X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu%2Fstatic%2Fwfcqueue.h;h=4ababbf0ee8e99974f585c1f3b236381a8f60b3c;hp=99643be98c393310bc36d591262fcddd5f0227af;hb=4d0d7cbccec1c35f544f6fee24b762e398a2f0b9;hpb=f878b49ebb78010f4f9466d3512a7e88787812b2

diff --git a/urcu/static/wfcqueue.h b/urcu/static/wfcqueue.h
index 99643be..4ababbf 100644
--- a/urcu/static/wfcqueue.h
+++ b/urcu/static/wfcqueue.h
@@ -106,6 +106,17 @@ static inline void _cds_wfcq_init(struct cds_wfcq_head *head,
 	assert(!ret);
 }
 
+/*
+ * __cds_wfcq_init: initialize wait-free queue.
+ */
+static inline void ___cds_wfcq_init(struct __cds_wfcq_head *head,
+		struct cds_wfcq_tail *tail)
+{
+	/* Set queue head and tail */
+	_cds_wfcq_node_init(&head->node);
+	tail->p = &head->node;
+}
+
 /*
  * cds_wfcq_empty: return whether wait-free queue is empty.
  *
@@ -118,9 +129,10 @@ static inline void _cds_wfcq_init(struct cds_wfcq_head *head,
  * make a queue appear empty if an enqueuer is preempted for a long time
  * between xchg() and setting the previous node's next pointer.
  */
-static inline bool _cds_wfcq_empty(struct cds_wfcq_head *head,
+static inline bool _cds_wfcq_empty(cds_wfcq_head_ptr_t u_head,
 		struct cds_wfcq_tail *tail)
 {
+	struct __cds_wfcq_head *head = u_head._h;
 	/*
 	 * Queue is empty if no node is pointed by head->node.next nor
 	 * tail->p. Even though the tail->p check is sufficient to find
@@ -150,11 +162,12 @@ static inline void _cds_wfcq_dequeue_unlock(struct cds_wfcq_head *head,
 	assert(!ret);
 }
 
-static inline bool ___cds_wfcq_append(struct cds_wfcq_head *head,
+static inline bool ___cds_wfcq_append(cds_wfcq_head_ptr_t u_head,
 		struct cds_wfcq_tail *tail,
 		struct cds_wfcq_node *new_head,
 		struct cds_wfcq_node *new_tail)
 {
+	struct __cds_wfcq_head *head = u_head._h;
 	struct cds_wfcq_node *old_tail;
 
 	/*
@@ -190,7 +203,7 @@ static inline bool ___cds_wfcq_append(struct cds_wfcq_head *head,
  * Returns false if the queue was empty prior to adding the node.
  * Returns true otherwise.
  */
-static inline bool _cds_wfcq_enqueue(struct cds_wfcq_head *head,
+static inline bool _cds_wfcq_enqueue(cds_wfcq_head_ptr_t head,
 		struct cds_wfcq_tail *tail,
 		struct cds_wfcq_node *new_tail)
 {
@@ -208,7 +221,7 @@ ___cds_wfcq_busy_wait(int *attempt, int blocking)
 	if (!blocking)
 		return 1;
 	if (++(*attempt) >= WFCQ_ADAPT_ATTEMPTS) {
-		poll(NULL, 0, WFCQ_WAIT);	/* Wait for 10ms */
+		(void) poll(NULL, 0, WFCQ_WAIT);	/* Wait for 10ms */
 		*attempt = 0;
 	} else {
 		caa_cpu_relax();
@@ -237,13 +250,14 @@ ___cds_wfcq_node_sync_next(struct cds_wfcq_node *node, int blocking)
 }
 
 static inline struct cds_wfcq_node *
-___cds_wfcq_first(struct cds_wfcq_head *head,
+___cds_wfcq_first(cds_wfcq_head_ptr_t u_head,
 		struct cds_wfcq_tail *tail,
 		int blocking)
 {
+	struct __cds_wfcq_head *head = u_head._h;
 	struct cds_wfcq_node *node;
 
-	if (_cds_wfcq_empty(head, tail))
+	if (_cds_wfcq_empty(__cds_wfcq_head_cast(head), tail))
 		return NULL;
 	node = ___cds_wfcq_node_sync_next(&head->node, blocking);
 	/* Load head->node.next before loading node's content */
@@ -262,9 +276,11 @@ ___cds_wfcq_first(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 queue is empty, first node otherwise.
  */
 static inline struct cds_wfcq_node *
-___cds_wfcq_first_blocking(struct cds_wfcq_head *head,
+___cds_wfcq_first_blocking(cds_wfcq_head_ptr_t head,
 		struct cds_wfcq_tail *tail)
 {
 	return ___cds_wfcq_first(head, tail, 1);
@@ -278,14 +294,14 @@ ___cds_wfcq_first_blocking(struct cds_wfcq_head *head,
  * it needs to block.
  */
 static inline struct cds_wfcq_node *
-___cds_wfcq_first_nonblocking(struct cds_wfcq_head *head,
+___cds_wfcq_first_nonblocking(cds_wfcq_head_ptr_t head,
 		struct cds_wfcq_tail *tail)
 {
 	return ___cds_wfcq_first(head, tail, 0);
 }
 
 static inline struct cds_wfcq_node *
-___cds_wfcq_next(struct cds_wfcq_head *head,
+___cds_wfcq_next(cds_wfcq_head_ptr_t head,
 		struct cds_wfcq_tail *tail,
 		struct cds_wfcq_node *node,
 		int blocking)
@@ -321,9 +337,12 @@ ___cds_wfcq_next(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,
+___cds_wfcq_next_blocking(cds_wfcq_head_ptr_t head,
 		struct cds_wfcq_tail *tail,
 		struct cds_wfcq_node *node)
 {
@@ -337,7 +356,7 @@ ___cds_wfcq_next_blocking(struct cds_wfcq_head *head,
  * it needs to block.
  */
 static inline struct cds_wfcq_node *
-___cds_wfcq_next_nonblocking(struct cds_wfcq_head *head,
+___cds_wfcq_next_nonblocking(cds_wfcq_head_ptr_t head,
 		struct cds_wfcq_tail *tail,
 		struct cds_wfcq_node *node)
 {
@@ -345,18 +364,25 @@ ___cds_wfcq_next_nonblocking(struct cds_wfcq_head *head,
 }
 
 static inline struct cds_wfcq_node *
-___cds_wfcq_dequeue(struct cds_wfcq_head *head,
+___cds_wfcq_dequeue_with_state(cds_wfcq_head_ptr_t u_head,
 		struct cds_wfcq_tail *tail,
+		int *state,
 		int blocking)
 {
+	struct __cds_wfcq_head *head = u_head._h;
 	struct cds_wfcq_node *node, *next;
 
-	if (_cds_wfcq_empty(head, tail))
+	if (state)
+		*state = 0;
+
+	if (_cds_wfcq_empty(__cds_wfcq_head_cast(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) {
 		/*
@@ -374,8 +400,11 @@ ___cds_wfcq_dequeue(struct cds_wfcq_head *head,
 		 * 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
@@ -399,7 +428,7 @@ ___cds_wfcq_dequeue(struct cds_wfcq_head *head,
 }
 
 /*
- * __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.
@@ -408,23 +437,49 @@ ___cds_wfcq_dequeue(struct cds_wfcq_head *head,
  * caller.
  */
 static inline struct cds_wfcq_node *
-___cds_wfcq_dequeue_blocking(struct cds_wfcq_head *head,
+___cds_wfcq_dequeue_with_state_blocking(cds_wfcq_head_ptr_t 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(cds_wfcq_head_ptr_t 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_nonblocking(struct cds_wfcq_head *head,
+___cds_wfcq_dequeue_with_state_nonblocking(cds_wfcq_head_ptr_t 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(cds_wfcq_head_ptr_t head,
 		struct cds_wfcq_tail *tail)
 {
-	return ___cds_wfcq_dequeue(head, tail, 0);
+	return ___cds_wfcq_dequeue_with_state_nonblocking(head, tail, NULL);
 }
 
 /*
@@ -439,12 +494,14 @@ ___cds_wfcq_dequeue_nonblocking(struct cds_wfcq_head *head,
  */
 static inline enum cds_wfcq_ret
 ___cds_wfcq_splice(
-		struct cds_wfcq_head *dest_q_head,
+		cds_wfcq_head_ptr_t u_dest_q_head,
 		struct cds_wfcq_tail *dest_q_tail,
-		struct cds_wfcq_head *src_q_head,
+		cds_wfcq_head_ptr_t u_src_q_head,
 		struct cds_wfcq_tail *src_q_tail,
 		int blocking)
 {
+	struct __cds_wfcq_head *dest_q_head = u_dest_q_head._h;
+	struct __cds_wfcq_head *src_q_head = u_src_q_head._h;
 	struct cds_wfcq_node *head, *tail;
 	int attempt = 0;
 
@@ -452,7 +509,7 @@ ___cds_wfcq_splice(
 	 * Initial emptiness check to speed up cases where queue is
 	 * empty: only require loads to check if queue is empty.
 	 */
-	if (_cds_wfcq_empty(src_q_head, src_q_tail))
+	if (_cds_wfcq_empty(__cds_wfcq_head_cast(src_q_head), src_q_tail))
 		return CDS_WFCQ_RET_SRC_EMPTY;
 
 	for (;;) {
@@ -482,7 +539,8 @@ ___cds_wfcq_splice(
 	 * Append the spliced content of src_q into dest_q. Does not
 	 * require mutual exclusion on dest_q (wait-free).
 	 */
-	if (___cds_wfcq_append(dest_q_head, dest_q_tail, head, tail))
+	if (___cds_wfcq_append(__cds_wfcq_head_cast(dest_q_head), dest_q_tail,
+			head, tail))
 		return CDS_WFCQ_RET_DEST_NON_EMPTY;
 	else
 		return CDS_WFCQ_RET_DEST_EMPTY;
@@ -500,9 +558,9 @@ ___cds_wfcq_splice(
  */
 static inline 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)
 {
 	return ___cds_wfcq_splice(dest_q_head, dest_q_tail,
@@ -517,9 +575,9 @@ ___cds_wfcq_splice_blocking(
  */
 static inline 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)
 {
 	return ___cds_wfcq_splice(dest_q_head, dest_q_tail,
@@ -527,26 +585,39 @@ ___cds_wfcq_splice_nonblocking(
 }
 
 /*
- * 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(cds_wfcq_head_cast(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.
  *
@@ -554,7 +625,7 @@ _cds_wfcq_dequeue_blocking(struct cds_wfcq_head *head,
  * 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.
@@ -569,8 +640,8 @@ _cds_wfcq_splice_blocking(
 	enum cds_wfcq_ret ret;
 
 	_cds_wfcq_dequeue_lock(src_q_head, src_q_tail);
-	ret = ___cds_wfcq_splice_blocking(dest_q_head, dest_q_tail,
-			src_q_head, src_q_tail);
+	ret = ___cds_wfcq_splice_blocking(cds_wfcq_head_cast(dest_q_head), dest_q_tail,
+			cds_wfcq_head_cast(src_q_head), src_q_tail);
 	_cds_wfcq_dequeue_unlock(src_q_head, src_q_tail);
 	return ret;
 }