How to identify not responding process programmatically

I'm looking to find a way how to identify a non responding (not zombie) process programmatically. I find some information to check TH_STATE_UNINTERRUPTIBLE status but there was some discussion that it's not the开发者_开发百科 right way.

I'm assuming you mean a spinning wheel application hang? There are many ways to freeze. The particular cause is important. If it's a Cocoa app, you could try sending your main thread / Window an event... or scripting up Spin Control.

A random answer … I'm not a programmer but I stumbled across something of possible interest whilst working through stuff in Ask Different …

sched_prim.c (Scheduling primitives) in relatively old xnu-124.7 includes:

#define MAX_STUCK_THREADS   128

/*
 *  do_thread_scan: scan for stuck threads.  A thread is stuck if
 *  it is runnable but its priority is so low that it has not
 *  run for several seconds.  Its priority should be higher, but
 *  won't be until it runs and calls update_priority.  The scanner
 *  finds these threads and does the updates.
 *
 *  Scanner runs in two passes.  Pass one squirrels likely
 *  thread ids away in an array  (takes out references for them).
 *  Pass two does the priority updates.  This is necessary because
 *  the run queue lock is required for the candidate scan, but
 *  cannot be held during updates [set_pri will deadlock].
 *
 *  Array length should be enough so that restart isn't necessary,
 *  but restart logic is included.  Does not scan processor runqs.
 *
 */
thread_t        stuck_threads[MAX_STUCK_THREADS];
int             stuck_count = 0;

/*
 *  do_runq_scan is the guts of pass 1.  It scans a runq for
 *  stuck threads.  A boolean is returned indicating whether
 *  a retry is needed.
 */

– is that, about stuck threads, food for thought?

Or too way off from the question about processes?

At a glance, no comparable block of code in sched_prim.c in xnu-1699.26.8 source for Mac OS X 10.7.4.