* 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 <urcu/uatomic.h>
+#include <stdint.h>
+
#include "rcuja-internal.h"
+#include "bitfield.h"
-enum rcu_ja_child_type {
+enum cds_ja_type_class {
RCU_JA_LINEAR = 0, /* Type A */
- /* 32-bit: 1 to 12 children, 8 to 64 bytes */
- /* 64-bit: 1 to 14 children, 16 to 128 bytes */
- RCU_JA_BITMAP = 1, /* Type B */
- /* 32-bit: 13 to 120 children, 128 to 512 bytes */
- /* 64-bit: 15 to 124 children, 256 to 1024 bytes */
+ /* 32-bit: 1 to 25 children, 8 to 128 bytes */
+ /* 64-bit: 1 to 28 children, 16 to 256 bytes */
+ RCU_JA_POOL = 1, /* Type B */
+ /* 32-bit: 26 to 100 children, 256 to 512 bytes */
+ /* 64-bit: 29 to 112 children, 512 to 1024 bytes */
RCU_JA_PIGEON = 2, /* Type C */
- /* 32-bit: 121 to 256 children, 1024 bytes */
- /* 64-bit: 125 to 256 children, 2048 bytes */
+ /* 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_select {
- enum rcu_ja_child_type type;
- uint16_t max_nr_child; /* 1 to 256 */
- uint16_t node_order; /* node size is (1 << node_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 */
};
+/*
+ * Number of least significant pointer bits reserved to represent the
+ * child type.
+ */
+#define JA_TYPE_BITS 3
+#define JA_TYPE_MAX_NR (1UL << JA_TYPE_BITS)
+#define JA_TYPE_MASK (JA_TYPE_MAX_NR - 1)
+#define JA_PTR_MASK (~JA_TYPE_MASK)
+
+#define JA_ENTRY_PER_NODE 256UL
+#define JA_LOG2_BITS_PER_BYTE 3U
+#define JA_BITS_PER_BYTE (1U << JA_LOG2_BITS_PER_BYTE)
+
+#define JA_MAX_DEPTH 9 /* Maximum depth, including leafs */
+
+/*
+ * Entry for NULL node is at index 8 of the table. It is never encoded
+ * in flags.
+ */
+#define NODE_INDEX_NULL 8
+
+/*
+ * Number of removals needed on a fallback node before we try to shrink
+ * it.
+ */
+#define JA_FALLBACK_REMOVAL_COUNT 8
+
/*
* Iteration on the array to find the right node size for the number of
- * children stops when it reaches max_nr_child == 0 (this is the largest
+ * children stops when it reaches .max_child == 256 (this is the largest
* possible node size, which contains 256 children).
+ * The min_child overlaps with the previous max_child to provide an
+ * hysteresis loop to reallocation for patterns of cyclic add/removal
+ * within the same node.
+ * 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.
*/
-const struct rcu_ja_type_select ja_select_u32[] = {
- { .type = RCU_JA_LINEAR, .max_nr_child = 1, .node_order = 3, },
- { .type = RCU_JA_LINEAR, .max_nr_child = 3, .node_order = 4, },
- { .type = RCU_JA_LINEAR, .max_nr_child = 6, .node_order = 5, },
- { .type = RCU_JA_LINEAR, .max_nr_child = 12, .node_order = 6, },
- { .type = RCU_JA_BITMAP, .max_nr_child = 24, .node_order = 7, },
- { .type = RCU_JA_BITMAP, .max_nr_child = 56, .node_order = 8, },
- { .type = RCU_JA_BITMAP, .max_nr_child = 120, .node_order = 9, },
+#if (CAA_BITS_PER_LONG < 64)
+/* 32-bit pointers */
+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 = 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, },
- { .type = RCU_JA_PIGEON, .max_nr_child = 256, .node_order = 10, },
+ /*
+ * 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, },
+
+ { .type_class = RCU_JA_NULL, .min_child = 0, .max_child = ja_type_8_max_child, },
+};
+#else /* !(CAA_BITS_PER_LONG < 64) */
+/* 64-bit pointers */
+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,
+};
+
+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,
};
-const struct rcu_ja_type_select ja_select_u64[] = {
- { .type = RCU_JA_LINEAR, .max_nr_child = 1, .node_order = 4, },
- { .type = RCU_JA_LINEAR, .max_nr_child = 3, .node_order = 5, },
- { .type = RCU_JA_LINEAR, .max_nr_child = 7, .node_order = 6, },
- { .type = RCU_JA_LINEAR, .max_nr_child = 14, .node_order = 7, },
+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, },
- { .type = RCU_JA_BITMAP, .max_nr_child = 28, .node_order = 8, },
- { .type = RCU_JA_BITMAP, .max_nr_child = 60, .node_order = 9, },
- { .type = RCU_JA_BITMAP, .max_nr_child = 124, .node_order = 10, },
+ /*
+ * 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 = RCU_JA_PIGEON, .max_nr_child = 256, .node_order = 11, },
+ { .type_class = RCU_JA_NULL, .min_child = 0, .max_child = ja_type_8_max_child, },
};
+#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;
+};
+
+enum ja_recompact {
+ JA_RECOMPACT,
+ JA_RECOMPACT_ADD,
+ JA_RECOMPACT_DEL,
};
-struct rcu_ja_node *create_rcu_ja_node(struct rcu_ja_type_select *sel)
+static
+struct cds_ja_inode_flag *ja_node_flag(struct cds_ja_inode *node,
+ unsigned long type)
{
- return zmalloc(1 << sel->node_order);
+ assert(type < (1UL << JA_TYPE_BITS));
+ return (struct cds_ja_inode_flag *) (((unsigned long) node) | type);
}
-void free_rcu_ja_node(struct rcu_ja_node *node)
+static
+struct cds_ja_inode *ja_node_ptr(struct cds_ja_inode_flag *node)
+{
+ return (struct cds_ja_inode *) (((unsigned long) node) & JA_PTR_MASK);
+}
+
+static
+unsigned long ja_node_type(struct cds_ja_inode_flag *node)
+{
+ unsigned long type;
+
+ if (ja_node_ptr(node) == NULL) {
+ return NODE_INDEX_NULL;
+ }
+ type = (unsigned int) ((unsigned long) node & JA_TYPE_MASK);
+ assert(type < (1UL << JA_TYPE_BITS));
+ return type;
+}
+
+struct cds_ja_inode *alloc_cds_ja_node(const struct cds_ja_type *ja_type)
+{
+ return calloc(1U << ja_type->order, sizeof(char));
+}
+
+void free_cds_ja_node(struct cds_ja_inode *node)
{
free(node);
}
+#define __JA_ALIGN_MASK(v, mask) (((v) + (mask)) & ~(mask))
+#define JA_ALIGN(v, align) __JA_ALIGN_MASK(v, (typeof(v)) (align) - 1)
+#define __JA_FLOOR_MASK(v, mask) ((v) & ~(mask))
+#define JA_FLOOR(v, align) __JA_FLOOR_MASK(v, (typeof(v)) (align) - 1)
+
+static
+uint8_t *align_ptr_size(uint8_t *ptr)
+{
+ return (uint8_t *) JA_ALIGN((unsigned long) ptr, sizeof(void *));
+}
+
+static
+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 rcu_dereference(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 cds_ja_inode_flag **pointers;
+ struct cds_ja_inode_flag *ptr;
+ unsigned int i;
+
+ assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL);
+
+ 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->u.data[1];
+ for (i = 0; i < nr_child; i++) {
+ if (CMM_LOAD_SHARED(values[i]) == n)
+ break;
+ }
+ if (i >= nr_child)
+ return NULL;
+ pointers = (struct cds_ja_inode_flag **) align_ptr_size(&values[type->max_linear_child]);
+ ptr = rcu_dereference(pointers[i]);
+ if (caa_unlikely(child_node_flag_ptr) && ptr)
+ *child_node_flag_ptr = &pointers[i];
+ return ptr;
+}
+
+static
+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)
+{
+ 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);
+ return (struct cds_ja_inode *)
+ &node->u.data[(unsigned int) i << type->pool_size_order];
+}
+
+static
+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);
+ child_node_flag = &((struct cds_ja_inode_flag **) node->u.data)[n];
+ dbg_printf("ja_pigeon_node_get_nth child_node_flag_ptr %p\n",
+ child_node_flag);
+ if (caa_unlikely(child_node_flag_ptr) && *child_node_flag)
+ *child_node_flag_ptr = child_node_flag;
+ return rcu_dereference(*child_node_flag);
+}
+
+static
+struct cds_ja_inode_flag *ja_pigeon_node_get_ith_pos(const struct cds_ja_type *type,
+ struct cds_ja_inode *node,
+ uint8_t i)
+{
+ return ja_pigeon_node_get_nth(type, node, NULL, i);
+}
+
+/*
+ * ja_node_get_nth: get nth item from a node.
+ * node_flag is already rcu_dereference'd.
+ */
+static
+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 cds_ja_inode *node;
+ const struct cds_ja_type *type;
+
+ node = ja_node_ptr(node_flag);
+ assert(node != NULL);
+ type_index = ja_node_type(node_flag);
+ type = &ja_types[type_index];
+
+ switch (type->type_class) {
+ case RCU_JA_LINEAR:
+ 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,
+ child_node_flag_ptr, n);
+ case RCU_JA_PIGEON:
+ return ja_pigeon_node_get_nth(type, node,
+ child_node_flag_ptr, n);
+ default:
+ assert(0);
+ return (void *) -1UL;
+ }
+}
+
+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, unused = 0;
+
+ assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL);
+
+ nr_child_ptr = &node->u.data[0];
+ dbg_printf("linear set nth: nr_child_ptr %p\n", nr_child_ptr);
+ nr_child = *nr_child_ptr;
+ assert(nr_child <= type->max_linear_child);
+
+ values = &node->u.data[1];
+ pointers = (struct cds_ja_inode_flag **) align_ptr_size(&values[type->max_linear_child]);
+ /* Check if node value is already populated */
+ for (i = 0; i < nr_child; i++) {
+ if (values[i] == n) {
+ if (pointers[i])
+ return -EEXIST;
+ else
+ break;
+ } else {
+ if (!pointers[i])
+ unused++;
+ }
+ }
+ if (i == nr_child && nr_child >= type->max_linear_child) {
+ if (unused)
+ return -ERANGE; /* recompact node */
+ else
+ return -ENOSPC; /* No space left in this node type */
+ }
+
+ assert(pointers[i] == NULL);
+ rcu_assign_pointer(pointers[i], child_node_flag);
+ /* If we expanded the nr_child, increment it */
+ if (i == nr_child) {
+ CMM_STORE_SHARED(values[nr_child], n);
+ /* write pointer and value before nr_child */
+ cmm_smp_wmb();
+ CMM_STORE_SHARED(*nr_child_ptr, nr_child + 1);
+ }
+ shadow_node->nr_child++;
+ dbg_printf("linear set nth: %u child, shadow: %u child, for node %p shadow %p\n",
+ (unsigned int) CMM_LOAD_SHARED(*nr_child_ptr),
+ (unsigned int) shadow_node->nr_child,
+ node, shadow_node);
+
+ 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.
+ */
+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;
+}
+
+static
+int ja_linear_node_clear_nth(const struct cds_ja_type *type,
+ struct cds_ja_inode *node,
+ struct cds_ja_shadow_node *shadow_node,
+ uint8_t n)
+{
+ 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];
+ dbg_printf("linear clear nth: nr_child_ptr %p\n", nr_child_ptr);
+ nr_child = *nr_child_ptr;
+ assert(nr_child <= type->max_linear_child);
+
+ values = &node->u.data[1];
+ pointers = (struct cds_ja_inode_flag **) align_ptr_size(&values[type->max_linear_child]);
+ for (i = 0; i < nr_child; i++) {
+ if (values[i] == n) {
+ if (pointers[i])
+ break;
+ else
+ return -ENOENT;
+ }
+ }
+ if (i >= nr_child)
+ return -ENOENT;
+ if (shadow_node->fallback_removal_count) {
+ shadow_node->fallback_removal_count--;
+ } else {
+ if (shadow_node->nr_child <= type->min_child) {
+ /* We need to try recompacting the node */
+ return -EFBIG;
+ }
+ }
+ assert(pointers[i] != NULL);
+ rcu_assign_pointer(pointers[i], NULL);
+ /*
+ * Value and nr_child are never changed (would cause ABA issue).
+ * Instead, we leave the pointer to NULL and recompact the node
+ * once in a while. It is allowed to set a NULL pointer to a new
+ * value without recompaction though.
+ * Only update the shadow node accounting.
+ */
+ shadow_node->nr_child--;
+ dbg_printf("linear set nth: %u child, shadow: %u child, for node %p shadow %p\n",
+ (unsigned int) CMM_LOAD_SHARED(*nr_child_ptr),
+ (unsigned int) shadow_node->nr_child,
+ node, shadow_node);
+
+ return 0;
+}
+
+static
+int ja_pool_node_clear_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 *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_clear_nth(type, linear, shadow_node, n);
+}
+
+static
+int ja_pigeon_node_clear_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 **ptr;
+
+ assert(type->type_class == RCU_JA_PIGEON);
+ ptr = &((struct cds_ja_inode_flag **) node->u.data)[n];
+ if (!*ptr)
+ return -ENOENT;
+ rcu_assign_pointer(*ptr, NULL);
+ shadow_node->nr_child--;
+ return 0;
+}
+
+/*
+ * _ja_node_clear_nth: clear nth item within a node. Return an error
+ * (negative error value) if it is not found (-ENOENT).
+ */
+static
+int _ja_node_clear_nth(const struct cds_ja_type *type,
+ struct cds_ja_inode *node,
+ struct cds_ja_shadow_node *shadow_node,
+ uint8_t n)
+{
+ switch (type->type_class) {
+ case RCU_JA_LINEAR:
+ return ja_linear_node_clear_nth(type, node, shadow_node, n);
+ case RCU_JA_POOL:
+ return ja_pool_node_clear_nth(type, node, shadow_node, n);
+ case RCU_JA_PIGEON:
+ return ja_pigeon_node_clear_nth(type, node, shadow_node, n);
+ case RCU_JA_NULL:
+ return -ENOENT;
+ 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, -EAGAIN if need to retry, or other negative
+ * error value otherwise.
+ */
+static
+int ja_node_recompact(enum ja_recompact mode,
+ 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;
+ struct cds_ja_shadow_node *new_shadow_node;
+ const struct cds_ja_type *new_type;
+ struct cds_ja_inode_flag *new_node_flag;
+ int ret;
+ int fallback = 0;
+
+ switch (mode) {
+ case JA_RECOMPACT:
+ new_type_index = old_type_index;
+ break;
+ case JA_RECOMPACT_ADD:
+ if (!shadow_node || old_type_index == NODE_INDEX_NULL) {
+ new_type_index = 0;
+ } else {
+ new_type_index = old_type_index + 1;
+ }
+ break;
+ case JA_RECOMPACT_DEL:
+ if (old_type_index == 0) {
+ new_type_index = NODE_INDEX_NULL;
+ } else {
+ new_type_index = old_type_index - 1;
+ }
+ break;
+ default:
+ assert(0);
+ }
+
+retry: /* for fallback */
+ dbg_printf("Recompact from type %d to type %d\n",
+ old_type_index, new_type_index);
+ new_type = &ja_types[new_type_index];
+ if (new_type_index != NODE_INDEX_NULL) {
+ new_node = alloc_cds_ja_node(new_type);
+ if (!new_node)
+ return -ENOMEM;
+ new_node_flag = ja_node_flag(new_node, new_type_index);
+ dbg_printf("Recompact inherit lock from %p\n", shadow_node);
+ new_shadow_node = rcuja_shadow_set(ja->ht, new_node, shadow_node);
+ if (!new_shadow_node) {
+ free(new_node);
+ return -ENOMEM;
+ }
+ if (fallback)
+ new_shadow_node->fallback_removal_count =
+ JA_FALLBACK_REMOVAL_COUNT;
+ } else {
+ new_node = NULL;
+ new_node_flag = NULL;
+ }
+
+ assert(mode != JA_RECOMPACT_ADD || old_type->type_class != RCU_JA_PIGEON);
+
+ if (new_type_index == NODE_INDEX_NULL)
+ goto skip_copy;
+
+ 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;
+ if (mode == JA_RECOMPACT_DEL && v == n)
+ continue;
+ ret = _ja_node_set_nth(new_type, new_node,
+ new_shadow_node,
+ v, iter);
+ if (new_type->type_class == RCU_JA_POOL && ret) {
+ goto fallback_toosmall;
+ }
+ 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;
+ if (mode == JA_RECOMPACT_DEL && v == n)
+ continue;
+ ret = _ja_node_set_nth(new_type, new_node,
+ new_shadow_node,
+ v, iter);
+ if (new_type->type_class == RCU_JA_POOL
+ && ret) {
+ goto fallback_toosmall;
+ }
+ assert(!ret);
+ }
+ }
+ break;
+ }
+ case RCU_JA_NULL:
+ assert(mode == JA_RECOMPACT_ADD);
+ break;
+ case RCU_JA_PIGEON:
+ {
+ uint8_t nr_child;
+ unsigned int i;
+
+ assert(mode == JA_RECOMPACT_DEL);
+ nr_child = shadow_node->nr_child;
+ for (i = 0; i < nr_child; i++) {
+ struct cds_ja_inode_flag *iter;
+
+ iter = ja_pigeon_node_get_ith_pos(old_type, old_node, i);
+ if (!iter)
+ continue;
+ if (mode == JA_RECOMPACT_DEL && i == n)
+ continue;
+ ret = _ja_node_set_nth(new_type, new_node,
+ new_shadow_node,
+ i, iter);
+ if (new_type->type_class == RCU_JA_POOL && ret) {
+ goto fallback_toosmall;
+ }
+ assert(!ret);
+ }
+ break;
+ }
+ default:
+ assert(0);
+ ret = -EINVAL;
+ goto end;
+ }
+skip_copy:
+
+ if (JA_RECOMPACT_ADD) {
+ /* add node */
+ ret = _ja_node_set_nth(new_type, new_node,
+ new_shadow_node,
+ n, child_node_flag);
+ assert(!ret);
+ }
+ /* Return pointer to new recompacted node through old_node_flag */
+ *old_node_flag = new_node_flag;
+ if (old_node) {
+ int flags;
+
+ flags = RCUJA_SHADOW_CLEAR_FREE_NODE;
+ /*
+ * It is OK to free the lock associated with a node
+ * going to NULL, since we are holding the parent lock.
+ * This synchronizes removal with re-add of that node.
+ */
+ if (new_type_index == NODE_INDEX_NULL)
+ flags = RCUJA_SHADOW_CLEAR_FREE_LOCK;
+ ret = rcuja_shadow_clear(ja->ht, old_node, shadow_node,
+ flags);
+ assert(!ret);
+ }
+
+ ret = 0;
+end:
+ return ret;
+
+fallback_toosmall:
+ /* fallback if next pool is too small */
+ ret = rcuja_shadow_clear(ja->ht, new_node, new_shadow_node,
+ RCUJA_SHADOW_CLEAR_FREE_NODE);
+ assert(!ret);
+
+ /* Choose fallback type: pigeon */
+ new_type_index = (1UL << JA_TYPE_BITS) - 1;
+ dbg_printf("Fallback to type %d\n", new_type_index);
+ uatomic_inc(&ja->nr_fallback);
+ fallback = 1;
+ goto retry;
+}
+
+/*
+ * Return 0 on success, -EAGAIN 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;
+
+ dbg_printf("ja_node_set_nth for n=%u, node %p, shadow %p\n",
+ (unsigned int) n, ja_node_ptr(*node_flag), shadow_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);
+ switch (ret) {
+ case -ENOSPC:
+ /* Not enough space in node, need to recompact. */
+ ret = ja_node_recompact(JA_RECOMPACT_ADD, ja, type_index, type, node,
+ shadow_node, node_flag, n, child_node_flag);
+ break;
+ case -ERANGE:
+ /* Node needs to be recompacted. */
+ ret = ja_node_recompact(JA_RECOMPACT, ja, type_index, type, node,
+ shadow_node, node_flag, n, child_node_flag);
+ break;
+ }
+ return ret;
+}
+
+/*
+ * Return 0 on success, -EAGAIN if need to retry, or other negative
+ * error value otherwise.
+ */
+static
+int ja_node_clear_nth(struct cds_ja *ja,
+ struct cds_ja_inode_flag **node_flag, uint8_t n,
+ struct cds_ja_shadow_node *shadow_node)
+{
+ int ret;
+ unsigned int type_index;
+ const struct cds_ja_type *type;
+ struct cds_ja_inode *node;
+
+ dbg_printf("ja_node_clear_nth for n=%u, node %p, shadow %p\n",
+ (unsigned int) n, ja_node_ptr(*node_flag), shadow_node);
+
+ node = ja_node_ptr(*node_flag);
+ type_index = ja_node_type(*node_flag);
+ type = &ja_types[type_index];
+ ret = _ja_node_clear_nth(type, node, shadow_node, n);
+ if (ret == -EFBIG) {
+ /* Should to try recompaction. */
+ ret = ja_node_recompact(JA_RECOMPACT_DEL, ja, type_index, type, node,
+ shadow_node, node_flag, n, NULL);
+ }
+ 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++) {
+ uint8_t iter_key;
+
+ iter_key = (uint8_t) (key >> (JA_BITS_PER_BYTE * (tree_depth - i - 1)));
+ node_flag = ja_node_get_nth(node_flag, NULL,
+ iter_key);
+ dbg_printf("cds_ja_lookup iter key lookup %u finds node_flag %p\n",
+ (unsigned int) iter_key, node_flag);
+ if (!ja_node_ptr(node_flag))
+ return NULL;
+ }
+
+ /* 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 level,
+ struct cds_ja_node *child_node)
+{
+ struct cds_ja_shadow_node *shadow_node = NULL,
+ *parent_shadow_node = NULL,
+ *iter_shadow_node;
+ 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_DEPTH];
+ int nr_created_nodes = 0;
+
+ dbg_printf("Attach node at level %u (node %p, node_flag %p)\n",
+ level, node, node_flag);
+
+ assert(node);
+ shadow_node = rcuja_shadow_lookup_lock(ja->ht, node);
+ if (!shadow_node) {
+ ret = -EAGAIN;
+ goto end;
+ }
+ if (parent_node) {
+ parent_shadow_node = rcuja_shadow_lookup_lock(ja->ht,
+ parent_node);
+ if (!parent_shadow_node) {
+ ret = -EAGAIN;
+ goto unlock_shadow;
+ }
+ }
+
+ /* Create new branch, starting from bottom */
+ CDS_INIT_HLIST_HEAD(&head);
+ cds_hlist_add_head_rcu(&child_node->list, &head);
+ iter_node_flag = (struct cds_ja_inode_flag *) head.next;
+
+ /* Create shadow node for the leaf node */
+ dbg_printf("leaf shadow node creation\n");
+ iter_shadow_node = rcuja_shadow_set(ja->ht,
+ ja_node_ptr(iter_node_flag), NULL);
+ if (!iter_shadow_node) {
+ ret = -ENOMEM;
+ goto check_error;
+ }
+ created_nodes[nr_created_nodes++] = iter_node_flag;
+
+ for (i = ja->tree_depth; i > (int) level; i--) {
+ uint8_t iter_key;
+
+ iter_key = (uint8_t) (key >> (JA_BITS_PER_BYTE * (ja->tree_depth - i)));
+ dbg_printf("branch creation level %d, key %u\n",
+ i - 1, (unsigned int) iter_key);
+ iter_dest_node_flag = NULL;
+ ret = ja_node_set_nth(ja, &iter_dest_node_flag,
+ iter_key,
+ 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;
+ }
+ if (level > 1) {
+ uint8_t iter_key;
+ iter_key = (uint8_t) (key >> (JA_BITS_PER_BYTE * (ja->tree_depth - level)));
+ /* We need to use set_nth on the previous level. */
+ iter_dest_node_flag = node_flag;
+ ret = ja_node_set_nth(ja, &iter_dest_node_flag,
+ iter_key,
+ iter_node_flag,
+ shadow_node);
+ if (ret)
+ goto check_error;
+ created_nodes[nr_created_nodes++] = iter_dest_node_flag;
+ iter_node_flag = iter_dest_node_flag;
+ }
+
+ /* Publish new branch */
+ dbg_printf("Publish branch %p, replacing %p\n",
+ iter_node_flag, *node_flag_ptr);
+ 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;
+ int flags;
+
+ flags = RCUJA_SHADOW_CLEAR_FREE_LOCK;
+ if (i)
+ flags |= RCUJA_SHADOW_CLEAR_FREE_NODE;
+ tmpret = rcuja_shadow_clear(ja->ht,
+ ja_node_ptr(created_nodes[i]),
+ NULL,
+ flags);
+ assert(!tmpret);
+ }
+ }
+ 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 -EAGAIN;
+ 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;
+ 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:
+ dbg_printf("cds_ja_add attempt: key %" PRIu64 ", node %p\n",
+ key, new_node);
+ parent2_node_flag = NULL;
+ parent_node_flag =
+ (struct cds_ja_inode_flag *) &ja->root; /* Use root ptr address as key for mutex */
+ node_flag_ptr = &ja->root;
+ node_flag = rcu_dereference(*node_flag_ptr);
+
+ /* Iterate on all internal levels */
+ for (i = 1; i < tree_depth; i++) {
+ uint8_t iter_key;
+
+ dbg_printf("cds_ja_add iter node_flag_ptr %p node_flag %p\n",
+ *node_flag_ptr, node_flag);
+ 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 == -EAGAIN || ret == -EEXIST)
+ goto retry;
+ else
+ goto end;
+ }
+ iter_key = (uint8_t) (key >> (JA_BITS_PER_BYTE * (tree_depth - i - 1)));
+ parent2_node_flag = parent_node_flag;
+ parent_node_flag = node_flag;
+ node_flag = ja_node_get_nth(node_flag,
+ &node_flag_ptr,
+ iter_key);
+ dbg_printf("cds_ja_add iter key lookup %u finds node_flag %p node_flag_ptr %p\n",
+ (unsigned int) iter_key, node_flag, *node_flag_ptr);
+ }
+
+ /*
+ * 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)) {
+ dbg_printf("cds_ja_add last node_flag_ptr %p node_flag %p\n",
+ *node_flag_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 == -EAGAIN)
+ 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;
+ int ret;
+ struct cds_ja_shadow_node *root_shadow_node;
+
+ 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_LOG2_BITS_PER_BYTE) + 1;
+ assert(ja->tree_depth <= JA_MAX_DEPTH);
+ ja->ht = rcuja_create_ht(flavor);
+ if (!ja->ht)
+ goto ht_error;
+
+ /*
+ * Note: we should not free this node until judy array destroy.
+ */
+ root_shadow_node = rcuja_shadow_set(ja->ht,
+ ja_node_ptr((struct cds_ja_inode_flag *) &ja->root),
+ NULL);
+ if (!root_shadow_node) {
+ ret = -ENOMEM;
+ goto ht_node_error;
+ }
+ root_shadow_node->is_root = 1;
+
+ return ja;
+
+ht_node_error:
+ ret = rcuja_delete_ht(ja->ht);
+ assert(!ret);
+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;
+ if (uatomic_read(&ja->nr_fallback))
+ fprintf(stderr,
+ "[warning] RCU Judy Array used %lu fallback node(s)\n",
+ uatomic_read(&ja->nr_fallback));
+ free(ja);
+ return 0;
+}
projects / userspace-rcu.git / blobdiff