[parrot/parrot] e48820: More threads sanity checks

[GitHub]

  Branch: refs/heads/threads
  Home:   https://github.com/parrot/parrot
  Commit: e4882026dae074586948db2ac0b32ded85da1a20
      https://github.com/parrot/parrot/commit/e4882026dae074586948db2ac0b32ded85da1a20
  Author: Reini Urban <rurban at cpanel.net>
  Date:   2012-09-16 (Sun, 16 Sep 2012)

  Changed paths:
    M src/scheduler.c

  Log Message:
  -----------
  More threads sanity checks

On single-cpu windows I had the case of NULL candidate, when looking
for the thread with the fewest tasks.
Bail out with "Could not find a free thread" when no free thread is found, even
when Parrot_thread_get_free_threads_array_index() returned -1 (all threads allocated).