poll

package
v0.0.19 Latest Latest
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 Go to latest Published: Jun 20, 2023 License: BSD-3-Clause Imports: 9 Imported by: 0

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

Constants

This section is empty.

Variables

View Source 
var Accept4Func func(int, int) (int, syscall.Sockaddr, error) = syscall.Accept4

Accept4Func is used to hook the accept4 call.

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

AcceptFunc is used to hook the accept call.

View Source 
var CloseFunc func(int) error = syscall.Close

CloseFunc is used to hook the close call.

View Source 
var ErrDeadlineExceeded error = &DeadlineExceededError{}

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

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

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

View Source 
var ErrNetClosing = errNetClosing{}

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

View Source 
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.

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

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

View Source 
var TestHookDidWritev = func(wrote int) {}

TestHookDidWritev is a hook for testing writev.

Functions

func CopyFileRange 

func CopyFileRange(dst, src *FD, remain int64) (written int64, handled bool, err error)

CopyFileRange copies at most remain bytes of data from src to dst, using the copy_file_range system call. dst and src must refer to regular files.

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.

func SendFile 

func SendFile(dstFD *FD, src int, remain int64) (int64, error, bool)

SendFile wraps the sendfile system call.

func Splice 

func Splice(dst, src *FD, remain int64) (written int64, handled bool, sc string, err error)

Splice transfers at most remain bytes of data from src to dst, using the splice system call to minimize copies of data from and to userspace.

Splice gets a pipe buffer from the pool or creates a new one if needed, to serve as a buffer for the data transfer. src and dst must both be stream-oriented sockets.

If err != nil, sc is the system call which caused the error.

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) 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) 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) 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) 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) 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)

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) SetsockoptByte 

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

SetsockoptByte wraps the setsockopt network call with a byte argument.

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) SetsockoptIPMreqn 

func (fd *FD) SetsockoptIPMreqn(level, name int, mreq *syscall.IPMreqn) error

SetsockoptIPMreqn wraps the setsockopt network call with an IPMreqn 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) 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.

func (*FD) Writev 

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

Writev wraps the 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
}

Source Files

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