From 945d9c7530dd22a7a500dd8833836d6054a17ab9 Mon Sep 17 00:00:00 2001 From: "Emilio G. Cota" Date: Sun, 19 Aug 2018 05:13:28 -0400 Subject: [PATCH] rcu_queue: add RCU QTAILQ Signed-off-by: Emilio G. Cota Message-Id: <20180819091335.22863-5-cota@braap.org> Signed-off-by: Paolo Bonzini --- include/qemu/rcu_queue.h | 66 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) diff --git a/include/qemu/rcu_queue.h b/include/qemu/rcu_queue.h index e0395c989a..904b3372dc 100644 --- a/include/qemu/rcu_queue.h +++ b/include/qemu/rcu_queue.h @@ -193,6 +193,72 @@ extern "C" { (var) && ((next) = atomic_rcu_read(&(var)->field.sqe_next), 1); \ (var) = (next)) +/* + * RCU tail queue + */ + +/* Tail queue access methods */ +#define QTAILQ_EMPTY_RCU(head) (atomic_read(&(head)->tqh_first) == NULL) +#define QTAILQ_FIRST_RCU(head) atomic_rcu_read(&(head)->tqh_first) +#define QTAILQ_NEXT_RCU(elm, field) atomic_rcu_read(&(elm)->field.tqe_next) + +/* Tail queue functions */ +#define QTAILQ_INSERT_HEAD_RCU(head, elm, field) do { \ + (elm)->field.tqe_next = (head)->tqh_first; \ + if ((elm)->field.tqe_next != NULL) { \ + (head)->tqh_first->field.tqe_prev = &(elm)->field.tqe_next; \ + } else { \ + (head)->tqh_last = &(elm)->field.tqe_next; \ + } \ + atomic_rcu_set(&(head)->tqh_first, (elm)); \ + (elm)->field.tqe_prev = &(head)->tqh_first; \ +} while (/*CONSTCOND*/0) + +#define QTAILQ_INSERT_TAIL_RCU(head, elm, field) do { \ + (elm)->field.tqe_next = NULL; \ + (elm)->field.tqe_prev = (head)->tqh_last; \ + atomic_rcu_set((head)->tqh_last, (elm)); \ + (head)->tqh_last = &(elm)->field.tqe_next; \ +} while (/*CONSTCOND*/0) + +#define QTAILQ_INSERT_AFTER_RCU(head, listelm, elm, field) do { \ + (elm)->field.tqe_next = (listelm)->field.tqe_next; \ + if ((elm)->field.tqe_next != NULL) { \ + (elm)->field.tqe_next->field.tqe_prev = &(elm)->field.tqe_next; \ + } else { \ + (head)->tqh_last = &(elm)->field.tqe_next; \ + } \ + atomic_rcu_set(&(listelm)->field.tqe_next, (elm)); \ + (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ +} while (/*CONSTCOND*/0) + +#define QTAILQ_INSERT_BEFORE_RCU(listelm, elm, field) do { \ + (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ + (elm)->field.tqe_next = (listelm); \ + atomic_rcu_set((listelm)->field.tqe_prev, (elm)); \ + (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ + } while (/*CONSTCOND*/0) + +#define QTAILQ_REMOVE_RCU(head, elm, field) do { \ + if (((elm)->field.tqe_next) != NULL) { \ + (elm)->field.tqe_next->field.tqe_prev = (elm)->field.tqe_prev; \ + } else { \ + (head)->tqh_last = (elm)->field.tqe_prev; \ + } \ + atomic_set((elm)->field.tqe_prev, (elm)->field.tqe_next); \ + (elm)->field.tqe_prev = NULL; \ +} while (/*CONSTCOND*/0) + +#define QTAILQ_FOREACH_RCU(var, head, field) \ + for ((var) = atomic_rcu_read(&(head)->tqh_first); \ + (var); \ + (var) = atomic_rcu_read(&(var)->field.tqe_next)) + +#define QTAILQ_FOREACH_SAFE_RCU(var, head, field, next) \ + for ((var) = atomic_rcu_read(&(head)->tqh_first); \ + (var) && ((next) = atomic_rcu_read(&(var)->field.tqe_next), 1); \ + (var) = (next)) + #ifdef __cplusplus } #endif -- 2.11.4.GIT