Source: fd_posix.go in package internal/poll

+build aix darwin dragonfly freebsd js,wasm linux netbsd openbsd solaris windows


package poll

import (
	"io"
	"syscall"
)

eofError returns io.EOF when fd is available for reading end of file.

func (fd *FD) eofError(n int, err error) error {
	if n == 0 && err == nil && fd.ZeroReadIsEOF {
		return io.EOF
	}
	return err
}

Shutdown wraps syscall.Shutdown.

func (fd *FD) Shutdown(how int) error {
	if err := fd.incref(); err != nil {
		return err
	}
	defer fd.decref()
	return syscall.Shutdown(fd.Sysfd, how)
}

Fchown wraps syscall.Fchown.

func (fd *FD) Fchown(uid, gid int) error {
	if err := fd.incref(); err != nil {
		return err
	}
	defer fd.decref()
	return ignoringEINTR(func() error {
		return syscall.Fchown(fd.Sysfd, uid, gid)
	})
}

Ftruncate wraps syscall.Ftruncate.

func (fd *FD) Ftruncate(size int64) error {
	if err := fd.incref(); err != nil {
		return err
	}
	defer fd.decref()
	return ignoringEINTR(func() error {
		return syscall.Ftruncate(fd.Sysfd, size)
	})
}

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

func (fd *FD) RawControl(f func(uintptr)) error {
	if err := fd.incref(); err != nil {
		return err
	}
	defer fd.decref()
	f(uintptr(fd.Sysfd))
	return nil
}

ignoringEINTR makes a function call and repeats it if it returns an EINTR error. This appears to be required even though we install all signal handlers with SA_RESTART: see #22838, #38033, #38836, #40846. Also #20400 and #36644 are issues in which a signal handler is installed without setting SA_RESTART. None of these are the common case, but there are enough of them that it seems that we can't avoid an EINTR loop.

func ignoringEINTR(fn func() error) error {
	for {
		err := fn()
		if err != syscall.EINTR {
			return err
		}
	}