const (
	SYS_MPROTECT      = 10
	SYS_FCNTL         = 72
	SYS_EPOLL_CTL     = 233
	SYS_EPOLL_PWAIT   = 281
	SYS_EPOLL_CREATE1 = 291
	SYS_EPOLL_PWAIT2  = 441
	SYS_EVENTFD2      = 290

	EFD_NONBLOCK = 0x800
)

type EpollEvent struct {
	Events uint32
	Data   [8]byte // unaligned uintptr

const unlinkatTrap uintptr = syscall.SYS_UNLINKAT
const openatTrap uintptr = syscall.SYS_OPENAT
const fstatatTrap uintptr = syscall.SYS_FSTATAT

const (
	AT_EACCESS          = 0x100
	AT_FDCWD            = -0x64
	AT_REMOVEDIR        = 0x800
	AT_SYMLINK_NOFOLLOW = 0x200

	UTIME_OMIT = (1 << 30) - 2

const (
	SYS_FCNTL         = 55
	SYS_MPROTECT      = 125
	SYS_EPOLL_CTL     = 251
	SYS_EPOLL_PWAIT   = 346
	SYS_EPOLL_CREATE1 = 357
	SYS_EPOLL_PWAIT2  = 441
	SYS_EVENTFD2      = 356

	EFD_NONBLOCK = 0x800
)

type EpollEvent struct {
	Events uint32
	_pad   uint32
	Data   [8]byte // to match amd64

    int i = 0;

    // This loop optimizes for pure ASCII.
    while (i < utf16Length && sequence.charAt(i) < 0x80) {
      i++;
    }

    // This loop optimizes for chars less than 0x800.
    for (; i < utf16Length; i++) {
      char c = sequence.charAt(i);
      if (c < 0x800) {
        utf8Length += ((0x7f - c) >>> 31); // branch free!
      } else {
        utf8Length += encodedLengthGeneral(sequence, i);

    int i = 0;

    // This loop optimizes for pure ASCII.
    while (i < utf16Length && sequence.charAt(i) < 0x80) {
      i++;
    }

    // This loop optimizes for chars less than 0x800.
    for (; i < utf16Length; i++) {
      char c = sequence.charAt(i);
      if (c < 0x800) {
        utf8Length += ((0x7f - c) >>> 31); // branch free!
      } else {
        utf8Length += encodedLengthGeneral(sequence, i);

	// Pad struct to the max size in the kernel.
	_ [_sigev_max_size - unsafe.Sizeof(sigeventFields{})]byte
}

const (
	_O_RDONLY    = 0x0
	_O_WRONLY    = 0x1
	_O_CREAT     = 0x40
	_O_TRUNC     = 0x200
	_O_NONBLOCK  = 0x800
	_O_CLOEXEC   = 0x80000
	_SA_RESTORER = 0
)

type stackt struct {
	ss_sp    *byte
	ss_flags int32
	ss_size  uintptr
}

type sigcontext struct {
	psw_mask uint64

}

// created by cgo -cdefs and then converted to Go
// cgo -cdefs defs_linux.go defs3_linux.go

const (
	_O_RDONLY    = 0x0
	_O_WRONLY    = 0x1
	_O_CREAT     = 0x40
	_O_TRUNC     = 0x200
	_O_NONBLOCK  = 0x800
	_O_CLOEXEC   = 0x80000
	_SA_RESTORER = 0
)

type ptregs struct {
	gpr       [32]uint64
	nip       uint64
	msr       uint64
	orig_gpr3 uint64
	ctr       uint64
	link      uint64

// ../cmd/cgo/cgo -cdefs defs_linux.go defs1_linux.go defs2_linux.go

const (
	_O_RDONLY   = 0x0
	_O_WRONLY   = 0x1
	_O_CREAT    = 0x40
	_O_TRUNC    = 0x200
	_O_NONBLOCK = 0x800
	_O_CLOEXEC  = 0x80000
)

type usigset struct {
	__val [16]uint64
}

type stackt struct {
	ss_sp     *byte
	ss_flags  int32
	pad_cgo_0 [4]byte
	ss_size   uintptr
}

	// Pad struct to the max size in the kernel.
	_ [_sigev_max_size - unsafe.Sizeof(sigeventFields{})]byte
}

const (
	_O_RDONLY   = 0x0
	_O_WRONLY   = 0x1
	_O_CREAT    = 0x40
	_O_TRUNC    = 0x200
	_O_NONBLOCK = 0x800
	_O_CLOEXEC  = 0x80000
)

type user_regs_struct struct {
	pc  uint64
	ra  uint64
	sp  uint64
	gp  uint64
	tp  uint64
	t0  uint64
	t1  uint64
	t2  uint64
	s0  uint64

	_ITIMER_VIRTUAL = 0x1
	_ITIMER_PROF    = 0x2

	_CLOCK_THREAD_CPUTIME_ID = 0x3

	_SIGEV_THREAD_ID = 0x4

	_O_RDONLY   = 0x0
	_O_WRONLY   = 0x1
	_O_CREAT    = 0x40
	_O_TRUNC    = 0x200
	_O_NONBLOCK = 0x800
	_O_CLOEXEC  = 0x80000

	_AF_UNIX    = 0x1
	_SOCK_DGRAM = 0x2
)

type fpreg struct {
	significand [4]uint16
	exponent    uint16
}

type fpxreg struct {