X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=urcu%2Fwfstack.h;h=b914f41e6cfdd17e42648ef0867bf92b4526da1c;hb=718eb63eed91f0a06afd1a129813275ecc3e21eb;hp=34ddb3f3e665465aa22b83fff4d7a2cdf8a7d385;hpb=150fc1bb007cfbbca35914b4c2890494d87ec489;p=userspace-rcu.git

diff --git a/urcu/wfstack.h b/urcu/wfstack.h
index 34ddb3f..b914f41 100644
--- a/urcu/wfstack.h
+++ b/urcu/wfstack.h
@@ -60,6 +60,10 @@ extern "C" {
 
 #define CDS_WFS_WOULDBLOCK	((void *) -1UL)
 
+enum cds_wfs_state {
+	CDS_WFS_STATE_LAST =		(1U << 0),
+};
+
 /*
  * struct cds_wfs_node is returned by __cds_wfs_pop, and also used as
  * iterator on stack. It is not safe to dereference the node next
@@ -79,11 +83,25 @@ struct cds_wfs_head {
 	struct cds_wfs_node node;
 };
 
+struct __cds_wfs_stack {
+	struct cds_wfs_head *head;
+};
+
 struct cds_wfs_stack {
 	struct cds_wfs_head *head;
 	pthread_mutex_t lock;
 };
 
+/*
+ * The transparent union allows calling functions that work on both
+ * struct cds_wfs_stack and struct __cds_wfs_stack on any of those two
+ * types.
+ */
+typedef union __attribute__((__transparent_union__)) {
+	struct __cds_wfs_stack *_s;
+	struct cds_wfs_stack *s;
+} cds_wfs_stack_ptr_t;
+
 #ifdef _LGPL_SOURCE
 
 #include <urcu/static/wfstack.h>
@@ -95,6 +113,7 @@ struct cds_wfs_stack {
 
 /* Locking performed internally */
 #define cds_wfs_pop_blocking		_cds_wfs_pop_blocking
+#define cds_wfs_pop_with_state_blocking	_cds_wfs_pop_with_state_blocking
 #define cds_wfs_pop_all_blocking	_cds_wfs_pop_all_blocking
 
 /*
@@ -111,7 +130,11 @@ struct cds_wfs_stack {
 
 /* Synchronization ensured by the caller. See synchronization table. */
 #define __cds_wfs_pop_blocking		___cds_wfs_pop_blocking
+#define __cds_wfs_pop_with_state_blocking	\
+					___cds_wfs_pop_with_state_blocking
 #define __cds_wfs_pop_nonblocking	___cds_wfs_pop_nonblocking
+#define __cds_wfs_pop_with_state_nonblocking	\
+					___cds_wfs_pop_with_state_nonblocking
 #define __cds_wfs_pop_all		___cds_wfs_pop_all
 
 #else /* !_LGPL_SOURCE */
@@ -126,12 +149,17 @@ extern void cds_wfs_node_init(struct cds_wfs_node *node);
  */
 extern void cds_wfs_init(struct cds_wfs_stack *s);
 
+/*
+ * __cds_wfs_init: initialize wait-free stack.
+ */
+extern void __cds_wfs_init(struct __cds_wfs_stack *s);
+
 /*
  * cds_wfs_empty: return whether wait-free stack is empty.
  *
  * No memory barrier is issued. No mutual exclusion is required.
  */
-extern bool cds_wfs_empty(struct cds_wfs_stack *s);
+extern bool cds_wfs_empty(cds_wfs_stack_ptr_t u_stack);
 
 /*
  * cds_wfs_push: push a node into the stack.
@@ -142,7 +170,7 @@ extern bool cds_wfs_empty(struct cds_wfs_stack *s);
  * Returns 0 if the stack was empty prior to adding the node.
  * Returns non-zero otherwise.
  */
-extern int cds_wfs_push(struct cds_wfs_stack *s, struct cds_wfs_node *node);
+extern int cds_wfs_push(cds_wfs_stack_ptr_t u_stack, struct cds_wfs_node *node);
 
 /*
  * cds_wfs_pop_blocking: pop a node from the stack.
@@ -151,6 +179,15 @@ extern int cds_wfs_push(struct cds_wfs_stack *s, struct cds_wfs_node *node);
  */
 extern struct cds_wfs_node *cds_wfs_pop_blocking(struct cds_wfs_stack *s);
 
+/*
+ * cds_wfs_pop_with_state_blocking: pop a node from the stack, with state.
+ *
+ * Same as cds_wfs_pop_blocking, but stores whether the stack was
+ * empty into state (CDS_WFS_STATE_LAST).
+ */
+extern struct cds_wfs_node *
+	cds_wfs_pop_with_state_blocking(struct cds_wfs_stack *s, int *state);
+
 /*
  * cds_wfs_pop_all_blocking: pop all nodes from a stack.
  *
@@ -223,6 +260,15 @@ extern void cds_wfs_pop_unlock(struct cds_wfs_stack *s);
  */
 extern struct cds_wfs_node *__cds_wfs_pop_blocking(struct cds_wfs_stack *s);
 
+/*
+ * __cds_wfs_pop_with_state_blocking: pop a node from the stack, with state.
+ *
+ * Same as __cds_wfs_pop_blocking, but stores whether the stack was
+ * empty into state (CDS_WFS_STATE_LAST).
+ */
+extern struct cds_wfs_node *
+	__cds_wfs_pop_with_state_blocking(struct cds_wfs_stack *s, int *state);
+
 /*
  * __cds_wfs_pop_nonblocking: pop a node from the stack.
  *
@@ -231,6 +277,16 @@ extern struct cds_wfs_node *__cds_wfs_pop_blocking(struct cds_wfs_stack *s);
  */
 extern struct cds_wfs_node *__cds_wfs_pop_nonblocking(struct cds_wfs_stack *s);
 
+/*
+ * __cds_wfs_pop_with_state_nonblocking: pop a node from the stack, with state.
+ *
+ * Same as __cds_wfs_pop_nonblocking, but stores whether the stack was
+ * empty into state (CDS_WFS_STATE_LAST).
+ */
+extern struct cds_wfs_node *
+	__cds_wfs_pop_with_state_nonblocking(struct cds_wfs_stack *s,
+		int *state);
+
 /*
  * __cds_wfs_pop_all: pop all nodes from a stack.
  *