| 1 | // SPDX-FileCopyrightText: Free Software Foundation, Inc. |
| 2 | // SPDX-FileCopyrightText: 2009 Pierre-Marc Fournier |
| 3 | // SPDX-FileCopyrightText: 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 4 | // |
| 5 | // SPDX-License-Identifier: LGPL-2.1-or-later |
| 6 | |
| 7 | /* |
| 8 | * (originally part of the GNU C Library) |
| 9 | * Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. |
| 10 | */ |
| 11 | |
| 12 | #ifndef _URCU_RCULIST_H |
| 13 | #define _URCU_RCULIST_H |
| 14 | |
| 15 | #include <urcu/list.h> |
| 16 | #include <urcu/arch.h> |
| 17 | #include <urcu-pointer.h> |
| 18 | |
| 19 | /* Add new element at the head of the list. */ |
| 20 | static inline |
| 21 | void cds_list_add_rcu(struct cds_list_head *newp, struct cds_list_head *head) |
| 22 | { |
| 23 | newp->next = head->next; |
| 24 | newp->prev = head; |
| 25 | head->next->prev = newp; |
| 26 | rcu_assign_pointer(head->next, newp); |
| 27 | } |
| 28 | |
| 29 | /* Add new element at the tail of the list. */ |
| 30 | static inline |
| 31 | void cds_list_add_tail_rcu(struct cds_list_head *newp, |
| 32 | struct cds_list_head *head) |
| 33 | { |
| 34 | newp->next = head; |
| 35 | newp->prev = head->prev; |
| 36 | rcu_assign_pointer(head->prev->next, newp); |
| 37 | head->prev = newp; |
| 38 | } |
| 39 | |
| 40 | /* |
| 41 | * Replace an old entry atomically with respect to concurrent RCU |
| 42 | * traversal. Mutual exclusion against concurrent updates is required |
| 43 | * though. |
| 44 | */ |
| 45 | static inline |
| 46 | void cds_list_replace_rcu(struct cds_list_head *old, struct cds_list_head *_new) |
| 47 | { |
| 48 | _new->next = old->next; |
| 49 | _new->prev = old->prev; |
| 50 | rcu_assign_pointer(_new->prev->next, _new); |
| 51 | _new->next->prev = _new; |
| 52 | } |
| 53 | |
| 54 | /* Remove element from list. */ |
| 55 | static inline |
| 56 | void cds_list_del_rcu(struct cds_list_head *elem) |
| 57 | { |
| 58 | elem->next->prev = elem->prev; |
| 59 | CMM_STORE_SHARED(elem->prev->next, elem->next); |
| 60 | } |
| 61 | |
| 62 | /* |
| 63 | * Iteration through all elements of the list must be done while rcu_read_lock() |
| 64 | * is held. |
| 65 | */ |
| 66 | |
| 67 | /* Iterate forward over the elements of the list. */ |
| 68 | #define cds_list_for_each_rcu(pos, head) \ |
| 69 | for (pos = rcu_dereference((head)->next); (pos) != (head); \ |
| 70 | pos = rcu_dereference((pos)->next)) |
| 71 | |
| 72 | /* Iterate through elements of the list. */ |
| 73 | #define cds_list_for_each_entry_rcu(pos, head, member) \ |
| 74 | for (pos = cds_list_entry(rcu_dereference((head)->next), __typeof__(*(pos)), member); \ |
| 75 | &(pos)->member != (head); \ |
| 76 | pos = cds_list_entry(rcu_dereference((pos)->member.next), __typeof__(*(pos)), member)) |
| 77 | |
| 78 | #endif /* _URCU_RCULIST_H */ |