pthread_attr_t attr;
	sigset_t ign, oset;
	pthread_t p;
	size_t size;
	int err;

	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	size = pthread_get_stacksize_np(pthread_self());
	pthread_attr_init(&attr);
	pthread_attr_setstacksize(&attr, size);
	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

void
_cgo_sys_thread_start(ThreadStart *ts)
{
	pthread_attr_t attr;
	sigset_t ign, oset;
	pthread_t p;
	size_t size;
	int err;

	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	pthread_attr_init(&attr);
	pthread_attr_getstacksize(&attr, &size);
	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

//
//go:nowritebarrier
func newosproc(mp *m) {
	var (
		attr pthreadattr
		oset sigset
		tid  pthread
		ret  int32
		size uint64
	)

	if pthread_attr_init(&attr) != 0 {
		throw("pthread_attr_init")
	}
	// Allocate a new 2MB stack.
	if pthread_attr_setstack(&attr, 0, 0x200000) != 0 {
		throw("pthread_attr_setstack")
	}
	// Read back the allocated stack.

void
_cgo_sys_thread_start(ThreadStart *ts)
{
	pthread_attr_t attr;
	sigset_t ign, oset;
	pthread_t p;
	size_t size;
	int err;

	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	pthread_attr_init(&attr);
	pthread_attr_getstacksize(&attr, &size);
	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

void
_cgo_sys_thread_start(ThreadStart *ts)
{
	pthread_attr_t attr;
	sigset_t ign, oset;
	pthread_t p;
	size_t size;
	int err;

	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	pthread_attr_init(&attr);
	pthread_attr_getstacksize(&attr, &size);
	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

void
_cgo_sys_thread_start(ThreadStart *ts)
{
	pthread_attr_t attr;
	sigset_t ign, oset;
	pthread_t p;
	size_t size;
	int err;

	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	pthread_attr_init(&attr);
	pthread_attr_getstacksize(&attr, &size);
	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

_cgo_sys_thread_start(ThreadStart *ts)
{
	pthread_attr_t attr;
	sigset_t ign, oset;
	pthread_t p;
	void *base;
	size_t size;
	int err;

	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	pthread_attr_init(&attr);

	if (pthread_attr_getstack(&attr, &base, &size) != 0)
		perror("runtime/cgo: pthread_attr_getstack failed");
	if (size == 0) {
		ts->g->stackhi = 2 << 20;

	//fprintf(stderr, "runtime/cgo: _cgo_sys_thread_start: fn=%p, g=%p\n", ts->fn, ts->g); // debug
	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	size = pthread_get_stacksize_np(pthread_self());
	pthread_attr_init(&attr);
	pthread_attr_setstacksize(&attr, size);
	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

	if false {
		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " id=", mp.id, " ostk=", &mp, "\n")
	}

	// Initialize an attribute object.
	var attr pthreadattr
	var err int32
	err = pthread_attr_init(&attr)
	if err != 0 {
		writeErrStr(failthreadcreate)
		exit(1)
	}

	// Find out OS stack size for our own stack guard.
	var stacksize uintptr
	if pthread_attr_getstacksize(&attr, &stacksize) != 0 {

	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	// Start a thread to handle exceptions.
	uintptr_t port_set = (uintptr_t)mach_exception_handler_port_set;
	pthread_attr_init(&attr);
	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
	ret = _cgo_try_pthread_create(&thr, &attr, mach_exception_handler, (void*)port_set);

	pthread_sigmask(SIG_SETMASK, &oset, nil);