X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu%2Fwfstack.h;h=9d693053117ceb93e69034e433f2196a22c3070d;hp=0adf392f7b317210befb027949d6d6205a133e53;hb=200d100e05ed8e10c47f971939042f2406df92ef;hpb=c7ba06ba1bd70d77a6530503cf216d3a9878d672

diff --git a/urcu/wfstack.h b/urcu/wfstack.h
index 0adf392..9d69305 100644
--- a/urcu/wfstack.h
+++ b/urcu/wfstack.h
@@ -38,9 +38,10 @@ extern "C" {
  * Stack implementing push, pop, pop_all operations, as well as iterator
  * on the stack head returned by pop_all.
  *
- * Wait-free operations: cds_wfs_push, __cds_wfs_pop_all.
- * Blocking operations: cds_wfs_pop, cds_wfs_pop_all, iteration on stack
- *                      head returned by pop_all.
+ * Wait-free operations: cds_wfs_push, __cds_wfs_pop_all, cds_wfs_empty,
+ *                       cds_wfs_first.
+ * Blocking operations: cds_wfs_pop, cds_wfs_pop_all, cds_wfs_next,
+ *                      iteration on stack head returned by pop_all.
  *
  * Synchronization table:
  *
@@ -57,6 +58,12 @@ extern "C" {
  * synchronization.
  */
 
+#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
@@ -76,22 +83,39 @@ 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 {
+	struct __cds_wfs_stack *_s;
+	struct cds_wfs_stack *s;
+} __attribute__((__transparent_union__)) cds_wfs_stack_ptr_t;
+
 #ifdef _LGPL_SOURCE
 
 #include <urcu/static/wfstack.h>
 
 #define cds_wfs_node_init		_cds_wfs_node_init
 #define cds_wfs_init			_cds_wfs_init
+#define cds_wfs_destroy			_cds_wfs_destroy
+#define __cds_wfs_init			___cds_wfs_init
 #define cds_wfs_empty			_cds_wfs_empty
 #define cds_wfs_push			_cds_wfs_push
 
 /* 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
 
 /*
@@ -100,6 +124,7 @@ struct cds_wfs_stack {
  */
 #define cds_wfs_first			_cds_wfs_first
 #define cds_wfs_next_blocking		_cds_wfs_next_blocking
+#define cds_wfs_next_nonblocking	_cds_wfs_next_nonblocking
 
 /* Pop locking with internal mutex */
 #define cds_wfs_pop_lock		_cds_wfs_pop_lock
@@ -107,6 +132,11 @@ 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 */
@@ -117,16 +147,29 @@ struct cds_wfs_stack {
 extern void cds_wfs_node_init(struct cds_wfs_node *node);
 
 /*
- * cds_wfs_init: initialize wait-free stack.
+ * cds_wfs_init: initialize wait-free stack (with lock). Pair with
+ * cds_wfs_destroy().
  */
 extern void cds_wfs_init(struct cds_wfs_stack *s);
 
+/*
+ * cds_wfs_destroy: destroy wait-free stack (with lock). Pair with
+ * cds_wfs_init().
+ */
+extern void cds_wfs_destroy(struct cds_wfs_stack *s);
+
+/*
+ * __cds_wfs_init: initialize wait-free stack (no lock). Don't pair with
+ * any destroy function.
+ */
+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.
@@ -137,7 +180,7 @@ 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.
@@ -146,6 +189,15 @@ 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.
  *
@@ -182,6 +234,14 @@ extern struct cds_wfs_node *cds_wfs_first(struct cds_wfs_head *head);
  */
 extern struct cds_wfs_node *cds_wfs_next_blocking(struct cds_wfs_node *node);
 
+/*
+ * cds_wfs_next_nonblocking: get next node of a popped stack.
+ *
+ * Same as cds_wfs_next_blocking, but returns CDS_WFS_WOULDBLOCK if it
+ * needs to block.
+ */
+extern struct cds_wfs_node *cds_wfs_next_nonblocking(struct cds_wfs_node *node);
+
 /*
  * cds_wfs_pop_lock: lock stack pop-protection mutex.
  */
@@ -208,7 +268,35 @@ extern void cds_wfs_pop_unlock(struct cds_wfs_stack *s);
  * 3) Ensuring that only ONE thread can call __cds_wfs_pop_blocking()
  *    and __cds_wfs_pop_all(). (multi-provider/single-consumer scheme).
  */
-extern struct cds_wfs_node *__cds_wfs_pop_blocking(struct cds_wfs_stack *s);
+extern struct cds_wfs_node *__cds_wfs_pop_blocking(cds_wfs_stack_ptr_t u_stack);
+
+/*
+ * __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(cds_wfs_stack_ptr_t u_stack,
+		int *state);
+
+/*
+ * __cds_wfs_pop_nonblocking: pop a node from the stack.
+ *
+ * Same as __cds_wfs_pop_blocking, but returns CDS_WFS_WOULDBLOCK if
+ * it needs to block.
+ */
+extern struct cds_wfs_node *__cds_wfs_pop_nonblocking(cds_wfs_stack_ptr_t u_stack);
+
+/*
+ * __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(cds_wfs_stack_ptr_t u_stack,
+		int *state);
 
 /*
  * __cds_wfs_pop_all: pop all nodes from a stack.
@@ -227,7 +315,7 @@ extern struct cds_wfs_node *__cds_wfs_pop_blocking(struct cds_wfs_stack *s);
  * 3) Ensuring that only ONE thread can call __cds_wfs_pop_blocking()
  *    and __cds_wfs_pop_all(). (multi-provider/single-consumer scheme).
  */
-extern struct cds_wfs_head *__cds_wfs_pop_all(struct cds_wfs_stack *s);
+extern struct cds_wfs_head *__cds_wfs_pop_all(cds_wfs_stack_ptr_t u_stack);
 
 #endif /* !_LGPL_SOURCE */