloseOnExec(fd int) (int, string, error)
• func IsPollDescriptor(fd uintptr) bool
• type DeadlineExceededError
• func (e *DeadlineExceededError) Error() string
• func (e *DeadlineExceededError) Temporary() bool
• func (e *DeadlineExceededError) Timeout() bool
• type FD
• func (fd *FD) Accept() (int, syscall.Sockaddr, string, error)
• func (fd *FD) Close() error
• func (fd *FD) Dup() (int, string, error)
• func (fd *FD) Fchdir() error
• func (fd *FD) Fchmod(mode uint32) error
• func (fd *FD) Fchown(uid, gid int) error
• func (fd *FD) Fstat(s *syscall.Stat_t) error
• func (fd *FD) Fsync() error
• func (fd *FD) Ftruncate(size int64) error
• func (fd *FD) Init(net string, pollable bool) error
• func (fd *FD) Pread(p []byte, off int64) (int, error)
• func (fd *FD) Pwrite(p []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(p []byte) (int, error)
• func (fd *FD) ReadDirent(buf []byte) (int, error)
• func (fd *FD) ReadFrom(p []byte) (int, syscall.Sockaddr, error)
• func (fd *FD) ReadFromInet4(p []byte, from *syscall.SockaddrInet4) (int, error)
• func (fd *FD) ReadFromInet6(p []byte, from *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) SetBlocking() 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) Shutdown(how int) error
• func (fd *FD) WaitWrite() error
• func (fd *FD) Write(p []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) WriteOnce(p []byte) (int, error)
• func (fd *FD) WriteTo(p []byte, sa syscall.Sockaddr) (int, error)
• func (fd *FD) WriteToInet4(p []byte, sa *syscall.SockaddrInet4) (int, error)
• func (fd *FD) WriteToInet6(p []byte, sa *syscall.SockaddrInet6) (int, error)
• type String
• type SysFile

Variables ¶

var AcceptFunc func(int) (int, syscall.Sockaddr, error) = syscall.Accept

AcceptFunc is used to hook the accept call.

var CloseFunc func(int) error = syscall.Close

CloseFunc is used to hook the close 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 TestHookDidWritev = func(wrote int) {}

TestHookDidWritev is a hook for testing writev.

Functions ¶

func DupCloseOnExec ¶

func DupCloseOnExec(fd int) (int, string, error)

DupCloseOnExec dups fd and marks it close-on-exec.

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.

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 int

	// Platform dependent state of the file descriptor.
	SysFile

	// Whether this is a streaming descriptor, as opposed to a
	// packet-based descriptor like a UDP socket. Immutable.
	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 use this type as a field of a larger type representing a network connection or OS file.

func (*FD) Accept ¶

func (fd *FD) Accept() (int, syscall.Sockaddr, string, error)

Accept wraps the accept network call.

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) Dup ¶

func (fd *FD) Dup() (int, string, error)

Dup duplicates the file descriptor.

func (*FD) Fchdir ¶

func (fd *FD) Fchdir() error

Fchdir wraps syscall.Fchdir.

func (*FD) Fchmod ¶

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

Fchmod wraps syscall.Fchmod.

func (*FD) Fchown ¶

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

Fchown wraps syscall.Fchown.

func (*FD) Fstat ¶

func (fd *FD) Fstat(s *syscall.Stat_t) error

Fstat wraps syscall.Fstat

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) Init ¶

func (fd *FD) Init(net string, pollable bool) 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". Set pollable to true if fd should be managed by runtime netpoll.

func (*FD) Pread ¶

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

Pread wraps the pread system call.

func (*FD) Pwrite ¶

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

Pwrite wraps the 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(p []byte) (int, error)

Read implements io.Reader.

func (*FD) ReadDirent ¶

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

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

func (*FD) ReadFrom ¶

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

ReadFrom wraps the recvfrom network call.

func (*FD) ReadFromInet4 ¶

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

ReadFromInet4 wraps the recvfrom network call for IPv4.

func (*FD) ReadFromInet6 ¶

func (fd *FD) ReadFromInet6(p []byte, from *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 recvmsg 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 for 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 for syscall.SockaddrInet6.

func (*FD) Seek ¶

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

Seek wraps syscall.Seek.

func (*FD) SetBlocking ¶

func (fd *FD) SetBlocking() error

SetBlocking puts the file into blocking mode.

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) Shutdown ¶

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

Shutdown wraps syscall.Shutdown.

func (*FD) WaitWrite ¶

func (fd *FD) WaitWrite() error

WaitWrite waits until data can be read from fd.

func (*FD) Write ¶

func (fd *FD) Write(p []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 sendmsg 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) WriteOnce ¶

func (fd *FD) WriteOnce(p []byte) (int, error)

WriteOnce is for testing only. It makes a single write call.

func (*FD) WriteTo ¶

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

WriteTo wraps the sendto network call.

func (*FD) WriteToInet4 ¶

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

WriteToInet4 wraps the sendto network call for IPv4 addresses.

func (*FD) WriteToInet6 ¶

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

WriteToInet6 wraps the sendto network call for IPv6 addresses.

type String ¶

type String string

String is an internal string definition for methods/functions that is not intended for use outside the standard libraries.

Other packages in std that import internal/poll and have some exported APIs (now we've got some in net.rawConn) which are only used internally and are not intended to be used outside the standard libraries, Therefore, we make those APIs use internal types like poll.FD or poll.String in their function signatures to disable the usability of these APIs from external codebase.

type SysFile ¶

type SysFile struct {
	// contains filtered or unexported fields
}

Source Files ¶

fd.go fd_fsync_posix.go fd_mutex.go fd_poll_js.go fd_posix.go fd_unix.go fd_unixjs.go hook_unix.go sys_cloexec.go