server-skynet-source-3rd-je.../include/jemalloc/internal/extent_structs.h

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#ifndef JEMALLOC_INTERNAL_EXTENT_STRUCTS_H
#define JEMALLOC_INTERNAL_EXTENT_STRUCTS_H
typedef enum {
extent_state_active = 0,
extent_state_dirty = 1,
extent_state_retained = 2
} extent_state_t;
/* Extent (span of pages). Use accessor functions for e_* fields. */
struct extent_s {
/* Arena from which this extent came, if any. */
arena_t *e_arena;
/* Pointer to the extent that this structure is responsible for. */
void *e_addr;
/* Extent size. */
size_t e_size;
/*
* Usable size, typically smaller than extent size due to large_pad or
* promotion of sampled small regions.
*/
size_t e_usize;
/*
* Serial number (potentially non-unique).
*
* In principle serial numbers can wrap around on 32-bit systems if
* JEMALLOC_MUNMAP is defined, but as long as comparison functions fall
* back on address comparison for equal serial numbers, stable (if
* imperfect) ordering is maintained.
*
* Serial numbers may not be unique even in the absence of wrap-around,
* e.g. when splitting an extent and assigning the same serial number to
* both resulting adjacent extents.
*/
size_t e_sn;
/* Extent state. */
extent_state_t e_state;
/*
* The zeroed flag is used by extent recycling code to track whether
* memory is zero-filled.
*/
bool e_zeroed;
/*
* True if physical memory is committed to the extent, whether
* explicitly or implicitly as on a system that overcommits and
* satisfies physical memory needs on demand via soft page faults.
*/
bool e_committed;
/*
* The slab flag indicates whether the extent is used for a slab of
* small regions. This helps differentiate small size classes, and it
* indicates whether interior pointers can be looked up via iealloc().
*/
bool e_slab;
union {
/* Small region slab metadata. */
arena_slab_data_t e_slab_data;
/* Profile counters, used for large objects. */
union {
void *e_prof_tctx_pun;
prof_tctx_t *e_prof_tctx;
};
};
/*
* List linkage, used by a variety of lists:
* - arena_bin_t's slabs_full
* - extents_t's LRU
* - stashed dirty extents
* - arena's large allocations
* - arena's extent structure freelist
*/
ql_elm(extent_t) ql_link;
/* Linkage for per size class sn/address-ordered heaps. */
phn(extent_t) ph_link;
};
typedef ql_head(extent_t) extent_list_t;
typedef ph(extent_t) extent_heap_t;
/* Quantized collection of extents, with built-in LRU queue. */
struct extents_s {
malloc_mutex_t mtx;
/*
* Quantized per size class heaps of extents.
*
* Synchronization: mtx.
*/
extent_heap_t heaps[NPSIZES+1];
/*
* LRU of all extents in heaps.
*
* Synchronization: mtx.
*/
extent_list_t lru;
/*
* Page sum for all extents in heaps.
*
* The synchronization here is a little tricky. Modifications to npages
* must hold mtx, but reads need not (though, a reader who sees npages
* without holding the mutex can't assume anything about the rest of the
* state of the extents_t).
*/
atomic_zu_t npages;
/* All stored extents must be in the same state. */
extent_state_t state;
/*
* If true, delay coalescing until eviction; otherwise coalesce during
* deallocation.
*/
bool delay_coalesce;
};
#endif /* JEMALLOC_INTERNAL_EXTENT_STRUCTS_H */