| /* Ring definitions. */ |
| #define qr(a_type) \ |
| struct { \ |
| a_type *qre_next; \ |
| a_type *qre_prev; \ |
| } |
| |
| /* Ring functions. */ |
| #define qr_new(a_qr, a_field) do { \ |
| (a_qr)->a_field.qre_next = (a_qr); \ |
| (a_qr)->a_field.qre_prev = (a_qr); \ |
| } while (0) |
| |
| #define qr_next(a_qr, a_field) ((a_qr)->a_field.qre_next) |
| |
| #define qr_prev(a_qr, a_field) ((a_qr)->a_field.qre_prev) |
| |
| #define qr_before_insert(a_qrelm, a_qr, a_field) do { \ |
| (a_qr)->a_field.qre_prev = (a_qrelm)->a_field.qre_prev; \ |
| (a_qr)->a_field.qre_next = (a_qrelm); \ |
| (a_qr)->a_field.qre_prev->a_field.qre_next = (a_qr); \ |
| (a_qrelm)->a_field.qre_prev = (a_qr); \ |
| } while (0) |
| |
| #define qr_after_insert(a_qrelm, a_qr, a_field) \ |
| do \ |
| { \ |
| (a_qr)->a_field.qre_next = (a_qrelm)->a_field.qre_next; \ |
| (a_qr)->a_field.qre_prev = (a_qrelm); \ |
| (a_qr)->a_field.qre_next->a_field.qre_prev = (a_qr); \ |
| (a_qrelm)->a_field.qre_next = (a_qr); \ |
| } while (0) |
| |
| #define qr_meld(a_qr_a, a_qr_b, a_field) do { \ |
| void *t; \ |
| (a_qr_a)->a_field.qre_prev->a_field.qre_next = (a_qr_b); \ |
| (a_qr_b)->a_field.qre_prev->a_field.qre_next = (a_qr_a); \ |
| t = (a_qr_a)->a_field.qre_prev; \ |
| (a_qr_a)->a_field.qre_prev = (a_qr_b)->a_field.qre_prev; \ |
| (a_qr_b)->a_field.qre_prev = t; \ |
| } while (0) |
| |
| /* qr_meld() and qr_split() are functionally equivalent, so there's no need to |
| * have two copies of the code. */ |
| #define qr_split(a_qr_a, a_qr_b, a_field) \ |
| qr_meld((a_qr_a), (a_qr_b), a_field) |
| |
| #define qr_remove(a_qr, a_field) do { \ |
| (a_qr)->a_field.qre_prev->a_field.qre_next \ |
| = (a_qr)->a_field.qre_next; \ |
| (a_qr)->a_field.qre_next->a_field.qre_prev \ |
| = (a_qr)->a_field.qre_prev; \ |
| (a_qr)->a_field.qre_next = (a_qr); \ |
| (a_qr)->a_field.qre_prev = (a_qr); \ |
| } while (0) |
| |
| #define qr_foreach(var, a_qr, a_field) \ |
| for ((var) = (a_qr); \ |
| (var) != NULL; \ |
| (var) = (((var)->a_field.qre_next != (a_qr)) \ |
| ? (var)->a_field.qre_next : NULL)) |
| |
| #define qr_reverse_foreach(var, a_qr, a_field) \ |
| for ((var) = ((a_qr) != NULL) ? qr_prev(a_qr, a_field) : NULL; \ |
| (var) != NULL; \ |
| (var) = (((var) != (a_qr)) \ |
| ? (var)->a_field.qre_prev : NULL)) |