2004-10-29 Marcus Brinkmann <marcus@gnu.org>

	* cap-server.h: Include <atomic.h>.
	(struct hurd_cap_obj): Change type of member refs
	from unsigned int to uatomic32_t.
	(hurd_cap_obj_ref): Use atomic_increment().
	(hurd_cap_obj_rele): Use atomic_decrement().
	* cap-server-intern.h (_hurd_cap_obj_drop): Remove unused variable
	cap_class.  Use atomic_decrement_and_test.
	* obj-dealloc.c (_hurd_cap_obj_dealloc): Assert that OBJ->refs is
	0, not 1.  Do not unlock the object.

4 files changed, 26 insertions, 19 deletions

diff --git a/libhurd-cap-server/ChangeLog b/libhurd-cap-server/ChangeLog
index ef9c175..58cb488 100644
--- a/libhurd-cap-server/ChangeLog
+++ b/libhurd-cap-server/ChangeLog
@@ -1,3 +1,15 @@
+2004-10-29  Marcus Brinkmann  <marcus@gnu.org>
+
+	* cap-server.h: Include <atomic.h>.
+	(struct hurd_cap_obj): Change type of member refs
+	from unsigned int to uatomic32_t.
+	(hurd_cap_obj_ref): Use atomic_increment().
+	(hurd_cap_obj_rele): Use atomic_decrement().
+	* cap-server-intern.h (_hurd_cap_obj_drop): Remove unused variable
+	cap_class.  Use atomic_decrement_and_test.
+	* obj-dealloc.c (_hurd_cap_obj_dealloc): Assert that OBJ->refs is
+	0, not 1.  Do not unlock the object.
+
 2004-10-25  Marcus Brinkmann  <marcus@gnu.org>
 
 	* Makefile.am (libhurd_cap_server_a_SOURCES): Add
diff --git a/libhurd-cap-server/cap-server-intern.h b/libhurd-cap-server/cap-server-intern.h
index d9b5ff8..a7787ba 100644
--- a/libhurd-cap-server/cap-server-intern.h
+++ b/libhurd-cap-server/cap-server-intern.h
@@ -114,13 +114,8 @@ void _hurd_cap_obj_dealloc (hurd_cap_obj_t obj)
 static inline void
 _hurd_cap_obj_drop (hurd_cap_obj_t obj)
 {
-  hurd_cap_class_t cap_class = obj->cap_class;
-
-  if (__builtin_expect (obj->refs > 1, 1))
-    {
-      hurd_cap_obj_rele (obj);
-      hurd_cap_obj_unlock (obj);
-    }
+  if (__builtin_expect (!atomic_decrement_and_test (&obj->refs), 1))
+    hurd_cap_obj_unlock (obj);
   else
     _hurd_cap_obj_dealloc (obj);
 }
diff --git a/libhurd-cap-server/cap-server.h b/libhurd-cap-server/cap-server.h
index 6b79c44..ce56619 100644
--- a/libhurd-cap-server/cap-server.h
+++ b/libhurd-cap-server/cap-server.h
@@ -26,6 +26,10 @@
 #include <errno.h>
 #include <pthread.h>
 
+/* FIXME: This is not a public header file!  So we may have to ship
+   a <hurd/atomic.h>.  */
+#include <atomic.h>
+
 #include <hurd/slab.h>
 #include <hurd/types.h>
 
@@ -213,7 +217,7 @@ struct hurd_cap_obj
   pthread_mutex_t lock;
 
   /* The reference counter for this object.  */
-  unsigned int refs;
+  uatomic32_t refs;
 
   /* The state of this object.  If this is _HURD_CAP_STATE_GREEN, you
      can use the capability object.  Otherwise, you should refrain
@@ -351,22 +355,18 @@ hurd_cap_obj_unlock (hurd_cap_obj_t obj)
 static inline void
 hurd_cap_obj_ref (hurd_cap_obj_t obj)
 {
-  assert (obj->refs < UINT_MAX);
-
-  obj->refs++;
+  atomic_increment (&obj->refs);
 }
 
 
-/* Remove one reference for the capability object OBJ, which must be
-   locked.  Note that the caller must have at least two references for
-   this capability object when using this function.  To release the
-   last reference, hurd_cap_obj_drop must be used instead.  */
+/* Remove one reference for the capability object OBJ.  Note that the
+   caller must have at least two references for this capability object
+   when using this function.  To release the last reference,
+   hurd_cap_obj_drop must be used instead.  */
 static inline void
 hurd_cap_obj_rele (hurd_cap_obj_t obj)
 {
-  assert (obj->refs > 1);
-
-  obj->refs--;
+  atomic_decrement (&obj->refs);
 }
 
 
diff --git a/libhurd-cap-server/obj-dealloc.c b/libhurd-cap-server/obj-dealloc.c
index b0abb55..de4421e 100644
--- a/libhurd-cap-server/obj-dealloc.c
+++ b/libhurd-cap-server/obj-dealloc.c
@@ -40,7 +40,7 @@ _hurd_cap_obj_dealloc (hurd_cap_obj_t obj)
   (*cap_class->obj_reinit) (cap_class, obj);
 
   /* Now do our part of the reinitialization.  */
-  assert (obj->refs == 1);
+  assert (obj->refs == 0);
   assert (obj->state == _HURD_CAP_STATE_GREEN);
   assert (obj->pending_rpcs == NULL);
   assert (obj->clients == NULL);