struct cds_lfs_node node;
};
+struct __cds_lfs_stack {
+ struct cds_lfs_head *head;
+};
+
struct cds_lfs_stack {
struct cds_lfs_head *head;
pthread_mutex_t lock;
};
+/*
+ * The transparent union allows calling functions that work on both
+ * struct cds_lfs_stack and struct __cds_lfs_stack on any of those two
+ * types.
+ */
+typedef union {
+ struct __cds_lfs_stack *_s;
+ struct cds_lfs_stack *s;
+} __attribute__((__transparent_union__)) cds_lfs_stack_ptr_t;
+
#ifdef _LGPL_SOURCE
#include <urcu/static/lfstack.h>
#define cds_lfs_node_init _cds_lfs_node_init
#define cds_lfs_init _cds_lfs_init
+#define cds_lfs_destroy _cds_lfs_destroy
+#define __cds_lfs_init ___cds_lfs_init
#define cds_lfs_empty _cds_lfs_empty
#define cds_lfs_push _cds_lfs_push
extern void cds_lfs_node_init(struct cds_lfs_node *node);
/*
- * cds_lfs_init: initialize lock-free stack.
+ * cds_lfs_init: initialize lock-free stack (with locking). Pair with
+ * cds_lfs_destroy().
*/
extern void cds_lfs_init(struct cds_lfs_stack *s);
+/*
+ * cds_lfs_destroy: destroy lock-free stack (with lock). Pair with
+ * cds_lfs_init().
+ */
+extern void cds_lfs_destroy(struct cds_lfs_stack *s);
+
+/*
+ * __cds_lfs_init: initialize lock-free stack (without lock).
+ * Don't pair with any destroy function.
+ */
+extern void __cds_lfs_init(struct __cds_lfs_stack *s);
+
/*
* cds_lfs_empty: return whether lock-free stack is empty.
*
* No memory barrier is issued. No mutual exclusion is required.
*/
-extern bool cds_lfs_empty(struct cds_lfs_stack *s);
+extern bool cds_lfs_empty(cds_lfs_stack_ptr_t s);
/*
* cds_lfs_push: push a node into the stack.
* Returns 0 if the stack was empty prior to adding the node.
* Returns non-zero otherwise.
*/
-extern bool cds_lfs_push(struct cds_lfs_stack *s,
+extern bool cds_lfs_push(cds_lfs_stack_ptr_t s,
struct cds_lfs_node *node);
/*
* __cds_lfs_pop needs to be synchronized using one of the following
* techniques:
*
- * 1) Calling __cds_lfs_pop under rcu read lock critical section. The
- * caller must wait for a grace period to pass before freeing the
- * returned node or modifying the cds_lfs_node structure.
+ * 1) Calling __cds_lfs_pop under rcu read lock critical section.
+ * Both __cds_lfs_pop and __cds_lfs_pop_all callers must wait for a
+ * grace period to pass before freeing the returned node or pushing
+ * the node back into the stack. It is valid to overwrite the content
+ * of cds_lfs_node immediately after __cds_lfs_pop and
+ * __cds_lfs_pop_all.
* 2) Using mutual exclusion (e.g. mutexes) to protect __cds_lfs_pop
* and __cds_lfs_pop_all callers.
* 3) Ensuring that only ONE thread can call __cds_lfs_pop() and
* __cds_lfs_pop_all(). (multi-provider/single-consumer scheme).
*/
-extern struct cds_lfs_node *__cds_lfs_pop(struct cds_lfs_stack *s);
+extern struct cds_lfs_node *__cds_lfs_pop(cds_lfs_stack_ptr_t s);
/*
* __cds_lfs_pop_all: pop all nodes from a stack.
* matching the technique used to synchronize __cds_lfs_pop:
*
* 1) If __cds_lfs_pop is called under rcu read lock critical section,
- * both __cds_lfs_pop and cds_lfs_pop_all callers must wait for a
- * grace period to pass before freeing the returned node or modifying
- * the cds_lfs_node structure. However, no RCU read-side critical
- * section is needed around __cds_lfs_pop_all.
+ * both __cds_lfs_pop and __cds_lfs_pop_all callers must wait for a
+ * grace period to pass before freeing the returned node or pushing
+ * the node back into the stack. It is valid to overwrite the content
+ * of cds_lfs_node immediately after __cds_lfs_pop and
+ * __cds_lfs_pop_all. No RCU read-side critical section is needed
+ * around __cds_lfs_pop_all.
* 2) Using mutual exclusion (e.g. mutexes) to protect __cds_lfs_pop and
* __cds_lfs_pop_all callers.
* 3) Ensuring that only ONE thread can call __cds_lfs_pop() and
* __cds_lfs_pop_all(). (multi-provider/single-consumer scheme).
*/
-extern struct cds_lfs_head *__cds_lfs_pop_all(struct cds_lfs_stack *s);
+extern struct cds_lfs_head *__cds_lfs_pop_all(cds_lfs_stack_ptr_t s);
#endif /* !_LGPL_SOURCE */