kern/thread: add reference counter

Counting thread references seems unavoidable for the near-future changes
that are currently brewing.

1 files changed, 5 insertions, 0 deletions

diff --git a/kern/thread_i.h b/kern/thread_i.h
index b3d09a05..a062773d 100644
--- a/kern/thread_i.h
+++ b/kern/thread_i.h
@@ -80,6 +80,9 @@ struct thread_fs_data {
 struct thread {
     struct tcb tcb;
 
+    /* Reference counter, must be changed atomically */
+    unsigned long nr_refs;
+
     /* Flags must be changed atomically */
     unsigned long flags;
 
@@ -130,6 +133,8 @@ struct thread {
 
 #define THREAD_ATTR_DETACHED 0x1
 
+void thread_destroy(struct thread *thread);
+
 /*
  * Flag access functions.
  */