/* * Copyright (c) 2019 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * @file * @brief Circular doubly linked list with head sentinel. * List entries are allocated out of a "supporting" pool and all pool entries * must contain a list anchor struct for each list they pertain to. */ #ifndef SRC_VPPINFRA_CLIB_LLIST_H_ #define SRC_VPPINFRA_CLIB_LLIST_H_ #include <vppinfra/types.h> #include <vppinfra/pool.h> typedef u32 clib_llist_index_t; typedef struct clib_llist_anchor { clib_llist_index_t prev; clib_llist_index_t next; } clib_llist_anchor_t; #define CLIB_LLIST_INVALID_INDEX ((u32)~0) /** * Local variable naming macro. */ #define _ll_var(v) _llist_##v /** * Local macros to grab llist anchor next and prev from pool entry */ #define _lnext(E,name) ((E)->name).next #define _lprev(E,name) ((E)->name).prev /** * Get list entry index * * @param LP linked list pool * @param E pool entry * @return pool entry index */ #define clib_llist_entry_index(LP,E) ((E) - (LP)) /** * Get prev list entry index * * @param E pool entry * @name list anchor name * @return previous index */ #define clib_llist_prev_index(E,name) _lprev(E,name) /** * Get next list entry index * * @param E pool entry * @name list anchor name * @return next index */ #define clib_llist_next_index(E,name) _lnext(E,name) /** * Get next pool entry * * @param LP linked list pool * @param name list anchor name * @param E pool entry * @return next pool entry */ #define clib_llist_next(LP,name,E) pool_elt_at_index((LP),_lnext((E),name)) /** * Get previous pool entry * * @param LP linked list pool * @param name list anchor name * @param E pool entry * @return previous pool entry */ #define clib_llist_prev(LP,name,E) pool_elt_at_index((LP),_lprev((E),name)) /** * Initialize element in llist for entry * * @param LP linked list pool * @param name list anchor name * @param E entry whose ll anchor is to be initialized */ #define clib_llist_anchor_init(LP,name,E) \ do { \ _lprev ((E),name) = clib_llist_entry_index ((LP), (E)); \ _lnext ((E),name) = _lprev ((E),name); \ } while (0) /** * Initialize llist head * * @param LP linked list pool * @param name list anchor name */ #define clib_llist_make_head(LP,name) \ ({ \ typeof (LP) _ll_var (head); \ pool_get_zero ((LP), _ll_var (head)); \ clib_llist_anchor_init ((LP),name,_ll_var (head)); \ clib_llist_entry_index ((LP), _ll_var (head)); \ }) /** * Check is list is empty * * @param LP linked list pool * @param name list anchor name * @param H list head * @return 1 if sentinel is the only node part of the list, 0 otherwise */ #define clib_llist_is_empty(LP,name,H) \ (clib_llist_entry_index (LP,H) == (H)->name.next) /** * Check if element is linked in a list * * @param E list element * @param name list anchor name */ #define clib_llist_elt_is_linked(E,name) \ ((E)->name.next != CLIB_LLIST_INVALID_INDEX \ && (E)->name.prev != CLIB_LLIST_INVALID_INDEX) /** * Insert entry between previous and next * * Internal use. * * @param LP linked list pool * @param name list anchor name * @param E new entry * @param P previous in list * @param N next in list */ #define _llist_insert(LP,name,E,P,N) \ do { \ _lprev (E,name) = _lprev(N,name); \ _lnext (E,name) = _lnext(P,name); \ _lprev ((N),name) = clib_llist_entry_index ((LP),(E)); \ _lnext ((P),name) = clib_llist_entry_index ((LP),(E)); \ } while (0) /** * Insert entry after previous * * @param LP linked list pool * @param name list anchor name * @param E new entry * @param P previous in list */ #define clib_llist_insert(LP,name,E,P) \ do { \ typeof (LP) _ll_var (N) = clib_llist_next (LP,name,P); \ _llist_insert ((LP),name,(E),(P), _ll_var (N)); \ } while (0) /** * Add entry after head * * @param LP linked list pool * @param name list anchor name * @param E new entry * @param H list head */ #define clib_llist_add(LP,name,E,H) clib_llist_insert ((LP),name,(E),(H)) /** * Add entry after tail * * @param LP linked list pool * @param name list anchor name * @param E new entry * @param H list head */ #define clib_llist_add_tail(LP,name,E,H) \ do { \ typeof (LP) _ll_var (P) = clib_llist_prev ((LP),name,(H)); \ _llist_insert ((LP),name,(E),_ll_var (P),(H)); \ } while (0) /** * Remove entry from list * * @param LP linked list pool * @param name list anchor name * @param E entry to be removed */ #define clib_llist_remove(LP,name,E) \ do { \ ASSERT ((E) != clib_llist_next (LP,name,E));/* don't remove sentinel */\ ASSERT (_lnext (E,name) != CLIB_LLIST_INVALID_INDEX); \ ASSERT (_lprev (E,name) != CLIB_LLIST_INVALID_INDEX); \ typeof (LP) _ll_var (P) = clib_llist_prev ((LP),name,E); \ typeof (LP) _ll_var (N) = clib_llist_next ((LP),name,E); \ _lnext (_ll_var (P),name) = _lnext (E,name); \ _lprev (_ll_var (N),name) = _lprev (E,name); \ _lnext (E,name) = _lprev (E,name) = CLIB_LLIST_INVALID_INDEX; \ }while (0) /** * Removes and returns the first element in the list. * * The element is not freed. It's the responsability of the caller to * free it. * * @param LP linked list pool * @param name list anchor name * @param E storage the first entry * @param H list head entry */ #define clib_llist_pop_first(LP,name,E,H) \ do { \ E = clib_llist_next (LP,name,H); \ clib_llist_remove (LP,name,E); \ } while (0) /** * Splice two lists at a given position * * List spliced into destination list is left with 0 entries, i.e., head * is made to point to itself. * * @param LP linked list pool * @param name list anchor name * @param P position in destination where source list is spliced * @param H head of source list that will be spliced into destination */ #define clib_llist_splice(LP,name,P,H) \ do { \ typeof (LP) _ll_var (fe) = clib_llist_next (LP,name,H); \ if (_ll_var (fe) != (H)) \ { \ typeof (LP) _ll_var (le) = clib_llist_prev (LP,name,H); \ typeof (LP) _ll_var (ne) = clib_llist_next (LP,name,P); \ _lprev (_ll_var (fe),name) = clib_llist_entry_index(LP,P); \ _lnext (_ll_var (le),name) = clib_llist_entry_index(LP,_ll_var (ne));\ _lnext (P,name) = clib_llist_entry_index (LP,_ll_var (fe)); \ _lprev (_ll_var (ne),name) = clib_llist_entry_index(LP,_ll_var (le));\ _lnext (H,name) = clib_llist_entry_index(LP,H); \ _lprev (H,name) = _lnext (H,name); \ } \ } while (0) /** * Walk list starting at head * * @param LP linked list pool * @param name list anchor name * @param H head entry * @param E entry iterator * @param body code to be executed */ #define clib_llist_foreach(LP,name,H,E,body) \ do { \ typeof (LP) _ll_var (n); \ (E) = clib_llist_next (LP,name,H); \ while (E != H) \ { \ _ll_var (n) = clib_llist_next (LP,name,E); \ do { body; } while (0); \ (E) = _ll_var (n); \ } \ } while (0) /** * Walk list starting at head safe * * @param LP linked list pool * @param name list anchor name * @param HI head index * @param EI entry index iterator * @param body code to be executed */ #define clib_llist_foreach_safe(LP,name,H,E,body) \ do { \ clib_llist_index_t _ll_var (HI) = clib_llist_entry_index (LP, H); \ clib_llist_index_t _ll_var (EI), _ll_var (NI); \ _ll_var (EI) = _lnext ((H),name); \ while (_ll_var (EI) != _ll_var (HI)) \ { \ (E) = pool_elt_at_index (LP, _ll_var (EI)); \ _ll_var (NI) = _lnext ((E),name); \ do { body; } while (0); \ _ll_var (EI) = _ll_var (NI); \ } \ } while (0) /** * Walk list starting at head in reverse order * * @param LP linked list pool * @param name list anchor name * @param H head entry * @param E entry iterator * @param body code to be executed */ #define clib_llist_foreach_reverse(LP,name,H,E,body) \ do { \ typeof (LP) _ll_var (p); \ (E) = clib_llist_prev (LP,name,H); \ while (E != H) \ { \ _ll_var (p) = clib_llist_prev (LP,name,E); \ do { body; } while (0); \ (E) = _ll_var (p); \ } \ } while (0) #endif /* SRC_VPPINFRA_CLIB_LLIST_H_ */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */