| /* |
| * include/common/mini-clist.h |
| * Circular list manipulation macros and structures. |
| * |
| * Copyright (C) 2002-2014 Willy Tarreau - w@1wt.eu |
| * |
| * 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, version 2.1 |
| * exclusively. |
| * |
| * 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 |
| */ |
| |
| #ifndef _COMMON_MINI_CLIST_H |
| #define _COMMON_MINI_CLIST_H |
| |
| #include <common/config.h> |
| |
| /* these are circular or bidirectionnal lists only. Each list pointer points to |
| * another list pointer in a structure, and not the structure itself. The |
| * pointer to the next element MUST be the first one so that the list is easily |
| * cast as a single linked list or pointer. |
| */ |
| struct list { |
| struct list *n; /* next */ |
| struct list *p; /* prev */ |
| }; |
| |
| /* a back-ref is a pointer to a target list entry. It is used to detect when an |
| * element being deleted is currently being tracked by another user. The best |
| * example is a user dumping the session table. The table does not fit in the |
| * output buffer so we have to set a mark on a session and go on later. But if |
| * that marked session gets deleted, we don't want the user's pointer to go in |
| * the wild. So we can simply link this user's request to the list of this |
| * session's users, and put a pointer to the list element in ref, that will be |
| * used as the mark for next iteration. |
| */ |
| struct bref { |
| struct list users; |
| struct list *ref; /* pointer to the target's list entry */ |
| }; |
| |
| /* a word list is a generic list with a pointer to a string in each element. */ |
| struct wordlist { |
| struct list list; |
| char *s; |
| }; |
| |
| /* this is the same as above with an additional pointer to a condition. */ |
| struct cond_wordlist { |
| struct list list; |
| void *cond; |
| char *s; |
| }; |
| |
| /* First undefine some macros which happen to also be defined on OpenBSD, |
| * in sys/queue.h, used by sys/event.h |
| */ |
| #undef LIST_HEAD |
| #undef LIST_INIT |
| #undef LIST_NEXT |
| |
| /* ILH = Initialized List Head : used to prevent gcc from moving an empty |
| * list to BSS. Some older version tend to trim all the array and cause |
| * corruption. |
| */ |
| #define ILH { .n = (struct list *)1, .p = (struct list *)2 } |
| |
| #define LIST_HEAD(a) ((void *)(&(a))) |
| |
| #define LIST_INIT(l) ((l)->n = (l)->p = (l)) |
| |
| #define LIST_HEAD_INIT(l) { &l, &l } |
| |
| /* adds an element at the beginning of a list ; returns the element */ |
| #define LIST_ADD(lh, el) ({ (el)->n = (lh)->n; (el)->n->p = (lh)->n = (el); (el)->p = (lh); (el); }) |
| |
| /* adds an element at the end of a list ; returns the element */ |
| #define LIST_ADDQ(lh, el) ({ (el)->p = (lh)->p; (el)->p->n = (lh)->p = (el); (el)->n = (lh); (el); }) |
| |
| /* adds the contents of a list <old> at the beginning of another list <new>. The old list head remains untouched. */ |
| #define LIST_SPLICE(new, old) do { \ |
| if (!LIST_ISEMPTY(old)) { \ |
| (old)->p->n = (new)->n; (old)->n->p = (new); \ |
| (new)->n->p = (old)->p; (new)->n = (old)->n; \ |
| } \ |
| } while (0) |
| |
| /* removes an element from a list and returns it */ |
| #define LIST_DEL(el) ({ typeof(el) __ret = (el); (el)->n->p = (el)->p; (el)->p->n = (el)->n; (__ret); }) |
| |
| /* removes an element from a list, initializes it and returns it. |
| * This is faster than LIST_DEL+LIST_INIT as we avoid reloading the pointers. |
| */ |
| #define LIST_DEL_INIT(el) ({ \ |
| typeof(el) __ret = (el); \ |
| typeof(__ret->n) __n = __ret->n; \ |
| typeof(__ret->p) __p = __ret->p; \ |
| __n->p = __p; __p->n = __n; \ |
| __ret->n = __ret->p = __ret; \ |
| __ret; \ |
| }) |
| |
| /* returns a pointer of type <pt> to a structure containing a list head called |
| * <el> at address <lh>. Note that <lh> can be the result of a function or macro |
| * since it's used only once. |
| * Example: LIST_ELEM(cur_node->args.next, struct node *, args) |
| */ |
| #define LIST_ELEM(lh, pt, el) ((pt)(((void *)(lh)) - ((void *)&((pt)NULL)->el))) |
| |
| /* checks if the list head <lh> is empty or not */ |
| #define LIST_ISEMPTY(lh) ((lh)->n == (lh)) |
| |
| /* checks if the list element <el> was added to a list or not. This only |
| * works when detached elements are reinitialized (using LIST_DEL_INIT) |
| */ |
| #define LIST_ADDED(el) ((el)->n != (el)) |
| |
| /* returns a pointer of type <pt> to a structure following the element |
| * which contains list head <lh>, which is known as element <el> in |
| * struct pt. |
| * Example: LIST_NEXT(args, struct node *, list) |
| */ |
| #define LIST_NEXT(lh, pt, el) (LIST_ELEM((lh)->n, pt, el)) |
| |
| |
| /* returns a pointer of type <pt> to a structure preceding the element |
| * which contains list head <lh>, which is known as element <el> in |
| * struct pt. |
| */ |
| #undef LIST_PREV |
| #define LIST_PREV(lh, pt, el) (LIST_ELEM((lh)->p, pt, el)) |
| |
| /* |
| * Simpler FOREACH_ITEM macro inspired from Linux sources. |
| * Iterates <item> through a list of items of type "typeof(*item)" which are |
| * linked via a "struct list" member named <member>. A pointer to the head of |
| * the list is passed in <list_head>. No temporary variable is needed. Note |
| * that <item> must not be modified during the loop. |
| * Example: list_for_each_entry(cur_acl, known_acl, list) { ... }; |
| */ |
| #define list_for_each_entry(item, list_head, member) \ |
| for (item = LIST_ELEM((list_head)->n, typeof(item), member); \ |
| &item->member != (list_head); \ |
| item = LIST_ELEM(item->member.n, typeof(item), member)) |
| |
| /* |
| * Same as list_for_each_entry but starting from current point |
| * Iterates <item> through the list starting from <item> |
| * It's basically the same macro but without initializing item to the head of |
| * the list. |
| */ |
| #define list_for_each_entry_from(item, list_head, member) \ |
| for ( ; &item->member != (list_head); \ |
| item = LIST_ELEM(item->member.n, typeof(item), member)) |
| |
| /* |
| * Simpler FOREACH_ITEM_SAFE macro inspired from Linux sources. |
| * Iterates <item> through a list of items of type "typeof(*item)" which are |
| * linked via a "struct list" member named <member>. A pointer to the head of |
| * the list is passed in <list_head>. A temporary variable <back> of same type |
| * as <item> is needed so that <item> may safely be deleted if needed. |
| * Example: list_for_each_entry_safe(cur_acl, tmp, known_acl, list) { ... }; |
| */ |
| #define list_for_each_entry_safe(item, back, list_head, member) \ |
| for (item = LIST_ELEM((list_head)->n, typeof(item), member), \ |
| back = LIST_ELEM(item->member.n, typeof(item), member); \ |
| &item->member != (list_head); \ |
| item = back, back = LIST_ELEM(back->member.n, typeof(back), member)) |
| |
| |
| /* |
| * Same as list_for_each_entry_safe but starting from current point |
| * Iterates <item> through the list starting from <item> |
| * It's basically the same macro but without initializing item to the head of |
| * the list. |
| */ |
| #define list_for_each_entry_safe_from(item, back, list_head, member) \ |
| for (back = LIST_ELEM(item->member.n, typeof(item), member); \ |
| &item->member != (list_head); \ |
| item = back, back = LIST_ELEM(back->member.n, typeof(back), member)) |
| |
| #include <common/hathreads.h> |
| #define LLIST_BUSY ((struct list *)1) |
| |
| /* |
| * Locked version of list manipulation macros. |
| * It is OK to use those concurrently from multiple threads, as long as the |
| * list is only used with the locked variants. The only "unlocked" macro you |
| * can use with a locked list is LIST_INIT. |
| */ |
| #define LIST_ADD_LOCKED(lh, el) \ |
| do { \ |
| while (1) { \ |
| struct list *n; \ |
| struct list *p; \ |
| n = _HA_ATOMIC_XCHG(&(lh)->n, LLIST_BUSY); \ |
| if (n == LLIST_BUSY) \ |
| continue; \ |
| p = _HA_ATOMIC_XCHG(&n->p, LLIST_BUSY); \ |
| if (p == LLIST_BUSY) { \ |
| (lh)->n = n; \ |
| __ha_barrier_store(); \ |
| continue; \ |
| } \ |
| (el)->n = n; \ |
| (el)->p = p; \ |
| __ha_barrier_store(); \ |
| n->p = (el); \ |
| __ha_barrier_store(); \ |
| p->n = (el); \ |
| __ha_barrier_store(); \ |
| break; \ |
| } \ |
| } while (0) |
| |
| #define LIST_ADDQ_LOCKED(lh, el) \ |
| do { \ |
| while (1) { \ |
| struct list *n; \ |
| struct list *p; \ |
| p = _HA_ATOMIC_XCHG(&(lh)->p, LLIST_BUSY); \ |
| if (p == LLIST_BUSY) \ |
| continue; \ |
| n = _HA_ATOMIC_XCHG(&p->n, LLIST_BUSY); \ |
| if (n == LLIST_BUSY) { \ |
| (lh)->p = p; \ |
| __ha_barrier_store(); \ |
| continue; \ |
| } \ |
| (el)->n = n; \ |
| (el)->p = p; \ |
| __ha_barrier_store(); \ |
| p->n = (el); \ |
| __ha_barrier_store(); \ |
| n->p = (el); \ |
| __ha_barrier_store(); \ |
| break; \ |
| } \ |
| } while (0) |
| |
| #define LIST_DEL_LOCKED(el) \ |
| do { \ |
| while (1) { \ |
| struct list *n, *n2; \ |
| struct list *p, *p2 = NULL; \ |
| n = _HA_ATOMIC_XCHG(&(el)->n, LLIST_BUSY); \ |
| if (n == LLIST_BUSY) \ |
| continue; \ |
| p = _HA_ATOMIC_XCHG(&(el)->p, LLIST_BUSY); \ |
| if (p == LLIST_BUSY) { \ |
| (el)->n = n; \ |
| __ha_barrier_store(); \ |
| continue; \ |
| } \ |
| if (p != (el)) { \ |
| p2 = _HA_ATOMIC_XCHG(&p->n, LLIST_BUSY); \ |
| if (p2 == LLIST_BUSY) { \ |
| (el)->p = p; \ |
| (el)->n = n; \ |
| __ha_barrier_store(); \ |
| continue; \ |
| } \ |
| } \ |
| if (n != (el)) { \ |
| n2 = _HA_ATOMIC_XCHG(&n->p, LLIST_BUSY); \ |
| if (n2 == LLIST_BUSY) { \ |
| if (p2 != NULL) \ |
| p->n = p2; \ |
| (el)->p = p; \ |
| (el)->n = n; \ |
| __ha_barrier_store(); \ |
| continue; \ |
| } \ |
| } \ |
| n->p = p; \ |
| p->n = n; \ |
| __ha_barrier_store(); \ |
| (el)->p = (el); \ |
| (el)->n = (el); \ |
| __ha_barrier_store(); \ |
| break; \ |
| } \ |
| } while (0) |
| |
| |
| /* Remove the first element from the list, and return it */ |
| #define LIST_POP_LOCKED(lh, pt, el) \ |
| ({ \ |
| void *_ret; \ |
| while (1) { \ |
| struct list *n, *n2; \ |
| struct list *p, *p2; \ |
| n = _HA_ATOMIC_XCHG(&(lh)->n, LLIST_BUSY); \ |
| if (n == LLIST_BUSY) \ |
| continue; \ |
| if (n == (lh)) { \ |
| (lh)->n = lh; \ |
| __ha_barrier_store(); \ |
| _ret = NULL; \ |
| break; \ |
| } \ |
| p = _HA_ATOMIC_XCHG(&n->p, LLIST_BUSY); \ |
| if (p == LLIST_BUSY) { \ |
| (lh)->n = n; \ |
| __ha_barrier_store(); \ |
| continue; \ |
| } \ |
| n2 = _HA_ATOMIC_XCHG(&n->n, LLIST_BUSY); \ |
| if (n2 == LLIST_BUSY) { \ |
| n->p = p; \ |
| __ha_barrier_store(); \ |
| (lh)->n = n; \ |
| __ha_barrier_store(); \ |
| continue; \ |
| } \ |
| p2 = _HA_ATOMIC_XCHG(&n2->p, LLIST_BUSY); \ |
| if (p2 == LLIST_BUSY) { \ |
| n->n = n2; \ |
| n->p = p; \ |
| __ha_barrier_store(); \ |
| (lh)->n = n; \ |
| __ha_barrier_store(); \ |
| continue; \ |
| } \ |
| (lh)->n = n2; \ |
| (n2)->p = (lh); \ |
| __ha_barrier_store(); \ |
| (n)->p = (n); \ |
| (n)->n = (n); \ |
| __ha_barrier_store(); \ |
| _ret = LIST_ELEM(n, pt, el); \ |
| break; \ |
| } \ |
| (_ret); \ |
| }) |
| |
| #endif /* _COMMON_MINI_CLIST_H */ |