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_BITS_PER_BYTE 3
-
-#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_child == 256 (this is the largest
} u;
};
-static
-struct cds_ja_inode_flag *ja_node_flag(struct cds_ja_inode *node,
- unsigned long type)
-{
- assert(type < (1UL << JA_TYPE_BITS));
- return (struct cds_ja_inode_flag *) (((unsigned long) node) | type);
-}
-
-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;
-}
+enum ja_recompact {
+ JA_RECOMPACT,
+ JA_RECOMPACT_ADD,
+ JA_RECOMPACT_DEL,
+};
struct cds_ja_inode *alloc_cds_ja_node(const struct cds_ja_type *ja_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]);
+ return rcu_dereference(node->u.data[0]);
}
/*
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,
+ struct cds_ja_inode_flag ***node_flag_ptr,
uint8_t n)
{
uint8_t nr_child;
if (CMM_LOAD_SHARED(values[i]) == n)
break;
}
- if (i >= nr_child)
+ if (i >= nr_child) {
+ if (caa_unlikely(node_flag_ptr))
+ *node_flag_ptr = NULL;
return NULL;
+ }
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);
+ if (caa_unlikely(child_node_flag_ptr) && ptr)
+ *child_node_flag_ptr = &pointers[i];
+ if (caa_unlikely(node_flag_ptr))
+ *node_flag_ptr = &pointers[i];
return ptr;
}
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,
+ struct cds_ja_inode_flag ***node_flag_ptr,
uint8_t n)
{
struct cds_ja_inode *linear;
*/
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);
+ return ja_linear_node_get_nth(type, linear, child_node_flag_ptr,
+ node_flag_ptr, n);
}
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,
+ struct cds_ja_inode_flag ***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];
- if (caa_unlikely(child_node_flag_ptr))
+ 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;
+ if (caa_unlikely(node_flag_ptr))
+ *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, 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,
+ struct cds_ja_inode_flag ***node_flag_ptr,
uint8_t n)
{
unsigned int type_index;
switch (type->type_class) {
case RCU_JA_LINEAR:
return ja_linear_node_get_nth(type, node,
- child_node_flag_ptr, n);
+ child_node_flag_ptr, node_flag_ptr, n);
case RCU_JA_POOL:
return ja_pool_node_get_nth(type, node,
- child_node_flag_ptr, n);
+ child_node_flag_ptr, node_flag_ptr, n);
case RCU_JA_PIGEON:
return ja_pigeon_node_get_nth(type, node,
- child_node_flag_ptr, n);
+ child_node_flag_ptr, node_flag_ptr, n);
default:
assert(0);
return (void *) -1UL;
}
}
-/*
- * 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,
uint8_t nr_child;
uint8_t *values, *nr_child_ptr;
struct cds_ja_inode_flag **pointers;
- unsigned int i;
+ unsigned int i, unused = 0;
assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL);
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)
- return -EEXIST;
+ if (values[i] == n) {
+ if (pointers[i])
+ return -EEXIST;
+ else
+ break;
+ } else {
+ if (!pointers[i])
+ unused++;
+ }
}
- if (nr_child >= type->max_linear_child) {
- /* No space left in this node type */
- return -ENOSPC;
+ 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);
}
- 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++;
dbg_printf("linear set nth: %u child, shadow: %u child, for node %p shadow %p\n",
(unsigned int) CMM_LOAD_SHARED(*nr_child_ptr),
/*
* _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,
return 0;
}
+static
+int ja_linear_node_clear_ptr(const struct cds_ja_type *type,
+ struct cds_ja_inode *node,
+ struct cds_ja_shadow_node *shadow_node,
+ struct cds_ja_inode_flag **node_flag_ptr)
+{
+ uint8_t nr_child;
+ uint8_t *nr_child_ptr;
+
+ assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL);
+
+ nr_child_ptr = &node->u.data[0];
+ dbg_printf("linear clear ptr: nr_child_ptr %p\n", nr_child_ptr);
+ nr_child = *nr_child_ptr;
+ assert(nr_child <= type->max_linear_child);
+
+ 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(*node_flag_ptr != NULL);
+ rcu_assign_pointer(*node_flag_ptr, 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 clear ptr: %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_ptr(const struct cds_ja_type *type,
+ struct cds_ja_inode *node,
+ struct cds_ja_shadow_node *shadow_node,
+ struct cds_ja_inode_flag **node_flag_ptr,
+ 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_ptr(type, linear, shadow_node, node_flag_ptr);
+}
+
+static
+int ja_pigeon_node_clear_ptr(const struct cds_ja_type *type,
+ struct cds_ja_inode *node,
+ struct cds_ja_shadow_node *shadow_node,
+ struct cds_ja_inode_flag **node_flag_ptr)
+{
+ assert(type->type_class == RCU_JA_PIGEON);
+ dbg_printf("ja_pigeon_node_clear_ptr: clearing ptr: %p\n", *node_flag_ptr);
+ rcu_assign_pointer(*node_flag_ptr, NULL);
+ shadow_node->nr_child--;
+ return 0;
+}
+
+/*
+ * _ja_node_clear_ptr: clear ptr item within a node. Return an error
+ * (negative error value) if it is not found (-ENOENT).
+ */
+static
+int _ja_node_clear_ptr(const struct cds_ja_type *type,
+ struct cds_ja_inode *node,
+ struct cds_ja_shadow_node *shadow_node,
+ struct cds_ja_inode_flag **node_flag_ptr,
+ uint8_t n)
+{
+ switch (type->type_class) {
+ case RCU_JA_LINEAR:
+ return ja_linear_node_clear_ptr(type, node, shadow_node, node_flag_ptr);
+ case RCU_JA_POOL:
+ return ja_pool_node_clear_ptr(type, node, shadow_node, node_flag_ptr, n);
+ case RCU_JA_PIGEON:
+ return ja_pigeon_node_clear_ptr(type, node, shadow_node, node_flag_ptr);
+ 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, -ENOENT if need to retry, or other negative
+ * Return 0 on success, -EAGAIN if need to retry, or other negative
* error value otherwise.
*/
static
-int ja_node_recompact_add(struct cds_ja *ja,
+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)
+ struct cds_ja_inode_flag **old_node_flag_ptr, uint8_t n,
+ struct cds_ja_inode_flag *child_node_flag,
+ struct cds_ja_inode_flag **nullify_node_flag_ptr)
{
unsigned int new_type_index;
struct cds_ja_inode *new_node;
- struct cds_ja_shadow_node *new_shadow_node;
+ struct cds_ja_shadow_node *new_shadow_node = NULL;
const struct cds_ja_type *new_type;
- struct cds_ja_inode_flag *new_node_flag;
+ struct cds_ja_inode_flag *new_node_flag, *old_node_flag;
int ret;
int fallback = 0;
- if (!shadow_node || old_type_index == NODE_INDEX_NULL) {
- new_type_index = 0;
- } else {
- new_type_index = old_type_index + 1;
+ old_node_flag = *old_node_flag_ptr;
+
+ 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 to type %d\n", new_type_index);
+ dbg_printf("Recompact from type %d to type %d\n",
+ old_type_index, new_type_index);
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);
-
- 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 (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_flag, shadow_node, ja);
+ 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;
}
- if (fallback)
- new_shadow_node->fallback_removal_count =
- JA_FALLBACK_REMOVAL_COUNT;
- assert(old_type->type_class != RCU_JA_PIGEON);
+ 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:
{
ja_linear_node_get_ith_pos(old_type, old_node, i, &v, &iter);
if (!iter)
continue;
+ if (mode == JA_RECOMPACT_DEL && *nullify_node_flag_ptr == iter)
+ continue;
ret = _ja_node_set_nth(new_type, new_node,
new_shadow_node,
v, iter);
j, &v, &iter);
if (!iter)
continue;
+ if (mode == JA_RECOMPACT_DEL && *nullify_node_flag_ptr == iter)
+ continue;
ret = _ja_node_set_nth(new_type, new_node,
new_shadow_node,
v, iter);
break;
}
case RCU_JA_NULL:
- /* Nothing to copy */
+ 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 && *nullify_node_flag_ptr == iter)
+ 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:
- /* 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 new through old_node_flag */
- *old_node_flag = new_node_flag;
+ if (mode == 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_ptr */
+ *old_node_flag_ptr = new_node_flag;
if (old_node) {
- ret = rcuja_shadow_clear(ja->ht, old_node, shadow_node,
- RCUJA_SHADOW_CLEAR_FREE_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_flag, shadow_node,
+ flags);
assert(!ret);
}
fallback_toosmall:
/* fallback if next pool is too small */
- ret = rcuja_shadow_clear(ja->ht, new_node, new_shadow_node,
+ assert(new_shadow_node);
+ ret = rcuja_shadow_clear(ja->ht, new_node_flag, new_shadow_node,
RCUJA_SHADOW_CLEAR_FREE_NODE);
assert(!ret);
- /* Last type: pigeon */
+ /* 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);
}
/*
- * Return 0 on success, -ENOENT if need to retry, or other negative
+ * Return 0 on success, -EAGAIN if need to retry, or other negative
* error value otherwise.
*/
static
type = &ja_types[type_index];
ret = _ja_node_set_nth(type, node, shadow_node,
n, child_node_flag);
- if (ret == -ENOSPC) {
+ switch (ret) {
+ case -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);
+ ret = ja_node_recompact(JA_RECOMPACT_ADD, ja, type_index, type, node,
+ shadow_node, node_flag, n, child_node_flag, NULL);
+ 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, NULL);
+ break;
}
return ret;
}
-struct cds_hlist_head *cds_ja_lookup(struct cds_ja *ja, uint64_t key)
+/*
+ * Return 0 on success, -EAGAIN if need to retry, or other negative
+ * error value otherwise.
+ */
+static
+int ja_node_clear_ptr(struct cds_ja *ja,
+ struct cds_ja_inode_flag **node_flag_ptr, /* Pointer to location to nullify */
+ struct cds_ja_inode_flag **parent_node_flag_ptr, /* Address of parent ptr in its parent */
+ struct cds_ja_shadow_node *shadow_node, /* of parent */
+ uint8_t n)
+{
+ int ret;
+ unsigned int type_index;
+ const struct cds_ja_type *type;
+ struct cds_ja_inode *node;
+
+ dbg_printf("ja_node_clear_ptr for node %p, shadow %p, target ptr %p\n",
+ ja_node_ptr(*parent_node_flag_ptr), shadow_node, node_flag_ptr);
+
+ node = ja_node_ptr(*parent_node_flag_ptr);
+ type_index = ja_node_type(*parent_node_flag_ptr);
+ type = &ja_types[type_index];
+ ret = _ja_node_clear_ptr(type, node, shadow_node, node_flag_ptr, n);
+ if (ret == -EFBIG) {
+ /* Should to try recompaction. */
+ ret = ja_node_recompact(JA_RECOMPACT_DEL, ja, type_index, type, node,
+ shadow_node, parent_node_flag_ptr, n, NULL,
+ node_flag_ptr);
+ }
+ 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;
+ struct cds_hlist_head head = { NULL };
if (caa_unlikely(key > ja->key_max))
- return NULL;
+ return head;
tree_depth = ja->tree_depth;
node_flag = rcu_dereference(ja->root);
/* level 0: root node */
if (!ja_node_ptr(node_flag))
- return NULL;
+ return head;
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,
+ node_flag = ja_node_get_nth(node_flag, NULL, 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;
+ return head;
}
/* Last level lookup succeded. We got an actual match. */
- return (struct cds_hlist_head *) node_flag;
+ head.next = (struct cds_hlist_node *) node_flag;
+ return head;
}
/*
*/
static
int ja_attach_node(struct cds_ja *ja,
+ struct cds_ja_inode_flag **attach_node_flag_ptr,
struct cds_ja_inode_flag **node_flag_ptr,
struct cds_ja_inode_flag *node_flag,
struct cds_ja_inode_flag *parent_node_flag,
struct cds_ja_node *child_node)
{
struct cds_ja_shadow_node *shadow_node = NULL,
- *parent_shadow_node = NULL,
- *iter_shadow_node;
+ *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 *created_nodes[JA_MAX_DEPTH];
int nr_created_nodes = 0;
- dbg_printf("Attach node at level %u\n", level);
+ 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);
+ shadow_node = rcuja_shadow_lookup_lock(ja->ht, node_flag);
if (!shadow_node) {
- ret = -ENOENT;
+ ret = -EAGAIN;
goto end;
}
if (parent_node) {
parent_shadow_node = rcuja_shadow_lookup_lock(ja->ht,
- parent_node);
+ parent_node_flag);
if (!parent_shadow_node) {
- ret = -ENOENT;
+ ret = -EAGAIN;
goto unlock_shadow;
}
}
+ if (node_flag_ptr && ja_node_ptr(*node_flag_ptr) != NULL) {
+ /*
+ * Attach point is non-NULL: it has been updated between
+ * RCU lookup and lock acquisition. We need to re-try
+ * lookup and attach.
+ */
+ ret = -EAGAIN;
+ goto unlock_parent;
+ }
+
/* 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;
/* 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);
+ iter_node_flag, *attach_node_flag_ptr);
+ rcu_assign_pointer(*attach_node_flag_ptr, iter_node_flag);
/* Success */
ret = 0;
if (i)
flags |= RCUJA_SHADOW_CLEAR_FREE_NODE;
tmpret = rcuja_shadow_clear(ja->ht,
- ja_node_ptr(created_nodes[i]),
+ created_nodes[i],
NULL,
flags);
assert(!tmpret);
}
}
+unlock_parent:
if (parent_shadow_node)
rcuja_shadow_unlock(parent_shadow_node);
unlock_shadow:
}
/*
- * 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.
+ * Lock the parent containing the hlist head pointer, and add node to list of
+ * duplicates. Failure can happen if concurrent update changes the
+ * parent before we get the lock. We return -EAGAIN in that case.
* Return 0 on success, negative error value on failure.
*/
static
int ja_chain_node(struct cds_ja *ja,
+ struct cds_ja_inode_flag *parent_node_flag,
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;
+ shadow_node = rcuja_shadow_lookup_lock(ja->ht, parent_node_flag);
+ if (!shadow_node) {
+ return -EAGAIN;
+ }
cds_hlist_add_head_rcu(&node->list, head);
rcuja_shadow_unlock(shadow_node);
return 0;
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 **attach_node_flag_ptr,
+ **node_flag_ptr;
struct cds_ja_inode_flag *node_flag,
*parent_node_flag,
*parent2_node_flag;
int ret;
- if (caa_unlikely(key > ja->key_max))
+ if (caa_unlikely(key > ja->key_max)) {
return -EINVAL;
+ }
tree_depth = ja->tree_depth;
retry:
parent2_node_flag = NULL;
parent_node_flag =
(struct cds_ja_inode_flag *) &ja->root; /* Use root ptr address as key for mutex */
+ attach_node_flag_ptr = &ja->root;
node_flag_ptr = &ja->root;
- node_flag = rcu_dereference(*node_flag_ptr);
+ node_flag = rcu_dereference(ja->root);
/* Iterate on all internal levels */
for (i = 1; i < tree_depth; i++) {
uint8_t iter_key;
+ dbg_printf("cds_ja_add iter attach_node_flag_ptr %p node_flag_ptr %p node_flag %p\n",
+ *attach_node_flag_ptr, *node_flag_ptr, node_flag);
if (!ja_node_ptr(node_flag)) {
- ret = ja_attach_node(ja, node_flag_ptr,
+ ret = ja_attach_node(ja, attach_node_flag_ptr,
+ node_flag_ptr,
parent_node_flag, parent2_node_flag,
key, i, new_node);
- if (ret == -ENOENT || ret == -EEXIST)
+ if (ret == -EAGAIN || 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,
+ &attach_node_flag_ptr,
&node_flag_ptr,
iter_key);
+ dbg_printf("cds_ja_add iter key lookup %u finds node_flag %p attach_node_flag_ptr %p node_flag_ptr %p\n",
+ (unsigned int) iter_key, node_flag,
+ *attach_node_flag_ptr,
+ *node_flag_ptr);
}
/*
* 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,
+ dbg_printf("cds_ja_add last attach_node_flag_ptr %p node_flag_ptr %p node_flag %p\n",
+ *attach_node_flag_ptr, *node_flag_ptr, node_flag);
+ ret = ja_attach_node(ja, attach_node_flag_ptr,
+ 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),
+ parent_node_flag,
+ (struct cds_hlist_head *) attach_node_flag_ptr,
new_node);
}
- if (ret == -ENOENT)
+ if (ret == -EAGAIN || ret == -EEXIST)
goto retry;
end:
return ret;
}
+/*
+ * Note: there is no need to lookup the pointer address associated with
+ * each node's nth item after taking the lock: it's already been done by
+ * cds_ja_del while holding the rcu read-side lock, and our node rules
+ * ensure that when a match value -> pointer is found in a node, it is
+ * _NEVER_ changed for that node without recompaction, and recompaction
+ * reallocates the node.
+ * However, when a child is removed from "linear" nodes, its pointer
+ * is set to NULL. We therefore check, while holding the locks, if this
+ * pointer is NULL, and return -ENOENT to the caller if it is the case.
+ */
+static
+int ja_detach_node(struct cds_ja *ja,
+ struct cds_ja_inode_flag **snapshot,
+ struct cds_ja_inode_flag ***snapshot_ptr,
+ uint8_t *snapshot_n,
+ int nr_snapshot,
+ uint64_t key,
+ struct cds_ja_node *node)
+{
+ struct cds_ja_shadow_node *shadow_nodes[JA_MAX_DEPTH];
+ struct cds_ja_inode_flag **node_flag_ptr = NULL,
+ *parent_node_flag = NULL,
+ **parent_node_flag_ptr = NULL;
+ struct cds_ja_inode_flag *iter_node_flag;
+ int ret, i, nr_shadow = 0, nr_clear = 0, nr_branch = 0;
+ uint8_t n = 0;
+
+ assert(nr_snapshot == ja->tree_depth + 1);
+
+ /*
+ * From the last internal level node going up, get the node
+ * lock, check if the node has only one child left. If it is the
+ * case, we continue iterating upward. When we reach a node
+ * which has more that one child left, we lock the parent, and
+ * proceed to the node deletion (removing its children too).
+ */
+ for (i = nr_snapshot - 2; i >= 1; i--) {
+ struct cds_ja_shadow_node *shadow_node;
+
+ shadow_node = rcuja_shadow_lookup_lock(ja->ht,
+ snapshot[i]);
+ if (!shadow_node) {
+ ret = -EAGAIN;
+ goto end;
+ }
+ assert(shadow_node->nr_child > 0);
+ shadow_nodes[nr_shadow++] = shadow_node;
+ if (shadow_node->nr_child == 1)
+ nr_clear++;
+ nr_branch++;
+ if (shadow_node->nr_child > 1 || i == 1) {
+ /* Lock parent and break */
+ shadow_node = rcuja_shadow_lookup_lock(ja->ht,
+ snapshot[i - 1]);
+ if (!shadow_node) {
+ ret = -EAGAIN;
+ goto end;
+ }
+ shadow_nodes[nr_shadow++] = shadow_node;
+ node_flag_ptr = snapshot_ptr[i + 1];
+ n = snapshot_n[i + 1];
+ parent_node_flag_ptr = snapshot_ptr[i];
+ parent_node_flag = snapshot[i];
+ if (i > 1) {
+ /*
+ * Lock parent's parent, in case we need
+ * to recompact parent.
+ */
+ shadow_node = rcuja_shadow_lookup_lock(ja->ht,
+ snapshot[i - 2]);
+ if (!shadow_node) {
+ ret = -EAGAIN;
+ goto end;
+ }
+ shadow_nodes[nr_shadow++] = shadow_node;
+ }
+ break;
+ }
+ }
+
+ /*
+ * Check if node has been removed between RCU lookup and lock
+ * acquisition.
+ */
+ assert(node_flag_ptr);
+ if (ja_node_ptr(*node_flag_ptr) == NULL) {
+ ret = -ENOENT;
+ goto end;
+ }
+
+ /*
+ * At this point, we want to delete all nodes that are about to
+ * be removed from shadow_nodes (except the last one, which is
+ * either the root or the parent of the upmost node with 1
+ * child). OK to as to free lock here, because RCU read lock is
+ * held, and free only performed in call_rcu.
+ */
+
+ for (i = 0; i < nr_clear; i++) {
+ ret = rcuja_shadow_clear(ja->ht,
+ shadow_nodes[i]->node_flag,
+ shadow_nodes[i],
+ RCUJA_SHADOW_CLEAR_FREE_NODE
+ | RCUJA_SHADOW_CLEAR_FREE_LOCK);
+ assert(!ret);
+ }
+
+ iter_node_flag = parent_node_flag;
+ /* Remove from parent */
+ ret = ja_node_clear_ptr(ja,
+ node_flag_ptr, /* Pointer to location to nullify */
+ &iter_node_flag, /* Old new parent ptr in its parent */
+ shadow_nodes[nr_branch - 1], /* of parent */
+ n);
+ if (ret)
+ goto end;
+
+ dbg_printf("ja_detach_node: publish %p instead of %p\n",
+ iter_node_flag, *parent_node_flag_ptr);
+ /* Update address of parent ptr in its parent */
+ rcu_assign_pointer(*parent_node_flag_ptr, iter_node_flag);
+
+end:
+ for (i = 0; i < nr_shadow; i++)
+ rcuja_shadow_unlock(shadow_nodes[i]);
+ return ret;
+}
+
+static
+int ja_unchain_node(struct cds_ja *ja,
+ struct cds_ja_inode_flag *parent_node_flag,
+ struct cds_hlist_head *head,
+ struct cds_ja_node *node)
+{
+ struct cds_ja_shadow_node *shadow_node;
+ struct cds_hlist_node *hlist_node;
+ int ret = 0, count = 0;
+
+ shadow_node = rcuja_shadow_lookup_lock(ja->ht, parent_node_flag);
+ if (!shadow_node)
+ return -EAGAIN;
+ /*
+ * Retry if another thread removed all but one of duplicates
+ * since check (that was performed without lock).
+ */
+ cds_hlist_for_each_rcu(hlist_node, head, list) {
+ count++;
+ }
+
+ if (count == 1) {
+ ret = -EAGAIN;
+ goto end;
+ }
+ cds_hlist_del_rcu(&node->list);
+end:
+ rcuja_shadow_unlock(shadow_node);
+ return ret;
+}
+
+/*
+ * Called with RCU read lock held.
+ */
+int cds_ja_del(struct cds_ja *ja, uint64_t key,
+ struct cds_ja_node *node)
+{
+ unsigned int tree_depth, i;
+ struct cds_ja_inode_flag *snapshot[JA_MAX_DEPTH];
+ struct cds_ja_inode_flag **snapshot_ptr[JA_MAX_DEPTH];
+ uint8_t snapshot_n[JA_MAX_DEPTH];
+ struct cds_ja_inode_flag *node_flag;
+ struct cds_ja_inode_flag **prev_node_flag_ptr;
+ int nr_snapshot;
+ int ret;
+
+ if (caa_unlikely(key > ja->key_max))
+ return -EINVAL;
+ tree_depth = ja->tree_depth;
+
+retry:
+ nr_snapshot = 0;
+ dbg_printf("cds_ja_del attempt: key %" PRIu64 ", node %p\n",
+ key, node);
+
+ /* snapshot for level 0 is only for shadow node lookup */
+ snapshot_n[0] = 0;
+ snapshot_n[1] = 0;
+ snapshot_ptr[nr_snapshot] = NULL;
+ snapshot[nr_snapshot++] = (struct cds_ja_inode_flag *) &ja->root;
+ node_flag = rcu_dereference(ja->root);
+ prev_node_flag_ptr = &ja->root;
+
+ /* Iterate on all internal levels */
+ for (i = 1; i < tree_depth; i++) {
+ uint8_t iter_key;
+
+ dbg_printf("cds_ja_del iter node_flag %p\n",
+ node_flag);
+ if (!ja_node_ptr(node_flag)) {
+ return -ENOENT;
+ }
+ iter_key = (uint8_t) (key >> (JA_BITS_PER_BYTE * (tree_depth - i - 1)));
+ snapshot_n[nr_snapshot + 1] = iter_key;
+ snapshot_ptr[nr_snapshot] = prev_node_flag_ptr;
+ snapshot[nr_snapshot++] = node_flag;
+ node_flag = ja_node_get_nth(node_flag,
+ &prev_node_flag_ptr,
+ NULL,
+ iter_key);
+ dbg_printf("cds_ja_del iter key lookup %u finds node_flag %p, prev_node_flag_ptr %p\n",
+ (unsigned int) iter_key, node_flag,
+ prev_node_flag_ptr);
+ }
+
+ /*
+ * We reached bottom of tree, try to find the node we are trying
+ * to remove. Fail if we cannot find it.
+ */
+ if (!ja_node_ptr(node_flag)) {
+ dbg_printf("cds_ja_del: no node found for key %" PRIu64 "\n",
+ key);
+ return -ENOENT;
+ } else {
+ struct cds_hlist_head hlist_head;
+ struct cds_hlist_node *hlist_node;
+ struct cds_ja_node *entry, *match = NULL;
+ int count = 0;
+
+ hlist_head.next =
+ (struct cds_hlist_node *) ja_node_ptr(node_flag);
+ cds_hlist_for_each_entry_rcu(entry,
+ hlist_node,
+ &hlist_head,
+ list) {
+ dbg_printf("cds_ja_del: compare %p with entry %p\n", node, entry);
+ if (entry == node)
+ match = entry;
+ count++;
+ }
+ if (!match) {
+ dbg_printf("cds_ja_del: no node match for node %p key %" PRIu64 "\n", node, key);
+ return -ENOENT;
+ }
+ assert(count > 0);
+ if (count == 1) {
+ /*
+ * Removing last of duplicates. Last snapshot
+ * does not have a shadow node (external leafs).
+ */
+ snapshot_ptr[nr_snapshot] = prev_node_flag_ptr;
+ snapshot[nr_snapshot++] = node_flag;
+ ret = ja_detach_node(ja, snapshot, snapshot_ptr,
+ snapshot_n, nr_snapshot, key, node);
+ } else {
+ ret = ja_unchain_node(ja, snapshot[nr_snapshot - 1],
+ &hlist_head, match);
+ }
+ }
+ /*
+ * Explanation of -ENOENT handling: caused by concurrent delete
+ * between RCU lookup and actual removal. Need to re-do the
+ * lookup and removal attempt.
+ */
+ if (ret == -EAGAIN || ret == -ENOENT)
+ goto retry;
+ return ret;
+}
+
struct cds_ja *_cds_ja_new(unsigned int key_bits,
const struct rcu_flavor_struct *flavor)
{
switch (key_bits) {
case 8:
- ja->key_max = UINT8_MAX;
- break;
case 16:
- ja->key_max = UINT16_MAX;
- break;
+ case 24:
case 32:
- ja->key_max = UINT32_MAX;
+ case 40:
+ case 48:
+ case 56:
+ ja->key_max = (1ULL << key_bits) - 1;
break;
case 64:
ja->key_max = UINT64_MAX;
/* ja->root is NULL */
/* tree_depth 0 is for pointer to root node */
- ja->tree_depth = (key_bits >> JA_BITS_PER_BYTE) + 1;
+ 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)
* 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);
+ (struct cds_ja_inode_flag *) &ja->root,
+ NULL, ja);
if (!root_shadow_node) {
ret = -ENOMEM;
goto ht_node_error;
}
+ root_shadow_node->level = 0;
return ja;
return NULL;
}
+/*
+ * Called from RCU read-side CS.
+ */
+__attribute__((visibility("protected")))
+void rcuja_free_all_children(struct cds_ja_shadow_node *shadow_node,
+ struct cds_ja_inode_flag *node_flag,
+ void (*free_node_cb)(struct rcu_head *head))
+{
+ const struct rcu_flavor_struct *flavor;
+ unsigned int type_index;
+ struct cds_ja_inode *node;
+ const struct cds_ja_type *type;
+
+ flavor = cds_lfht_rcu_flavor(shadow_node->ja->ht);
+ 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:
+ {
+ uint8_t nr_child =
+ ja_linear_node_get_nr_child(type, node);
+ unsigned int i;
+
+ for (i = 0; i < nr_child; i++) {
+ struct cds_ja_inode_flag *iter;
+ struct cds_hlist_head head;
+ struct cds_ja_node *entry;
+ struct cds_hlist_node *pos;
+ uint8_t v;
+
+ ja_linear_node_get_ith_pos(type, node, i, &v, &iter);
+ if (!iter)
+ continue;
+ head.next = (struct cds_hlist_node *) iter;
+ cds_hlist_for_each_entry_rcu(entry, pos, &head, list) {
+ flavor->update_call_rcu(&entry->head, free_node_cb);
+ }
+ }
+ break;
+ }
+ case RCU_JA_POOL:
+ {
+ unsigned int pool_nr;
+
+ for (pool_nr = 0; pool_nr < (1U << type->nr_pool_order); pool_nr++) {
+ struct cds_ja_inode *pool =
+ ja_pool_node_get_ith_pool(type, node, pool_nr);
+ uint8_t nr_child =
+ ja_linear_node_get_nr_child(type, pool);
+ unsigned int j;
+
+ for (j = 0; j < nr_child; j++) {
+ struct cds_ja_inode_flag *iter;
+ struct cds_hlist_head head;
+ struct cds_ja_node *entry;
+ struct cds_hlist_node *pos;
+ uint8_t v;
+
+ ja_linear_node_get_ith_pos(type, node, j, &v, &iter);
+ if (!iter)
+ continue;
+ head.next = (struct cds_hlist_node *) iter;
+ cds_hlist_for_each_entry_rcu(entry, pos, &head, list) {
+ flavor->update_call_rcu(&entry->head, free_node_cb);
+ }
+ }
+ }
+ break;
+ }
+ case RCU_JA_NULL:
+ break;
+ case RCU_JA_PIGEON:
+ {
+ uint8_t nr_child;
+ unsigned int i;
+
+ nr_child = shadow_node->nr_child;
+ for (i = 0; i < nr_child; i++) {
+ struct cds_ja_inode_flag *iter;
+ struct cds_hlist_head head;
+ struct cds_ja_node *entry;
+ struct cds_hlist_node *pos;
+
+ iter = ja_pigeon_node_get_ith_pos(type, node, i);
+ if (!iter)
+ continue;
+ head.next = (struct cds_hlist_node *) iter;
+ cds_hlist_for_each_entry_rcu(entry, pos, &head, list) {
+ flavor->update_call_rcu(&entry->head, free_node_cb);
+ }
+ }
+ break;
+ }
+ default:
+ assert(0);
+ }
+}
+
/*
* 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 cds_ja_destroy(struct cds_ja *ja,
+ void (*free_node_cb)(struct rcu_head *head))
{
int ret;
rcuja_shadow_prune(ja->ht,
- RCUJA_SHADOW_CLEAR_FREE_NODE | RCUJA_SHADOW_CLEAR_FREE_LOCK);
+ RCUJA_SHADOW_CLEAR_FREE_NODE | RCUJA_SHADOW_CLEAR_FREE_LOCK,
+ free_node_cb);
ret = rcuja_delete_ht(ja->ht);
if (ret)
return ret;
projects / urcu.git / blobdiff