sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
	var ret int32
	for tries := 0; tries < 20; tries++ {
		// pthread_create can fail with EAGAIN for no reasons
		// but it will be ok if it retries.
		ret = pthread_create(&tid, &attr, fn, nil)
		if ret != _EAGAIN {
			break
		}
		usleep(uint32(tries+1) * 1000) // Milliseconds.
	}
	sigprocmask(_SIG_SETMASK, &oset, nil)
	if ret != 0 {

// the stack is safe to reclaim.
//
//go:noescape
func exitThread(wait *atomic.Uint32)

//go:noescape
func obsdsigprocmask(how int32, new sigset) sigset

//go:nosplit
//go:nowritebarrierrec
func sigprocmask(how int32, new, old *sigset) {
	n := sigset(0)
	if new != nil {
		n = *new
	}
	r := obsdsigprocmask(how, n)
	if old != nil {
		*old = r
	}
}

func pipe2(flags int32) (r, w int32, errno int32)

	KeepAlive(new)
	KeepAlive(old)
}
func sigaction_trampoline()

//go:nosplit
//go:cgo_unsafe_args
func sigprocmask(how uint32, new *sigset, old *sigset) {
	// sigprocmask is called from sigsave, which is called from needm.
	// As such, we have to be able to run with no g here.
	asmcgocall_no_g(unsafe.Pointer(abi.FuncPCABI0(sigprocmask_trampoline)), unsafe.Pointer(&how))