This parameterizes the GC a bit to make it thread-ready.

The basic idea is that whenever a thread "exits lisp" -- that is,
releases the global lock in favor of another thread -- it must save
its stack boundaries in the thread object.  This way the boundaries
are always available for marking.  This is the purpose of
flush_stack_call_func.

I haven't tested this under all the possible GC configurations.
There is a new FIXME in a spot that i didn't convert.

Arguably all_threads should go in the previous patch.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/thread.h b/src/thread.h
index b2eb04d42e8..6d61d0e5fcf 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -133,8 +133,13 @@ struct thread_state
   /* Regexp to use to replace spaces, or NULL meaning don't.  */
   /*re_char*/ unsigned char *m_whitespace_regexp;
 #define whitespace_regexp (current_thread->m_whitespace_regexp)
+
+  /* Threads are kept on a linked list.  */
+  struct thread_state *next_thread;
 };
 
 extern struct thread_state *current_thread;
 
+extern void unmark_threads (void);
+
 #endif /* THREAD_H */