select {
			case <-stop:
				return
			case <-time.After(time.Millisecond * 100):
			}
		}
	}()
	defer close(stop)

	for i := 0; i < 1000; i++ {
		if !C.Ctid() {
			t.Fatalf("cgo has not locked OS thread")
		}
	}

	return 0;
}

void
doAdd(int max, int nthread)
{
	enum { MaxThread = 20 };
	int i;
	uintptr_t thread_id[MaxThread];
	
	if(nthread > MaxThread)
		nthread = MaxThread;
	for(i=0; i<nthread; i++)
		thread_id[i] = _beginthreadex(0, 0, addThread, &max, 0, 0);
	for(i=0; i<nthread; i++) {
		WaitForSingleObject((HANDLE)thread_id[i], INFINITE);
		CloseHandle((HANDLE)thread_id[i]);
	}
}

__stdcall

//   int i;
//   nts = argc;
//   t = calloc(nts, sizeof(pthread_t));
//   pthread_mutex_init(&mu, NULL);
//   for (i = 0; i < nts; i++) {
//     pthread_create(&t[i], NULL, aFn, NULL);
//   }
// }
//
// void cleanup(void) {
//   int i;
//   pthread_mutex_lock(&mu);
//   all_done = 1;
//   pthread_mutex_unlock(&mu);
//   for (i = 0; i < nts; i++) {
//     pthread_join(t[i], NULL);
//   }
//   pthread_mutex_destroy(&mu);

	for(i=0; i<nthread; i++)
		pthread_join(thread_id[i], 0);		
}

static void*
goDummyCallbackThread(void* p)
{
	int i, max;

	max = *(int*)p;
	for(i=0; i<max; i++)
		goDummy();
	return NULL;
}

int
callGoInCThread(int max)
{
	pthread_t thread;

	if (pthread_create(&thread, NULL, goDummyCallbackThread, (void*)(&max)) != 0)
		return -1;

When using cgo, Go must not assume that it owns all details of the
process. In particular it needs to coordinate with C in the use of
threads and thread-local storage. The runtime package declares a few
variables:

	var (
		iscgo             bool
		_cgo_init         unsafe.Pointer
		_cgo_thread_start unsafe.Pointer
	)

Any package using cgo imports "runtime/cgo", which provides

	if lockedOSThread() {
		t.Fatal("locked OS thread on entry to TestCallbackPanic")
	}
	defer func() {
		s := recover()
		if s == nil {
			t.Fatal("did not panic")
		}
		if s.(string) != "callback panic" {
			t.Fatal("wrong panic:", s)
		}
		if lockedOSThread() {
			t.Fatal("locked OS thread on exit from TestCallbackPanic")
		}
	}()
	nestedCall(func() { panic("callback panic") })

		var rlim syscall.Rlimit
		if syscall.Getrlimit(nproc, &rlim) == nil {
			max := int(rlim.Cur) / (threads + 5)
			if attempts > max {
				t.Logf("lowering attempts from %d to %d for RLIMIT_NPROC", attempts, max)
				attempts = max
			}
		}
	}

	if os.Getenv("test18146") == "exec" {
		runtime.GOMAXPROCS(1)
		for n := threads; n > 0; n-- {
			go func() {
				for {
					_ = md5.Sum([]byte("Hello, !"))
				}
			}()

<code>T</code>’s embedded interfaces.
</p>

<pre>
type Reader interface {
	Read(p []byte) (n int, err error)
	Close() error
}

type Writer interface {
	Write(p []byte) (n int, err error)
	Close() error
}

// ReadWriter's methods are Read, Write, and Close.
type ReadWriter interface {
	Reader  // includes methods of Reader in ReadWriter's method set

pkg debug/macho, type SymtabCmd struct, Strsize uint32
pkg debug/macho, type SymtabCmd struct, Symoff uint32
pkg debug/macho, type Thread struct
pkg debug/macho, type Thread struct, Cmd LoadCmd
pkg debug/macho, type Thread struct, Data []uint32
pkg debug/macho, type Thread struct, Len uint32
pkg debug/macho, type Thread struct, Type uint32
pkg debug/macho, type Type uint32
pkg debug/pe, const IMAGE_FILE_MACHINE_AM33 ideal-int

<li>
<code>LOCAL</code> = 128
<br>
This symbol is local to the dynamic shared object.
</li>
<li>
<code>TLSBSS</code> = 256
<br>
(For <code>DATA</code> and <code>GLOBL</code> items.)
Put this data in thread local storage.
</li>
<li>
<code>NOFRAME</code> = 512
<br>
(For <code>TEXT</code> items.)
Do not insert instructions to allocate a stack frame and save/restore the return