[tarantool-patches] Re: [PATCH v7 1/1] box: create bigrefs for tuples

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

Thanks for the patch! I have pushed a separate commit with my fixes, but
it does not pass the test. Please, fix it.

And use unit.h helpers: ok, isnt, is, fail etc to test something instead
of assertions. Assert is omitted in Release build, and the test will test
nothing.

On 09/06/2018 17:40, imeevma@tarantool.org wrote:
> Due to limitation of reference counters for tuple being only
> 65535 it was possible to reach this limitation. This patch
> increases capacity of reference counters to 4 billions.
> 
> Closes #3224
> ---
> Branch: https://github.com/tarantool/tarantool/commits/imeevma/gh-3224-tuple-bigrefs
> Issue: https://github.com/tarantool/tarantool/issues/3224
> 
>   src/box/box.cc                |  20 +++---
>   src/box/errcode.h             |   2 +-
>   src/box/index.cc              |  20 +++---
>   src/box/lua/tuple.c           |   5 +-
>   src/box/port.c                |   8 +--
>   src/box/tuple.c               | 143 ++++++++++++++++++++++++++++++++++++++++--
>   src/box/tuple.h               | 105 ++++++++++++-------------------
>   src/box/vinyl.c               |  38 +++++------
>   test/box/misc.result          |  39 ++++++------
>   test/box/select.result        |  43 +++++++++++--
>   test/box/select.test.lua      |  21 +++++--
>   test/unit/CMakeLists.txt      |   3 +
>   test/unit/tuple_bigref.c      | 117 ++++++++++++++++++++++++++++++++++
>   test/unit/tuple_bigref.result |   5 ++
>   14 files changed, 413 insertions(+), 156 deletions(-)
>   create mode 100644 test/unit/tuple_bigref.c
>   create mode 100644 test/unit/tuple_bigref.result
> 
> diff --git a/src/box/box.cc b/src/box/box.cc
> index c728a4c..4257861 100644
> --- a/src/box/box.cc
> +++ b/src/box/box.cc
> @@ -174,20 +174,22 @@ process_rw(struct request *request, struct space *space, struct tuple **result)
>   		txn_rollback_stmt();
>   		return -1;
>   	}
> +	if (result == NULL)
> +		return txn_commit_stmt(txn, request);
> +	*result = tuple;
> +	if (tuple == NULL)
> +		return txn_commit_stmt(txn, request);
>   	/*
>   	 * Pin the tuple locally before the commit,
>   	 * otherwise it may go away during yield in
>   	 * when WAL is written in autocommit mode.
>   	 */
> -	TupleRefNil ref(tuple);
> -	if (txn_commit_stmt(txn, request) != 0)
> -		return -1;
> -	if (result != NULL) {
> -		if (tuple != NULL && tuple_bless(tuple) == NULL)
> -			return -1;
> -		*result = tuple;
> -	}
> -	return 0;
> +	tuple_ref(tuple);
> +	int rc = txn_commit_stmt(txn, request);
> +	if (rc == 0)
> +		tuple_bless(tuple);
> +	tuple_unref(tuple);
> +	return rc;
>   }
>   
>   void
> diff --git a/src/box/errcode.h b/src/box/errcode.h
> index a0759f8..e009524 100644
> --- a/src/box/errcode.h
> +++ b/src/box/errcode.h
> @@ -138,7 +138,7 @@ struct errcode_record {
>   	/* 83 */_(ER_ROLE_EXISTS,		"Role '%s' already exists") \
>   	/* 84 */_(ER_CREATE_ROLE,		"Failed to create role '%s': %s") \
>   	/* 85 */_(ER_INDEX_EXISTS,		"Index '%s' already exists") \
> -	/* 86 */_(ER_TUPLE_REF_OVERFLOW,	"Tuple reference counter overflow") \
> +	/* 86 */_(ER_UNUSED6,			"") \
>   	/* 87 */_(ER_ROLE_LOOP,			"Granting role '%s' to role '%s' would create a loop") \
>   	/* 88 */_(ER_GRANT,			"Incorrect grant arguments: %s") \
>   	/* 89 */_(ER_PRIV_GRANTED,		"User '%s' already has %s access on %s '%s'") \
> diff --git a/src/box/index.cc b/src/box/index.cc
> index 3c62ec1..f992bc9 100644
> --- a/src/box/index.cc
> +++ b/src/box/index.cc
> @@ -220,8 +220,8 @@ box_index_random(uint32_t space_id, uint32_t index_id, uint32_t rnd,
>   	/* No tx management, random() is for approximation anyway. */
>   	if (index_random(index, rnd, result) != 0)
>   		return -1;
> -	if (*result != NULL && tuple_bless(*result) == NULL)
> -		return -1;
> +	if (*result != NULL)
> +		tuple_bless(*result);
>   	return 0;
>   }
>   
> @@ -253,8 +253,8 @@ box_index_get(uint32_t space_id, uint32_t index_id, const char *key,
>   	txn_commit_ro_stmt(txn);
>   	/* Count statistics. */
>   	rmean_collect(rmean_box, IPROTO_SELECT, 1);
> -	if (*result != NULL && tuple_bless(*result) == NULL)
> -		return -1;
> +	if (*result != NULL)
> +		tuple_bless(*result);
>   	return 0;
>   }
>   
> @@ -285,8 +285,8 @@ box_index_min(uint32_t space_id, uint32_t index_id, const char *key,
>   		return -1;
>   	}
>   	txn_commit_ro_stmt(txn);
> -	if (*result != NULL && tuple_bless(*result) == NULL)
> -		return -1;
> +	if (*result != NULL)
> +		tuple_bless(*result);
>   	return 0;
>   }
>   
> @@ -317,8 +317,8 @@ box_index_max(uint32_t space_id, uint32_t index_id, const char *key,
>   		return -1;
>   	}
>   	txn_commit_ro_stmt(txn);
> -	if (*result != NULL && tuple_bless(*result) == NULL)
> -		return -1;
> +	if (*result != NULL)
> +		tuple_bless(*result);
>   	return 0;
>   }
>   
> @@ -397,8 +397,8 @@ box_iterator_next(box_iterator_t *itr, box_tuple_t **result)
>   	assert(result != NULL);
>   	if (iterator_next(itr, result) != 0)
>   		return -1;
> -	if (*result != NULL && tuple_bless(*result) == NULL)
> -		return -1;
> +	if (*result != NULL)
> +		tuple_bless(*result);
>   	return 0;
>   }
>   
> diff --git a/src/box/lua/tuple.c b/src/box/lua/tuple.c
> index 8057331..22fe696 100644
> --- a/src/box/lua/tuple.c
> +++ b/src/box/lua/tuple.c
> @@ -496,10 +496,7 @@ luaT_pushtuple(struct lua_State *L, box_tuple_t *tuple)
>   		luaL_pushcdata(L, CTID_CONST_STRUCT_TUPLE_REF);
>   	*ptr = tuple;
>   	/* The order is important - first reference tuple, next set gc */
> -	if (box_tuple_ref(tuple) != 0) {
> -		luaT_error(L);
> -		return;
> -	}
> +	box_tuple_ref(tuple);
>   	lua_pushcfunction(L, lbox_tuple_gc);
>   	luaL_setcdatagc(L, -2);
>   }
> diff --git a/src/box/port.c b/src/box/port.c
> index 03f6be7..9b6b858 100644
> --- a/src/box/port.c
> +++ b/src/box/port.c
> @@ -45,8 +45,7 @@ port_tuple_add(struct port *base, struct tuple *tuple)
>   	struct port_tuple *port = port_tuple(base);
>   	struct port_tuple_entry *e;
>   	if (port->size == 0) {
> -		if (tuple_ref(tuple) != 0)
> -			return -1;
> +		tuple_ref(tuple);
>   		e = &port->first_entry;
>   		port->first = port->last = e;
>   	} else {
> @@ -55,10 +54,7 @@ port_tuple_add(struct port *base, struct tuple *tuple)
>   			diag_set(OutOfMemory, sizeof(*e), "mempool_alloc", "e");
>   			return -1;
>   		}
> -		if (tuple_ref(tuple) != 0) {
> -			mempool_free(&port_tuple_entry_pool, e);
> -			return -1;
> -		}
> +		tuple_ref(tuple);
>   		port->last->next = e;
>   		port->last = e;
>   	}
> diff --git a/src/box/tuple.c b/src/box/tuple.c
> index 014f374..b632183 100644
> --- a/src/box/tuple.c
> +++ b/src/box/tuple.c
> @@ -48,6 +48,28 @@ enum {
>   	OBJSIZE_MIN = 16,
>   };
>   
> +/**
> + * Container for big reference counters. Contains array of big
> + * reference counters, size of this array and number of non-zero
> + * big reference counters. When reference counter of tuple becomes
> + * more than 32767, field refs of this tuple becomes index of big
> + * reference counter in big reference counter array and field
> + * is_bigref is set true. The moment big reference becomes equal
> + * 32767 it is set to 0, refs of the tuple becomes 32767 and
> + * is_bigref becomes false. Big reference counter can be equal to
> + * 0 or be more than 32767.
> + */
> +static struct bigref_list {
> +	/** Array of big reference counters. */
> +	uint32_t *refs;
> +	/** Number of non-zero elements in the array. */
> +	uint16_t size;
> +	/** Capacity of the array. */
> +	uint16_t capacity;
> +	/** Index of first free element. */
> +	uint16_t vacant_index;
> +} bigref_list;
> +
>   static const double ALLOC_FACTOR = 1.05;
>   
>   /**
> @@ -151,6 +173,13 @@ tuple_validate_raw(struct tuple_format *format, const char *tuple)
>   	return 0;
>   }
>   
> +/** Initialize big references container. */
> +static inline void
> +bigref_list_create()
> +{
> +	memset(&bigref_list, 0, sizeof(bigref_list));
> +}
> +
>   /**
>    * Incremented on every snapshot and is used to distinguish tuples
>    * which were created after start of a snapshot (these tuples can
> @@ -211,6 +240,8 @@ tuple_init(field_name_hash_f hash)
>   
>   	box_tuple_last = NULL;
>   
> +	bigref_list_create();
> +
>   	if (coll_id_cache_init() != 0)
>   		return -1;
>   
> @@ -244,6 +275,107 @@ tuple_arena_create(struct slab_arena *arena, struct quota *quota,
>   	}
>   }
>   
> +enum {
> +	BIGREF_FACTOR = 2,
> +	BIGREF_MAX = UINT32_MAX,
> +	BIGREF_MIN_CAPACITY = 16,
> +	/**
> +	 * Only 15 bits are available for bigref list index in
> +	 * struct tuple.
> +	 */
> +	BIGREF_MAX_CAPACITY = UINT16_MAX >> 1
> +};
> +
> +/** Destroy big references and free memory that was allocated. */
> +static inline void
> +bigref_list_reset()
> +{
> +	free(bigref_list.refs);
> +	bigref_list_create();
> +}
> +
> +/**
> + * Increase capacity of bigref_list.
> + */
> +static inline void
> +bigref_list_increase_capacity()
> +{
> +	assert(bigref_list.capacity == bigref_list.vacant_index);
> +	uint32_t *refs = bigref_list.refs;
> +	uint16_t capacity = bigref_list.capacity;
> +	if (capacity == 0)
> +		capacity = BIGREF_MIN_CAPACITY;
> +	else if (capacity < BIGREF_MAX_CAPACITY)
> +		capacity = MIN(capacity * BIGREF_FACTOR, BIGREF_MAX_CAPACITY);
> +	else
> +		panic("Too many big references");
> +	refs = (uint32_t *) realloc(refs, capacity * sizeof(*refs));
> +	if (refs == NULL) {
> +		panic("failed to reallocate %zu bytes: Cannot allocate "\
> +		      "memory.", capacity * sizeof(*refs));
> +	}
> +	for(uint16_t i = bigref_list.capacity; i < capacity; ++i) {
> +		refs[i] = i + 1;
> +	}
> +	bigref_list.refs = refs;
> +	bigref_list.capacity = capacity;
> +}
> +
> +/**
> + * Return index for new big reference counter and allocate memory
> + * if needed.
> + * @retval index for new big reference counter.
> + */
> +static inline uint16_t
> +bigref_list_new_index()
> +{
> +	if (bigref_list.size == bigref_list.capacity)
> +		bigref_list_increase_capacity();
> +	++bigref_list.size;
> +	uint16_t vacant_index = bigref_list.vacant_index;
> +	bigref_list.vacant_index = bigref_list.refs[vacant_index];
> +	return vacant_index;
> +}
> +
> +void
> +tuple_ref_slow(struct tuple *tuple)
> +{
> +	assert(tuple->is_bigref || tuple->refs == TUPLE_REF_MAX);
> +	if (! tuple->is_bigref) {
> +		tuple->ref_index = bigref_list_new_index();
> +		tuple->is_bigref = true;
> +		bigref_list.refs[tuple->ref_index] = TUPLE_REF_MAX;
> +	} else if (bigref_list.refs[tuple->ref_index] == BIGREF_MAX) {
> +		panic("Tuple big reference counter overflow");
> +	}
> +	bigref_list.refs[tuple->ref_index]++;
> +}
> +
> +/**
> + * Free index and add it to free-index-list. Free memory
> + * when size == 0.
> + */
> +static inline void
> +bigref_list_delete_index(uint16_t index)
> +{
> +	bigref_list.refs[index] = bigref_list.vacant_index;
> +	bigref_list.vacant_index = index;
> +	if (--bigref_list.size == 0)
> +		bigref_list_reset();
> +}
> +
> +void
> +tuple_unref_slow(struct tuple *tuple)
> +{
> +	assert(tuple->is_bigref &&
> +	       bigref_list.refs[tuple->ref_index] > TUPLE_REF_MAX);
> +	if(--bigref_list.refs[tuple->ref_index] == TUPLE_REF_MAX) {
> +		bigref_list_delete_index(tuple->ref_index);
> +		tuple->ref_index = TUPLE_REF_MAX;
> +		tuple->is_bigref = false;
> +	}
> +}
> +
>   void
>   tuple_arena_destroy(struct slab_arena *arena)
>   {
> @@ -265,6 +397,8 @@ tuple_free(void)
>   	tuple_format_free();
>   
>   	coll_id_cache_destroy();
> +
> +	bigref_list_reset();
>   }
>   
>   box_tuple_format_t *
> @@ -288,7 +422,8 @@ int
>   box_tuple_ref(box_tuple_t *tuple)
>   {
>   	assert(tuple != NULL);
> -	return tuple_ref(tuple);
> +	tuple_ref(tuple);
> +	return 0;
>   }
>   
>   void
> @@ -357,10 +492,7 @@ box_tuple_iterator(box_tuple_t *tuple)
>   			 "mempool", "new slab");
>   		return NULL;
>   	}
> -	if (tuple_ref(tuple) != 0) {
> -		mempool_free(&tuple_iterator_pool, it);
> -		return NULL;
> -	}
> +	tuple_ref(tuple);
>   	tuple_rewind(it, tuple);
>   	return it;
>   }
> @@ -451,7 +583,6 @@ box_tuple_new(box_tuple_format_t *format, const char *data, const char *end)
>   	struct tuple *ret = tuple_new(format, data, end);
>   	if (ret == NULL)
>   		return NULL;
> -	/* Can't fail on zero refs. */
>   	return tuple_bless(ret);
>   }
>   
> diff --git a/src/box/tuple.h b/src/box/tuple.h
> index e2384dd..14dbd40 100644
> --- a/src/box/tuple.h
> +++ b/src/box/tuple.h
> @@ -105,8 +105,7 @@ typedef struct tuple box_tuple_t;
>    * tuple will leak.
>    *
>    * \param tuple a tuple
> - * \retval -1 on error (check box_error_last())
> - * \retval 0 on success
> + * \retval 0 always
>    * \sa box_tuple_unref()
>    */
>   int
> @@ -269,8 +268,7 @@ box_tuple_next(box_tuple_iterator_t *it);
>    * Use box_tuple_format_default() to create space-independent tuple.
>    * \param data tuple data in MsgPack Array format ([field1, field2, ...]).
>    * \param end the end of \a data
> - * \retval NULL on out of memory
> - * \retval tuple otherwise
> + * \retval tuple
>    * \pre data, end is valid MsgPack Array
>    * \sa \code box.tuple.new(data) \endcode
>    */
> @@ -307,9 +305,17 @@ box_tuple_upsert(const box_tuple_t *tuple, const char *expr, const
>    */
>   struct PACKED tuple
>   {
> -	/** reference counter */
> -	uint16_t refs;
> -	/** format identifier */
> +	union {
> +		/** Reference counter. */
> +		uint16_t refs;
> +		struct {
> +			/** Index of big reference counter. */
> +			uint16_t ref_index : 15;
> +			/** Big reference flag. */
> +			bool is_bigref : 1;
> +		};
> +	};
> +	/** Format identifier. */
>   	uint16_t format_id;
>   	/**
>   	 * Length of the MessagePack data in raw part of the
> @@ -774,26 +780,36 @@ tuple_field_uuid(const struct tuple *tuple, int fieldno,
>   	return 0;
>   }
>   
> -enum { TUPLE_REF_MAX = UINT16_MAX };
> +enum { TUPLE_REF_MAX = UINT16_MAX >> 1 };
> +
> +/**
> + * Increase tuple big reference counter.
> + * @param tuple Tuple to reference.
> + */
> +void
> +tuple_ref_slow(struct tuple *tuple);
>   
>   /**
>    * Increment tuple reference counter.
>    * @param tuple Tuple to reference.
> - * @retval  0 Success.
> - * @retval -1 Too many refs error.
>    */
> -static inline int
> +static inline void
>   tuple_ref(struct tuple *tuple)
>   {
> -	if (tuple->refs + 1 > TUPLE_REF_MAX) {
> -		diag_set(ClientError, ER_TUPLE_REF_OVERFLOW);
> -		return -1;
> -	}
> -	tuple->refs++;
> -	return 0;
> +	if (unlikely(tuple->refs >= TUPLE_REF_MAX))
> +		tuple_ref_slow(tuple);
> +	else
> +		tuple->refs++;
>   }
>   
>   /**
> + * Decrease tuple big reference counter.
> + * @param tuple Tuple to reference.
> + */
> +void
> +tuple_unref_slow(struct tuple *tuple);
> +
> +/**
>    * Decrement tuple reference counter. If it has reached zero, free the tuple.
>    *
>    * @pre tuple->refs + count >= 0
> @@ -802,10 +818,9 @@ static inline void
>   tuple_unref(struct tuple *tuple)
>   {
>   	assert(tuple->refs - 1 >= 0);
> -
> -	tuple->refs--;
> -
> -	if (tuple->refs == 0)
> +	if (unlikely(tuple->is_bigref))
> +		tuple_unref_slow(tuple);
> +	else if (--tuple->refs == 0)
>   		tuple_delete(tuple);
>   }
>   
> @@ -813,25 +828,18 @@ extern struct tuple *box_tuple_last;
>   
>   /**
>    * Convert internal `struct tuple` to public `box_tuple_t`.
> - * \retval tuple on success
> - * \retval NULL on error, check diag
> + * \retval tuple
>    * \post \a tuple ref counted until the next call.
> - * \post tuple_ref() doesn't fail at least once
>    * \sa tuple_ref
>    */
>   static inline box_tuple_t *
>   tuple_bless(struct tuple *tuple)
>   {
>   	assert(tuple != NULL);
> -	/* Ensure tuple can be referenced at least once after return */
> -	if (tuple->refs + 2 > TUPLE_REF_MAX) {
> -		diag_set(ClientError, ER_TUPLE_REF_OVERFLOW);
> -		return NULL;
> -	}
> -	tuple->refs++;
> +	tuple_ref(tuple);
>   	/* Remove previous tuple */
>   	if (likely(box_tuple_last != NULL))
> -		tuple_unref(box_tuple_last); /* do not throw */
> +		tuple_unref(box_tuple_last);
>   	/* Remember current tuple */
>   	box_tuple_last = tuple;
>   	return tuple;
> @@ -849,41 +857,6 @@ tuple_to_buf(const struct tuple *tuple, char *buf, size_t size);
>   #include "tuple_update.h"
>   #include "errinj.h"
>   
> -/**
> - * \copydoc tuple_ref()
> - * \throws if overflow detected.
> - */
> -static inline void
> -tuple_ref_xc(struct tuple *tuple)
> -{
> -	if (tuple_ref(tuple))
> -		diag_raise();
> -}
> -
> -/**
> - * \copydoc tuple_bless
> - * \throw ER_TUPLE_REF_OVERFLOW
> - */
> -static inline box_tuple_t *
> -tuple_bless_xc(struct tuple *tuple)
> -{
> -	box_tuple_t *blessed = tuple_bless(tuple);
> -	if (blessed == NULL)
> -		diag_raise();
> -	return blessed;
> -}
> -
> -/** Make tuple references exception-friendly in absence of @finally. */
> -struct TupleRefNil {
> -	struct tuple *tuple;
> -	TupleRefNil (struct tuple *arg) :tuple(arg)
> -	{ if (tuple) tuple_ref_xc(tuple); }
> -	~TupleRefNil() { if (tuple) tuple_unref(tuple); }
> -
> -	TupleRefNil(const TupleRefNil&) = delete;
> -	void operator=(const TupleRefNil&) = delete;
> -};
> -
>   /* @copydoc tuple_field_with_type() */
>   static inline const char *
>   tuple_field_with_type_xc(const struct tuple *tuple, uint32_t fieldno,
> diff --git a/src/box/vinyl.c b/src/box/vinyl.c
> index f0d2687..dc0d020 100644
> --- a/src/box/vinyl.c
> +++ b/src/box/vinyl.c
> @@ -3822,7 +3822,6 @@ vinyl_iterator_primary_next(struct iterator *base, struct tuple **ret)
>   	assert(base->next = vinyl_iterator_primary_next);
>   	struct vinyl_iterator *it = (struct vinyl_iterator *)base;
>   	assert(it->lsm->index_id == 0);
> -	struct tuple *tuple;
>   
>   	if (it->tx == NULL) {
>   		diag_set(ClientError, ER_CURSOR_NO_TRANSACTION);
> @@ -3833,18 +3832,15 @@ vinyl_iterator_primary_next(struct iterator *base, struct tuple **ret)
>   		goto fail;
>   	}
>   
> -	if (vy_read_iterator_next(&it->iterator, &tuple) != 0)
> +	if (vy_read_iterator_next(&it->iterator, ret) != 0)
>   		goto fail;
> -
> -	if (tuple == NULL) {
> +	if (*ret == NULL) {
>   		/* EOF. Close the iterator immediately. */
>   		vinyl_iterator_close(it);
> -		*ret = NULL;
> -		return 0;
> +	} else {
> +		tuple_bless(*ret);
>   	}
> -	*ret = tuple_bless(tuple);
> -	if (*ret != NULL)
> -		return 0;
> +	return 0;
>   fail:
>   	vinyl_iterator_close(it);
>   	return -1;
> @@ -3890,11 +3886,10 @@ next:
>   	 * Note, there's no need in vy_tx_track() as the
>   	 * tuple is already tracked in the secondary index.
>   	 */
> -	struct tuple *full_tuple;
>   	if (vy_point_lookup(it->lsm->pk, it->tx, vy_tx_read_view(it->tx),
> -			    tuple, &full_tuple) != 0)
> +			    tuple, ret) != 0)
>   		goto fail;
> -	if (full_tuple == NULL) {
> +	if (*ret == NULL) {
>   		/*
>   		 * All indexes of a space must be consistent, i.e.
>   		 * if a tuple is present in one index, it must be
> @@ -3908,10 +3903,9 @@ next:
>   			 vy_lsm_name(it->lsm), vy_stmt_str(tuple));
>   		goto next;
>   	}
> -	*ret = tuple_bless(full_tuple);
> -	tuple_unref(full_tuple);
> -	if (*ret != NULL)
> -		return 0;
> +	tuple_bless(*ret);
> +	tuple_unref(*ret);
> +	return 0;
>   fail:
>   	vinyl_iterator_close(it);
>   	return -1;
> @@ -3997,16 +3991,12 @@ vinyl_index_get(struct index *index, const char *key,
>   	const struct vy_read_view **rv = (tx != NULL ? vy_tx_read_view(tx) :
>   					  &env->xm->p_global_read_view);
>   
> -	struct tuple *tuple;
> -	if (vy_lsm_full_by_key(lsm, tx, rv, key, part_count, &tuple) != 0)
> +	if (vy_lsm_full_by_key(lsm, tx, rv, key, part_count, ret) != 0)
>   		return -1;
> -
> -	if (tuple != NULL) {
> -		*ret = tuple_bless(tuple);
> -		tuple_unref(tuple);
> -		return *ret == NULL ? -1 : 0;
> +	if (*ret != NULL) {
> +		tuple_bless(*ret);
> +		tuple_unref(*ret);
>   	}
> -	*ret = NULL;
>   	return 0;
>   }
>   
> diff --git a/test/box/misc.result b/test/box/misc.result
> index 8f94f55..f7703ba 100644
> --- a/test/box/misc.result
> +++ b/test/box/misc.result
> @@ -332,7 +332,6 @@ t;
>     - 'box.error.UNKNOWN_UPDATE_OP : 28'
>     - 'box.error.WRONG_COLLATION_OPTIONS : 151'
>     - 'box.error.CURSOR_NO_TRANSACTION : 80'
> -  - 'box.error.TUPLE_REF_OVERFLOW : 86'
>     - 'box.error.ALTER_SEQUENCE : 143'
>     - 'box.error.INVALID_XLOG_NAME : 75'
>     - 'box.error.SAVEPOINT_EMPTY_TX : 60'
> @@ -360,7 +359,7 @@ t;
>     - 'box.error.VINYL_MAX_TUPLE_SIZE : 139'
>     - 'box.error.LOAD_FUNCTION : 99'
>     - 'box.error.INVALID_XLOG : 74'
> -  - 'box.error.PRIV_NOT_GRANTED : 91'
> +  - 'box.error.READ_VIEW_ABORTED : 130'
>     - 'box.error.TRANSACTION_CONFLICT : 97'
>     - 'box.error.GUEST_USER_PASSWORD : 96'
>     - 'box.error.PROC_C : 102'
> @@ -405,7 +404,7 @@ t;
>     - 'box.error.injection : table: <address>
>     - 'box.error.NULLABLE_MISMATCH : 153'
>     - 'box.error.LAST_DROP : 15'
> -  - 'box.error.NO_SUCH_ROLE : 82'
> +  - 'box.error.TUPLE_FORMAT_LIMIT : 16'
>     - 'box.error.DECOMPRESSION : 124'
>     - 'box.error.CREATE_SEQUENCE : 142'
>     - 'box.error.CREATE_USER : 43'
> @@ -414,66 +413,66 @@ t;
>     - 'box.error.SEQUENCE_OVERFLOW : 147'
>     - 'box.error.SYSTEM : 115'
>     - 'box.error.KEY_PART_IS_TOO_LONG : 118'
> -  - 'box.error.TUPLE_FORMAT_LIMIT : 16'
> -  - 'box.error.BEFORE_REPLACE_RET : 53'
> +  - 'box.error.INJECTION : 8'
> +  - 'box.error.INVALID_MSGPACK : 20'
>     - 'box.error.NO_SUCH_SAVEPOINT : 61'
>     - 'box.error.TRUNCATE_SYSTEM_SPACE : 137'
>     - 'box.error.VY_QUOTA_TIMEOUT : 135'
>     - 'box.error.WRONG_INDEX_OPTIONS : 108'
>     - 'box.error.INVALID_VYLOG_FILE : 133'
>     - 'box.error.INDEX_FIELD_COUNT_LIMIT : 127'
> -  - 'box.error.READ_VIEW_ABORTED : 130'
> +  - 'box.error.PRIV_NOT_GRANTED : 91'
>     - 'box.error.USER_MAX : 56'
> -  - 'box.error.PROTOCOL : 104'
> +  - 'box.error.BEFORE_REPLACE_RET : 53'
>     - 'box.error.TUPLE_NOT_ARRAY : 22'
>     - 'box.error.KEY_PART_COUNT : 31'
>     - 'box.error.ALTER_SPACE : 12'
>     - 'box.error.ACTIVE_TRANSACTION : 79'
>     - 'box.error.EXACT_FIELD_COUNT : 38'
>     - 'box.error.DROP_SEQUENCE : 144'
> -  - 'box.error.INVALID_MSGPACK : 20'
>     - 'box.error.MORE_THAN_ONE_TUPLE : 41'
> -  - 'box.error.RTREE_RECT : 101'
> -  - 'box.error.SUB_STMT_MAX : 121'
> +  - 'box.error.UPSERT_UNIQUE_SECONDARY_KEY : 105'
>     - 'box.error.UNKNOWN_REQUEST_TYPE : 48'
> -  - 'box.error.SPACE_EXISTS : 10'
> +  - 'box.error.SUB_STMT_MAX : 121'
>     - 'box.error.PROC_LUA : 32'
> +  - 'box.error.SPACE_EXISTS : 10'
>     - 'box.error.ROLE_NOT_GRANTED : 92'
> +  - 'box.error.UNSUPPORTED : 5'
>     - 'box.error.NO_SUCH_SPACE : 36'
>     - 'box.error.WRONG_INDEX_PARTS : 107'
> -  - 'box.error.DROP_SPACE : 11'
>     - 'box.error.MIN_FIELD_COUNT : 39'
>     - 'box.error.REPLICASET_UUID_MISMATCH : 63'
>     - 'box.error.UPDATE_FIELD : 29'
> +  - 'box.error.INDEX_EXISTS : 85'
>     - 'box.error.COMPRESSION : 119'
>     - 'box.error.INVALID_ORDER : 68'
> -  - 'box.error.INDEX_EXISTS : 85'
>     - 'box.error.SPLICE : 25'
>     - 'box.error.UNKNOWN : 0'
> +  - 'box.error.IDENTIFIER : 70'
>     - 'box.error.DROP_PRIMARY_KEY : 17'
>     - 'box.error.NULLABLE_PRIMARY : 152'
>     - 'box.error.NO_SUCH_SEQUENCE : 145'
>     - 'box.error.RELOAD_CFG : 58'
>     - 'box.error.INVALID_UUID : 64'
> -  - 'box.error.INJECTION : 8'
> +  - 'box.error.DROP_SPACE : 11'
>     - 'box.error.TIMEOUT : 78'
> -  - 'box.error.IDENTIFIER : 70'
>     - 'box.error.ITERATOR_TYPE : 72'
>     - 'box.error.REPLICA_MAX : 73'
> +  - 'box.error.NO_SUCH_ROLE : 82'
>     - 'box.error.MISSING_REQUEST_FIELD : 69'
>     - 'box.error.MISSING_SNAPSHOT : 93'
>     - 'box.error.WRONG_SPACE_OPTIONS : 111'
>     - 'box.error.READONLY : 7'
> -  - 'box.error.UNSUPPORTED : 5'
>     - 'box.error.UPDATE_INTEGER_OVERFLOW : 95'
> +  - 'box.error.RTREE_RECT : 101'
>     - 'box.error.NO_CONNECTION : 77'
>     - 'box.error.INVALID_XLOG_ORDER : 76'
> -  - 'box.error.UPSERT_UNIQUE_SECONDARY_KEY : 105'
> -  - 'box.error.ROLLBACK_IN_SUB_STMT : 123'
>     - 'box.error.WRONG_SCHEMA_VERSION : 109'
> -  - 'box.error.UNSUPPORTED_INDEX_FEATURE : 112'
> -  - 'box.error.INDEX_PART_TYPE_MISMATCH : 24'
> +  - 'box.error.ROLLBACK_IN_SUB_STMT : 123'
> +  - 'box.error.PROTOCOL : 104'
>     - 'box.error.INVALID_XLOG_TYPE : 125'
> +  - 'box.error.INDEX_PART_TYPE_MISMATCH : 24'
> +  - 'box.error.UNSUPPORTED_INDEX_FEATURE : 112'
>   ...
>   test_run:cmd("setopt delimiter ''");
>   ---
> diff --git a/test/box/select.result b/test/box/select.result
> index 4aed706..b3ee6cd 100644
> --- a/test/box/select.result
> +++ b/test/box/select.result
> @@ -619,31 +619,62 @@ collectgarbage('collect')
>   ---
>   - 0
>   ...
> +-- gh-3224 resurrect tuple bigrefs
> +collectgarbage('stop')
> +---
> +- 0
> +...
>   s = box.schema.space.create('select', { temporary = true })
>   ---
>   ...
>   index = s:create_index('primary', { type = 'tree' })
>   ---
>   ...
> -a = s:insert{0}
> +_ = s:insert{0}
> +---
> +...
> +_ = s:insert{1}
> +---
> +...
> +_ = s:insert{2}
> +---
> +...
> +_ = s:insert{3}
> +---
> +...
> +lots_of_links = setmetatable({}, {__mode = 'v'})
>   ---
>   ...
> -lots_of_links = {}
> +i = 0
> +---
> +...
> +while (i < 33000) do table.insert(lots_of_links, s:get{0}) i = i + 1 end
> +---
> +...
> +while (i < 66000) do table.insert(lots_of_links, s:get{1}) i = i + 1 end
> +---
> +...
> +while (i < 100000) do table.insert(lots_of_links, s:get{2}) i = i + 1 end
>   ---
>   ...
>   ref_count = 0
>   ---
>   ...
> -while (true) do table.insert(lots_of_links, s:get{0}) ref_count = ref_count + 1 end
> +for k, v in pairs(lots_of_links) do ref_count = ref_count + 1 end
>   ---
> -- error: Tuple reference counter overflow
>   ...
>   ref_count
>   ---
> -- 65531
> +- 100000
>   ...
> -lots_of_links = {}
> +-- check that tuples are deleted after gc is activated
> +collectgarbage('collect')
>   ---
> +- 0
> +...
> +lots_of_links
> +---
> +- []
>   ...
>   s:drop()
>   ---
> diff --git a/test/box/select.test.lua b/test/box/select.test.lua
> index 54c2ecc..3400bda 100644
> --- a/test/box/select.test.lua
> +++ b/test/box/select.test.lua
> @@ -124,12 +124,25 @@ test.random(s.index[0], 48)
>   s:drop()
>   
>   collectgarbage('collect')
> +
> +-- gh-3224 resurrect tuple bigrefs
> +
> +collectgarbage('stop')
>   s = box.schema.space.create('select', { temporary = true })
>   index = s:create_index('primary', { type = 'tree' })
> -a = s:insert{0}
> -lots_of_links = {}
> +_ = s:insert{0}
> +_ = s:insert{1}
> +_ = s:insert{2}
> +_ = s:insert{3}
> +lots_of_links = setmetatable({}, {__mode = 'v'})
> +i = 0
> +while (i < 33000) do table.insert(lots_of_links, s:get{0}) i = i + 1 end
> +while (i < 66000) do table.insert(lots_of_links, s:get{1}) i = i + 1 end
> +while (i < 100000) do table.insert(lots_of_links, s:get{2}) i = i + 1 end
>   ref_count = 0
> -while (true) do table.insert(lots_of_links, s:get{0}) ref_count = ref_count + 1 end
> +for k, v in pairs(lots_of_links) do ref_count = ref_count + 1 end
>   ref_count
> -lots_of_links = {}
> +-- check that tuples are deleted after gc is activated
> +collectgarbage('collect')
> +lots_of_links
>   s:drop()
> diff --git a/test/unit/CMakeLists.txt b/test/unit/CMakeLists.txt
> index dbc02cd..aef5316 100644
> --- a/test/unit/CMakeLists.txt
> +++ b/test/unit/CMakeLists.txt
> @@ -192,3 +192,6 @@ target_link_libraries(vy_cache.test ${ITERATOR_TEST_LIBS})
>   
>   add_executable(coll.test coll.cpp)
>   target_link_libraries(coll.test core unit ${ICU_LIBRARIES} misc)
> +
> +add_executable(tuple_bigref.test tuple_bigref.c)
> +target_link_libraries(tuple_bigref.test tuple unit)
> diff --git a/test/unit/tuple_bigref.c b/test/unit/tuple_bigref.c
> new file mode 100644
> index 0000000..97095dc
> --- /dev/null
> +++ b/test/unit/tuple_bigref.c
> @@ -0,0 +1,117 @@
> +#include "vy_iterators_helper.h"
> +#include "memory.h"
> +#include "fiber.h"
> +#include "unit.h"
> +#include <msgpuck.h>
> +#include "trivia/util.h"
> +
> +enum {
> +	BIGREF_DIFF = 10,
> +	BIGREF_COUNT = 70003,
> +	BIGREF_CAPACITY = 107,
> +};
> +
> +static char tuple_buf[64];
> +static char *tuple_end = tuple_buf;
> +
> +/**
> + * This function creates new tuple with refs == 1.
> + */
> +static inline struct tuple *
> +create_tuple()
> +{
> +	struct tuple *ret =
> +		tuple_new(box_tuple_format_default(), tuple_buf, tuple_end);
> +	tuple_ref(ret);
> +	return ret;
> +}
> +
> +/**
> + * This test performs overall check of bigrefs.
> + * What it checks:
> + * 1) Till refs <= TUPLE_REF_MAX it shows number of refs
> + * of tuple and it isn't a bigref.
> + * 2) When refs > TUPLE_REF_MAX first 15 bits of it becomes
> + * index of bigref and the last bit becomes true which
> + * shows that it is bigref.
> + * 3) Each of tuple has its own number of refs, but all
> + * these numbers more than it is needed for getting a bigref.
> + * 4) Indexes of bigrefs are given sequentially.
> + * 5) After some tuples are sequentially deleted all of
> + * others bigrefs are fine. In this test BIGREF_CAPACITY
> + * tuples created and each of their ref counter increased
> + * to (BIGREF_COUNT - index of tuple). Tuples are created
> + * consistently.
> + */
> +static int
> +test_bigrefs_1()
> +{
> +	struct tuple **tuples = (struct tuple **) malloc(BIGREF_CAPACITY *
> +							 sizeof(*tuples));
> +	for(int i = 0; i < BIGREF_CAPACITY; ++i)
> +		tuples[i] = create_tuple();
> +	for(int i = 0; i < BIGREF_CAPACITY; ++i) {
> +		assert(tuples[i]->refs == 1);
> +		for(int j = 1; j < TUPLE_REF_MAX; ++j)
> +			tuple_ref(tuples[i]);
> +		assert(! tuples[i]->is_bigref);
> +		tuple_ref(tuples[i]);
> +		assert(tuples[i]->is_bigref);
> +		for(int j = TUPLE_REF_MAX + 1; j < BIGREF_COUNT - i; ++j)
> +			tuple_ref(tuples[i]);
> +		assert(tuples[i]->is_bigref);
> +	}
> +	for(int i = 0; i < BIGREF_CAPACITY; ++i) {
> +		for(int j = 1; j < BIGREF_COUNT - i; ++j)
> +			tuple_unref(tuples[i]);
> +		assert(tuples[i]->refs == 1);
> +		tuple_unref(tuples[i]);
> +	}
> +	free(tuples);
> +	return 0;
> +}
> +
> +/**
> + * This test checks that bigrefs works fine after being
> + * created and destroyed BIGREF_DIFF times.
> + */
> +static int
> +test_bigrefs_2()
> +{
> +	struct tuple *tuple = create_tuple();
> +	for(int i = 0; i < 2; ++i) {
> +		assert(tuple->refs == 1);
> +		for(int j = 1; j < BIGREF_COUNT; ++j)
> +			tuple_ref(tuple);
> +		assert(tuple->is_bigref);
> +		for(int j = 1; j < BIGREF_COUNT; ++j)
> +			tuple_unref(tuple);
> +		assert(tuple->refs == 1);
> +	}
> +	tuple_unref(tuple);
> +	return 0;
> +}
> +
> +int
> +main()
> +{
> +	header();
> +	plan(2);
> +
> +	memory_init();
> +	fiber_init(fiber_c_invoke);
> +	tuple_init(NULL);
> +
> +	tuple_end = mp_encode_array(tuple_end, 1);
> +	tuple_end = mp_encode_uint(tuple_end, 2);
> +
> +	ok(test_bigrefs_1() == 0, "Overall test passed.");
> +	ok(test_bigrefs_2() == 0, "Create/destroy test passed.");
> +
> +	tuple_free();
> +	fiber_free();
> +	memory_free();
> +
> +	footer();
> +	check_plan();
> +}
> diff --git a/test/unit/tuple_bigref.result b/test/unit/tuple_bigref.result
> new file mode 100644
> index 0000000..ad22f45
> --- /dev/null
> +++ b/test/unit/tuple_bigref.result
> @@ -0,0 +1,5 @@
> +	*** main ***
> +1..2
> +ok 1 - Overall test passed.
> +ok 2 - Create/destroy test passed.
> +	*** main: done ***
>