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eset.h revision 1.1 
      1 #ifndef JEMALLOC_INTERNAL_ESET_H
      2 #define JEMALLOC_INTERNAL_ESET_H
      3 
      4 #include "jemalloc/internal/atomic.h"
      5 #include "jemalloc/internal/fb.h"
      6 #include "jemalloc/internal/edata.h"
      7 #include "jemalloc/internal/mutex.h"
      8 
      9 /*
     10  * An eset ("extent set") is a quantized collection of extents, with built-in
     11  * LRU queue.
     12  *
     13  * This class is not thread-safe; synchronization must be done externally if
     14  * there are mutating operations.  One exception is the stats counters, which
     15  * may be read without any locking.
     16  */
     17 
     18 typedef struct eset_bin_s eset_bin_t;
     19 struct eset_bin_s {
     20 	edata_heap_t heap;
     21 	/*
     22 	 * We do first-fit across multiple size classes.  If we compared against
     23 	 * the min element in each heap directly, we'd take a cache miss per
     24 	 * extent we looked at.  If we co-locate the edata summaries, we only
     25 	 * take a miss on the edata we're actually going to return (which is
     26 	 * inevitable anyways).
     27 	 */
     28 	edata_cmp_summary_t heap_min;
     29 };
     30 
     31 typedef struct eset_bin_stats_s eset_bin_stats_t;
     32 struct eset_bin_stats_s {
     33 	atomic_zu_t nextents;
     34 	atomic_zu_t nbytes;
     35 };
     36 
     37 typedef struct eset_s eset_t;
     38 struct eset_s {
     39 	/* Bitmap for which set bits correspond to non-empty heaps. */
     40 	fb_group_t bitmap[FB_NGROUPS(SC_NPSIZES + 1)];
     41 
     42 	/* Quantized per size class heaps of extents. */
     43 	eset_bin_t bins[SC_NPSIZES + 1];
     44 
     45 	eset_bin_stats_t bin_stats[SC_NPSIZES + 1];
     46 
     47 	/* LRU of all extents in heaps. */
     48 	edata_list_inactive_t lru;
     49 
     50 	/* Page sum for all extents in heaps. */
     51 	atomic_zu_t npages;
     52 
     53 	/*
     54 	 * A duplication of the data in the containing ecache.  We use this only
     55 	 * for assertions on the states of the passed-in extents.
     56 	 */
     57 	extent_state_t state;
     58 };
     59 
     60 void eset_init(eset_t *eset, extent_state_t state);
     61 
     62 size_t eset_npages_get(eset_t *eset);
     63 /* Get the number of extents in the given page size index. */
     64 size_t eset_nextents_get(eset_t *eset, pszind_t ind);
     65 /* Get the sum total bytes of the extents in the given page size index. */
     66 size_t eset_nbytes_get(eset_t *eset, pszind_t ind);
     67 
     68 void eset_insert(eset_t *eset, edata_t *edata);
     69 void eset_remove(eset_t *eset, edata_t *edata);
     70 /*
     71  * Select an extent from this eset of the given size and alignment.  Returns
     72  * null if no such item could be found.
     73  */
     74 edata_t *eset_fit(eset_t *eset, size_t esize, size_t alignment, bool exact_only,
     75     unsigned lg_max_fit);
     76 
     77 #endif /* JEMALLOC_INTERNAL_ESET_H */
     78