package unix

import (
	"syscall"
	"unsafe"
)

// Note that pgid should really be pid_t, however _C_int (aka int32) is
// generally equivalent.

func Tcsetpgrp(fd int, pgid int32) (err error) {
	_, _, errno := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), uintptr(syscall.TIOCSPGRP), uintptr(unsafe.Pointer(&pgid)), 0, 0, 0)
	if errno != 0 {
		return errno
	}
	return nil

		t.Skipf("not supported on %s", runtime.GOOS)
	}
	filename := "/etc/services" // a nice big file

	fd, err := os.Open(filename)
	if err != nil {
		// The file is missing even on some Unix systems.
		t.Skipf("skipping because failed to open /etc/services: %v", err)
	}
	defer fd.Close()
	br := bufio.NewReader(fd)

	file, err := open(filename)
	if file == nil {
		t.Fatal(err)
	}
	defer file.close()

	}
	return nil
}

// openFileWithFD return 'fd' based file descriptor
func openFileWithFD(name string, flag int, perm os.FileMode) (fd int, err error) {
	switch flag & writeMode {
	case writeMode:
		defer updateOSMetrics(osMetricOpenFileWFd, name)(err)
	default:
		defer updateOSMetrics(osMetricOpenFileRFd, name)(err)
	}
	var e error
	fd, e = syscall.Open(name, flag|syscall.O_CLOEXEC, uint32(perm))
	if e != nil {

	if e != nil {
		return "", e
	}
	return UTF16ToString(b[:n]), nil
}

func Ftruncate(fd Handle, length int64) (err error) {
	curoffset, e := Seek(fd, 0, 1)
	if e != nil {
		return e
	}
	defer Seek(fd, curoffset, 0)
	_, e = Seek(fd, length, 0)
	if e != nil {
		return e
	}
	e = SetEndOfFile(fd)
	if e != nil {
		return e
	}
	return nil
}

	// libc clean up threads.
	throw("exitThread")
}

var urandom_dev = []byte("/dev/urandom\x00")

//go:nosplit
func readRandom(r []byte) int {
	fd := open(&urandom_dev[0], 0 /* O_RDONLY */, 0)
	n := read(fd, unsafe.Pointer(&r[0]), int32(len(r)))
	closefd(fd)
	return int(n)
}

func goenvs() {
	goenvs_unix()
}

// Called to initialize a new m (including the bootstrap m).

	if err = MkdirAll(dpath, 0777); err != nil {
		t.Fatalf("MkdirAll %q: %s", dpath, err)
	}
	fd, err = Create(fpath)
	if err != nil {
		t.Fatalf("create %q: %s", fpath, err)
	}
	fd.Close()
	fd, err = Create(dpath + "/file")
	if err != nil {
		t.Fatalf("create %q: %s", fpath, err)
	}
	fd.Close()
	if err = RemoveAll(path); err != nil {
		t.Fatalf("RemoveAll %q (third): %s", path, err)
	}

	// Get a pidfd of the current process (opening of "/proc/self" won't
	// work for waitid).
	fd, err := unix.PidFDOpen(syscall.Getpid(), 0)
	if err != nil {
		return NewSyscallError("pidfd_open", err)
	}
	defer syscall.Close(int(fd))

	// Check waitid(P_PIDFD) works.
	for {
		_, _, err = syscall.Syscall6(syscall.SYS_WAITID, _P_PIDFD, fd, 0, syscall.WEXITED, 0, 0)
		if err != syscall.EINTR {
			break
		}
	}

		}
		println("runtime: netpoll: break fd ready for", ev.ident)
		throw("runtime: netpoll: break fd ready for something unexpected")
	}
	return false
}

func drainWakeupEvent(kq int32) {
	ev := keventt{
		ident:  kqIdent,
		filter: _EVFILT_USER,
		flags:  _EV_DISABLE,
	}
	kevent(kq, &ev, 1, nil, 0, nil)
}

func netpollIsPollDescriptor(fd uintptr) bool {
	return fd == uintptr(kq)

func read(fd int32, p unsafe.Pointer, n int32) int32

func closefd(fd int32) int32

func exit(code int32)
func usleep(usec uint32)

//go:nosplit
func usleep_no_g(usec uint32) {
	usleep(usec)
}

// write1 calls the write system call.
// It returns a non-negative number of bytes written or a negative errno value.
//
//go:noescape
func write1(fd uintptr, p unsafe.Pointer, n int32) int32

		t.Fatal("never called poll.CopyFileRange")
	}
	if hook.called && hook.dstfd != int(dst.Fd()) {
		t.Fatalf("wrong destination file descriptor: got %d, want %d", hook.dstfd, dst.Fd())
	}
	if hook.called && hook.srcfd != int(src.Fd()) {
		t.Fatalf("wrong source file descriptor: got %d, want %d", hook.srcfd, src.Fd())
	}

	// Check that the offsets after the transfer make sense, that the size