static void init() {
	struct sigaction sa;

	memset(&sa, 0, sizeof sa);
	sa.sa_sigaction = ioHandler;
	if (sigemptyset(&sa.sa_mask) < 0) {
		die("sigemptyset");
	}
	sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
	if (sigaction(SIGIO, &sa, NULL) < 0) {
		die("sigaction");
	}
}

// Test raising SIGIO on a C thread with an alternate signal stack
// when there is a Go signal handler for SIGIO.

)

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

type sigactiont struct {
	__sigaction_u [8]byte
	sa_tramp      unsafe.Pointer
	sa_mask       uint32
	sa_flags      int32
}

type usigactiont struct {
	__sigaction_u [8]byte
	sa_mask       uint32
	sa_flags      int32
}

type siginfo struct {
	si_signo  int32

}

type timeval struct {
	tv_sec  int64
	tv_usec int64
}

func (tv *timeval) set_usec(x int32) {
	tv.tv_usec = int64(x)
}

type sigactiont struct {
	sa_handler  uintptr
	sa_flags    uint64
	sa_restorer uintptr
	sa_mask     uint64
}

type siginfoFields struct {
	si_signo int32
	si_errno int32
	si_code  int32
	// below here is a union; si_addr is the only field we use

}

type timeval struct {
	tv_sec  int64
	tv_usec int64
}

func (tv *timeval) set_usec(x int32) {
	tv.tv_usec = int64(x)
}

type sigactiont struct {
	sa_handler  uintptr
	sa_flags    uint64
	sa_restorer uintptr
	sa_mask     uint64
}

type siginfoFields struct {
	si_signo int32
	si_errno int32
	si_code  int32
	// below here is a union; si_addr is the only field we use

)

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

type sigactiont struct {
	__sigaction_u [8]byte
	sa_tramp      unsafe.Pointer
	sa_mask       uint32
	sa_flags      int32
}

type usigactiont struct {
	__sigaction_u [8]byte
	sa_mask       uint32
	sa_flags      int32
}

type siginfo struct {
	si_signo  int32

}

type timeval struct {
	tv_sec  int64
	tv_usec int64
}

func (tv *timeval) set_usec(x int32) {
	tv.tv_usec = int64(x)
}

type sigactiont struct {
	sa_handler  uintptr
	sa_flags    uint64
	sa_restorer uintptr
	sa_mask     uint64
}

type siginfoFields struct {
	si_signo int32
	si_errno int32
	si_code  int32
	// below here is a union; si_addr is the only field we use

}

type timeval struct {
	tv_sec  int64
	tv_usec int64
}

func (tv *timeval) set_usec(x int32) {
	tv.tv_usec = int64(x)
}

type sigactiont struct {
	sa_handler uintptr
	sa_flags   uint64
	sa_mask    uint64
	// Linux on riscv64 does not have the sa_restorer field, but the setsig
	// function references it (for x86). Not much harm to include it at the end.
	sa_restorer uintptr
}

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

type sigactiont struct {
	sa_handler uintptr
	sa_flags   uint64
	sa_mask    uint64
	// Linux on loong64 does not have the sa_restorer field, but the setsig
	// function references it (for x86). Not much harm to include it at the end.
	sa_restorer uintptr
}

	ts.tv_nsec = ns % 1e9
}

type timeval struct {
	tv_sec  int64
	tv_usec int64
}

func (tv *timeval) set_usec(x int32) {
	tv.tv_usec = int64(x)
}

type sigactiont struct {
	sa_flags   uint32
	sa_handler uintptr
	sa_mask    [2]uint64
	// linux header does not have sa_restorer field,
	// but it is used in setsig(). it is no harm to put it here
	sa_restorer uintptr
}

}

type timeval struct {
	tv_sec  int32
	tv_usec int32
}

//go:nosplit
func (tv *timeval) set_usec(x int32) {
	tv.tv_usec = x
}

type sigactiont struct {
	sa_flags   uint32
	sa_handler uintptr
	sa_mask    [4]uint32
	// linux header does not have sa_restorer field,
	// but it is used in setsig(). it is no harm to put it here
	sa_restorer uintptr
}