Re: [Chicken-users] thread blocking reason

[Felix Winkelmann]

Joerg F. Wittenberger wrote:
> Hi Felix,
>
> I have a (thread-list) function which I'd like to extent to display
> the reason, why threads are blocked.  But somehow I can't figure out,
> how to derive the info.  Apparently the thread structure carries just
> 'blocked or some other state.
>
> I'm not really in favor of changing the structure to include yet
> another field, which, at the end, can become a bug source.  The
> function is a debugging aid and may take it's time.  But how would you
> go about it?

You can investigate slot #11 of a thread (via `(##sys#slot THREAD 11)):

- If the thread is waiting for another thread (thread-join!), it
  contains the waited for thread.
- If waiting for timeout, it contains the timeout value.
- If waiting for I/O, it contains a pair (FD . FLAG),
  where FD is the file-descriptor, and FLAG is true, when waiting
  for input (or false, when waiting for output).

Note that it's currently not possible to find out which threads
are suspended (thread-suspend!) or blocked for mutexes.


cheers,
felix