87 lines
2.6 KiB
C
87 lines
2.6 KiB
C
|
#ifndef JEMALLOC_INTERNAL_RTREE_STRUCTS_H
|
||
|
|
#define JEMALLOC_INTERNAL_RTREE_STRUCTS_H
|
||
|
|
|
||
|
|
struct rtree_elm_s {
|
||
|
|
union {
|
||
|
|
void *pun;
|
||
|
|
rtree_elm_t *child;
|
||
|
|
extent_t *extent;
|
||
|
|
};
|
||
|
|
};
|
||
|
|
|
||
|
|
struct rtree_elm_witness_s {
|
||
|
|
const rtree_elm_t *elm;
|
||
|
|
witness_t witness;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct rtree_elm_witness_tsd_s {
|
||
|
|
rtree_elm_witness_t witnesses[RTREE_ELM_ACQUIRE_MAX];
|
||
|
|
};
|
||
|
|
|
||
|
|
struct rtree_level_s {
|
||
|
|
/*
|
||
|
|
* A non-NULL subtree points to a subtree rooted along the hypothetical
|
||
|
|
* path to the leaf node corresponding to key 0. Depending on what keys
|
||
|
|
* have been used to store to the tree, an arbitrary combination of
|
||
|
|
* subtree pointers may remain NULL.
|
||
|
|
*
|
||
|
|
* Suppose keys comprise 48 bits, and LG_RTREE_BITS_PER_LEVEL is 4.
|
||
|
|
* This results in a 3-level tree, and the leftmost leaf can be directly
|
||
|
|
* accessed via levels[2], the subtree prefixed by 0x0000 (excluding
|
||
|
|
* 0x00000000) can be accessed via levels[1], and the remainder of the
|
||
|
|
* tree can be accessed via levels[0].
|
||
|
|
*
|
||
|
|
* levels[0] : [<unused> | 0x0001******** | 0x0002******** | ...]
|
||
|
|
*
|
||
|
|
* levels[1] : [<unused> | 0x00000001**** | 0x00000002**** | ... ]
|
||
|
|
*
|
||
|
|
* levels[2] : [extent(0x000000000000) | extent(0x000000000001) | ...]
|
||
|
|
*
|
||
|
|
* This has practical implications on x64, which currently uses only the
|
||
|
|
* lower 47 bits of virtual address space in userland, thus leaving
|
||
|
|
* levels[0] unused and avoiding a level of tree traversal.
|
||
|
|
*/
|
||
|
|
union {
|
||
|
|
void *subtree_pun;
|
||
|
|
rtree_elm_t *subtree;
|
||
|
|
};
|
||
|
|
/* Number of key bits distinguished by this level. */
|
||
|
|
unsigned bits;
|
||
|
|
/*
|
||
|
|
* Cumulative number of key bits distinguished by traversing to
|
||
|
|
* corresponding tree level.
|
||
|
|
*/
|
||
|
|
unsigned cumbits;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct rtree_ctx_s {
|
||
|
|
/* If false, key/elms have not yet been initialized by a lookup. */
|
||
|
|
bool valid;
|
||
|
|
/* Key that corresponds to the tree path recorded in elms. */
|
||
|
|
uintptr_t key;
|
||
|
|
/* Memoized rtree_start_level(key). */
|
||
|
|
unsigned start_level;
|
||
|
|
/*
|
||
|
|
* A path through rtree, driven by key. Only elements that could
|
||
|
|
* actually be used for subsequent lookups are initialized, i.e. if
|
||
|
|
* start_level = rtree_start_level(key) is non-zero, the first
|
||
|
|
* start_level elements are uninitialized. The last element contains a
|
||
|
|
* pointer to the leaf node element that corresponds to key, so that
|
||
|
|
* exact matches require no tree node offset computation.
|
||
|
|
*/
|
||
|
|
rtree_elm_t *elms[RTREE_HEIGHT_MAX + 1];
|
||
|
|
};
|
||
|
|
|
||
|
|
struct rtree_s {
|
||
|
|
unsigned height;
|
||
|
|
/*
|
||
|
|
* Precomputed table used to convert from the number of leading 0 key
|
||
|
|
* bits to which subtree level to start at.
|
||
|
|
*/
|
||
|
|
unsigned start_level[RTREE_HEIGHT_MAX + 1];
|
||
|
|
rtree_level_t levels[RTREE_HEIGHT_MAX];
|
||
|
|
malloc_mutex_t init_lock;
|
||
|
|
};
|
||
|
|
|
||
|
|
#endif /* JEMALLOC_INTERNAL_RTREE_STRUCTS_H */
|