From 13d8ef7dda07aaf199db2dc2611c22b1089dec34 Mon Sep 17 00:00:00 2001 From: "Emilio G. Cota" Date: Sun, 19 Aug 2018 05:13:27 -0400 Subject: rcu_queue: add RCU QSIMPLEQ Signed-off-by: Emilio G. Cota Message-Id: <20180819091335.22863-4-cota@braap.org> Signed-off-by: Paolo Bonzini --- include/qemu/rcu_queue.h | 65 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) (limited to 'include/qemu') diff --git a/include/qemu/rcu_queue.h b/include/qemu/rcu_queue.h index 6881ea5..e0395c9 100644 --- a/include/qemu/rcu_queue.h +++ b/include/qemu/rcu_queue.h @@ -128,6 +128,71 @@ extern "C" { ((next_var) = atomic_rcu_read(&(var)->field.le_next), 1); \ (var) = (next_var)) +/* + * RCU simple queue + */ + +/* Simple queue access methods */ +#define QSIMPLEQ_EMPTY_RCU(head) (atomic_read(&(head)->sqh_first) == NULL) +#define QSIMPLEQ_FIRST_RCU(head) atomic_rcu_read(&(head)->sqh_first) +#define QSIMPLEQ_NEXT_RCU(elm, field) atomic_rcu_read(&(elm)->field.sqe_next) + +/* Simple queue functions */ +#define QSIMPLEQ_INSERT_HEAD_RCU(head, elm, field) do { \ + (elm)->field.sqe_next = (head)->sqh_first; \ + if ((elm)->field.sqe_next == NULL) { \ + (head)->sqh_last = &(elm)->field.sqe_next; \ + } \ + atomic_rcu_set(&(head)->sqh_first, (elm)); \ +} while (/*CONSTCOND*/0) + +#define QSIMPLEQ_INSERT_TAIL_RCU(head, elm, field) do { \ + (elm)->field.sqe_next = NULL; \ + atomic_rcu_set((head)->sqh_last, (elm)); \ + (head)->sqh_last = &(elm)->field.sqe_next; \ +} while (/*CONSTCOND*/0) + +#define QSIMPLEQ_INSERT_AFTER_RCU(head, listelm, elm, field) do { \ + (elm)->field.sqe_next = (listelm)->field.sqe_next; \ + if ((elm)->field.sqe_next == NULL) { \ + (head)->sqh_last = &(elm)->field.sqe_next; \ + } \ + atomic_rcu_set(&(listelm)->field.sqe_next, (elm)); \ +} while (/*CONSTCOND*/0) + +#define QSIMPLEQ_REMOVE_HEAD_RCU(head, field) do { \ + atomic_set(&(head)->sqh_first, (head)->sqh_first->field.sqe_next); \ + if ((head)->sqh_first == NULL) { \ + (head)->sqh_last = &(head)->sqh_first; \ + } \ +} while (/*CONSTCOND*/0) + +#define QSIMPLEQ_REMOVE_RCU(head, elm, type, field) do { \ + if ((head)->sqh_first == (elm)) { \ + QSIMPLEQ_REMOVE_HEAD_RCU((head), field); \ + } else { \ + struct type *curr = (head)->sqh_first; \ + while (curr->field.sqe_next != (elm)) { \ + curr = curr->field.sqe_next; \ + } \ + atomic_set(&curr->field.sqe_next, \ + curr->field.sqe_next->field.sqe_next); \ + if (curr->field.sqe_next == NULL) { \ + (head)->sqh_last = &(curr)->field.sqe_next; \ + } \ + } \ +} while (/*CONSTCOND*/0) + +#define QSIMPLEQ_FOREACH_RCU(var, head, field) \ + for ((var) = atomic_rcu_read(&(head)->sqh_first); \ + (var); \ + (var) = atomic_rcu_read(&(var)->field.sqe_next)) + +#define QSIMPLEQ_FOREACH_SAFE_RCU(var, head, field, next) \ + for ((var) = atomic_rcu_read(&(head)->sqh_first); \ + (var) && ((next) = atomic_rcu_read(&(var)->field.sqe_next), 1); \ + (var) = (next)) + #ifdef __cplusplus } #endif -- cgit v1.1