* enqueue/dequeue are expected from many CPUs. This eliminates
* false-sharing between enqueue and dequeue.
*/
+struct __cds_wfcq_head {
+ struct cds_wfcq_node node;
+};
+
struct cds_wfcq_head {
struct cds_wfcq_node node;
pthread_mutex_t lock;
};
+/*
+ * The transparent union allows calling functions that work on both
+ * struct cds_wfcq_head and struct __cds_wfcq_head on any of those two
+ * types.
+ */
+typedef union {
+ struct __cds_wfcq_head *_h;
+ struct cds_wfcq_head *h;
+} __attribute__((__transparent_union__)) cds_wfcq_head_ptr_t;
+
struct cds_wfcq_tail {
struct cds_wfcq_node *p;
};
extern void cds_wfcq_init(struct cds_wfcq_head *head,
struct cds_wfcq_tail *tail);
+/*
+ * __cds_wfcq_init: initialize wait-free queue.
+ */
+extern void __cds_wfcq_init(struct __cds_wfcq_head *head,
+ struct cds_wfcq_tail *tail);
+
/*
* cds_wfcq_empty: return whether wait-free queue is empty.
*
* No memory barrier is issued. No mutual exclusion is required.
*/
-extern bool cds_wfcq_empty(struct cds_wfcq_head *head,
+extern bool cds_wfcq_empty(cds_wfcq_head_ptr_t head,
struct cds_wfcq_tail *tail);
/*
* Returns false if the queue was empty prior to adding the node.
* Returns true otherwise.
*/
-extern bool cds_wfcq_enqueue(struct cds_wfcq_head *head,
+extern bool cds_wfcq_enqueue(cds_wfcq_head_ptr_t head,
struct cds_wfcq_tail *tail,
struct cds_wfcq_node *node);
* ensured.
*
* Returns enum cds_wfcq_ret which indicates the state of the src or
- * dest queue. Cannot block.
+ * dest queue.
*/
extern enum cds_wfcq_ret cds_wfcq_splice_blocking(
struct cds_wfcq_head *dest_q_head,
* caller.
*/
extern struct cds_wfcq_node *__cds_wfcq_dequeue_blocking(
- struct cds_wfcq_head *head,
+ cds_wfcq_head_ptr_t head,
struct cds_wfcq_tail *tail);
/*
* last node of the queue into state (CDS_WFCQ_STATE_LAST).
*/
extern struct cds_wfcq_node *__cds_wfcq_dequeue_with_state_blocking(
- struct cds_wfcq_head *head,
+ cds_wfcq_head_ptr_t head,
struct cds_wfcq_tail *tail,
int *state);
* if it needs to block.
*/
extern struct cds_wfcq_node *__cds_wfcq_dequeue_nonblocking(
- struct cds_wfcq_head *head,
+ cds_wfcq_head_ptr_t head,
struct cds_wfcq_tail *tail);
/*
* the last node of the queue into state (CDS_WFCQ_STATE_LAST).
*/
extern struct cds_wfcq_node *__cds_wfcq_dequeue_with_state_nonblocking(
- struct cds_wfcq_head *head,
+ cds_wfcq_head_ptr_t head,
struct cds_wfcq_tail *tail,
int *state);
* dest queue. Never returns CDS_WFCQ_RET_WOULDBLOCK.
*/
extern enum cds_wfcq_ret __cds_wfcq_splice_blocking(
- struct cds_wfcq_head *dest_q_head,
+ cds_wfcq_head_ptr_t dest_q_head,
struct cds_wfcq_tail *dest_q_tail,
- struct cds_wfcq_head *src_q_head,
+ cds_wfcq_head_ptr_t src_q_head,
struct cds_wfcq_tail *src_q_tail);
/*
* CDS_WFCQ_RET_WOULDBLOCK if it needs to block.
*/
extern enum cds_wfcq_ret __cds_wfcq_splice_nonblocking(
- struct cds_wfcq_head *dest_q_head,
+ cds_wfcq_head_ptr_t dest_q_head,
struct cds_wfcq_tail *dest_q_tail,
- struct cds_wfcq_head *src_q_head,
+ cds_wfcq_head_ptr_t src_q_head,
struct cds_wfcq_tail *src_q_tail);
/*
* Returns NULL if queue is empty, first node otherwise.
*/
extern struct cds_wfcq_node *__cds_wfcq_first_blocking(
- struct cds_wfcq_head *head,
+ cds_wfcq_head_ptr_t head,
struct cds_wfcq_tail *tail);
/*
* it needs to block.
*/
extern struct cds_wfcq_node *__cds_wfcq_first_nonblocking(
- struct cds_wfcq_head *head,
+ cds_wfcq_head_ptr_t head,
struct cds_wfcq_tail *tail);
/*
* otherwise.
*/
extern struct cds_wfcq_node *__cds_wfcq_next_blocking(
- struct cds_wfcq_head *head,
+ cds_wfcq_head_ptr_t head,
struct cds_wfcq_tail *tail,
struct cds_wfcq_node *node);
* it needs to block.
*/
extern struct cds_wfcq_node *__cds_wfcq_next_nonblocking(
- struct cds_wfcq_head *head,
+ cds_wfcq_head_ptr_t head,
struct cds_wfcq_tail *tail,
struct cds_wfcq_node *node);
/*
* __cds_wfcq_for_each_blocking: Iterate over all nodes in a queue,
* without dequeuing them.
- * @head: head of the queue (struct cds_wfcq_head pointer).
+ * @head: head of the queue (struct cds_wfcq_head or __cds_wfcq_head pointer).
* @tail: tail of the queue (struct cds_wfcq_tail pointer).
* @node: iterator on the queue (struct cds_wfcq_node pointer).
*
/*
* __cds_wfcq_for_each_blocking_safe: Iterate over all nodes in a queue,
* without dequeuing them. Safe against deletion.
- * @head: head of the queue (struct cds_wfcq_head pointer).
+ * @head: head of the queue (struct cds_wfcq_head or __cds_wfcq_head pointer).
* @tail: tail of the queue (struct cds_wfcq_tail pointer).
* @node: iterator on the queue (struct cds_wfcq_node pointer).
* @n: struct cds_wfcq_node pointer holding the next pointer (used