#include <pthread.h>
#include <assert.h>
#include <string.h>
+#include <unistd.h>
+#include <errno.h>
#include <urcu/rcurbtree.h>
#include <urcu-pointer.h>
#include <urcu-call-rcu.h>
+#include <urcu/compiler.h>
-#define DEBUG
+/*
+ * Explanation of next/prev walk coherency and search coherency when
+ * performed concurrently with updates.
+ *
+ * next/prev walk coherency with respect to concurrent updates:
+ *
+ * There are 3 scenarios for which we need to model and validate this:
+ * rotation, transplant and "teleportation" (the latter being a remote
+ * transplant in a remove non-nil case).
+ *
+ * - rotation left (right is symmetric)
+ * xl and yr point to the same parent nodes before/after left
+ * rotation. yll and ylr also point to the same parent node
+ * before/after left rotation.
+ * As we are copying x, y and yl (the 3 nodes which parent/child
+ * relationship are changed) to "new" version of this node cluster,
+ * all external references to the cluster either point to the old
+ * cluster or the new one. If we take this cluster as a "black box"
+ * from the point of view of next/prev traversal, all we have to
+ * ensure is that the old and the new cluster behave in the exact same
+ * way with respect to traversal order.
+ *
+ * - transplant
+ * In this operation, we transplant a copy of "v" into its parent
+ * location (u), thus replacing it. The children of "v", vl and vr,
+ * still point to v (new version) after the transplant, so it does not
+ * change the behavior when considering the next/prev traversal. "v"
+ * being copied to a new version ensures that the parent pointers of v
+ * are pointing to its new parent (parent of u) before it is published
+ * to readers (by setting the child pointer of u's parent to the new
+ * copy of v).
+ *
+ * - teleportation
+ * This one is probably the most tricky and will require some ascii
+ * art to explain.
+ *
+ * We want to remove z from this tree:
+ *
+ * zp
+ * \
+ * z
+ * / \
+ * zl zr
+ * /
+ * a
+ * / \
+ * b ar
+ * / \
+ * y br
+ * \
+ * yr
+ * / \
+ * yrl yrr
+ *
+ * What we are going to do is to "teleport" y into z's location,
+ * reparenting yr to b. We are taking care to create a new cluster
+ * copy that is isolated from any reader. We will represent the new
+ * members of the cluster with capital letters.
+ *
+ * zp
+ * \
+ * Y
+ * / \
+ * zl ZR
+ * /
+ * A
+ * / \
+ * B ar
+ * / \
+ * YR br
+ * / \
+ * yrl yrr
+ *
+ * In this transient state, we notice that the pointers within the
+ * cluster all point to the new cluster nodes, and they point to the
+ * correct external nodes. However, no external pointer point to the
+ * cluster (yet). The first pointer to point to this cluster will be
+ * "zp->right". It will therefore make the cluster visible for search.
+ *
+ * In this intermediate state, we can walk through the new cluster
+ * when coming from the top (in a next/prev traversal), but can come
+ * back to the old cluster when going back up from the children nodes.
+ * All we have to ensure is that the two clusters, taken as a black
+ * box from a next/prev traversal perspective, yield to the exact same
+ * result.
+ *
+ * Search coherency with concurrent updates:
+ *
+ * Simple "search" (only going down the tree) is also handled by this
+ * cluster scheme. The explanation is a subset of the prev/next
+ * explanation, where we don't have to care about the intermediate
+ * stages where the children point to the old cluster, because we only
+ * ever use the top level pointers to go down into the children nodes,
+ * we never go back up. So by simply making sure that all the cluster
+ * internal nodes pointers are setup correctly before making the
+ * cluster visible to the readers (by setting the parent pointer to
+ * the topmost new node in the cluster), we are sure that readers will
+ * see a coherent view of the cluster at all times.
+ */
#ifdef DEBUG
#define dbg_printf(args...) printf(args)
+#define dbg_usleep(usecs) usleep(usecs)
#else
#define dbg_printf(args...)
+#define dbg_usleep(usecs)
#endif
+/*
+ * Undefine this to enable the non-RCU rotate and transplant functions
+ * (for debugging). Note that these versions don't support the tree
+ * max_end updates, so lookups must be performed with
+ * rcu_rbtree_search_begin_key when using this debug facility.
+ */
+#define RBTREE_RCU_SUPPORT_ROTATE_LEFT
+#define RBTREE_RCU_SUPPORT_ROTATE_RIGHT
+#define RBTREE_RCU_SUPPORT_TRANSPLANT
+#define RBTREE_RCU_SUPPORT
+
+#ifdef RBTREE_RCU_SUPPORT
+#define c_rcu_dereference(x) rcu_dereference(x)
+#define c_cmm_smp_wmb() cmm_smp_wmb()
+#define c_cmm_smp_wmc() cmm_smp_wmc()
+#define C_CMM_STORE_SHARED(x, v) CMM_STORE_SHARED(x, v)
+#define C__CMM_STORE_SHARED(x, v) _CMM_STORE_SHARED(x, v)
+#else
+#define c_rcu_dereference(x) (x)
+#define c_cmm_smp_wmb()
+#define c_cmm_smp_wmc()
+#define C_CMM_STORE_SHARED(x, v) ((x) = (v))
+#define C__CMM_STORE_SHARED(x, v) ((x) = (v))
+#endif
+
+/*
+ * Add internal mutex locking within the RBTree, for debugging. Enable this
+ * define and add mutexes to RCU readers to debug races with with rotation or
+ * transplant.
+ */
+/* #define RBTREE_INTERNAL_LOCKING */
+
+#ifdef RBTREE_INTERNAL_LOCKING
+static pthread_mutex_t test_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t outer_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+static
+void lock_outer_mutex(void)
+{
+ pthread_mutex_lock(&outer_mutex);
+}
+
+static
+void unlock_outer_mutex(void)
+{
+ pthread_mutex_unlock(&outer_mutex);
+}
+
+static
+void lock_test_mutex(void)
+{
+ pthread_mutex_lock(&test_mutex);
+}
+
+static
+void unlock_test_mutex(void)
+{
+ pthread_mutex_unlock(&test_mutex);
+}
+#else
+static
+void lock_outer_mutex(void)
+{
+}
+
+static
+void unlock_outer_mutex(void)
+{
+}
+
+static
+void lock_test_mutex(void)
+{
+}
+
+static
+void unlock_test_mutex(void)
+{
+}
+#endif
+
+static
+void set_parent(struct rcu_rbtree_node *node,
+ struct rcu_rbtree_node *parent,
+ unsigned int pos)
+{
+ C__CMM_STORE_SHARED(node->parent, ((unsigned long) parent) | pos);
+}
+
+static
+struct rcu_rbtree_node *get_parent(struct rcu_rbtree_node *node)
+{
+ return (struct rcu_rbtree_node *) (node->parent & ~1UL);
+}
+
+static
+unsigned int get_pos(struct rcu_rbtree_node *node)
+{
+ return (unsigned int) (node->parent & 1UL);
+}
+
+static
+struct rcu_rbtree_node *get_parent_and_pos(struct rcu_rbtree_node *node,
+ unsigned int *pos)
+{
+ unsigned long parent_pos = c_rcu_dereference(node->parent);
+
+ *pos = (unsigned int) (parent_pos & 1UL);
+ return (struct rcu_rbtree_node *) (parent_pos & ~1UL);
+}
+
static
void set_decay(struct rcu_rbtree_node *x, struct rcu_rbtree_node *xc)
{
static
struct rcu_rbtree_node *get_decay(struct rcu_rbtree_node *x)
{
+ if (!x)
+ return NULL;
while (x->decay_next)
x = x->decay_next;
return x;
return x->decay_next;
}
+static
+struct rcu_rbtree_node *_rcu_rbtree_alloc_node(struct rcu_rbtree *rbtree)
+{
+ return rbtree->rballoc(sizeof(struct rcu_rbtree_node));
+}
+
+static
+void _rcu_rbtree_free_node(struct rcu_head *head)
+{
+ struct rcu_rbtree_node *node =
+ caa_container_of(head, struct rcu_rbtree_node, head);
+ node->rbtree->rbfree(node);
+}
+
+#ifdef RBTREE_RCU_SUPPORT
+
static
struct rcu_rbtree_node *dup_decay_node(struct rcu_rbtree *rbtree,
struct rcu_rbtree_node *x)
{
struct rcu_rbtree_node *xc;
- if (rcu_rbtree_is_nil(x))
+ if (rcu_rbtree_is_nil(rbtree, x))
return x;
- xc = rbtree->rballoc();
- memcpy(xc, x, sizeof(struct rcu_rbtree_node));
+ xc = _rcu_rbtree_alloc_node(rbtree);
+ memcpy(xc, x, sizeof(*xc));
xc->decay_next = NULL;
set_decay(x, xc);
- call_rcu(&x->head, rbtree->rbfree);
+ rbtree->call_rcu(&x->head, _rcu_rbtree_free_node);
return xc;
}
+#else /* RBTREE_RCU_SUPPORT */
+
+static
+struct rcu_rbtree_node *dup_decay_node(struct rcu_rbtree *rbtree,
+ struct rcu_rbtree_node *x)
+{
+ return x;
+}
+
+#endif
+
+/*
+ * Info for range lookups:
+ * Range lookup information is only valid when used when searching for
+ * ranges. It should never be used in next/prev traversal because the
+ * pointers to parents are not in sync with the parent vision of the
+ * children range.
+ */
+static
+void set_left(struct rcu_rbtree *rbtree, struct rcu_rbtree_node *node,
+ struct rcu_rbtree_node *left)
+{
+ node->_left = left;
+}
+
+static
+void set_right(struct rcu_rbtree *rbtree, struct rcu_rbtree_node *node,
+ struct rcu_rbtree_node *right)
+{
+ node->_right = right;
+}
+
+static
+void *calculate_node_max_end(struct rcu_rbtree *rbtree, struct rcu_rbtree_node *node)
+{
+ void *max_end;
+
+ max_end = node->end;
+ if (!rcu_rbtree_is_nil(rbtree, node->_right)) {
+ if (rbtree->comp(max_end, node->_right->max_end) < 0)
+ max_end = node->_right->max_end;
+ }
+ if (!rcu_rbtree_is_nil(rbtree, node->_left)) {
+ if (rbtree->comp(max_end, node->_left->max_end) < 0)
+ max_end = node->_left->max_end;
+ }
+ return max_end;
+}
+
/*
* TODO
* Deal with memory allocation errors.
* Can be ensured by reserving a pool of memory entries before doing the
* insertion, which will have to be function of number of
- * transplantations/rotations required for the operation.
+ * transplantations/rotations required for the operation (which is a
+ * multiple of the tree height).
*/
+#ifdef DEBUG
static
void show_tree(struct rcu_rbtree *rbtree)
{
struct rcu_rbtree_node *node;
node = rcu_rbtree_min(rbtree, rbtree->root);
- while (!rcu_rbtree_is_nil(node)) {
+ while (!rcu_rbtree_is_nil(rbtree, node)) {
assert(!is_decay(node));
- printf("{ 0x%lX p:%lX r:%lX l:%lX %s %s %s} ",
- (unsigned long)node->key,
- (unsigned long) node->p->key,
- (unsigned long) node->right->key,
- (unsigned long) node->left->key,
+ printf("{ b:%lX e:%lX pb: %lX r:%lX l:%lX %s %s %s} ",
+ (unsigned long) node->begin,
+ (unsigned long) node->end,
+ (unsigned long) get_parent(node)->begin,
+ (unsigned long) node->_right->begin,
+ (unsigned long) node->_left->begin,
node->color ? "red" : "black",
- node->pos ? "right" : "left",
- node->nil ? "nil" : "");
+ get_pos(node) ? "right" : "left",
+ rcu_rbtree_is_nil(rbtree, node) ? "nil" : "");
node = rcu_rbtree_next(rbtree, node);
}
printf("\n");
}
+#define check_max_end(rbtree, x) \
+ do { \
+ if (rcu_rbtree_is_nil(rbtree, x)) \
+ break; \
+ assert(rbtree->comp(x->max_end, \
+ calculate_node_max_end(rbtree, x)) == 0); \
+ } while (0)
+
+#else /* DEBUG */
+static
+void show_tree(struct rcu_rbtree *rbtree)
+{
+}
+
+static
+void check_max_end(struct rcu_rbtree *rbtree, struct rcu_rbtree_node *x)
+{
+}
+#endif /* DEBUG */
+
static
struct rcu_rbtree_node *make_nil(struct rcu_rbtree *rbtree)
{
/*
* Iterative rbtree search.
*/
-struct rcu_rbtree_node* rcu_rbtree_search(struct rcu_rbtree *rbtree,
+struct rcu_rbtree_node *rcu_rbtree_search(struct rcu_rbtree *rbtree,
+ struct rcu_rbtree_node *x,
+ void *point)
+{
+ struct rcu_rbtree_node *xl;
+
+ dbg_printf("searching point 0x%lx\n", (unsigned long) point);
+ x = c_rcu_dereference(x);
+
+ while (!rcu_rbtree_is_nil(rbtree, x)) {
+ dbg_usleep(10);
+ xl = c_rcu_dereference(x->_left);
+ dbg_printf("search x %lx x_end %lx x_max_end %lx\n", (unsigned long) x->begin,
+ (unsigned long) x->end, (unsigned long) x->max_end);
+ dbg_printf("search xl %lx xl_end %lx xl_max_end %lx\n", (unsigned long) xl->begin,
+ (unsigned long) xl->end, (unsigned long) xl->max_end);
+ if (!rcu_rbtree_is_nil(rbtree, xl)
+ && (rbtree->comp(xl->max_end, point) > 0)) {
+ dbg_printf("go left\n");
+ x = xl;
+ } else if (rbtree->comp(x->begin, point) <= 0
+ && rbtree->comp(point, x->end) < 0) {
+ dbg_printf("got it!\n");
+ break;
+ } else if (rbtree->comp(point, x->begin) > 0) {
+ dbg_printf("go right\n");
+ x = c_rcu_dereference(x->_right);
+ } else {
+ dbg_printf("not found!\n");
+ x = make_nil(rbtree);
+ }
+ }
+ if (rcu_rbtree_is_nil(rbtree, x))
+ dbg_printf("Reached bottom of tree.\n");
+
+ return x;
+}
+
+struct rcu_rbtree_node *rcu_rbtree_search_range(struct rcu_rbtree *rbtree,
+ struct rcu_rbtree_node *x,
+ void *begin, void *end)
+{
+ struct rcu_rbtree_node *node;
+
+ node = rcu_rbtree_search(rbtree, x, begin);
+ if (rcu_rbtree_is_nil(rbtree, node))
+ return node;
+ if (rbtree->comp(node->end, end) < 0)
+ return NULL; /* High is outside lookup range */
+ return node;
+}
+
+/*
+ * Search by exact range start value.
+ */
+struct rcu_rbtree_node *rcu_rbtree_search_begin_key(struct rcu_rbtree *rbtree,
struct rcu_rbtree_node *x,
void *k)
{
- x = rcu_dereference(x);
+ x = c_rcu_dereference(x);
+ int comp;
- while (!rcu_rbtree_is_nil(x) && k != x->key) {
- if (rbtree->comp(k, x->key) < 0)
- x = rcu_dereference(x->left);
+ while (!rcu_rbtree_is_nil(rbtree, x) && (comp = rbtree->comp(k, x->begin)) != 0) {
+ dbg_usleep(10);
+ if (comp < 0)
+ x = c_rcu_dereference(x->_left);
else
- x = rcu_dereference(x->right);
+ x = c_rcu_dereference(x->_right);
+ }
+ return x;
+}
+
+static
+struct rcu_rbtree_node *rcu_rbtree_min_dup_decay(struct rcu_rbtree *rbtree,
+ struct rcu_rbtree_node *x,
+ struct rcu_rbtree_node **zr)
+{
+ struct rcu_rbtree_node *xl;
+
+ x = c_rcu_dereference(x);
+
+ if (rcu_rbtree_is_nil(rbtree, x)) {
+ *zr = x;
+ return x;
+ } else
+ *zr = x = dup_decay_node(rbtree, x);
+
+ while (!rcu_rbtree_is_nil(rbtree, xl = c_rcu_dereference(x->_left))) {
+ x = dup_decay_node(rbtree, xl);
+ set_parent(x, get_decay(get_parent(x)), get_pos(x));
+ get_parent(x)->_left = get_decay(get_parent(x)->_left);
+ }
+ return x;
+}
+
+static
+struct rcu_rbtree_node *rcu_rbtree_min_update_decay(struct rcu_rbtree *rbtree,
+ struct rcu_rbtree_node *x)
+{
+ struct rcu_rbtree_node *xl;
+
+ x = c_rcu_dereference(x);
+
+ if (rcu_rbtree_is_nil(rbtree, x))
+ return x;
+ else {
+ set_parent(x->_right, get_decay(get_parent(x->_right)),
+ get_pos(x->_right));
+ set_parent(x->_left, get_decay(get_parent(x->_left)),
+ get_pos(x->_left));
+ }
+
+ while (!rcu_rbtree_is_nil(rbtree, xl = c_rcu_dereference(x->_left))) {
+ x = xl;
+ set_parent(x->_right, get_decay(get_parent(x->_right)),
+ get_pos(x->_right));
+ set_parent(x->_left, get_decay(get_parent(x->_left)),
+ get_pos(x->_left));
}
return x;
}
{
struct rcu_rbtree_node *xl;
- x = rcu_dereference(x);
+ x = c_rcu_dereference(x);
- if (rcu_rbtree_is_nil(x))
+ if (rcu_rbtree_is_nil(rbtree, x))
return x;
- while (!rcu_rbtree_is_nil(xl = rcu_dereference(x->left)))
+ while (!rcu_rbtree_is_nil(rbtree, xl = c_rcu_dereference(x->_left)))
x = xl;
return x;
}
{
struct rcu_rbtree_node *xr;
- x = rcu_dereference(x);
+ x = c_rcu_dereference(x);
- if (rcu_rbtree_is_nil(x))
+ if (rcu_rbtree_is_nil(rbtree, x))
return x;
- while (!rcu_rbtree_is_nil(xr = rcu_dereference(x->right)))
+ while (!rcu_rbtree_is_nil(rbtree, xr = c_rcu_dereference(x->_right)))
x = xr;
return x;
}
/*
- * FIXME:
- * Updates should wait for a grace period between update of the
- * redirect pointer and update of the parent child pointer. This is to make sure
- * that no reference to the old entry exist.
- */
-
-/*
- * next and prev need to have mutex held to ensure that parent pointer is
- * coherent.
+ * RCU read lock must be held across the next/prev calls to ensure validity of
+ * the returned node.
*/
struct rcu_rbtree_node *rcu_rbtree_next(struct rcu_rbtree *rbtree,
struct rcu_rbtree_node *x)
{
struct rcu_rbtree_node *xr, *y;
+ unsigned int x_pos;
- x = rcu_dereference(x);
+ x = c_rcu_dereference(x);
- if (!rcu_rbtree_is_nil(xr = rcu_dereference(x->right)))
+ if (!rcu_rbtree_is_nil(rbtree, xr = c_rcu_dereference(x->_right)))
return rcu_rbtree_min(rbtree, xr);
- y = rcu_dereference(x->p);
- while (!rcu_rbtree_is_nil(y) && x->pos == IS_RIGHT) {
+ y = get_parent_and_pos(x, &x_pos);
+ while (!rcu_rbtree_is_nil(rbtree, y) && x_pos == IS_RIGHT) {
x = y;
- y = rcu_dereference(y->p);
+ y = get_parent_and_pos(y, &x_pos);
}
return y;
}
struct rcu_rbtree_node *x)
{
struct rcu_rbtree_node *xl, *y;
+ unsigned int x_pos;
- x = rcu_dereference(x);
+ x = c_rcu_dereference(x);
- if (!rcu_rbtree_is_nil(xl = rcu_dereference(x->left)))
- return rcu_rbtree_min(rbtree, xl);
- y = rcu_dereference(x->p);
- while (!rcu_rbtree_is_nil(y) && x->pos == IS_LEFT) {
+ if (!rcu_rbtree_is_nil(rbtree, xl = c_rcu_dereference(x->_left)))
+ return rcu_rbtree_max(rbtree, xl);
+ y = get_parent_and_pos(x, &x_pos);
+ while (!rcu_rbtree_is_nil(rbtree, y) && x_pos == IS_LEFT) {
x = y;
- y = rcu_dereference(y->p);
+ y = get_parent_and_pos(y, &x_pos);
}
return y;
}
+/*
+ * "node" needs to be non-visible by readers.
+ */
+static
+void populate_node_end(struct rcu_rbtree *rbtree, struct rcu_rbtree_node *node,
+ unsigned int copy_parents, struct rcu_rbtree_node *stop)
+{
+ struct rcu_rbtree_node *prev = NULL, *orig_node = node, *top;
+
+ do {
+ void *max_end;
+
+ assert(node);
+ assert(!rcu_rbtree_is_nil(rbtree, node));
+
+ if (prev && copy_parents) {
+ node = dup_decay_node(rbtree, node);
+ if (get_pos(prev) == IS_RIGHT)
+ node->_right = prev;
+ else
+ node->_left = prev;
+ set_parent(prev, node, get_pos(prev));
+ }
+
+ max_end = calculate_node_max_end(rbtree, node);
+ /*
+ * Compare the node max_end keys to make sure we replace
+ * references to a key belonging to a node we remove
+ * from the tree. Otherwise we would still be using this
+ * pointer as an invalid reference after garbage
+ * collection of the node and of its associated
+ * begin/end pointers.
+ */
+ if (max_end != node->max_end) {
+ node->max_end = max_end;
+ } else {
+ top = get_parent(node);
+ c_cmm_smp_wmb(); /* write into node before publish */
+ /* make new branch visible to readers */
+ if (rcu_rbtree_is_nil(rbtree, top))
+ C__CMM_STORE_SHARED(rbtree->root, node);
+ if (get_pos(node) == IS_LEFT)
+ C__CMM_STORE_SHARED(top->_left, node);
+ else
+ C__CMM_STORE_SHARED(top->_right, node);
+ goto end;
+ }
+
+ /* Check for propagation stop */
+ if (node == stop)
+ return;
+
+ prev = node;
+ node = get_parent(node);
+ } while (!rcu_rbtree_is_nil(rbtree, node));
+
+ top = node; /* nil */
+ c_cmm_smp_wmb(); /* write into node before publish */
+ /* make new branch visible to readers */
+ C__CMM_STORE_SHARED(rbtree->root, prev);
+
+end:
+ if (!copy_parents)
+ return;
+ /* update children */
+ node = orig_node;
+ do {
+ assert(!rcu_rbtree_is_nil(rbtree, node));
+ set_parent(node->_left, get_decay(get_parent(node->_left)), IS_LEFT);
+ set_parent(node->_right, get_decay(get_parent(node->_right)), IS_RIGHT);
+ } while ((node = get_parent(node)) != top);
+}
+
/*
* We have to ensure these assumptions are correct for prev/next
* traversal:
*
* with x being a right child, the assumption that:
- * x->p->right == x
+ * get_parent(x)->_right == x
* or if x is a left child, the assumption that:
- * x->p->left == x
+ * get_parent(x)->_left == x
*
* This explains why we have to allocate a vc copy of the node for left_rotate,
* right_rotate and transplant operations.
/* RCU: copy x and y, atomically point to new versions. GC old. */
/* Should be eventually followed by a cmm_smp_wmc() */
+#ifdef RBTREE_RCU_SUPPORT_ROTATE_LEFT
+
static
void left_rotate(struct rcu_rbtree *rbtree,
struct rcu_rbtree_node *x)
{
- struct rcu_rbtree_node *y, *y_left, *x_p;
- unsigned int x_pos;
+ struct rcu_rbtree_node *y, *y_left;
+
+ dbg_printf("left rotate %lx\n", (unsigned long) x->begin);
- y = x->right;
- y_left = y->left;
+ y = x->_right;
+ y_left = y->_left;
/* Now operate on new copy, decay old versions */
x = dup_decay_node(rbtree, x);
y = dup_decay_node(rbtree, y);
y_left = dup_decay_node(rbtree, y_left);
- x_pos = x->pos;
- x_p = x->p;
+ check_max_end(rbtree, get_parent(x));
+ check_max_end(rbtree, x);
+ check_max_end(rbtree, y);
/* Internal node modifications */
- x->right = y_left;
- y->p = x->p;
- y->pos = x->pos;
- x->pos = IS_LEFT;
- y->left = x;
- x->p = y;
- if (!rcu_rbtree_is_nil(y_left)) {
- y_left->p = x;
- y_left->pos = IS_RIGHT;
- }
+ set_parent(y, get_parent(x), get_pos(x));
+ set_parent(x, y, IS_LEFT);
+ set_left(rbtree, y, x);
+ set_right(rbtree, x, y_left);
+
+ if (!rcu_rbtree_is_nil(rbtree, y_left))
+ set_parent(y_left, x, IS_RIGHT);
+
+ /*
+ * We only changed the relative position of x and y wrt their
+ * children, and reparented y (but are keeping the same nodes in
+ * place, so its parent does not need to have end value
+ * recalculated).
+ */
+ x->max_end = calculate_node_max_end(rbtree, x);
+ y->max_end = calculate_node_max_end(rbtree, y);
- cmm_smp_wmb(); /* write into node before publish */
+ c_cmm_smp_wmb(); /* write into node before publish */
/* External references update (visible by readers) */
- if (rcu_rbtree_is_nil(x_p))
- _CMM_STORE_SHARED(rbtree->root, y);
- else if (x_pos == IS_LEFT)
- _CMM_STORE_SHARED(x_p->left, y);
+ if (rcu_rbtree_is_nil(rbtree, get_parent(y)))
+ C__CMM_STORE_SHARED(rbtree->root, y);
+ else if (get_pos(y) == IS_LEFT)
+ C__CMM_STORE_SHARED(get_parent(y)->_left, y);
else
- _CMM_STORE_SHARED(x_p->right, y);
-
- /* Point children to new copy (parent only used by updates) */
- if (!rcu_rbtree_is_nil(x->left))
- x->left->p = x;
- if (!rcu_rbtree_is_nil(y->right))
- y->right->p = y;
+ C__CMM_STORE_SHARED(get_parent(y)->_right, y);
+
+ /* Point children to new copy (parent only used by updates/next/prev) */
+ set_parent(x->_left, get_decay(get_parent(x->_left)),
+ get_pos(x->_left));
+ set_parent(y->_right, get_decay(get_parent(y->_right)),
+ get_pos(y->_right));
+ if (!rcu_rbtree_is_nil(rbtree, y_left)) {
+ set_parent(y_left->_right,
+ get_decay(get_parent(y_left->_right)),
+ get_pos(y_left->_right));
+ set_parent(y_left->_left,
+ get_decay(get_parent(y_left->_left)),
+ get_pos(y_left->_left));
+ }
/* Sanity checks */
- assert(y == rbtree->root || y->p->left == y || y->p->right == y);
- assert(x == rbtree->root || x->p->left == x || x->p->right == x);
- assert(rcu_rbtree_is_nil(x->right) || x->right->p == x);
- assert(rcu_rbtree_is_nil(x->left) || x->left->p == x);
- assert(rcu_rbtree_is_nil(y->right) || y->right->p == y);
- assert(rcu_rbtree_is_nil(y->left) || y->left->p == y);
+ assert(y == rbtree->root || get_parent(y)->_left == y
+ || get_parent(y)->_right == y);
+ assert(x == rbtree->root || get_parent(x)->_left == x
+ || get_parent(x)->_right == x);
+ assert(rcu_rbtree_is_nil(rbtree, x->_right) || get_parent(x->_right) == x);
+ assert(rcu_rbtree_is_nil(rbtree, x->_left) || get_parent(x->_left) == x);
+ assert(rcu_rbtree_is_nil(rbtree, y->_right) || get_parent(y->_right) == y);
+ assert(rcu_rbtree_is_nil(rbtree, y->_left) || get_parent(y->_left) == y);
assert(!is_decay(rbtree->root));
assert(!is_decay(x));
assert(!is_decay(y));
- assert(!is_decay(x->right));
- assert(!is_decay(x->left));
- assert(!is_decay(y->right));
- assert(!is_decay(y->left));
+ assert(!is_decay(x->_right));
+ assert(!is_decay(x->_left));
+ assert(!is_decay(y->_right));
+ assert(!is_decay(y->_left));
+ check_max_end(rbtree, get_parent(y));
+ check_max_end(rbtree, x);
+ check_max_end(rbtree, y);
}
+#else
+
+/* non-rcu version */
+static
+void left_rotate(struct rcu_rbtree *rbtree,
+ struct rcu_rbtree_node *x)
+{
+ struct rcu_rbtree_node *y;
+
+ lock_test_mutex();
+ y = x->_right;
+ x->_right = y->_left;
+ if (!rcu_rbtree_is_nil(rbtree, y->_left))
+ set_parent(y->_left, x, IS_RIGHT);
+ set_parent(y, get_parent(x), get_pos(x));
+ if (rcu_rbtree_is_nil(rbtree, get_parent(x)))
+ rbtree->root = y;
+ else if (x == get_parent(x)->_left) {
+ get_parent(x)->_left = y;
+ } else {
+ get_parent(x)->_right = y;
+ }
+ y->_left = x;
+ set_parent(x, y, IS_LEFT);
+
+ /*
+ * We only changed the relative position of x and y wrt their
+ * children, and reparented y (but are keeping the same nodes in
+ * place, so its parent does not need to have end value
+ * recalculated).
+ */
+ x->max_end = calculate_node_max_end(rbtree, x);
+ y->max_end = calculate_node_max_end(rbtree, y);
+
+ unlock_test_mutex();
+}
+
+#endif
+
+#ifdef RBTREE_RCU_SUPPORT_ROTATE_RIGHT
static
void right_rotate(struct rcu_rbtree *rbtree,
struct rcu_rbtree_node *x)
{
- struct rcu_rbtree_node *y, *y_right, *x_p;
- unsigned int x_pos;
+ struct rcu_rbtree_node *y, *y_right;
- y = x->left;
- y_right = y->right;
+ dbg_printf("right rotate %lx\n", (unsigned long) x->begin);
+
+ y = x->_left;
+ y_right = y->_right;
/* Now operate on new copy, decay old versions */
x = dup_decay_node(rbtree, x);
y = dup_decay_node(rbtree, y);
y_right = dup_decay_node(rbtree, y_right);
- x_pos = x->pos;
- x_p = x->p;
+ check_max_end(rbtree, get_parent(x));
+ check_max_end(rbtree, x);
+ check_max_end(rbtree, y);
/* Internal node modifications */
- x->left = y_right;
- y->p = x->p;
- y->pos = x->pos;
- x->pos = IS_RIGHT;
- y->right = x;
- x->p = y;
- if (!rcu_rbtree_is_nil(y_right)) {
- y_right->p = x;
- y_right->pos = IS_LEFT;
- }
+ set_parent(y, get_parent(x), get_pos(x));
+ set_parent(x, y, IS_RIGHT);
+ set_right(rbtree, y, x);
+ set_left(rbtree, x, y_right);
- cmm_smp_wmb(); /* write into node before publish */
+ if (!rcu_rbtree_is_nil(rbtree, y_right))
+ set_parent(y_right, x, IS_LEFT);
+
+ /*
+ * We only changed the relative position of x and y wrt their
+ * children, and reparented y (but are keeping the same nodes in
+ * place, so its parent does not need to have end value
+ * recalculated).
+ */
+ x->max_end = calculate_node_max_end(rbtree, x);
+ y->max_end = calculate_node_max_end(rbtree, y);
+
+ c_cmm_smp_wmb(); /* write into node before publish */
/* External references update (visible by readers) */
- if (rcu_rbtree_is_nil(x_p))
- _CMM_STORE_SHARED(rbtree->root, y);
- else if (x_pos == IS_RIGHT)
- _CMM_STORE_SHARED(x_p->right, y);
+ if (rcu_rbtree_is_nil(rbtree, get_parent(y)))
+ C__CMM_STORE_SHARED(rbtree->root, y);
+ else if (get_pos(y) == IS_RIGHT)
+ C__CMM_STORE_SHARED(get_parent(y)->_right, y);
else
- _CMM_STORE_SHARED(x_p->left, y);
-
- /* Point children to new copy (parent only used by updates) */
- if (!rcu_rbtree_is_nil(x->right))
- x->right->p = x;
- if (!rcu_rbtree_is_nil(y->left))
- y->left->p = y;
+ C__CMM_STORE_SHARED(get_parent(y)->_left, y);
+
+ /* Point children to new copy (parent only used by updates/next/prev) */
+ set_parent(x->_right, get_decay(get_parent(x->_right)),
+ get_pos(x->_right));
+ set_parent(y->_left, get_decay(get_parent(y->_left)),
+ get_pos(y->_left));
+ if (!rcu_rbtree_is_nil(rbtree, y_right)) {
+ set_parent(y_right->_left,
+ get_decay(get_parent(y_right->_left)),
+ get_pos(y_right->_left));
+ set_parent(y_right->_right,
+ get_decay(get_parent(y_right->_right)),
+ get_pos(y_right->_right));
+ }
/* Sanity checks */
- assert(y == rbtree->root || y->p->right == y || y->p->left == y);
- assert(x == rbtree->root || x->p->right == x || x->p->left == x);
- assert(rcu_rbtree_is_nil(x->left) || x->left->p == x);
- assert(rcu_rbtree_is_nil(x->right) || x->right->p == x);
- assert(rcu_rbtree_is_nil(y->left) || y->left->p == y);
- assert(rcu_rbtree_is_nil(y->right) || y->right->p == y);
+ assert(y == rbtree->root || get_parent(y)->_right == y
+ || get_parent(y)->_left == y);
+ assert(x == rbtree->root || get_parent(x)->_right == x
+ || get_parent(x)->_left == x);
+ assert(rcu_rbtree_is_nil(rbtree, x->_left) || get_parent(x->_left) == x);
+ assert(rcu_rbtree_is_nil(rbtree, x->_right) || get_parent(x->_right) == x);
+ assert(rcu_rbtree_is_nil(rbtree, y->_left) || get_parent(y->_left) == y);
+ assert(rcu_rbtree_is_nil(rbtree, y->_right) || get_parent(y->_right) == y);
assert(!is_decay(rbtree->root));
assert(!is_decay(x));
assert(!is_decay(y));
- assert(!is_decay(x->left));
- assert(!is_decay(x->right));
- assert(!is_decay(y->left));
- assert(!is_decay(y->right));
+ assert(!is_decay(x->_left));
+ assert(!is_decay(x->_right));
+ assert(!is_decay(y->_left));
+ assert(!is_decay(y->_right));
+ check_max_end(rbtree, x);
+ check_max_end(rbtree, y);
+ check_max_end(rbtree, get_parent(y));
+}
+
+#else
+
+/* non-rcu version */
+static
+void right_rotate(struct rcu_rbtree *rbtree,
+ struct rcu_rbtree_node *x)
+{
+ struct rcu_rbtree_node *y;
+
+ lock_test_mutex();
+ y = x->_left;
+ x->_left = y->_right;
+ if (!rcu_rbtree_is_nil(rbtree, y->_right))
+ set_parent(y->_right, x, IS_LEFT);
+ set_parent(y, get_parent(x), get_pos(x));
+ if (rcu_rbtree_is_nil(rbtree, get_parent(x)))
+ rbtree->root = y;
+ else if (x == get_parent(x)->_right) {
+ get_parent(x)->_right = y;
+ } else {
+ get_parent(x)->_left = y;
+ }
+ y->_right = x;
+ set_parent(x, y, IS_RIGHT);
+
+ /*
+ * We only changed the relative position of x and y wrt their
+ * children, and reparented y (but are keeping the same nodes in
+ * place, so its parent does not need to have end value
+ * recalculated).
+ */
+ x->max_end = calculate_node_max_end(rbtree, x);
+ y->max_end = calculate_node_max_end(rbtree, y);
+
+ unlock_test_mutex();
}
+#endif
+
static void rcu_rbtree_insert_fixup(struct rcu_rbtree *rbtree,
struct rcu_rbtree_node *z)
{
struct rcu_rbtree_node *y;
- dbg_printf("insert fixup %p\n", z->key);
+ dbg_printf("insert fixup %p\n", z->begin);
assert(!is_decay(rbtree->root));
- while (z->p->color == COLOR_RED) {
- if (z->p == z->p->p->left) {
- y = z->p->p->right;
+ while (get_parent(z)->color == COLOR_RED) {
+ if (get_parent(z) == get_parent(get_parent(z))->_left) {
+ y = get_parent(get_parent(z))->_right;
if (y->color == COLOR_RED) {
- z->p->color = COLOR_BLACK;
+ get_parent(z)->color = COLOR_BLACK;
y->color = COLOR_BLACK;
- z->p->p->color = COLOR_RED;
- z = z->p->p;
+ get_parent(get_parent(z))->color = COLOR_RED;
+ z = get_parent(get_parent(z));
} else {
- if (z == z->p->right) {
- z = z->p;
+ if (z == get_parent(z)->_right) {
+ z = get_parent(z);
left_rotate(rbtree, z);
z = get_decay(z);
assert(!is_decay(rbtree->root));
}
- z->p->color = COLOR_BLACK;
- z->p->p->color = COLOR_RED;
+ get_parent(z)->color = COLOR_BLACK;
+ get_parent(get_parent(z))->color = COLOR_RED;
assert(!is_decay(z));
- assert(!is_decay(z->p));
- assert(!is_decay(z->p->p));
- right_rotate(rbtree, z->p->p);
+ assert(!is_decay(get_parent(z)));
+ assert(!is_decay(get_parent(get_parent(z))));
+ right_rotate(rbtree, get_parent(get_parent(z)));
assert(!is_decay(z));
assert(!is_decay(rbtree->root));
}
} else {
- y = z->p->p->left;
+ y = get_parent(get_parent(z))->_left;
if (y->color == COLOR_RED) {
- z->p->color = COLOR_BLACK;
+ get_parent(z)->color = COLOR_BLACK;
y->color = COLOR_BLACK;
- z->p->p->color = COLOR_RED;
- z = z->p->p;
+ get_parent(get_parent(z))->color = COLOR_RED;
+ z = get_parent(get_parent(z));
} else {
- if (z == z->p->left) {
- z = z->p;
+ if (z == get_parent(z)->_left) {
+ z = get_parent(z);
right_rotate(rbtree, z);
z = get_decay(z);
assert(!is_decay(rbtree->root));
}
- z->p->color = COLOR_BLACK;
- z->p->p->color = COLOR_RED;
- left_rotate(rbtree, z->p->p);
+ get_parent(z)->color = COLOR_BLACK;
+ get_parent(get_parent(z))->color = COLOR_RED;
+ left_rotate(rbtree, get_parent(get_parent(z)));
assert(!is_decay(z));
assert(!is_decay(rbtree->root));
}
* Returns 0 on success, or < 0 on error.
*/
int rcu_rbtree_insert(struct rcu_rbtree *rbtree,
- struct rcu_rbtree_node *z)
+ void *begin, void *end)
{
- struct rcu_rbtree_node *x, *y;
+ struct rcu_rbtree_node *x, *y, *z;
+
+ z = _rcu_rbtree_alloc_node(rbtree);
+ if (!z)
+ return -ENOMEM;
+ z->begin = begin;
+ z->end = end;
- dbg_printf("insert %p\n", z->key);
+ dbg_printf("insert %p\n", z->begin);
assert(!is_decay(rbtree->root));
y = make_nil(rbtree);
- if (!rbtree->root)
- rbtree->root = make_nil(rbtree);
x = rbtree->root;
- while (!rcu_rbtree_is_nil(x)) {
+ while (!rcu_rbtree_is_nil(rbtree, x)) {
y = x;
- if (rbtree->comp(z->key, x->key) < 0)
- x = x->left;
+ if (rbtree->comp(z->begin, x->begin) < 0)
+ x = x->_left;
else
- x = x->right;
+ x = x->_right;
}
- z->p = y;
-
- z->left = make_nil(rbtree);
- z->right = make_nil(rbtree);
+ z->_left = make_nil(rbtree);
+ z->_right = make_nil(rbtree);
z->color = COLOR_RED;
- z->nil = 0;
z->decay_next = NULL;
-
- if (rcu_rbtree_is_nil(y))
- z->pos = IS_RIGHT; /* arbitrary for root node */
- else if (rbtree->comp(z->key, y->key) < 0)
- z->pos = IS_LEFT;
- else
- z->pos = IS_RIGHT;
-
- /*
- * Order stores to z (children/parents) before stores that will make it
- * visible to the rest of the tree.
- */
- cmm_smp_wmb();
-
- if (rcu_rbtree_is_nil(y))
- _CMM_STORE_SHARED(rbtree->root, z);
- else if (rbtree->comp(z->key, y->key) < 0)
- _CMM_STORE_SHARED(y->left, z);
- else
- _CMM_STORE_SHARED(y->right, z);
+ z->max_end = z->end;
+ z->rbtree = rbtree;
+
+ if (rcu_rbtree_is_nil(rbtree, y)) {
+ set_parent(z, y, IS_RIGHT); /* pos arbitrary for root node */
+ /*
+ * Order stores to z (children/parents) before stores
+ * that will make it visible to the rest of the tree.
+ */
+ c_cmm_smp_wmb();
+ C__CMM_STORE_SHARED(rbtree->root, z);
+ } else if (rbtree->comp(z->begin, y->begin) < 0) {
+ y = dup_decay_node(rbtree, y);
+ set_parent(z, y, IS_LEFT);
+ if (get_pos(z) == IS_LEFT)
+ C__CMM_STORE_SHARED(y->_left, z);
+ else
+ C__CMM_STORE_SHARED(y->_right, z);
+ populate_node_end(rbtree, y, 1, NULL);
+ } else {
+ y = dup_decay_node(rbtree, y);
+ set_parent(z, y, IS_RIGHT);
+ if (get_pos(z) == IS_LEFT)
+ C__CMM_STORE_SHARED(y->_left, z);
+ else
+ C__CMM_STORE_SHARED(y->_right, z);
+ populate_node_end(rbtree, y, 1, NULL);
+ }
rcu_rbtree_insert_fixup(rbtree, z);
/*
- * Make sure to commit all _CMM_STORE_SHARED() for non-coherent caches.
+ * Make sure to commit all C__CMM_STORE_SHARED() for non-coherent caches.
*/
- cmm_smp_wmc();
+ c_cmm_smp_wmc();
show_tree(rbtree);
+ check_max_end(rbtree, z);
+ check_max_end(rbtree, y);
return 0;
}
/*
* Transplant v into u position.
*/
+
+#ifdef RBTREE_RCU_SUPPORT_TRANSPLANT
+
static
void rcu_rbtree_transplant(struct rcu_rbtree *rbtree,
struct rcu_rbtree_node *u,
- struct rcu_rbtree_node *v)
+ struct rcu_rbtree_node *v,
+ unsigned int copy_parents,
+ struct rcu_rbtree_node *stop)
{
- dbg_printf("transplant %p\n", v->key);
+ dbg_printf("transplant %p\n", v->begin);
- if (!rcu_rbtree_is_nil(v))
+ if (!rcu_rbtree_is_nil(rbtree, v))
v = dup_decay_node(rbtree, v);
- if (rcu_rbtree_is_nil(u->p)) {
- v->p = u->p;
- cmm_smp_wmb(); /* write into node before publish */
- _CMM_STORE_SHARED(rbtree->root, v);
- } else if (u == u->p->left) {
- v->pos = IS_LEFT;
- v->p = u->p;
- cmm_smp_wmb(); /* write into node before publish */
- _CMM_STORE_SHARED(u->p->left, v);
+ if (rcu_rbtree_is_nil(rbtree, get_parent(u))) {
+ /* pos is arbitrary for root node */
+ set_parent(v, get_parent(u), IS_RIGHT);
+ c_cmm_smp_wmb(); /* write into node before publish */
+ C__CMM_STORE_SHARED(rbtree->root, v);
} else {
- v->pos = IS_RIGHT;
- v->p = u->p;
- cmm_smp_wmb(); /* write into node before publish */
- _CMM_STORE_SHARED(u->p->right, v);
+ struct rcu_rbtree_node *vp;
+
+ vp = get_parent(u);
+ if (copy_parents)
+ vp = dup_decay_node(rbtree, vp);
+ set_parent(v, vp, get_pos(u));
+ if (get_pos(v) == IS_LEFT)
+ C__CMM_STORE_SHARED(vp->_left, v);
+ else
+ C__CMM_STORE_SHARED(vp->_right, v);
+ populate_node_end(rbtree, vp, copy_parents, stop);
+ check_max_end(rbtree, vp);
}
- /* Set children parent to new node (only used by updates) */
- if (!rcu_rbtree_is_nil(v)) {
- v->right->p = v;
- v->left->p = v;
+
+ /* Point children to new copy (parent only used by updates/next/prev) */
+ if (!rcu_rbtree_is_nil(rbtree, v)) {
+ set_parent(v->_right, get_decay(get_parent(v->_right)),
+ get_pos(v->_right));
+ set_parent(v->_left, get_decay(get_parent(v->_left)),
+ get_pos(v->_left));
}
assert(!is_decay(rbtree->root));
+ check_max_end(rbtree, v);
+}
+
+#else
+
+/* Non-RCU version */
+static
+void rcu_rbtree_transplant(struct rcu_rbtree *rbtree,
+ struct rcu_rbtree_node *u,
+ struct rcu_rbtree_node *v,
+ unsigned int copy_parents,
+ struct rcu_rbtree_node *stop)
+{
+ dbg_printf("transplant %p\n", v->begin);
+
+ lock_test_mutex();
+ if (rcu_rbtree_is_nil(rbtree, get_parent(u))) {
+ rbtree->root = v;
+ } else {
+ if (u == get_parent(u)->_left)
+ get_parent(u)->_left = v;
+ else
+ get_parent(u)->_right = v;
+ populate_node_end(rbtree, get_parent(u), copy_parents, stop);
+ }
+ set_parent(v, get_parent(u), get_pos(u));
+ unlock_test_mutex();
}
+#endif
+
static void rcu_rbtree_remove_fixup(struct rcu_rbtree *rbtree,
struct rcu_rbtree_node *x)
{
- dbg_printf("remove fixup %p\n", x->key);
+ dbg_printf("remove fixup %p\n", x->begin);
while (x != rbtree->root && x->color == COLOR_BLACK) {
- assert(!is_decay(x->p));
- assert(!is_decay(x->p->left));
- if (x == x->p->left) {
+ assert(!is_decay(get_parent(x)));
+ assert(!is_decay(get_parent(x)->_left));
+ if (x == get_parent(x)->_left) {
struct rcu_rbtree_node *w;
- w = x->p->right;
+ w = get_parent(x)->_right;
if (w->color == COLOR_RED) {
w->color = COLOR_BLACK;
- x->p->color = COLOR_RED;
- left_rotate(rbtree, x->p);
+ get_parent(x)->color = COLOR_RED;
+ left_rotate(rbtree, get_parent(x));
x = get_decay(x);
assert(!is_decay(rbtree->root));
- w = x->p->right;
+ w = get_parent(x)->_right;
}
- if (w->left->color == COLOR_BLACK
- && w->right->color == COLOR_BLACK) {
+ if (w->_left->color == COLOR_BLACK
+ && w->_right->color == COLOR_BLACK) {
w->color = COLOR_RED;
- x = x->p;
+ x = get_parent(x);
assert(!is_decay(rbtree->root));
assert(!is_decay(x));
} else {
- if (w->right->color == COLOR_BLACK) {
- w->left->color = COLOR_BLACK;
+ if (w->_right->color == COLOR_BLACK) {
+ w->_left->color = COLOR_BLACK;
w->color = COLOR_RED;
right_rotate(rbtree, w);
assert(!is_decay(rbtree->root));
x = get_decay(x);
- w = x->p->right;
+ w = get_parent(x)->_right;
}
- w->color = x->p->color;
- x->p->color = COLOR_BLACK;
- w->right->color = COLOR_BLACK;
- left_rotate(rbtree, x->p);
+ w->color = get_parent(x)->color;
+ get_parent(x)->color = COLOR_BLACK;
+ w->_right->color = COLOR_BLACK;
+ left_rotate(rbtree, get_parent(x));
assert(!is_decay(rbtree->root));
x = rbtree->root;
}
} else {
struct rcu_rbtree_node *w;
- w = x->p->left;
+ w = get_parent(x)->_left;
if (w->color == COLOR_RED) {
w->color = COLOR_BLACK;
- x->p->color = COLOR_RED;
- right_rotate(rbtree, x->p);
+ get_parent(x)->color = COLOR_RED;
+ right_rotate(rbtree, get_parent(x));
assert(!is_decay(rbtree->root));
x = get_decay(x);
- w = x->p->left;
+ w = get_parent(x)->_left;
}
- if (w->right->color == COLOR_BLACK
- && w->left->color == COLOR_BLACK) {
+ if (w->_right->color == COLOR_BLACK
+ && w->_left->color == COLOR_BLACK) {
w->color = COLOR_RED;
- x = x->p;
+ x = get_parent(x);
assert(!is_decay(rbtree->root));
assert(!is_decay(x));
} else {
- if (w->left->color == COLOR_BLACK) {
- w->right->color = COLOR_BLACK;
+ if (w->_left->color == COLOR_BLACK) {
+ w->_right->color = COLOR_BLACK;
w->color = COLOR_RED;
left_rotate(rbtree, w);
assert(!is_decay(rbtree->root));
x = get_decay(x);
- w = x->p->left;
+ w = get_parent(x)->_left;
}
- w->color = x->p->color;
- x->p->color = COLOR_BLACK;
- w->left->color = COLOR_BLACK;
- right_rotate(rbtree, x->p);
+ w->color = get_parent(x)->color;
+ get_parent(x)->color = COLOR_BLACK;
+ w->_left->color = COLOR_BLACK;
+ right_rotate(rbtree, get_parent(x));
assert(!is_decay(rbtree->root));
x = rbtree->root;
}
{
struct rcu_rbtree_node *x;
- dbg_printf("remove nonil %p\n", z->key);
+ dbg_printf("remove nonil %p\n", z->begin);
show_tree(rbtree);
assert(!is_decay(z));
assert(!is_decay(y));
- assert(!is_decay(y->right));
- assert(!is_decay(y->p));
- x = y->right;
+ assert(!is_decay(y->_right));
+ assert(!is_decay(get_parent(y)));
+ x = y->_right;
assert(!is_decay(x));
- if (y->p == z)
- x->p = y;
- else {
- rcu_rbtree_transplant(rbtree, y, y->right);
+ if (get_parent(y) == z) {
+ y = dup_decay_node(rbtree, y);
+ set_parent(x, y, get_pos(x)); /* parent for nil */
+ /* y is z's right node */
+ set_left(rbtree, y, z->_left);
+ y->max_end = calculate_node_max_end(rbtree, y);
+ rcu_rbtree_transplant(rbtree, z, y, 1, NULL);
+ } else {
+ struct rcu_rbtree_node *oy_right, *z_right;
+
+ /*
+ * Need to make sure y is always visible by readers.
+ */
+ y = rcu_rbtree_min_dup_decay(rbtree, z->_right, &z_right);
assert(!is_decay(y));
assert(!is_decay(z));
- assert(!is_decay(z->right));
- y->right = z->right;
- y->right->p = y;
+ oy_right = y->_right;
+
+ /*
+ * The max child begin of z_right does not change, because
+ * we're only changing its left children.
+ */
+ y->_right = z_right;
+ set_parent(y->_right, y, IS_RIGHT);
+ assert(!is_decay(z->_left));
+ y->_left = z->_left;
+ assert(!is_decay(oy_right));
+ /*
+ * Transplant of oy_right to old y's location will only
+ * trigger a "end" value update of the already copied branch
+ * (which is not visible yet). We are transplanting
+ * oy_right as a left child of old y's parent, so the
+ * min values update propagated upward necessarily stops
+ * at z_right.
+ */
+ rcu_rbtree_transplant(rbtree, y, oy_right, 0, y);
+ y->max_end = calculate_node_max_end(rbtree, y);
+ rcu_rbtree_transplant(rbtree, z, y, 1, NULL);
+ /* Update children */
+ (void) rcu_rbtree_min_update_decay(rbtree, y->_right);
}
- rcu_rbtree_transplant(rbtree, z, y);
y = get_decay(y);
assert(!is_decay(z));
- assert(!is_decay(z->left));
- y->left = z->left;
- y->left->p = y;
+ assert(!is_decay(z->_left));
y->color = z->color;
+ set_parent(y->_left, y, IS_LEFT);
+ set_parent(y->_right, get_decay(get_parent(y->_right)), IS_RIGHT);
+ assert(!is_decay(y->_left));
+ assert(!is_decay(y->_right));
}
int rcu_rbtree_remove(struct rcu_rbtree *rbtree,
unsigned int y_original_color;
assert(!is_decay(rbtree->root));
- dbg_printf("remove %p\n", z->key);
+ dbg_printf("remove %p\n", z->begin);
show_tree(rbtree);
assert(!is_decay(z));
y = z;
y_original_color = y->color;
- if (rcu_rbtree_is_nil(z->left)) {
- rcu_rbtree_transplant(rbtree, z, z->right);
+ if (rcu_rbtree_is_nil(rbtree, z->_left)) {
+ rcu_rbtree_transplant(rbtree, z, z->_right, 1, NULL);
assert(!is_decay(z));
- x = get_decay(z->right);
+ x = get_decay(z->_right);
show_tree(rbtree);
- } else if (rcu_rbtree_is_nil(z->right)) {
- rcu_rbtree_transplant(rbtree, z, z->left);
+ } else if (rcu_rbtree_is_nil(rbtree, z->_right)) {
+ rcu_rbtree_transplant(rbtree, z, z->_left, 1, NULL);
assert(!is_decay(z));
- x = get_decay(z->left);
+ x = get_decay(z->_left);
show_tree(rbtree);
} else {
- y = rcu_rbtree_min(rbtree, z->right);
+ y = rcu_rbtree_min(rbtree, z->_right);
assert(!is_decay(y));
y_original_color = y->color;
+ x = y->_right;
rcu_rbtree_remove_nonil(rbtree, z, y);
- x = get_decay(y->right);
+ x = get_decay(x);
show_tree(rbtree);
}
if (y_original_color == COLOR_BLACK)
rcu_rbtree_remove_fixup(rbtree, x);
show_tree(rbtree);
+ check_max_end(rbtree, x);
+ check_max_end(rbtree, get_decay(y));
/*
- * Commit all _CMM_STORE_SHARED().
+ * Commit all C__CMM_STORE_SHARED().
*/
- cmm_smp_wmc();
+ c_cmm_smp_wmc();
+#ifdef RBTREE_RCU_SUPPORT
+ rbtree->call_rcu(&z->head, _rcu_rbtree_free_node);
+#else
+ _rcu_rbtree_free_node(&z->head);
+#endif
return 0;
}
projects / urcu.git / blobdiff