+++ /dev/null
-#ifndef _URCU_LFSTACK_H
-#define _URCU_LFSTACK_H
-
-/*
- * lfstack.h
- *
- * Userspace RCU library - Lock-Free Stack
- *
- * Copyright 2010-2012 - 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
- */
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#include <stdbool.h>
-#include <pthread.h>
-
-/*
- * Lock-free stack.
- *
- * Stack implementing push, pop, pop_all operations, as well as iterator
- * on the stack head returned by pop_all.
- *
- * Synchronization table:
- *
- * External synchronization techniques described in the API below is
- * required between pairs marked with "X". No external synchronization
- * required between pairs marked with "-".
- *
- * cds_lfs_push __cds_lfs_pop __cds_lfs_pop_all
- * cds_lfs_push - - -
- * __cds_lfs_pop - X X
- * __cds_lfs_pop_all - X -
- *
- * cds_lfs_pop_blocking and cds_lfs_pop_all_blocking use an internal
- * mutex to provide synchronization.
- */
-
-/*
- * struct cds_lfs_node is returned by cds_lfs_pop, and also used as
- * iterator on stack. It is not safe to dereference the node next
- * pointer when returned by cds_lfs_pop.
- */
-struct cds_lfs_node {
- struct cds_lfs_node *next;
-};
-
-/*
- * struct cds_lfs_head is returned by __cds_lfs_pop_all, and can be used
- * to begin iteration on the stack. "node" needs to be the first field
- * of cds_lfs_head, so the end-of-stack pointer value can be used for
- * both types.
- */
-struct cds_lfs_head {
- struct cds_lfs_node node;
-};
-
-struct __cds_lfs_stack {
- struct cds_lfs_head *head;
-};
-
-struct cds_lfs_stack {
- struct cds_lfs_head *head;
- pthread_mutex_t lock;
-};
-
-/*
- * The transparent union allows calling functions that work on both
- * struct cds_lfs_stack and struct __cds_lfs_stack on any of those two
- * types.
- */
-typedef union {
- struct __cds_lfs_stack *_s;
- struct cds_lfs_stack *s;
-} __attribute__((__transparent_union__)) cds_lfs_stack_ptr_t;
-
-#ifdef _LGPL_SOURCE
-
-#include <urcu/static/lfstack.h>
-
-#define cds_lfs_node_init _cds_lfs_node_init
-#define cds_lfs_init _cds_lfs_init
-#define cds_lfs_destroy _cds_lfs_destroy
-#define __cds_lfs_init ___cds_lfs_init
-#define cds_lfs_empty _cds_lfs_empty
-#define cds_lfs_push _cds_lfs_push
-
-/* Locking performed internally */
-#define cds_lfs_pop_blocking _cds_lfs_pop_blocking
-#define cds_lfs_pop_all_blocking _cds_lfs_pop_all_blocking
-
-/* Synchronize pop with internal mutex */
-#define cds_lfs_pop_lock _cds_lfs_pop_lock
-#define cds_lfs_pop_unlock _cds_lfs_pop_unlock
-
-/* Synchronization ensured by the caller. See synchronization table. */
-#define __cds_lfs_pop ___cds_lfs_pop
-#define __cds_lfs_pop_all ___cds_lfs_pop_all
-
-#else /* !_LGPL_SOURCE */
-
-/*
- * cds_lfs_node_init: initialize lock-free stack node.
- */
-extern void cds_lfs_node_init(struct cds_lfs_node *node);
-
-/*
- * cds_lfs_init: initialize lock-free stack (with locking). Pair with
- * cds_lfs_destroy().
- */
-extern void cds_lfs_init(struct cds_lfs_stack *s);
-
-/*
- * cds_lfs_destroy: destroy lock-free stack (with lock). Pair with
- * cds_lfs_init().
- */
-extern void cds_lfs_destroy(struct cds_lfs_stack *s);
-
-/*
- * __cds_lfs_init: initialize lock-free stack (without lock).
- * Don't pair with any destroy function.
- */
-extern void __cds_lfs_init(struct __cds_lfs_stack *s);
-
-/*
- * cds_lfs_empty: return whether lock-free stack is empty.
- *
- * No memory barrier is issued. No mutual exclusion is required.
- */
-extern bool cds_lfs_empty(cds_lfs_stack_ptr_t s);
-
-/*
- * cds_lfs_push: push a node into the stack.
- *
- * Does not require any synchronization with other push nor pop.
- *
- * Returns 0 if the stack was empty prior to adding the node.
- * Returns non-zero otherwise.
- */
-extern bool cds_lfs_push(cds_lfs_stack_ptr_t s,
- struct cds_lfs_node *node);
-
-/*
- * cds_lfs_pop_blocking: pop a node from the stack.
- *
- * Calls __cds_lfs_pop with an internal pop mutex held.
- */
-extern struct cds_lfs_node *cds_lfs_pop_blocking(struct cds_lfs_stack *s);
-
-/*
- * cds_lfs_pop_all_blocking: pop all nodes from a stack.
- *
- * Calls __cds_lfs_pop_all with an internal pop mutex held.
- */
-extern struct cds_lfs_head *cds_lfs_pop_all_blocking(struct cds_lfs_stack *s);
-
-/*
- * cds_lfs_pop_lock: lock stack pop-protection mutex.
- */
-extern void cds_lfs_pop_lock(struct cds_lfs_stack *s);
-
-/*
- * cds_lfs_pop_unlock: unlock stack pop-protection mutex.
- */
-extern void cds_lfs_pop_unlock(struct cds_lfs_stack *s);
-
-/*
- * __cds_lfs_pop: pop a node from the stack.
- *
- * Returns NULL if stack is empty.
- *
- * __cds_lfs_pop needs to be synchronized using one of the following
- * techniques:
- *
- * 1) Calling __cds_lfs_pop under rcu read lock critical section.
- * Both __cds_lfs_pop and __cds_lfs_pop_all callers must wait for a
- * grace period to pass before freeing the returned node or pushing
- * the node back into the stack. It is valid to overwrite the content
- * of cds_lfs_node immediately after __cds_lfs_pop and
- * __cds_lfs_pop_all.
- * 2) Using mutual exclusion (e.g. mutexes) to protect __cds_lfs_pop
- * and __cds_lfs_pop_all callers.
- * 3) Ensuring that only ONE thread can call __cds_lfs_pop() and
- * __cds_lfs_pop_all(). (multi-provider/single-consumer scheme).
- */
-extern struct cds_lfs_node *__cds_lfs_pop(cds_lfs_stack_ptr_t s);
-
-/*
- * __cds_lfs_pop_all: pop all nodes from a stack.
- *
- * __cds_lfs_pop_all does not require any synchronization with other
- * push, nor with other __cds_lfs_pop_all, but requires synchronization
- * matching the technique used to synchronize __cds_lfs_pop:
- *
- * 1) If __cds_lfs_pop is called under rcu read lock critical section,
- * both __cds_lfs_pop and __cds_lfs_pop_all callers must wait for a
- * grace period to pass before freeing the returned node or pushing
- * the node back into the stack. It is valid to overwrite the content
- * of cds_lfs_node immediately after __cds_lfs_pop and
- * __cds_lfs_pop_all. No RCU read-side critical section is needed
- * around __cds_lfs_pop_all.
- * 2) Using mutual exclusion (e.g. mutexes) to protect __cds_lfs_pop and
- * __cds_lfs_pop_all callers.
- * 3) Ensuring that only ONE thread can call __cds_lfs_pop() and
- * __cds_lfs_pop_all(). (multi-provider/single-consumer scheme).
- */
-extern struct cds_lfs_head *__cds_lfs_pop_all(cds_lfs_stack_ptr_t s);
-
-#endif /* !_LGPL_SOURCE */
-
-/*
- * cds_lfs_for_each: Iterate over all nodes returned by
- * __cds_lfs_pop_all.
- * @__head: node returned by __cds_lfs_pop_all (struct cds_lfs_head pointer).
- * @__node: node to use as iterator (struct cds_lfs_node pointer).
- *
- * Content written into each node before push is guaranteed to be
- * consistent, but no other memory ordering is ensured.
- */
-#define cds_lfs_for_each(__head, __node) \
- for (__node = &__head->node; \
- __node != NULL; \
- __node = __node->next)
-
-/*
- * cds_lfs_for_each_safe: Iterate over all nodes returned by
- * __cds_lfs_pop_all, safe against node deletion.
- * @__head: node returned by __cds_lfs_pop_all (struct cds_lfs_head pointer).
- * @__node: node to use as iterator (struct cds_lfs_node pointer).
- * @__n: struct cds_lfs_node pointer holding the next pointer (used
- * internally).
- *
- * Content written into each node before push is guaranteed to be
- * consistent, but no other memory ordering is ensured.
- */
-#define cds_lfs_for_each_safe(__head, __node, __n) \
- for (__node = &__head->node, __n = (__node ? __node->next : NULL); \
- __node != NULL; \
- __node = __n, __n = (__node ? __node->next : NULL))
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* _URCU_LFSTACK_H */
projects / urcu.git / blobdiff