* Used by for-like iteration macros in urcu/wfqueue.h:
* __cds_wfcq_for_each_blocking()
* __cds_wfcq_for_each_blocking_safe()
+ *
+ * Returns NULL if queue is empty, first node otherwise.
*/
static inline struct cds_wfcq_node *
___cds_wfcq_first_blocking(struct cds_wfcq_head *head,
* Used by for-like iteration macros in urcu/wfqueue.h:
* __cds_wfcq_for_each_blocking()
* __cds_wfcq_for_each_blocking_safe()
+ *
+ * Returns NULL if reached end of queue, non-NULL next queue node
+ * otherwise.
*/
static inline struct cds_wfcq_node *
___cds_wfcq_next_blocking(struct cds_wfcq_head *head,
}
static inline struct cds_wfcq_node *
-___cds_wfcq_dequeue(struct cds_wfcq_head *head,
+___cds_wfcq_dequeue_with_state(struct cds_wfcq_head *head,
struct cds_wfcq_tail *tail,
+ int *state,
int blocking)
{
struct cds_wfcq_node *node, *next;
- if (_cds_wfcq_empty(head, tail))
+ if (state)
+ *state = 0;
+
+ if (_cds_wfcq_empty(head, tail)) {
return NULL;
+ }
node = ___cds_wfcq_node_sync_next(&head->node, blocking);
- if (!blocking && node == CDS_WFCQ_WOULDBLOCK)
+ if (!blocking && node == CDS_WFCQ_WOULDBLOCK) {
return CDS_WFCQ_WOULDBLOCK;
+ }
if ((next = CMM_LOAD_SHARED(node->next)) == NULL) {
/*
* content.
*/
_cds_wfcq_node_init(&head->node);
- if (uatomic_cmpxchg(&tail->p, node, &head->node) == node)
+ if (uatomic_cmpxchg(&tail->p, node, &head->node) == node) {
+ if (state)
+ *state |= CDS_WFCQ_STATE_LAST;
return node;
+ }
next = ___cds_wfcq_node_sync_next(node, blocking);
/*
* In nonblocking mode, if we would need to block to
}
/*
- * __cds_wfcq_dequeue_blocking: dequeue a node from the queue.
+ * __cds_wfcq_dequeue_with_state_blocking: dequeue node from queue, with state.
*
* Content written into the node before enqueue is guaranteed to be
* consistent, but no other memory ordering is ensured.
* caller.
*/
static inline struct cds_wfcq_node *
+___cds_wfcq_dequeue_with_state_blocking(struct cds_wfcq_head *head,
+ struct cds_wfcq_tail *tail, int *state)
+{
+ return ___cds_wfcq_dequeue_with_state(head, tail, state, 1);
+}
+
+/*
+ * ___cds_wfcq_dequeue_blocking: dequeue node from queue.
+ *
+ * Same as __cds_wfcq_dequeue_with_state_blocking, but without saving
+ * state.
+ */
+static inline struct cds_wfcq_node *
___cds_wfcq_dequeue_blocking(struct cds_wfcq_head *head,
struct cds_wfcq_tail *tail)
{
- return ___cds_wfcq_dequeue(head, tail, 1);
+ return ___cds_wfcq_dequeue_with_state_blocking(head, tail, NULL);
}
/*
- * __cds_wfcq_dequeue_nonblocking: dequeue a node from a wait-free queue.
+ * __cds_wfcq_dequeue_with_state_nonblocking: dequeue node, with state.
*
* Same as __cds_wfcq_dequeue_blocking, but returns CDS_WFCQ_WOULDBLOCK
* if it needs to block.
*/
static inline struct cds_wfcq_node *
+___cds_wfcq_dequeue_with_state_nonblocking(struct cds_wfcq_head *head,
+ struct cds_wfcq_tail *tail, int *state)
+{
+ return ___cds_wfcq_dequeue_with_state(head, tail, state, 0);
+}
+
+/*
+ * ___cds_wfcq_dequeue_nonblocking: dequeue node from queue.
+ *
+ * Same as __cds_wfcq_dequeue_with_state_nonblocking, but without saving
+ * state.
+ */
+static inline struct cds_wfcq_node *
___cds_wfcq_dequeue_nonblocking(struct cds_wfcq_head *head,
struct cds_wfcq_tail *tail)
{
- return ___cds_wfcq_dequeue(head, tail, 0);
+ return ___cds_wfcq_dequeue_with_state_nonblocking(head, tail, NULL);
}
/*
}
/*
- * cds_wfcq_dequeue_blocking: dequeue a node from a wait-free queue.
+ * cds_wfcq_dequeue_with_state_blocking: dequeue a node from a wait-free queue.
*
* Content written into the node before enqueue is guaranteed to be
* consistent, but no other memory ordering is ensured.
- * Mutual exlusion with cds_wfcq_splice_blocking and dequeue lock is
+ * Mutual exclusion with cds_wfcq_splice_blocking and dequeue lock is
* ensured.
* It is valid to reuse and free a dequeued node immediately.
*/
static inline struct cds_wfcq_node *
-_cds_wfcq_dequeue_blocking(struct cds_wfcq_head *head,
- struct cds_wfcq_tail *tail)
+_cds_wfcq_dequeue_with_state_blocking(struct cds_wfcq_head *head,
+ struct cds_wfcq_tail *tail, int *state)
{
struct cds_wfcq_node *retval;
_cds_wfcq_dequeue_lock(head, tail);
- retval = ___cds_wfcq_dequeue_blocking(head, tail);
+ retval = ___cds_wfcq_dequeue_with_state_blocking(head, tail, state);
_cds_wfcq_dequeue_unlock(head, tail);
return retval;
}
+/*
+ * cds_wfcq_dequeue_blocking: dequeue node from queue.
+ *
+ * Same as cds_wfcq_dequeue_blocking, but without saving state.
+ */
+static inline struct cds_wfcq_node *
+_cds_wfcq_dequeue_blocking(struct cds_wfcq_head *head,
+ struct cds_wfcq_tail *tail)
+{
+ return _cds_wfcq_dequeue_with_state_blocking(head, tail, NULL);
+}
+
/*
* cds_wfcq_splice_blocking: enqueue all src_q nodes at the end of dest_q.
*
* dest_q must be already initialized.
* Content written into the node before enqueue is guaranteed to be
* consistent, but no other memory ordering is ensured.
- * Mutual exlusion with cds_wfcq_dequeue_blocking and dequeue lock is
+ * Mutual exclusion with cds_wfcq_dequeue_blocking and dequeue lock is
* ensured.
* Returns enum cds_wfcq_ret which indicates the state of the src or
* dest queue. Never returns CDS_WFCQ_RET_WOULDBLOCK.
projects / urcu.git / blobdiff