hurd-l4/libhurd-cap cap-user.c cap-move.c

[Marcus Brinkmann]

CVSROOT:        /cvsroot/hurd
Module name:    hurd-l4
Branch:         
Changes by:     Marcus Brinkmann <address@hidden>       03/08/27 20:13:27

Modified files:
        libhurd-cap    : cap-user.c 
Added files:
        libhurd-cap    : cap-move.c 

Log message:
        Roughly lay out how capabilities can be moved/copied.

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/hurd/hurd-l4/libhurd-cap/cap-move.c?rev=1.1
http://savannah.gnu.org/cgi-bin/viewcvs/hurd/hurd-l4/libhurd-cap/cap-user.c.diff?tr1=1.6&tr2=1.7&r1=text&r2=text

Patches:
Index: hurd-l4/libhurd-cap/cap-user.c
diff -u hurd-l4/libhurd-cap/cap-user.c:1.6 hurd-l4/libhurd-cap/cap-user.c:1.7
--- hurd-l4/libhurd-cap/cap-user.c:1.6  Wed Aug 27 18:51:59 2003
+++ hurd-l4/libhurd-cap/cap-user.c      Wed Aug 27 20:13:27 2003
@@ -101,74 +101,70 @@
 
 /* Enter a new send capability provided by the server SERVER_THREAD
    (with the task ID reference SERVER_TASK_ID) and the cap ID SCID.
-   If successful, the locked capability is returned with one
-   (additional) reference in CAP.  The server connection and
+   SCONN is the server connection for SERVER_THREAD, if known.  It
+   should be unlocked.  If SCONN is NULL, then SERVER_TASK_INFO should
+   be the task info capability for the server SERVER_THREAD, otherwise
+   it must be HURD_CAP_NULL.  Both, SCONN and SERVER_TASK_INFO, are
+   consumed if used.  If successful, the locked capability is returned
+   with one (additional) reference in CAP.  The server connection and
    capability object are created if necessary.  */
 error_t
-_hurd_cap_sconn_enter (l4_thread_id_t server_thread, uint32_t scid,
+_hurd_cap_sconn_enter (hurd_cap_sconn_t sconn_provided,
+                      hurd_task_info_t server_task_info,
+                      l4_thread_id_t server_thread, uint32_t scid,
                       hurd_cap_t *cap)
 {
-  hurd_cap_sconn_t sconn;
+  hurd_cap_sconn_t sconn = sconn_provided;
   int sconn_created = 0;
 
-  pthread_mutex_lock (&server_to_sconn_lock);
-  sconn = hurd_ihash_find (&server_to_sconn, server_thread);
-  if (!sconn)
+  if (sconn)
+    assert (sconn->server_thread == server_thread);
+  else
     {
-      error_t err;
-      hurd_task_id_t server_task = hurd_task_id_from_thread_id (server_thread);
-      hurd_task_id_t taskserver_task;
-
-      taskserver_task = hurd_task_id_from_thread_id
-       (hurd_cap_get_thread_id (hurd_task_self()));
-
-      sconn = malloc (sizeof (*sconn));
-      if (!sconn)
-       {
-         pthread_mutex_unlock (&server_to_sconn_lock);
-         return errno;
-       }
-      err = pthread_mutex_init (&sconn->lock, NULL);
-      if (err)
-       {
-         free (sconn);
-         pthread_mutex_unlock (&server_to_sconn_lock);
-         return errno;
-       }
-        
-      if (server_task != taskserver_task)
+      /* It might have become available by now.  */
+      pthread_mutex_lock (&server_to_sconn_lock);
+      sconn = hurd_ihash_find (&server_to_sconn, server_thread);
+      if (sconn)
+       hurd_cap_deallocate (server_task_info);
+      else
        {
-         err = hurd_task_info_create (hurd_task_self (),
-                                      server_task,
-                                      &sconn->server_task_id);
+         error_t err;
+
+         sconn = malloc (sizeof (*sconn));
+         if (!sconn)
+           {
+             pthread_mutex_unlock (&server_to_sconn_lock);
+             hurd_cap_deallocate (server_task_info);
+             return errno;
+           }
+         err = pthread_mutex_init (&sconn->lock, NULL);
          if (err)
            {
-             pthread_mutex_destroy (&sconn->lock);
              free (sconn);
              pthread_mutex_unlock (&server_to_sconn_lock);
+             hurd_cap_deallocate (server_task_info);
              return errno;
            }
-       }
-      else
-       sconn->server_task_id = 0;
 
-      hurd_ihash_init (&sconn->id_to_cap);
-      sconn->server_thread = server_thread;
-      sconn->refs = 0;
+         hurd_ihash_init (&sconn->id_to_cap);
+         sconn->server_thread = server_thread;
+         sconn->server_task_id = server_task_info;
+         sconn->refs = 0;
 
-      /* Enter the new server connection object.  */
-      err = hurd_ihash_add (&server_to_sconn, server_thread, sconn);
-      if (err)
-       {
-         pthread_mutex_destroy (&sconn->lock);
-         hurd_ihash_destroy (&sconn->id_to_cap);
-         free (sconn);
-         pthread_mutex_unlock (&server_to_sconn_lock);
-         return errno;
+         /* Enter the new server connection object.  */
+         err = hurd_ihash_add (&server_to_sconn, server_thread, sconn);
+         if (err)
+           {
+             pthread_mutex_destroy (&sconn->lock);
+             hurd_ihash_destroy (&sconn->id_to_cap);
+             free (sconn);
+             pthread_mutex_unlock (&server_to_sconn_lock);
+             hurd_cap_deallocate (server_task_id);
+             return errno;
+           }
        }
     }
   pthread_mutex_lock (&sconn->lock);
-  sconn->refs++;
   pthread_mutex_unlock (&server_to_sconn_lock);
 
   cap = hurd_ihash_find (&sconn->id_to_cap, scid);
@@ -195,6 +191,10 @@
     }
   pthread_mutex_lock (&cap->lock);
   cap->srefs++;
+  /* We have to add a reference for the capability we have added,
+     unless we are consuming the reference that was provided.  */
+  if (!sconn_provided)
+    sconn->refs++;
   pthread_mutex_unlock (&sconn->lock);
 
   return 0;