server-skynet-source-3rd-je.../include/jemalloc/internal/rtree_structs.h
David Goldblatt 77cccac8cd Break up headers into constituent parts
This is part of a broader change to make header files better represent the
dependencies between one another (see
https://github.com/jemalloc/jemalloc/issues/533). It breaks up component headers
into smaller parts that can be made to have a simpler dependency graph.

For the autogenerated headers (smoothstep.h and size_classes.h), no splitting
was necessary, so I didn't add support to emit multiple headers.
2017-01-12 15:43:51 -08:00

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 */