X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=rcuja%2Frcuja.c;h=1c1d6e4677849f7b96bfb0ac644c3e535e8f78de;hb=5a9a87dd2a194207a0d98ee999d69b7db7183dea;hp=04cbd6c29ea4401eca0bd612605bb3fea178cc95;hpb=fd80077697a32434d2b7eaa8336f447904150f0e;p=userspace-rcu.git

diff --git a/rcuja/rcuja.c b/rcuja/rcuja.c
index 04cbd6c..1c1d6e4 100644
--- a/rcuja/rcuja.c
+++ b/rcuja/rcuja.c
@@ -20,16 +20,21 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#define _LGPL_SOURCE
 #include <stdint.h>
+#include <errno.h>
 #include <limits.h>
 #include <urcu/rcuja.h>
 #include <urcu/compiler.h>
 #include <urcu/arch.h>
 #include <assert.h>
+#include <urcu-pointer.h>
+#include <stdint.h>
+
 #include "rcuja-internal.h"
 #include "bitfield.h"
 
-enum rcu_ja_type_class {
+enum cds_ja_type_class {
 	RCU_JA_LINEAR = 0,	/* Type A */
 			/* 32-bit: 1 to 25 children, 8 to 128 bytes */
 			/* 64-bit: 1 to 28 children, 16 to 256 bytes */
@@ -40,13 +45,17 @@ enum rcu_ja_type_class {
 			/* 32-bit: 101 to 256 children, 1024 bytes */
 			/* 64-bit: 113 to 256 children, 2048 bytes */
 	/* Leaf nodes are implicit from their height in the tree */
+	RCU_JA_NR_TYPES,
+
+	RCU_JA_NULL,	/* not an encoded type, but keeps code regular */
 };
 
-struct rcu_ja_type {
-	enum rcu_ja_type_class type_class;
-	uint16_t min_child;	/* minimum number of children: 1 to 256 */
-	uint16_t max_child;	/* maximum number of children: 1 to 256 */
-	uint16_t order;		/* node size is (1 << order), in bytes */
+struct cds_ja_type {
+	enum cds_ja_type_class type_class;
+	uint16_t min_child;		/* minimum number of children: 1 to 256 */
+	uint16_t max_child;		/* maximum number of children: 1 to 256 */
+	uint16_t max_linear_child;	/* per-pool max nr. children: 1 to 256 */
+	uint16_t order;			/* node size is (1 << order), in bytes */
 	uint16_t nr_pool_order;		/* number of pools */
 	uint16_t pool_size_order;	/* pool size */
 };
@@ -61,6 +70,15 @@ struct rcu_ja_type {
 #define JA_PTR_MASK	(~JA_TYPE_MASK)
 
 #define JA_ENTRY_PER_NODE	256UL
+#define JA_BITS_PER_BYTE	3
+
+#define JA_MAX_INTERNAL_DEPTH	5	/* Maximum depth, excluding leafs */
+
+/*
+ * Entry for NULL node is at index 8 of the table. It is never encoded
+ * in flags.
+ */
+#define NODE_INDEX_NULL		8
 
 /*
  * Iteration on the array to find the right node size for the number of
@@ -72,87 +90,201 @@ struct rcu_ja_type {
  * The node the index within the following arrays is represented on 3
  * bits. It identifies the node type, min/max number of children, and
  * the size order.
+ * The max_child values for the RCU_JA_POOL below result from
+ * statistical approximation: over million populations, the max_child
+ * covers between 97% and 99% of the populations generated. Therefore, a
+ * fallback should exist to cover the rare extreme population unbalance
+ * cases, but it will not have a major impact on speed nor space
+ * consumption, since those are rare cases.
  */
 
 #if (CAA_BITS_PER_LONG < 64)
 /* 32-bit pointers */
-const struct rcu_ja_type ja_types[] = {
-	{ .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = 1, .order = 3, },
-	{ .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = 3, .order = 4, },
-	{ .type_class = RCU_JA_LINEAR, .min_child = 3, .max_child = 6, .order = 5, },
-	{ .type_class = RCU_JA_LINEAR, .min_child = 4, .max_child = 12, .order = 6, },
-	{ .type_class = RCU_JA_LINEAR, .min_child = 10, .max_child = 25, .order = 7, },
+enum {
+	ja_type_0_max_child = 1,
+	ja_type_1_max_child = 3,
+	ja_type_2_max_child = 6,
+	ja_type_3_max_child = 12,
+	ja_type_4_max_child = 25,
+	ja_type_5_max_child = 48,
+	ja_type_6_max_child = 92,
+	ja_type_7_max_child = 256,
+	ja_type_8_max_child = 0,	/* NULL */
+};
+
+enum {
+	ja_type_0_max_linear_child = 1,
+	ja_type_1_max_linear_child = 3,
+	ja_type_2_max_linear_child = 6,
+	ja_type_3_max_linear_child = 12,
+	ja_type_4_max_linear_child = 25,
+	ja_type_5_max_linear_child = 24,
+	ja_type_6_max_linear_child = 23,
+};
+
+enum {
+	ja_type_5_nr_pool_order = 1,
+	ja_type_6_nr_pool_order = 2,
+};
+
+const struct cds_ja_type ja_types[] = {
+	{ .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = ja_type_0_max_child, .max_linear_child = ja_type_0_max_linear_child, .order = 3, },
+	{ .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = ja_type_1_max_child, .max_linear_child = ja_type_1_max_linear_child, .order = 4, },
+	{ .type_class = RCU_JA_LINEAR, .min_child = 3, .max_child = ja_type_2_max_child, .max_linear_child = ja_type_2_max_linear_child, .order = 5, },
+	{ .type_class = RCU_JA_LINEAR, .min_child = 4, .max_child = ja_type_3_max_child, .max_linear_child = ja_type_3_max_linear_child, .order = 6, },
+	{ .type_class = RCU_JA_LINEAR, .min_child = 10, .max_child = ja_type_4_max_child, .max_linear_child = ja_type_4_max_linear_child, .order = 7, },
 
 	/* Pools may fill sooner than max_child */
-	{ .type_class = RCU_JA_POOL, .min_child = 20, .max_child = 50, .order = 8, .nr_pool_order = 1, .pool_size_order = 7, },
-	{ .type_class = RCU_JA_POOL, .min_child = 42, .max_child = 100, .order = 9, .nr_pool_order = 2, .pool_size_order = 7, },
+	{ .type_class = RCU_JA_POOL, .min_child = 20, .max_child = ja_type_5_max_child, .max_linear_child = ja_type_5_max_linear_child, .order = 8, .nr_pool_order = ja_type_5_nr_pool_order, .pool_size_order = 7, },
+	{ .type_class = RCU_JA_POOL, .min_child = 45, .max_child = ja_type_6_max_child, .max_linear_child = ja_type_6_max_linear_child, .order = 9, .nr_pool_order = ja_type_6_nr_pool_order, .pool_size_order = 7, },
+
+	/*
+	 * TODO: Upon node removal below min_child, if child pool is
+	 * filled beyond capacity, we need to roll back to pigeon.
+	 */
+	{ .type_class = RCU_JA_PIGEON, .min_child = 89, .max_child = ja_type_7_max_child, .order = 10, },
 
-	/* TODO: Upon downsize, if at least one pool is filled, we need to keep pigeon */
-	{ .type_class = RCU_JA_PIGEON, .min_child = 90, .max_child = 256, .order = 10, },
+	{ .type_class = RCU_JA_NULL, .min_child = 0, .max_child = ja_type_8_max_child, },
 };
-CAA_BUILD_BUG_ON(CAA_ARRAY_SIZE(ja_types) > JA_TYPE_MAX_NR);
 #else /* !(CAA_BITS_PER_LONG < 64) */
 /* 64-bit pointers */
-const struct rcu_ja_type ja_types[] = {
-	{ .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = 1, .order = 4, },
-	{ .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = 3, .order = 5, },
-	{ .type_class = RCU_JA_LINEAR, .min_child = 3, .max_child = 7, .order = 6, },
-	{ .type_class = RCU_JA_LINEAR, .min_child = 5, .max_child = 14, .order = 7, },
-	{ .type_class = RCU_JA_LINEAR, .min_child = 10, .max_child = 28, .order = 8, },
+enum {
+	ja_type_0_max_child = 1,
+	ja_type_1_max_child = 3,
+	ja_type_2_max_child = 7,
+	ja_type_3_max_child = 14,
+	ja_type_4_max_child = 28,
+	ja_type_5_max_child = 54,
+	ja_type_6_max_child = 104,
+	ja_type_7_max_child = 256,
+	ja_type_8_max_child = 256,
+};
 
-	/* Pools may fill sooner than max_child */
-	{ .type_class = RCU_JA_POOL, .min_child = 22, .max_child = 56, .order = 9, .nr_pool_order = 1, .pool_size_order = 8, },
-	{ .type_class = RCU_JA_POOL, .min_child = 44, .max_child = 112, .order = 10, .nr_pool_order = 2, .pool_size_order = 8, },
+enum {
+	ja_type_0_max_linear_child = 1,
+	ja_type_1_max_linear_child = 3,
+	ja_type_2_max_linear_child = 7,
+	ja_type_3_max_linear_child = 14,
+	ja_type_4_max_linear_child = 28,
+	ja_type_5_max_linear_child = 27,
+	ja_type_6_max_linear_child = 26,
+};
 
-	/* TODO: Upon downsize, if at least one pool is filled, we need to keep pigeon */
-	{ .type_class = RCU_JA_PIGEON, .min_child = 100, .max_child = 256, .order = 11, },
+enum {
+	ja_type_5_nr_pool_order = 1,
+	ja_type_6_nr_pool_order = 2,
+};
+
+const struct cds_ja_type ja_types[] = {
+	{ .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = ja_type_0_max_child, .max_linear_child = ja_type_0_max_linear_child, .order = 4, },
+	{ .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = ja_type_1_max_child, .max_linear_child = ja_type_1_max_linear_child, .order = 5, },
+	{ .type_class = RCU_JA_LINEAR, .min_child = 3, .max_child = ja_type_2_max_child, .max_linear_child = ja_type_2_max_linear_child, .order = 6, },
+	{ .type_class = RCU_JA_LINEAR, .min_child = 5, .max_child = ja_type_3_max_child, .max_linear_child = ja_type_3_max_linear_child, .order = 7, },
+	{ .type_class = RCU_JA_LINEAR, .min_child = 10, .max_child = ja_type_4_max_child, .max_linear_child = ja_type_4_max_linear_child, .order = 8, },
+
+	/* Pools may fill sooner than max_child. */
+	{ .type_class = RCU_JA_POOL, .min_child = 22, .max_child = ja_type_5_max_child, .max_linear_child = ja_type_5_max_linear_child, .order = 9, .nr_pool_order = ja_type_5_nr_pool_order, .pool_size_order = 8, },
+	{ .type_class = RCU_JA_POOL, .min_child = 51, .max_child = ja_type_6_max_child, .max_linear_child = ja_type_6_max_linear_child, .order = 10, .nr_pool_order = ja_type_6_nr_pool_order, .pool_size_order = 8, },
+
+	/*
+	 * TODO: Upon node removal below min_child, if child pool is
+	 * filled beyond capacity, we need to roll back to pigeon.
+	 */
+	{ .type_class = RCU_JA_PIGEON, .min_child = 101, .max_child = ja_type_7_max_child, .order = 11, },
+
+	{ .type_class = RCU_JA_NULL, .min_child = 0, .max_child = ja_type_8_max_child, },
 };
-CAA_BUILD_BUG_ON(CAA_ARRAY_SIZE(ja_types) > JA_TYPE_MAX_NR);
 #endif /* !(BITS_PER_LONG < 64) */
 
+static inline __attribute__((unused))
+void static_array_size_check(void)
+{
+	CAA_BUILD_BUG_ON(CAA_ARRAY_SIZE(ja_types) < JA_TYPE_MAX_NR);
+}
+
 /*
- * The rcu_ja_node starts with a byte counting the number of children in
- * the node. Then, the node-specific data is placed.
- * TODO: where should we put the mutex for the node ?
- *  -> mutex could be a 0-value node count.
- * TODO: where do we keep nr children for pigeon ?
+ * The cds_ja_node contains the compressed node data needed for
+ * read-side. For linear and pool node configurations, it starts with a
+ * byte counting the number of children in the node.  Then, the
+ * node-specific data is placed.
+ * The node mutex, if any is needed, protecting concurrent updated of
+ * each node is placed in a separate hash table indexed by node address.
+ * For the pigeon configuration, the number of children is also kept in
+ * a separate hash table, indexed by node address, because it is only
+ * required for updates.
  */
-struct rcu_ja_node {
-	char data[];
+
+#define DECLARE_LINEAR_NODE(index)								\
+	struct {										\
+		uint8_t nr_child;								\
+		uint8_t child_value[ja_type_## index ##_max_linear_child];			\
+		struct cds_ja_inode_flag *child_ptr[ja_type_## index ##_max_linear_child];	\
+	}
+
+#define DECLARE_POOL_NODE(index)								\
+	struct {										\
+		struct {									\
+			uint8_t nr_child;							\
+			uint8_t child_value[ja_type_## index ##_max_linear_child];		\
+			struct cds_ja_inode_flag *child_ptr[ja_type_## index ##_max_linear_child]; \
+		} linear[1U << ja_type_## index ##_nr_pool_order];				\
+	}
+
+struct cds_ja_inode {
+	union {
+		/* Linear configuration */
+		DECLARE_LINEAR_NODE(0) conf_0;
+		DECLARE_LINEAR_NODE(1) conf_1;
+		DECLARE_LINEAR_NODE(2) conf_2;
+		DECLARE_LINEAR_NODE(3) conf_3;
+		DECLARE_LINEAR_NODE(4) conf_4;
+
+		/* Pool configuration */
+		DECLARE_POOL_NODE(5) conf_5;
+		DECLARE_POOL_NODE(6) conf_6;
+
+		/* Pigeon configuration */
+		struct {
+			struct cds_ja_inode_flag *child[ja_type_7_max_child];
+		} conf_7;
+		/* data aliasing nodes for computed accesses */
+		uint8_t data[sizeof(struct cds_ja_inode_flag *) * ja_type_7_max_child];
+	} u;
 };
 
-/* Never declared. Opaque type used to store flagged node pointers. */
-struct rcu_ja_node_flag;
+static
+struct cds_ja_inode_flag *ja_node_flag(struct cds_ja_inode *node,
+		unsigned int type)
+{
+	assert(type < RCU_JA_NR_TYPES);
+	return (struct cds_ja_inode_flag *) (((unsigned long) node) | type);
+}
 
 static
-struct rcu_ja_node_flag *ja_node_flag(struct rcu_ja_node *node, unsigned int type)
+struct cds_ja_inode *ja_node_ptr(struct cds_ja_inode_flag *node)
 {
-	assert(type < JA_TYPE_NR);
-	return (struct rcu_ja_node_flag *) (((unsigned long) node) | type);
+	return (struct cds_ja_inode *) (((unsigned long) node) | JA_PTR_MASK);
 }
 
 static
-unsigned int ja_node_type(struct rcu_ja_node_flag *node)
+unsigned int ja_node_type(struct cds_ja_inode_flag *node)
 {
 	unsigned int type;
 
+	if (ja_node_ptr(node) == NULL) {
+		return NODE_INDEX_NULL;
+	}
 	type = (unsigned int) ((unsigned long) node & JA_TYPE_MASK);
-	assert(type < JA_TYPE_NR);
+	assert(type < RCU_JA_NR_TYPES);
 	return type;
 }
 
-static
-struct rcu_ja_node *ja_node_ptr(struct rcu_ja_node_flag *node)
-{
-	return (struct rcu_ja_node *) (((unsigned long) node) | JA_PTR_MASK);
-}
-
-struct rcu_ja_node *alloc_rcu_ja_node(struct rcu_ja_type *ja_type)
+struct cds_ja_inode *alloc_cds_ja_node(const struct cds_ja_type *ja_type)
 {
-	return zmalloc(1 << ja_type->node_order);
+	return calloc(1U << ja_type->order, sizeof(char));
 }
 
-void free_rcu_ja_node(struct rcu_ja_node *node)
+void free_cds_ja_node(struct cds_ja_inode *node)
 {
 	free(node);
 }
@@ -163,76 +295,133 @@ void free_rcu_ja_node(struct rcu_ja_node *node)
 #define JA_FLOOR(v, align)		__JA_FLOOR_MASK(v, (typeof(v)) (align) - 1)
 
 static
-char *align_ptr_size(char *ptr)
+uint8_t *align_ptr_size(uint8_t *ptr)
 {
-	return JA_ALIGN(ptr, sizeof(ptr));
+	return (uint8_t *) JA_ALIGN((unsigned long) ptr, sizeof(void *));
 }
 
 static
-struct rcu_ja_node_flag *ja_linear_node_get_nth(const struct rcu_ja_type *type,
-					struct rcu_ja_node *node,
-					uint8_t n)
+uint8_t ja_linear_node_get_nr_child(const struct cds_ja_type *type,
+		struct cds_ja_inode *node)
+{
+	assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL);
+	return CMM_LOAD_SHARED(node->u.data[0]);
+}
+
+/*
+ * The order in which values and pointers are does does not matter: if
+ * a value is missing, we return NULL. If a value is there, but its
+ * associated pointers is still NULL, we return NULL too.
+ */
+static
+struct cds_ja_inode_flag *ja_linear_node_get_nth(const struct cds_ja_type *type,
+		struct cds_ja_inode *node,
+		struct cds_ja_inode_flag ***child_node_flag_ptr,
+		uint8_t n)
 {
 	uint8_t nr_child;
 	uint8_t *values;
-	struct rcu_ja_node_flag *pointers;
-	struct rcu_ja_node_flag *ptr;
+	struct cds_ja_inode_flag **pointers;
+	struct cds_ja_inode_flag *ptr;
 	unsigned int i;
 
-	assert(!type || type->type_class == RCU_JA_LINEAR);
+	assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL);
 
-	nr_child = node->data[0];
-	cmm_smp_rmb();	/* read nr_child before values */
-	assert(!type || nr_child <= type->max_child);
-	assert(!type || nr_child >= type->min_child);
+	nr_child = ja_linear_node_get_nr_child(type, node);
+	cmm_smp_rmb();	/* read nr_child before values and pointers */
+	assert(nr_child <= type->max_linear_child);
+	assert(type->type_class != RCU_JA_LINEAR || nr_child >= type->min_child);
 
-	values = &node[1];
+	values = &node->u.data[1];
 	for (i = 0; i < nr_child; i++) {
-		if (values[i] == n)
+		if (CMM_LOAD_SHARED(values[i]) == n)
 			break;
 	}
 	if (i >= nr_child)
 		return NULL;
-	cmm_smp_rmb();	/* read values before pointer */
-	pointers = align_ptr_size(&values[nr_child]);
-	ptr = pointers[i];
+	pointers = (struct cds_ja_inode_flag **) align_ptr_size(&values[type->max_linear_child]);
+	if (caa_unlikely(child_node_flag_ptr))
+		*child_node_flag_ptr = &pointers[i];
+	ptr = rcu_dereference(pointers[i]);
 	assert(ja_node_ptr(ptr) != NULL);
 	return ptr;
 }
 
 static
-struct rcu_ja_node_flag *ja_pool_node_get_nth(const struct rcu_ja_type *type,
-					struct rcu_ja_node *node,
-					uint8_t n)
+void ja_linear_node_get_ith_pos(const struct cds_ja_type *type,
+		struct cds_ja_inode *node,
+		uint8_t i,
+		uint8_t *v,
+		struct cds_ja_inode_flag **iter)
 {
-	struct rcu_ja_node_flag *ptr;
-	struct rcu_ja_node *linear;
+	uint8_t *values;
+	struct cds_ja_inode_flag **pointers;
+
+	assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL);
+	assert(i < ja_linear_node_get_nr_child(type, node));
+
+	values = &node->u.data[1];
+	*v = values[i];
+	pointers = (struct cds_ja_inode_flag **) align_ptr_size(&values[type->max_linear_child]);
+	*iter = pointers[i];
+}
 
+static
+struct cds_ja_inode_flag *ja_pool_node_get_nth(const struct cds_ja_type *type,
+		struct cds_ja_inode *node,
+		struct cds_ja_inode_flag ***child_node_flag_ptr,
+		uint8_t n)
+{
+	struct cds_ja_inode *linear;
+
+	assert(type->type_class == RCU_JA_POOL);
+	/*
+	 * TODO: currently, we select the pool by highest bits. We
+	 * should support various encodings.
+	 */
+	linear = (struct cds_ja_inode *)
+		&node->u.data[((unsigned long) n >> (CHAR_BIT - type->nr_pool_order)) << type->pool_size_order];
+	return ja_linear_node_get_nth(type, linear, child_node_flag_ptr, n);
+}
+
+static
+struct cds_ja_inode *ja_pool_node_get_ith_pool(const struct cds_ja_type *type,
+		struct cds_ja_inode *node,
+		uint8_t i)
+{
 	assert(type->type_class == RCU_JA_POOL);
-	linear = (struct rcu_ja_node *)
-		&node->data[(n >> (CHAR_BIT - type->nr_pool_order)) << type->pool_size_order];
-	return ja_linear_node_get_nth(NULL, linear, n);
+	return (struct cds_ja_inode *)
+		&node->u.data[(unsigned int) i << type->pool_size_order];
 }
 
 static
-struct rcu_ja_node_flag *ja_pigeon_node_get_nth(const struct rcu_ja_type *type,
-					struct rcu_ja_node *node,
-					uint8_t n)
+struct cds_ja_inode_flag *ja_pigeon_node_get_nth(const struct cds_ja_type *type,
+		struct cds_ja_inode *node,
+		struct cds_ja_inode_flag ***child_node_flag_ptr,
+		uint8_t n)
 {
+	struct cds_ja_inode_flag **child_node_flag;
+
 	assert(type->type_class == RCU_JA_PIGEON);
-	return ((struct rcu_ja_node_flag *) node->data)[n];
+	child_node_flag = &((struct cds_ja_inode_flag **) node->u.data)[n];
+	if (caa_unlikely(child_node_flag_ptr))
+		*child_node_flag_ptr = child_node_flag;
+	return rcu_dereference(*child_node_flag);
 }
 
-/* ja_node_get_nth: get nth item from a node */
+/*
+ * ja_node_get_nth: get nth item from a node.
+ * node_flag is already rcu_dereference'd.
+ */
 static
-struct rcu_ja_node_flag *ja_node_get_nth(struct rcu_ja_node_flag *node_flag,
-					uint8_t n)
+struct cds_ja_inode_flag * ja_node_get_nth(struct cds_ja_inode_flag *node_flag,
+		struct cds_ja_inode_flag ***child_node_flag_ptr,
+		uint8_t n)
 {
 	unsigned int type_index;
-	struct rcu_ja_node *node;
-	const struct rcu_ja_type *type;
+	struct cds_ja_inode *node;
+	const struct cds_ja_type *type;
 
-	node_flag = rcu_dereference(node_flag);
 	node = ja_node_ptr(node_flag);
 	assert(node != NULL);
 	type_index = ja_node_type(node_flag);
@@ -240,11 +429,14 @@ struct rcu_ja_node_flag *ja_node_get_nth(struct rcu_ja_node_flag *node_flag,
 
 	switch (type->type_class) {
 	case RCU_JA_LINEAR:
-		return ja_linear_node_get_nth(type, node, n);
+		return ja_linear_node_get_nth(type, node,
+				child_node_flag_ptr, n);
 	case RCU_JA_POOL:
-		return ja_pool_node_get_nth(type, node, n);
+		return ja_pool_node_get_nth(type, node,
+				child_node_flag_ptr, n);
 	case RCU_JA_PIGEON:
-		return ja_pigeon_node_get_nth(type, node, n);
+		return ja_pigeon_node_get_nth(type, node,
+				child_node_flag_ptr, n);
 	default:
 		assert(0);
 		return (void *) -1UL;
@@ -252,7 +444,534 @@ struct rcu_ja_node_flag *ja_node_get_nth(struct rcu_ja_node_flag *node_flag,
 }
 
 /*
- * ja_node_set_nth: set nth item within a node. asserts that it is not
- * there yet.
+ * TODO: use ja_get_nr_child to monitor limits triggering shrink
+ * recompaction.
+ * Also use ja_get_nr_child to make the difference between resize and
+ * pool change of compaction bit(s).
+ */
+static
+unsigned int ja_get_nr_child(struct cds_ja_shadow_node *shadow_node)
+{
+	return shadow_node->nr_child;
+}
+
+static
+int ja_linear_node_set_nth(const struct cds_ja_type *type,
+		struct cds_ja_inode *node,
+		struct cds_ja_shadow_node *shadow_node,
+		uint8_t n,
+		struct cds_ja_inode_flag *child_node_flag)
+{
+	uint8_t nr_child;
+	uint8_t *values, *nr_child_ptr;
+	struct cds_ja_inode_flag **pointers;
+	unsigned int i;
+
+	assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL);
+
+	nr_child_ptr = &node->u.data[0];
+	nr_child = *nr_child_ptr;
+	assert(nr_child <= type->max_linear_child);
+	assert(type->type_class != RCU_JA_LINEAR || nr_child >= type->min_child);
+
+	values = &node->u.data[1];
+	for (i = 0; i < nr_child; i++) {
+		if (values[i] == n)
+			return -EEXIST;
+	}
+	if (nr_child >= type->max_linear_child) {
+		/* No space left in this node type */
+		return -ENOSPC;
+	}
+	pointers = (struct cds_ja_inode_flag **) align_ptr_size(&values[type->max_linear_child]);
+	assert(pointers[nr_child] == NULL);
+	rcu_assign_pointer(pointers[nr_child], child_node_flag);
+	CMM_STORE_SHARED(values[nr_child], n);
+	cmm_smp_wmb();	/* write value and pointer before nr_child */
+	CMM_STORE_SHARED(*nr_child_ptr, nr_child + 1);
+	shadow_node->nr_child++;
+	return 0;
+}
+
+static
+int ja_pool_node_set_nth(const struct cds_ja_type *type,
+		struct cds_ja_inode *node,
+		struct cds_ja_shadow_node *shadow_node,
+		uint8_t n,
+		struct cds_ja_inode_flag *child_node_flag)
+{
+	struct cds_ja_inode *linear;
+
+	assert(type->type_class == RCU_JA_POOL);
+	linear = (struct cds_ja_inode *)
+		&node->u.data[((unsigned long) n >> (CHAR_BIT - type->nr_pool_order)) << type->pool_size_order];
+	return ja_linear_node_set_nth(type, linear, shadow_node,
+			n, child_node_flag);
+}
+
+static
+int ja_pigeon_node_set_nth(const struct cds_ja_type *type,
+		struct cds_ja_inode *node,
+		struct cds_ja_shadow_node *shadow_node,
+		uint8_t n,
+		struct cds_ja_inode_flag *child_node_flag)
+{
+	struct cds_ja_inode_flag **ptr;
+
+	assert(type->type_class == RCU_JA_PIGEON);
+	ptr = &((struct cds_ja_inode_flag **) node->u.data)[n];
+	if (*ptr)
+		return -EEXIST;
+	rcu_assign_pointer(*ptr, child_node_flag);
+	shadow_node->nr_child++;
+	return 0;
+}
+
+/*
+ * _ja_node_set_nth: set nth item within a node. Return an error
+ * (negative error value) if it is already there.
+ * TODO: exclusive access on node.
+ */
+static
+int _ja_node_set_nth(const struct cds_ja_type *type,
+		struct cds_ja_inode *node,
+		struct cds_ja_shadow_node *shadow_node,
+		uint8_t n,
+		struct cds_ja_inode_flag *child_node_flag)
+{
+	switch (type->type_class) {
+	case RCU_JA_LINEAR:
+		return ja_linear_node_set_nth(type, node, shadow_node, n,
+				child_node_flag);
+	case RCU_JA_POOL:
+		return ja_pool_node_set_nth(type, node, shadow_node, n,
+				child_node_flag);
+	case RCU_JA_PIGEON:
+		return ja_pigeon_node_set_nth(type, node, shadow_node, n,
+				child_node_flag);
+	case RCU_JA_NULL:
+		return -ENOSPC;
+	default:
+		assert(0);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * ja_node_recompact_add: recompact a node, adding a new child.
+ * TODO: for pool type, take selection bit(s) into account.
+ * Return 0 on success, -ENOENT if need to retry, or other negative
+ * error value otherwise.
  */
+static
+int ja_node_recompact_add(struct cds_ja *ja,
+		unsigned int old_type_index,
+		const struct cds_ja_type *old_type,
+		struct cds_ja_inode *old_node,
+		struct cds_ja_shadow_node *shadow_node,
+		struct cds_ja_inode_flag **old_node_flag, uint8_t n,
+		struct cds_ja_inode_flag *child_node_flag)
+{
+	unsigned int new_type_index;
+	struct cds_ja_inode *new_node;
+	const struct cds_ja_type *new_type;
+	struct cds_ja_inode_flag *new_node_flag;
+	int new_shadow = 0;
+	int ret;
+
+	if (!shadow_node) {
+		new_type_index = 0;
+	} else {
+		new_type_index = old_type_index + 1;
+	}
+	new_type = &ja_types[new_type_index];
+	new_node = alloc_cds_ja_node(new_type);
+	if (!new_node)
+		return -ENOMEM;
+	new_node_flag = ja_node_flag(new_node, new_type_index);
+
+	ret = rcuja_shadow_set(ja->ht, new_node, shadow_node);
+	if (ret) {
+		free(new_node);
+		return ret;
+	}
+
+	if (!shadow_node) {
+		shadow_node = rcuja_shadow_lookup_lock(ja->ht, new_node);
+		assert(shadow_node);
+		new_shadow = 1;
+	}
+
+	/*
+	 * We need to clear nr_child, because it will be re-incremented
+	 * by _ja_node_set_nth().
+	 */
+	shadow_node->nr_child = 0;
 
+	assert(old_type->type_class != RCU_JA_PIGEON);
+	switch (old_type->type_class) {
+	case RCU_JA_LINEAR:
+	{
+		uint8_t nr_child =
+			ja_linear_node_get_nr_child(old_type, old_node);
+		unsigned int i;
+
+		for (i = 0; i < nr_child; i++) {
+			struct cds_ja_inode_flag *iter;
+			uint8_t v;
+
+			ja_linear_node_get_ith_pos(old_type, old_node, i, &v, &iter);
+			if (!iter)
+				continue;
+			ret = _ja_node_set_nth(new_type, new_node, shadow_node,
+					v, iter);
+			assert(!ret);
+		}
+		break;
+	}
+	case RCU_JA_POOL:
+	{
+		unsigned int pool_nr;
+
+		for (pool_nr = 0; pool_nr < (1U << old_type->nr_pool_order); pool_nr++) {
+			struct cds_ja_inode *pool =
+				ja_pool_node_get_ith_pool(old_type,
+					old_node, pool_nr);
+			uint8_t nr_child =
+				ja_linear_node_get_nr_child(old_type, pool);
+			unsigned int j;
+
+			for (j = 0; j < nr_child; j++) {
+				struct cds_ja_inode_flag *iter;
+				uint8_t v;
+
+				ja_linear_node_get_ith_pos(old_type, pool,
+						j, &v, &iter);
+				if (!iter)
+					continue;
+				ret = _ja_node_set_nth(new_type, new_node, shadow_node,
+						v, iter);
+				assert(!ret);
+			}
+		}
+		break;
+	}
+	case RCU_JA_PIGEON:
+	default:
+		assert(0);
+		ret = -EINVAL;
+		goto unlock_new_shadow;
+	}
+
+	/* add node */
+	ret = _ja_node_set_nth(new_type, new_node, shadow_node,
+			n, child_node_flag);
+	assert(!ret);
+	/* Return pointer to new recompacted new through old_node_flag */
+	*old_node_flag = new_node_flag;
+	ret = rcuja_shadow_clear(ja->ht, old_node,
+			RCUJA_SHADOW_CLEAR_FREE_NODE);
+	assert(!ret);
+
+	ret = 0;
+
+unlock_new_shadow:
+	if (new_shadow)
+		rcuja_shadow_unlock(shadow_node);
+	return ret;
+}
+
+/*
+ * Return 0 on success, -ENOENT if need to retry, or other negative
+ * error value otherwise.
+ */
+static
+int ja_node_set_nth(struct cds_ja *ja,
+		struct cds_ja_inode_flag **node_flag, uint8_t n,
+		struct cds_ja_inode_flag *child_node_flag,
+		struct cds_ja_shadow_node *shadow_node)
+{
+	int ret;
+	unsigned int type_index;
+	const struct cds_ja_type *type;
+	struct cds_ja_inode *node;
+
+	node = ja_node_ptr(*node_flag);
+	type_index = ja_node_type(*node_flag);
+	type = &ja_types[type_index];
+	ret = _ja_node_set_nth(type, node, shadow_node,
+			n, child_node_flag);
+	if (ret == -ENOSPC) {
+		/* Not enough space in node, need to recompact. */
+		ret = ja_node_recompact_add(ja, type_index, type, node,
+				shadow_node, node_flag, n, child_node_flag);
+	}
+	return ret;
+}
+
+struct cds_hlist_head *cds_ja_lookup(struct cds_ja *ja, uint64_t key)
+{
+	unsigned int tree_depth, i;
+	struct cds_ja_inode_flag *node_flag;
+
+	if (caa_unlikely(key > ja->key_max))
+		return NULL;
+	tree_depth = ja->tree_depth;
+	node_flag = rcu_dereference(ja->root);
+
+	/* level 0: root node */
+	if (!ja_node_ptr(node_flag))
+		return NULL;
+
+	for (i = 1; i < tree_depth; i++) {
+		node_flag = ja_node_get_nth(node_flag, NULL,
+			(unsigned char) key);
+		if (!ja_node_ptr(node_flag))
+			return NULL;
+		key >>= JA_BITS_PER_BYTE;
+	}
+
+	/* Last level lookup succeded. We got an actual match. */
+	return (struct cds_hlist_head *) node_flag;
+}
+
+/*
+ * We reached an unpopulated node. Create it and the children we need,
+ * and then attach the entire branch to the current node. This may
+ * trigger recompaction of the current node.  Locks needed: node lock
+ * (for add), and, possibly, parent node lock (to update pointer due to
+ * node recompaction).
+ *
+ * First take node lock, check if recompaction is needed, then take
+ * parent lock (if needed).  Then we can proceed to create the new
+ * branch. Publish the new branch, and release locks.
+ * TODO: we currently always take the parent lock even when not needed.
+ */
+static
+int ja_attach_node(struct cds_ja *ja,
+		struct cds_ja_inode_flag **node_flag_ptr,
+		struct cds_ja_inode_flag *node_flag,
+		struct cds_ja_inode_flag *parent_node_flag,
+		uint64_t key,
+		unsigned int depth,
+		struct cds_ja_node *child_node)
+{
+	struct cds_ja_shadow_node *shadow_node = NULL,
+			*parent_shadow_node = NULL;
+	struct cds_ja_inode *node = ja_node_ptr(node_flag);
+	struct cds_ja_inode *parent_node = ja_node_ptr(parent_node_flag);
+	struct cds_hlist_head head;
+	struct cds_ja_inode_flag *iter_node_flag, *iter_dest_node_flag;
+	int ret, i;
+	struct cds_ja_inode_flag *created_nodes[JA_MAX_INTERNAL_DEPTH];
+	int nr_created_nodes = 0;
+
+	assert(node);
+	shadow_node = rcuja_shadow_lookup_lock(ja->ht, node);
+	if (!shadow_node) {
+		ret = -ENOENT;
+		goto end;
+	}
+	if (parent_node) {
+		parent_shadow_node = rcuja_shadow_lookup_lock(ja->ht,
+						parent_node);
+		if (!parent_shadow_node) {
+			ret = -ENOENT;
+			goto unlock_shadow;
+		}
+	}
+
+	CDS_INIT_HLIST_HEAD(&head);
+	cds_hlist_add_head_rcu(&child_node->list, &head);
+
+	iter_dest_node_flag = NULL;
+	ret = ja_node_set_nth(ja, &iter_dest_node_flag,
+			key >> (JA_BITS_PER_BYTE * (ja->tree_depth - 2)),
+			(struct cds_ja_inode_flag *) head.next,
+			NULL);
+	if (ret)
+		goto unlock_parent;
+	created_nodes[nr_created_nodes++] = iter_dest_node_flag;
+	iter_node_flag = iter_dest_node_flag;
+
+	/* Create new branch, starting from bottom */
+	for (i = ja->tree_depth - 2; i >= (int) depth; i--) {
+		iter_dest_node_flag = NULL;
+		ret = ja_node_set_nth(ja, &iter_dest_node_flag,
+			key >> (JA_BITS_PER_BYTE * (i - 1)),
+			iter_node_flag,
+			NULL);
+		if (ret)
+			goto check_error;
+		created_nodes[nr_created_nodes++] = iter_dest_node_flag;
+		iter_node_flag = iter_dest_node_flag;
+	}
+
+	/* Publish new branch */
+	rcu_assign_pointer(*node_flag_ptr, iter_node_flag);
+
+	/* Success */
+	ret = 0;
+
+check_error:
+	if (ret) {
+		for (i = 0; i < nr_created_nodes; i++) {
+			int tmpret;
+			tmpret = rcuja_shadow_clear(ja->ht,
+					ja_node_ptr(created_nodes[i]),
+					RCUJA_SHADOW_CLEAR_FREE_NODE
+					| RCUJA_SHADOW_CLEAR_FREE_LOCK);
+			assert(!tmpret);
+		}
+	}
+unlock_parent:
+	if (parent_shadow_node)
+		rcuja_shadow_unlock(parent_shadow_node);
+unlock_shadow:
+	if (shadow_node)
+		rcuja_shadow_unlock(shadow_node);
+end:
+	return ret;
+}
+
+/*
+ * Lock the hlist head shadow node mutex, and add node to list of
+ * duplicates. Failure can happen if concurrent removal removes the last
+ * node with same key before we get the lock.
+ * Return 0 on success, negative error value on failure.
+ */
+static
+int ja_chain_node(struct cds_ja *ja,
+		struct cds_hlist_head *head,
+		struct cds_ja_node *node)
+{
+	struct cds_ja_shadow_node *shadow_node;
+
+	shadow_node = rcuja_shadow_lookup_lock(ja->ht,
+		(struct cds_ja_inode *) head);
+	if (!shadow_node)
+		return -ENOENT;
+	cds_hlist_add_head_rcu(&node->list, head);
+	rcuja_shadow_unlock(shadow_node);
+	return 0;
+}
+
+int cds_ja_add(struct cds_ja *ja, uint64_t key,
+		struct cds_ja_node *new_node)
+{
+	unsigned int tree_depth, i;
+	uint64_t iter_key;
+	struct cds_ja_inode_flag **node_flag_ptr;	/* in parent */
+	struct cds_ja_inode_flag *node_flag,
+		*parent_node_flag,
+		*parent2_node_flag;
+	int ret;
+
+	if (caa_unlikely(key > ja->key_max))
+		return -EINVAL;
+	tree_depth = ja->tree_depth;
+
+retry:
+	iter_key = key;
+	parent2_node_flag = NULL;
+	parent_node_flag = NULL;
+	node_flag_ptr = &ja->root;
+	node_flag = rcu_dereference(*node_flag_ptr);
+
+	/* Iterate on all internal levels */
+	for (i = 0; i < tree_depth - 1; i++) {
+		if (!ja_node_ptr(node_flag)) {
+			ret = ja_attach_node(ja, node_flag_ptr,
+					parent_node_flag, parent2_node_flag,
+					key, i, new_node);
+			if (ret == -ENOENT || ret == -EEXIST)
+				goto retry;
+			else
+				goto end;
+		}
+		parent2_node_flag = parent_node_flag;
+		parent_node_flag = node_flag;
+		node_flag = ja_node_get_nth(node_flag,
+			&node_flag_ptr,
+			(unsigned char) iter_key);
+		iter_key >>= JA_BITS_PER_BYTE;
+	}
+
+	/*
+	 * We reached bottom of tree, simply add node to last internal
+	 * level, or chain it if key is already present.
+	 */
+	if (!ja_node_ptr(node_flag)) {
+		ret = ja_attach_node(ja, node_flag_ptr, parent_node_flag,
+				parent2_node_flag, key, i, new_node);
+	} else {
+		ret = ja_chain_node(ja,
+			(struct cds_hlist_head *) ja_node_ptr(node_flag),
+			new_node);
+	}
+	if (ret == -ENOENT)
+		goto retry;
+end:
+	return ret;
+}
+
+struct cds_ja *_cds_ja_new(unsigned int key_bits,
+		const struct rcu_flavor_struct *flavor)
+{
+	struct cds_ja *ja;
+
+	ja = calloc(sizeof(*ja), 1);
+	if (!ja)
+		goto ja_error;
+
+	switch (key_bits) {
+	case 8:
+		ja->key_max = UINT8_MAX;
+		break;
+	case 16:
+		ja->key_max = UINT16_MAX;
+		break;
+	case 32:
+		ja->key_max = UINT32_MAX;
+		break;
+	case 64:
+		ja->key_max = UINT64_MAX;
+		break;
+	default:
+		goto check_error;
+	}
+
+	/* ja->root is NULL */
+	/* tree_depth 0 is for pointer to root node */
+	ja->tree_depth = (key_bits >> JA_BITS_PER_BYTE) + 1;
+	assert(ja->tree_depth <= JA_MAX_INTERNAL_DEPTH + 1);
+	ja->ht = rcuja_create_ht(flavor);
+	if (!ja->ht)
+		goto ht_error;
+	return ja;
+
+ht_error:
+check_error:
+	free(ja);
+ja_error:
+	return NULL;
+}
+
+/*
+ * There should be no more concurrent add to the judy array while it is
+ * being destroyed (ensured by the caller).
+ */
+int cds_ja_destroy(struct cds_ja *ja)
+{
+	int ret;
+
+	rcuja_shadow_prune(ja->ht,
+		RCUJA_SHADOW_CLEAR_FREE_NODE | RCUJA_SHADOW_CLEAR_FREE_LOCK);
+	ret = rcuja_delete_ht(ja->ht);
+	if (ret)
+		return ret;
+	free(ja);
+	return 0;
+}