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-rw-r--r--libhurd-cap/cap.c236
1 files changed, 0 insertions, 236 deletions
diff --git a/libhurd-cap/cap.c b/libhurd-cap/cap.c
deleted file mode 100644
index c5ed161..0000000
--- a/libhurd-cap/cap.c
+++ /dev/null
@@ -1,236 +0,0 @@
-/* Copyright (C) 2003, 2005 Free Software Foundation, Inc.
- Written by Marcus Brinkmann <marcus@gnu.org>
-
- This file is part of the GNU Hurd.
-
- This program is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- This program is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with this program; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
-
-#if HAVE_CONFIG_H
-#include <config.h>
-#endif
-
-#include <stdlib.h>
-#include <assert.h>
-#include <errno.h>
-#include <stdint.h>
-
-#include <pthread.h>
-
-#include <hurd/cap.h>
-
-#include "cap-intern.h"
-
-
-/* The slab space for capability objects. */
-hurd_slab_space_t cap_space;
-
-
-/* Initialize a new capability, allocated by the slab allocator. */
-static error_t
-cap_constructor (void *hook, void *buffer)
-{
- hurd_cap_t cap = (hurd_cap_t) buffer;
- error_t err;
-
- err = pthread_mutex_init (&cap->lock, NULL);
- if (err)
- return err;
-
- cap->srefs = 0;
- cap->orefs = 0;
-
- /* The other data is filled in by the creator. */
- return 0;
-}
-
-
-/* Release all resources allocated by the capability, which is in its
- freshly initialized state. */
-static void
-cap_destructor (void *hook, void *buffer)
-{
- hurd_cap_t cap = (hurd_cap_t) buffer;
-
- assert (cap->srefs == 0);
- assert (cap->orefs == 0);
-
- pthread_mutex_destroy (&cap->lock);
-}
-
-
-/* Initialize the capability system. */
-error_t
-hurd_cap_init (void)
-{
- return hurd_slab_create (sizeof (struct hurd_cap), 0, NULL, NULL,
- cap_constructor, cap_destructor, NULL,
- &cap_space);
-}
-
-
-/* Modify the number of send references for the capability CAP by
- DELTA. */
-error_t
-hurd_cap_mod_refs (hurd_cap_t cap, int delta)
-{
- hurd_cap_sconn_t sconn;
-
- pthread_mutex_lock (&cap->lock);
-
- /* Verify that CAP->srefs is not 0 and will not become negative. */
- if (cap->srefs == 0 || (delta < 0 && cap->srefs < -delta))
- {
- pthread_mutex_unlock (&cap->lock);
- return EINVAL;
- }
-
- /* Verify that CAP->srefs will not overflow. */
- if (delta > 0 && cap->srefs > UINT32_MAX - delta)
- {
- pthread_mutex_unlock (&cap->lock);
- return EOVERFLOW;
- }
-
- cap->srefs += delta;
- if (cap->srefs != 0)
- {
- pthread_mutex_unlock (&cap->lock);
- return 0;
- }
-
- /* This was the last send reference we held. Deallocate the server
- capability. This is not so easy, though, as some other thread
- might concurrently try to enter a new reference for this
- capability. Instead of doing reference counting for the
- capability IDs in the server connection, we get a temporary
- reference and acquire the server connection lock while the
- capability is temporarily unlocked. Then we can check if we
- still have to deallocate the capabilty. */
- sconn = cap->sconn;
-
- cap->srefs = 1;
- pthread_mutex_unlock (&cap->lock);
-
- /* Now we can try to remove ourselve from the server capability
- list. CAP->sconn will not change while we hold our
- reference. */
- pthread_mutex_lock (&sconn->lock);
- pthread_mutex_lock (&cap->lock);
-
- assert (cap->sconn == sconn);
- assert (cap->srefs != 0);
- cap->srefs--;
- if (cap->srefs != 0)
- {
- /* Someone else came in and got a reference to the almost dead
- send capability. Give up. */
- pthread_mutex_unlock (&cap->lock);
- pthread_mutex_unlock (&sconn->lock);
- return 0;
- }
-
- /* The capability can now finally be removed. */
- _hurd_cap_sconn_remove (sconn, cap->scid);
-
- if (cap->orefs == 0)
- {
- /* Return the capability to the pool. */
- pthread_mutex_unlock (&cap->lock);
- hurd_slab_dealloc (cap_space, (void *) cap);
- }
- else
- pthread_mutex_unlock (&cap->lock);
-
- return 0;
-}
-
-
-/* Modify the number of object references for the capability CAP by
- DELTA. */
-error_t
-hurd_cap_obj_mod_refs (hurd_cap_t cap, int delta)
-{
- hurd_cap_ulist_t ulist;
-
- pthread_mutex_lock (&cap->lock);
-
- /* Verify that CAP->orefs is not 0 and will not become negative. */
- if (cap->orefs == 0 || (delta < 0 && cap->orefs < -delta))
- {
- pthread_mutex_unlock (&cap->lock);
- return EINVAL;
- }
-
- /* Verify that CAP->orefs will not overflow. */
- if (delta > 0 && cap->orefs > UINT32_MAX - delta)
- {
- pthread_mutex_unlock (&cap->lock);
- return EOVERFLOW;
- }
-
- cap->orefs += delta;
- if (cap->orefs != 0)
- {
- pthread_mutex_unlock (&cap->lock);
- return 0;
- }
-
- /* The object is going to be destroyed. Remove the capability from
- each user. This is not so easy, though, as some other thread
- might concurrently try to enter a new reference for this
- capability (for example, because of an incoming RPC). Instead of
- doing reference counting for the capability in each user list, we
- get a temporary reference and acquire the user list lock while
- the capability is temporarily unlocked. Then we can check if we
- still have to deallocate the capabilty. */
- ulist = cap->ouser;
-
- cap->orefs = 1;
- pthread_mutex_unlock (&cap->lock);
-
- /* Now we can try to remove ourselve from the user lists.
- CAP->ulist will not change while we hold our reference. */
- pthread_mutex_lock (&ulist->lock);
- pthread_mutex_lock (&cap->lock);
-
- assert (cap->ouser == ulist);
- assert (cap->orefs != 0);
- cap->orefs--;
- if (cap->orefs != 0)
- {
- /* Someone else came in and got a reference to the almost dead
- capability object. Give up. */
- pthread_mutex_unlock (&cap->lock);
- pthread_mutex_unlock (&ulist->lock);
- return 0;
- }
-
- /* The capability object can now finally be removed. */
- _hurd_cap_ulist_remove (ulist, cap);
- pthread_mutex_unlock (&ulist->lock);
-
- if (cap->srefs == 0)
- {
- /* Return the capability to the pool. */
- pthread_mutex_unlock (&cap->lock);
- hurd_slab_dealloc (cap_space, (void *) cap);
- }
- else
- pthread_mutex_unlock (&cap->lock);
-
- return 0;
-
-}
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