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#define JEMALLOC_RTREE_C_
#include "jemalloc/internal/jemalloc_internal.h"
static unsigned
hmin(unsigned ha, unsigned hb)
{
return (ha < hb ? ha : hb);
}
/* Only the most significant bits of keys passed to rtree_[gs]et() are used. */
bool
rtree_new(rtree_t *rtree, unsigned bits, rtree_node_alloc_t *alloc,
rtree_node_dalloc_t *dalloc)
{
unsigned bits_in_leaf, height, i;
assert(RTREE_HEIGHT_MAX == ((ZU(1) << (LG_SIZEOF_PTR+3)) /
RTREE_BITS_PER_LEVEL));
assert(bits > 0 && bits <= (sizeof(uintptr_t) << 3));
bits_in_leaf = (bits % RTREE_BITS_PER_LEVEL) == 0 ? RTREE_BITS_PER_LEVEL
: (bits % RTREE_BITS_PER_LEVEL);
if (bits > bits_in_leaf) {
height = 1 + (bits - bits_in_leaf) / RTREE_BITS_PER_LEVEL;
if ((height-1) * RTREE_BITS_PER_LEVEL + bits_in_leaf != bits)
height++;
} else
height = 1;
assert((height-1) * RTREE_BITS_PER_LEVEL + bits_in_leaf == bits);
rtree->alloc = alloc;
rtree->dalloc = dalloc;
rtree->height = height;
/* Root level. */
rtree->levels[0].subtree = NULL;
rtree->levels[0].bits = (height > 1) ? RTREE_BITS_PER_LEVEL :
bits_in_leaf;
rtree->levels[0].cumbits = rtree->levels[0].bits;
/* Interior levels. */
for (i = 1; i < height-1; i++) {
rtree->levels[i].subtree = NULL;
rtree->levels[i].bits = RTREE_BITS_PER_LEVEL;
rtree->levels[i].cumbits = rtree->levels[i-1].cumbits +
RTREE_BITS_PER_LEVEL;
}
/* Leaf level. */
if (height > 1) {
rtree->levels[height-1].subtree = NULL;
rtree->levels[height-1].bits = bits_in_leaf;
rtree->levels[height-1].cumbits = bits;
}
/* Compute lookup table to be used by rtree_start_level(). */
for (i = 0; i < RTREE_HEIGHT_MAX; i++) {
rtree->start_level[i] = hmin(RTREE_HEIGHT_MAX - 1 - i, height -
1);
}
return (false);
}
static void
rtree_delete_subtree(rtree_t *rtree, rtree_node_elm_t *node, unsigned level)
{
if (level + 1 < rtree->height) {
size_t nchildren, i;
nchildren = ZU(1) << rtree->levels[level].bits;
for (i = 0; i < nchildren; i++) {
rtree_node_elm_t *child = node[i].child;
if (child != NULL)
rtree_delete_subtree(rtree, child, level + 1);
}
}
rtree->dalloc(node);
}
void
rtree_delete(rtree_t *rtree)
{
unsigned i;
for (i = 0; i < rtree->height; i++) {
rtree_node_elm_t *subtree = rtree->levels[i].subtree;
if (subtree != NULL)
rtree_delete_subtree(rtree, subtree, i);
}
}
static rtree_node_elm_t *
rtree_node_init(rtree_t *rtree, unsigned level, rtree_node_elm_t **elmp)
{
rtree_node_elm_t *node;
if (atomic_cas_p((void **)elmp, NULL, RTREE_NODE_INITIALIZING)) {
/*
* Another thread is already in the process of initializing.
* Spin-wait until initialization is complete.
*/
do {
CPU_SPINWAIT;
node = atomic_read_p((void **)elmp);
} while (node == RTREE_NODE_INITIALIZING);
} else {
node = rtree->alloc(ZU(1) << rtree->levels[level].bits);
if (node == NULL)
return (NULL);
atomic_write_p((void **)elmp, node);
}
return (node);
}
rtree_node_elm_t *
rtree_subtree_read_hard(rtree_t *rtree, unsigned level)
{
return (rtree_node_init(rtree, level, &rtree->levels[level].subtree));
}
rtree_node_elm_t *
rtree_child_read_hard(rtree_t *rtree, rtree_node_elm_t *elm, unsigned level)
{
return (rtree_node_init(rtree, level, &elm->child));
}
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