Fix segfaults when mainthread exits with other threads running:

 - track number of running threads
 - if main thread calls perl_destruct() with other threads running
   skip most of cleanup (with a warning).

p4raw-id: //depot/perlio@15698

1 files changed, 2 insertions, 0 deletions

diff --git a/perlapi.h b/perlapi.h
index 5070d1dbe7..24f790a8fe 100644
--- a/perlapi.h
+++ b/perlapi.h
@@ -968,6 +968,8 @@ END_EXTERN_C
 #define PL_sharehook		(*Perl_Gsharehook_ptr(NULL))
 #undef  PL_thr_key
 #define PL_thr_key		(*Perl_Gthr_key_ptr(NULL))
+#undef  PL_threadhook
+#define PL_threadhook		(*Perl_Gthreadhook_ptr(NULL))
 #undef  PL_unlockhook
 #define PL_unlockhook		(*Perl_Gunlockhook_ptr(NULL))