pointer.h: Fix the rcu_cmpxchg_pointer documentation

[userspace-rcu.git] / urcu / wfstack.h

diff --git a/urcu/wfstack.h b/urcu/wfstack.h
deleted file mode 100644 (file)
index b3ee2e7..0000000
--- a/urcu/wfstack.h
+++ /dev/null
@@ -1,129 +0,0 @@
-#ifndef _URCU_WFSTACK_H
-#define _URCU_WFSTACK_H
-
-/*
- * rcuwfstack.h
- *
- * Userspace RCU library - Stack with Wait-Free push, Blocking pop.
- *
- * Copyright 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library 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 library 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 library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <pthread.h>
-#include <assert.h>
-#include <urcu/compiler.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#if (!defined(_GNU_SOURCE) && !defined(_LGPL_SOURCE))
-#error "Dynamic loader LGPL wrappers not implemented yet"
-#endif
-
-#define WF_STACK_END                   ((void *)0x1UL)
-#define WFS_ADAPT_ATTEMPTS             10      /* Retry if being set */
-#define WFS_WAIT                       10      /* Wait 10 ms if being set */
-
-struct wfs_node {
-       struct wfs_node *next;
-};
-
-struct wfs_stack {
-       struct wfs_node *head;
-       pthread_mutex_t lock;
-};
-
-void wfs_node_init(struct wfs_node *node)
-{
-       node->next = NULL;
-}
-
-void wfs_init(struct wfs_stack *s)
-{
-       int ret;
-
-       s->head = WF_STACK_END;
-       ret = pthread_mutex_init(&s->lock, NULL);
-       assert(!ret);
-}
-
-void wfs_push(struct wfs_stack *s, struct wfs_node *node)
-{
-       struct wfs_node *old_head;
-
-       assert(node->next == NULL);
-       /*
-        * uatomic_xchg() implicit memory barrier orders earlier stores to node
-        * (setting it to NULL) before publication.
-        */
-       old_head = uatomic_xchg(&s->head, node);
-       /*
-        * At this point, dequeuers see a NULL node->next, they should busy-wait
-        * until node->next is set to old_head.
-        */
-       STORE_SHARED(node->next, old_head);
-}
-
-/*
- * Returns NULL if stack is empty.
- */
-struct wfs_node *
-__wfs_pop_blocking(struct wfs_stack *s)
-{
-       struct wfs_node *head, *next;
-       int attempt = 0;
-
-retry:
-       head = LOAD_SHARED(s->head);
-       if (head == WF_STACK_END)
-               return NULL;
-       /*
-        * Adaptative busy-looping waiting for push to complete.
-        */
-       while ((next = LOAD_SHARED(head->next)) == NULL) {
-               if (++attempt >= WFS_ADAPT_ATTEMPTS) {
-                       poll(NULL, 0, WFS_WAIT);        /* Wait for 10ms */
-                       attempt = 0;
-               } else
-                       cpu_relax();
-       }
-       if (uatomic_cmpxchg(&s->head, head, next) == head)
-               return head;
-       else
-               goto retry;             /* Concurrent modification. Retry. */
-}
-
-struct wfs_node *
-wfs_pop_blocking(struct wfs_stack *s)
-{
-       struct wfs_node *retnode;
-       int ret;
-
-       ret = pthread_mutex_lock(&s->lock);
-       assert(!ret);
-       retnode = __wfs_pop_blocking(s);
-       ret = pthread_mutex_unlock(&s->lock);
-       assert(!ret);
-       return retnode;
-}
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* _URCU_WFSTACK_H */