// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package syscall

import "unsafe"

func setTimespec(sec, nsec int64) Timespec {
	return Timespec{Sec: int32(sec), Nsec: int32(nsec)}
}

func setTimeval(sec, usec int64) Timeval {
	return Timeval{Sec: int32(sec), Usec: int32(usec)}
}

func SetKevent(k *Kevent_t, fd, mode, flags int) {
	k.Ident = uint32(fd)
	k.Filter = int16(mode)
	k.Flags = uint16(flags)
}

func (iov *Iovec) SetLen(length int) {
	iov.Len = uint32(length)
}

func (msghdr *Msghdr) SetControllen(length int) {
	msghdr.Controllen = uint32(length)
}

func (cmsg *Cmsghdr) SetLen(length int) {
	cmsg.Len = uint32(length)
}

func sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {
	var writtenOut uint64 = 0
	_, _, e1 := Syscall9(SYS_SENDFILE, uintptr(infd), uintptr(outfd), uintptr(*offset), uintptr((*offset)>>32), uintptr(count), 0, uintptr(unsafe.Pointer(&writtenOut)), 0, 0)

	// For some reason on the freebsd-386 builder writtenOut
	// is modified when the system call returns EINVAL.
	// The man page says that the value is only written for
	// success, EINTR, or EAGAIN, so only use those cases.
	if e1 == 0 || e1 == EINTR || e1 == EAGAIN {
		written = int(writtenOut)
	}

	if e1 != 0 {
		err = e1
	}
	return
}

func Syscall9(num, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr, err Errno) // sic