#ifndef JEMALLOC_INTERNAL_EXTENT_STRUCTS_H

#define JEMALLOC_INTERNAL_EXTENT_STRUCTS_H

#include "jemalloc/internal/atomic.h"

#include "jemalloc/internal/bit_util.h"

#include "jemalloc/internal/bitmap.h"

#include "jemalloc/internal/mutex.h"

#include "jemalloc/internal/ql.h"

#include "jemalloc/internal/ph.h"

#include "jemalloc/internal/sc.h"

typedef enum {

	extent_state_active   = 0,

	extent_state_dirty    = 1,

	extent_state_muzzy    = 2,

	extent_state_retained = 3

} extent_state_t;

/* Extent (span of pages).  Use accessor functions for e_* fields. */

struct extent_s {

	/*

	 * Bitfield containing several fields:

	 *

	 * a: arena_ind

	 * b: slab

	 * c: committed

	 * d: dumpable

	 * z: zeroed

	 * t: state

	 * i: szind

	 * f: nfree

	 * s: bin_shard

	 * n: sn

	 *

	 * nnnnnnnn ... nnnnnnss ssssffff ffffffii iiiiiitt zdcbaaaa aaaaaaaa

	 *

	 * arena_ind: Arena from which this extent came, or all 1 bits if

	 *            unassociated.

	 *

	 * slab: 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().

	 *

	 * committed: The committed flag indicates whether 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.

	 *

	 * dumpable: The dumpable flag indicates whether or not we've set the

	 *           memory in question to be dumpable.  Note that this

	 *           interacts somewhat subtly with user-specified extent hooks,

	 *           since we don't know if *they* are fiddling with

	 *           dumpability (in which case, we don't want to undo whatever

	 *           they're doing).  To deal with this scenario, we:

	 *             - Make dumpable false only for memory allocated with the

	 *               default hooks.

	 *             - Only allow memory to go from non-dumpable to dumpable,

	 *               and only once.

	 *             - Never make the OS call to allow dumping when the

	 *               dumpable bit is already set.

	 *           These three constraints mean that we will never

	 *           accidentally dump user memory that the user meant to set

	 *           nondumpable with their extent hooks.

	 *

	 *

	 * zeroed: The zeroed flag is used by extent recycling code to track

	 *         whether memory is zero-filled.

	 *

	 * state: The state flag is an extent_state_t.

	 *

	 * szind: The szind flag indicates usable size class index for

	 *        allocations residing in this extent, regardless of whether the

	 *        extent is a slab.  Extent size and usable size often differ

	 *        even for non-slabs, either due to sz_large_pad or promotion of

	 *        sampled small regions.

	 *

	 * nfree: Number of free regions in slab.

	 *

	 * bin_shard: the shard of the bin from which this extent came.

	 *

	 * sn: Serial number (potentially non-unique).

	 *

	 *     Serial numbers may wrap around if !opt_retain, 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.

	 */

	uint64_t		e_bits;

#define MASK(CURRENT_FIELD_WIDTH, CURRENT_FIELD_SHIFT) ((((((uint64_t)0x1U) << (CURRENT_FIELD_WIDTH)) - 1)) << (CURRENT_FIELD_SHIFT))

#define EXTENT_BITS_ARENA_WIDTH  MALLOCX_ARENA_BITS

#define EXTENT_BITS_ARENA_SHIFT  0

#define EXTENT_BITS_ARENA_MASK  MASK(EXTENT_BITS_ARENA_WIDTH, EXTENT_BITS_ARENA_SHIFT)

#define EXTENT_BITS_SLAB_WIDTH  1

#define EXTENT_BITS_SLAB_SHIFT  (EXTENT_BITS_ARENA_WIDTH + EXTENT_BITS_ARENA_SHIFT)

#define EXTENT_BITS_SLAB_MASK  MASK(EXTENT_BITS_SLAB_WIDTH, EXTENT_BITS_SLAB_SHIFT)

#define EXTENT_BITS_COMMITTED_WIDTH  1

#define EXTENT_BITS_COMMITTED_SHIFT  (EXTENT_BITS_SLAB_WIDTH + EXTENT_BITS_SLAB_SHIFT)

#define EXTENT_BITS_COMMITTED_MASK  MASK(EXTENT_BITS_COMMITTED_WIDTH, EXTENT_BITS_COMMITTED_SHIFT)

#define EXTENT_BITS_DUMPABLE_WIDTH  1

#define EXTENT_BITS_DUMPABLE_SHIFT  (EXTENT_BITS_COMMITTED_WIDTH + EXTENT_BITS_COMMITTED_SHIFT)

#define EXTENT_BITS_DUMPABLE_MASK  MASK(EXTENT_BITS_DUMPABLE_WIDTH, EXTENT_BITS_DUMPABLE_SHIFT)

#define EXTENT_BITS_ZEROED_WIDTH  1

#define EXTENT_BITS_ZEROED_SHIFT  (EXTENT_BITS_DUMPABLE_WIDTH + EXTENT_BITS_DUMPABLE_SHIFT)

#define EXTENT_BITS_ZEROED_MASK  MASK(EXTENT_BITS_ZEROED_WIDTH, EXTENT_BITS_ZEROED_SHIFT)

#define EXTENT_BITS_STATE_WIDTH  2

#define EXTENT_BITS_STATE_SHIFT  (EXTENT_BITS_ZEROED_WIDTH + EXTENT_BITS_ZEROED_SHIFT)

#define EXTENT_BITS_STATE_MASK  MASK(EXTENT_BITS_STATE_WIDTH, EXTENT_BITS_STATE_SHIFT)

#define EXTENT_BITS_SZIND_WIDTH  LG_CEIL(SC_NSIZES)

#define EXTENT_BITS_SZIND_SHIFT  (EXTENT_BITS_STATE_WIDTH + EXTENT_BITS_STATE_SHIFT)

#define EXTENT_BITS_SZIND_MASK  MASK(EXTENT_BITS_SZIND_WIDTH, EXTENT_BITS_SZIND_SHIFT)

#define EXTENT_BITS_NFREE_WIDTH  (LG_SLAB_MAXREGS + 1)

#define EXTENT_BITS_NFREE_SHIFT  (EXTENT_BITS_SZIND_WIDTH + EXTENT_BITS_SZIND_SHIFT)

#define EXTENT_BITS_NFREE_MASK  MASK(EXTENT_BITS_NFREE_WIDTH, EXTENT_BITS_NFREE_SHIFT)

#define EXTENT_BITS_BINSHARD_WIDTH  6

#define EXTENT_BITS_BINSHARD_SHIFT  (EXTENT_BITS_NFREE_WIDTH + EXTENT_BITS_NFREE_SHIFT)

#define EXTENT_BITS_BINSHARD_MASK  MASK(EXTENT_BITS_BINSHARD_WIDTH, EXTENT_BITS_BINSHARD_SHIFT)

#define EXTENT_BITS_IS_HEAD_WIDTH 1

#define EXTENT_BITS_IS_HEAD_SHIFT  (EXTENT_BITS_BINSHARD_WIDTH + EXTENT_BITS_BINSHARD_SHIFT)

#define EXTENT_BITS_IS_HEAD_MASK  MASK(EXTENT_BITS_IS_HEAD_WIDTH, EXTENT_BITS_IS_HEAD_SHIFT)

#define EXTENT_BITS_SN_SHIFT   (EXTENT_BITS_IS_HEAD_WIDTH + EXTENT_BITS_IS_HEAD_SHIFT)

#define EXTENT_BITS_SN_MASK  (UINT64_MAX << EXTENT_BITS_SN_SHIFT)

	/* Pointer to the extent that this structure is responsible for. */

	void			*e_addr;

	union {

		/*

		 * Extent size and serial number associated with the extent

		 * structure (different than the serial number for the extent at

		 * e_addr).

		 *

		 * ssssssss [...] ssssssss ssssnnnn nnnnnnnn

		 */

		size_t			e_size_esn;

	#define EXTENT_SIZE_MASK	((size_t)~(PAGE-1))

	#define EXTENT_ESN_MASK		((size_t)PAGE-1)

		/* Base extent size, which may not be a multiple of PAGE. */

		size_t			e_bsize;

	};

	/*

	 * List linkage, used by a variety of lists:

	 * - bin_t's slabs_full

	 * - extents_t's LRU

	 * - stashed dirty extents

	 * - arena's large allocations

	 */

	ql_elm(extent_t)	ql_link;

	/*

	 * Linkage for per size class sn/address-ordered heaps, and

	 * for extent_avail

	 */

	phn(extent_t)		ph_link;

	union {

		/* Small region slab metadata. */

		arena_slab_data_t	e_slab_data;

		/* Profiling data, used for large objects. */

		struct {

			/* Time when this was allocated. */

			nstime_t		e_alloc_time;

			/* Points to a prof_tctx_t. */

			atomic_p_t		e_prof_tctx;

		};

	};

};

typedef ql_head(extent_t) extent_list_t;

typedef ph(extent_t) extent_tree_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[SC_NPSIZES + 1];

	atomic_zu_t		nextents[SC_NPSIZES + 1];

	atomic_zu_t		nbytes[SC_NPSIZES + 1];

	/*

	 * Bitmap for which set bits correspond to non-empty heaps.

	 *

	 * Synchronization: mtx.

	 */

	bitmap_t		bitmap[BITMAP_GROUPS(SC_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;

};

/*

 * The following two structs are for experimental purposes. See

 * experimental_utilization_query_ctl and

 * experimental_utilization_batch_query_ctl in src/ctl.c.

 */

struct extent_util_stats_s {

	size_t nfree;

	size_t nregs;

	size_t size;

};

struct extent_util_stats_verbose_s {

	void *slabcur_addr;

	size_t nfree;

	size_t nregs;

	size_t size;

	size_t bin_nfree;

	size_t bin_nregs;

};

#endif /* JEMALLOC_INTERNAL_EXTENT_STRUCTS_H */