1 /* 2 * %CopyrightBegin% 3 * 4 * Copyright Ericsson AB 2013-2016. All Rights Reserved. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 * 18 * %CopyrightEnd% 19 */ 20 21 #ifndef ERL_UTIL_QUEUE_H_ 22 #define ERL_UTIL_QUEUE_H_ 23 24 #define erts_circleq_head(Q) ((Q)->next) 25 #define erts_circleq_tail(Q) ((Q)->prev) 26 #define erts_circleq_next(Q) ((Q)->next) 27 #define erts_circleq_prev(Q) ((Q)->prev) 28 #define erts_circleq_is_empty(Q) ((Q)->next == (void *)(Q)) 29 30 #define erts_circleq_remove(N) \ 31 do { \ 32 (N)->next->prev = (N)->prev; \ 33 (N)->prev->next = (N)->next; \ 34 (N)->next = (N); \ 35 (N)->prev = (N); \ 36 } while(0) 37 38 #define erts_circleq_pop_head(Q, N) \ 39 do { \ 40 (N) = (Q)->next; \ 41 (N)->next->prev = (N)->prev; \ 42 (N)->prev->next = (N)->next; \ 43 (N)->next = (N); \ 44 (N)->prev = (N); \ 45 } while(0) 46 47 #define erts_circleq_pop_tail(Q, N) \ 48 do { \ 49 (N) = (Q)->prev; \ 50 (N)->next->prev = (N)->prev; \ 51 (N)->prev->next = (N)->next; \ 52 (N)->next = (N); \ 53 (N)->prev = (N); \ 54 } while(0) 55 56 #define erts_circleq_push_head(Q, N) \ 57 do { \ 58 (N)->next = (Q)->next; \ 59 (N)->prev = (void *)(Q); \ 60 (Q)->next->prev = (N); \ 61 (Q)->next = (N); \ 62 } while(0) 63 64 #define erts_circleq_push_tail(Q, N) \ 65 do { \ 66 (N)->prev = (Q)->prev; \ 67 (N)->next = (void *)(Q); \ 68 (Q)->prev->next = (N); \ 69 (Q)->prev = (N); \ 70 } while(0) 71 72 #define erts_circleq_foreach(V, Q) \ 73 for ((V) = (Q)->next; (V) != (const void *)(Q); (V) = (V)->next) 74 75 #define erts_circleq_foreach_reverse(V, Q) \ 76 for ((V) = (Q)->prev; (V) != (const void *)(Q); (V) = (V)->prev) 77 78 #endif 79