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 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) ReadMsg(p []byte, oob []byte) (int, int, int, syscall.Sockaddr, 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) WriteOnce(p []byte) (int, error)
• func (fd *FD) WriteTo(p []byte, sa syscall.Sockaddr) (int, error)
• type TimeoutError
• func (e *TimeoutError) Error() string
• func (e *TimeoutError) Temporary() bool
• func (e *TimeoutError) Timeout() bool

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

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

var ErrNetClosing = errors.New("use of closed network connection")

ErrNetClosing is returned when a network descriptor is used after it has been closed. Keep this string consistent because of issue #4373: since historically programs have not been able to detect this error, they look for the string.

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 ErrTimeout error = &TimeoutError{}

ErrTimeout is returned for an expired deadline.

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 FD ¶

type FD struct {

	// System file descriptor. Immutable until Close.
	Sysfd int

	// 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) ReadMsg ¶

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

ReadMsg wraps the recvmsg network call.

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 the shutdown network call.

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) 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.

type TimeoutError ¶

type TimeoutError struct{}

TimeoutError is returned for an expired deadline.

func (*TimeoutError) Error ¶

func (e *TimeoutError) Error() string

Implement the net.Error interface.

func (*TimeoutError) Temporary ¶

func (e *TimeoutError) Temporary() bool

func (*TimeoutError) Timeout ¶

func (e *TimeoutError) Timeout() bool

Source Files ¶

fd.go fd_fsync_posix.go fd_mutex.go fd_poll_nacljs.go fd_posix.go fd_unix.go hook_unix.go sys_cloexec.go