Hi all,

well, another "i must be doing something wrong" issue...

here is the quick sample program:

#include <unistd.h>
#include <pthread.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xatom.h>

#include <GL/glx.h>
#include <GL/gl.h>

void * blockingThread (void *opaque)
{
	Display *dpy (XOpenDisplay (NULL));
	if (dpy != NULL)
	{
		if (glXQueryExtension(dpy, NULL, NULL))
		{
			int majorVersionNumber, minorVersionNumber;
			glXQueryVersion (dpy, &majorVersionNumber, &minorVersionNumber);
		}
	}
	return NULL;
}

int main ()
{
	XInitThreads ();
	pthread_t blockingThreadId;
	pthread_create (&blockingThreadId, NULL, blockingThread, NULL);
	sleep (10);

	return 0;
}

Here is a rough build description

gcc -I/usr/X11R6/include main.cc -L/usr/X11R6/lib -lGL -lX11 -lstdc++
-lm -lpthread

generates:

/usr/X11R6/lib/libX11.so: warning: warning: reference to compatibility
socket(); include <sys/socket.h> for correct reference
/usr/X11R6/lib/libX11.so: warning: warning: reference to compatibility
__stat13(); include <sys/stat.h> to generate correct reference
/usr/X11R6/lib/libX11.so: warning: warning: reference to compatibility
__fstat13(); include <sys/stat.h> to generate correct reference

and at runtime:

a.out: Error detected by libpthread: Unlocking unlocked mutex.
Detected by file "/usr/src/lib/libpthread/pthread_mutex.c", line 369,
function "pthread_mutex_unlock".
See pthread(3) for information.

I have noticed that I am not closing the X display in this sample
code...  but don't think this is the cause of the problem (in the
actual app there is a correspording XCloseDisplay call) - I shall try
this sample code with XCloseDisplay as well... - not near my NetBSD
box, as currently I rarely get a chance to play with it...

Can anyone out there reproduce the "unlocking unlocked mutex" error
(in my case, I can get rid of it if I take out "XInitThreads" but in
practice (my app) the "XInitThreads" needs to remain) ?