package poll

Import Path
	internal/poll (on go.dev)

Dependency Relation
	imports 10 packages, and imported by 3 packages

Involved Source Files

	    copy_file_range_linux.go
	    errno_unix.go
	  d fd.go
		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.

	    fd_fsync_posix.go
	    fd_mutex.go
	    fd_poll_runtime.go
	    fd_posix.go
	    fd_unix.go
	    fd_unixjs.go
	    fd_writev_unix.go
	    hook_cloexec.go
	    hook_unix.go
	    iovec_unix.go
	    sendfile.go
	    sendfile_linux.go
	    sock_cloexec.go
	    sockopt.go
	    sockopt_linux.go
	    sockopt_unix.go
	    sockoptip.go
	    splice_linux.go
	    writev.go
Package-Level Type Names (total 4)

	/* sort by: alphabet | popularity */
	 type DeadlineExceededError (struct)
		DeadlineExceededError is returned for an expired deadline.

		Methods (total 3)
			(*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.

			(*DeadlineExceededError) Temporary() bool
			(*DeadlineExceededError) Timeout() bool
		Implements (at least 2)
			*DeadlineExceededError : error
			*DeadlineExceededError : net.Error

	 type FD (struct)
		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.

		Fields (total 4)
			IsStream bool
				Whether this is a streaming descriptor, as opposed to a
				packet-based descriptor like a UDP socket. Immutable.

			SysFile SysFile
				Platform dependent state of the file descriptor.

			Sysfd int
				System file descriptor. Immutable until Close.

			ZeroReadIsEOF bool
				Whether a zero byte read indicates EOF. This is false for a
				message based socket connection.

		Methods (total 47)
			(*FD) Accept() (int, syscall.Sockaddr, string, error)
				Accept wraps the accept network call.

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

			(*FD) Dup() (int, string, error)
				Dup duplicates the file descriptor.

			(*FD) Fchdir() error
				Fchdir wraps syscall.Fchdir.

			(*FD) Fchmod(mode uint32) error
				Fchmod wraps syscall.Fchmod.

			(*FD) Fchown(uid, gid int) error
				Fchown wraps syscall.Fchown.

			(*FD) Fstat(s *syscall.Stat_t) error
				Fstat wraps syscall.Fstat

			(*FD) Fsync() error
				Fsync wraps syscall.Fsync.

			(*FD) Ftruncate(size int64) error
				Ftruncate wraps syscall.Ftruncate.

			(*FD) GetsockoptInt(level, name int) (int, error)
				GetsockoptInt wraps the getsockopt network call with an int argument.

			(*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.

			(*FD) Pread(p []byte, off int64) (int, error)
				Pread wraps the pread system call.

			(*FD) Pwrite(p []byte, off int64) (int, error)
				Pwrite wraps the pwrite system call.

			(*FD) RawControl(f func(uintptr)) error
				RawControl invokes the user-defined function f for a non-IO
				operation.

			(*FD) RawRead(f func(uintptr) bool) error
				RawRead invokes the user-defined function f for a read operation.

			(*FD) RawWrite(f func(uintptr) bool) error
				RawWrite invokes the user-defined function f for a write operation.

			(*FD) Read(p []byte) (int, error)
				Read implements io.Reader.

			(*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.

			(*FD) ReadFrom(p []byte) (int, syscall.Sockaddr, error)
				ReadFrom wraps the recvfrom network call.

			(*FD) ReadFromInet4(p []byte, from *syscall.SockaddrInet4) (int, error)
				ReadFromInet4 wraps the recvfrom network call for IPv4.

			(*FD) ReadFromInet6(p []byte, from *syscall.SockaddrInet6) (int, error)
				ReadFromInet6 wraps the recvfrom network call for IPv6.

			(*FD) ReadMsg(p []byte, oob []byte, flags int) (int, int, int, syscall.Sockaddr, error)
				ReadMsg wraps the recvmsg network call.

			(*FD) ReadMsgInet4(p []byte, oob []byte, flags int, sa4 *syscall.SockaddrInet4) (int, int, int, error)
				ReadMsgInet4 is ReadMsg, but specialized for syscall.SockaddrInet4.

			(*FD) ReadMsgInet6(p []byte, oob []byte, flags int, sa6 *syscall.SockaddrInet6) (int, int, int, error)
				ReadMsgInet6 is ReadMsg, but specialized for syscall.SockaddrInet6.

			(*FD) Seek(offset int64, whence int) (int64, error)
				Seek wraps syscall.Seek.

			(*FD) SetBlocking() error
				SetBlocking puts the file into blocking mode.

			(*FD) SetDeadline(t time.Time) error
				SetDeadline sets the read and write deadlines associated with fd.

			(*FD) SetReadDeadline(t time.Time) error
				SetReadDeadline sets the read deadline associated with fd.

			(*FD) SetWriteDeadline(t time.Time) error
				SetWriteDeadline sets the write deadline associated with fd.

			(*FD) SetsockoptByte(level, name int, arg byte) error
				SetsockoptByte wraps the setsockopt network call with a byte argument.

			(*FD) SetsockoptIPMreq(level, name int, mreq *syscall.IPMreq) error
				SetsockoptIPMreq wraps the setsockopt network call with an IPMreq argument.

			(*FD) SetsockoptIPMreqn(level, name int, mreq *syscall.IPMreqn) error
				SetsockoptIPMreqn wraps the setsockopt network call with an IPMreqn argument.

			(*FD) SetsockoptIPv6Mreq(level, name int, mreq *syscall.IPv6Mreq) error
				SetsockoptIPv6Mreq wraps the setsockopt network call with an IPv6Mreq argument.

			(*FD) SetsockoptInet4Addr(level, name int, arg [4]byte) error
				SetsockoptInet4Addr wraps the setsockopt network call with an IPv4 address.

			(*FD) SetsockoptInt(level, name, arg int) error
				SetsockoptInt wraps the setsockopt network call with an int argument.

			(*FD) SetsockoptLinger(level, name int, l *syscall.Linger) error
				SetsockoptLinger wraps the setsockopt network call with a Linger argument.

			(*FD) Shutdown(how int) error
				Shutdown wraps syscall.Shutdown.

			(*FD) WaitWrite() error
				WaitWrite waits until data can be written to fd.

			(*FD) Write(p []byte) (int, error)
				Write implements io.Writer.

			(*FD) WriteMsg(p []byte, oob []byte, sa syscall.Sockaddr) (int, int, error)
				WriteMsg wraps the sendmsg network call.

			(*FD) WriteMsgInet4(p []byte, oob []byte, sa *syscall.SockaddrInet4) (int, int, error)
				WriteMsgInet4 is WriteMsg specialized for syscall.SockaddrInet4.

			(*FD) WriteMsgInet6(p []byte, oob []byte, sa *syscall.SockaddrInet6) (int, int, error)
				WriteMsgInet6 is WriteMsg specialized for syscall.SockaddrInet6.

			(*FD) WriteOnce(p []byte) (int, error)
				WriteOnce is for testing only. It makes a single write call.

			(*FD) WriteTo(p []byte, sa syscall.Sockaddr) (int, error)
				WriteTo wraps the sendto network call.

			(*FD) WriteToInet4(p []byte, sa *syscall.SockaddrInet4) (int, error)
				WriteToInet4 wraps the sendto network call for IPv4 addresses.

			(*FD) WriteToInet6(p []byte, sa *syscall.SockaddrInet6) (int, error)
				WriteToInet6 wraps the sendto network call for IPv6 addresses.

			(*FD) Writev(v *[][]byte) (int64, error)
				Writev wraps the writev system call.

		Implements (at least 13)
			*FD : internal/bisect.Writer
			*FD : io.Closer
			*FD : io.ReadCloser
			*FD : io.Reader
			*FD : io.ReadSeekCloser
			*FD : io.ReadSeeker
			*FD : io.ReadWriteCloser
			*FD : io.ReadWriter
			*FD : io.ReadWriteSeeker
			*FD : io.Seeker
			*FD : io.WriteCloser
			*FD : io.Writer
			*FD : io.WriteSeeker
		As Inputs Of (at least 3)
			func CopyFileRange(dst, src *FD, remain int64) (written int64, handled bool, err error)
			func SendFile(dstFD *FD, src int, remain int64) (written int64, err error, handled bool)
			func Splice(dst, src *FD, remain int64) (written int64, handled bool, err error)

	 type String string (basic type)
		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 (struct)
Package-Level Functions (total 5)

	 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(fd int) (int, string, error)
		DupCloseOnExec dups fd and marks it close-on-exec.

	 func IsPollDescriptor(fd uintptr) bool
		IsPollDescriptor reports whether fd is the descriptor being used by the poller.
		This is only used for testing.
		
		IsPollDescriptor should be an internal detail,
		but widely used packages access it using linkname.
		Notable members of the hall of shame include:
		  - github.com/opencontainers/runc
		
		Do not remove or change the type signature.
		See go.dev/issue/67401.

	 func SendFile(dstFD *FD, src int, remain int64) (written int64, err error, handled bool)
		SendFile wraps the sendfile system call.

	 func Splice(dst, src *FD, remain int64) (written int64, handled bool, 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.


Package-Level Variables (total 10)

	  var Accept4Func (int, int) (int, syscall.Sockaddr, error)
		Accept4Func is used to hook the accept4 call.

	  var AcceptFunc (int) (int, syscall.Sockaddr, error)
		AcceptFunc is used to hook the accept call.

	  var CloseFunc (int) error
		CloseFunc is used to hook the close call.

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

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

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

	  var TestHookDidSendFile func(dstFD *FD, src int, written int64, err error, handled bool)
	  var TestHookDidWritev func(wrote int)
		TestHookDidWritev is a hook for testing writev.

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