[PATCH 1/8] memtx: init index extent allocator in engine constructor

[Vladimir Davydov <vdavydov.dev@gmail.com>]

Postponing it until a memtx index is created for the first time saves us
no memory or cpu, it only makes the code more difficult to follow.
---
 src/box/memtx_bitset.c |  2 --
 src/box/memtx_engine.c | 34 +++++++---------------------------
 src/box/memtx_engine.h |  9 ---------
 src/box/memtx_hash.c   |  2 --
 src/box/memtx_rtree.c  |  2 --
 src/box/memtx_tree.c   |  2 --
 6 files changed, 7 insertions(+), 44 deletions(-)

diff --git a/src/box/memtx_bitset.c b/src/box/memtx_bitset.c
index 7d8ee11a..93b4a00a 100644
--- a/src/box/memtx_bitset.c
+++ b/src/box/memtx_bitset.c
@@ -490,8 +490,6 @@ memtx_bitset_index_new(struct memtx_engine *memtx, struct index_def *def)
 	assert(def->iid > 0);
 	assert(!def->opts.is_unique);
 
-	memtx_index_arena_init();
-
 	if (!mempool_is_initialized(&memtx->bitset_iterator_pool)) {
 		mempool_create(&memtx->bitset_iterator_pool, cord_slab_cache(),
 			       sizeof(struct bitset_index_iterator));
diff --git a/src/box/memtx_engine.c b/src/box/memtx_engine.c
index ee3afaec..fd93491e 100644
--- a/src/box/memtx_engine.c
+++ b/src/box/memtx_engine.c
@@ -55,7 +55,6 @@
  * box.slab.info(), @sa lua/slab.cc
  */
 extern struct quota memtx_quota;
-static bool memtx_index_arena_initialized = false;
 struct slab_arena memtx_arena; /* used by memtx_tuple.cc */
 static struct slab_cache memtx_index_slab_cache;
 struct mempool memtx_index_extent_pool;
@@ -971,6 +970,13 @@ memtx_engine_new(const char *snap_dirname, bool force_recovery,
 	if (memtx->gc_fiber == NULL)
 		goto fail;
 
+	/* Initialize index extent allocator. */
+	slab_cache_create(&memtx_index_slab_cache, &memtx_arena);
+	mempool_create(&memtx_index_extent_pool, &memtx_index_slab_cache,
+		       MEMTX_EXTENT_SIZE);
+	memtx_index_num_reserved_extents = 0;
+	memtx_index_reserved_extents = NULL;
+
 	memtx->state = MEMTX_INITIALIZED;
 	memtx->force_recovery = force_recovery;
 
@@ -1007,32 +1013,6 @@ memtx_engine_set_max_tuple_size(struct memtx_engine *memtx, size_t max_size)
 }
 
 /**
- * Initialize arena for indexes.
- * The arena is used for memtx_index_extent_alloc
- *  and memtx_index_extent_free.
- * Can be called several times, only first call do the work.
- */
-void
-memtx_index_arena_init(void)
-{
-	if (memtx_index_arena_initialized) {
-		/* already done.. */
-		return;
-	}
-	/* Creating slab cache */
-	slab_cache_create(&memtx_index_slab_cache, &memtx_arena);
-	/* Creating mempool */
-	mempool_create(&memtx_index_extent_pool,
-		       &memtx_index_slab_cache,
-		       MEMTX_EXTENT_SIZE);
-	/* Empty reserved list */
-	memtx_index_num_reserved_extents = 0;
-	memtx_index_reserved_extents = 0;
-	/* Done */
-	memtx_index_arena_initialized = true;
-}
-
-/**
  * Allocate a block of size MEMTX_EXTENT_SIZE for memtx index
  */
 void *
diff --git a/src/box/memtx_engine.h b/src/box/memtx_engine.h
index 2ce597b4..72f40528 100644
--- a/src/box/memtx_engine.h
+++ b/src/box/memtx_engine.h
@@ -154,15 +154,6 @@ enum {
 };
 
 /**
- * Initialize arena for indexes.
- * The arena is used for memtx_index_extent_alloc
- *  and memtx_index_extent_free.
- * Can be called several times, only first call do the work.
- */
-void
-memtx_index_arena_init(void);
-
-/**
  * Allocate a block of size MEMTX_EXTENT_SIZE for memtx index
  */
 void *
diff --git a/src/box/memtx_hash.c b/src/box/memtx_hash.c
index 20d6ac5d..08ba84ad 100644
--- a/src/box/memtx_hash.c
+++ b/src/box/memtx_hash.c
@@ -461,8 +461,6 @@ static const struct index_vtab memtx_hash_index_vtab = {
 struct memtx_hash_index *
 memtx_hash_index_new(struct memtx_engine *memtx, struct index_def *def)
 {
-	memtx_index_arena_init();
-
 	if (!mempool_is_initialized(&memtx->hash_iterator_pool)) {
 		mempool_create(&memtx->hash_iterator_pool, cord_slab_cache(),
 			       sizeof(struct hash_iterator));
diff --git a/src/box/memtx_rtree.c b/src/box/memtx_rtree.c
index 6afd5521..baeffa26 100644
--- a/src/box/memtx_rtree.c
+++ b/src/box/memtx_rtree.c
@@ -350,8 +350,6 @@ memtx_rtree_index_new(struct memtx_engine *memtx, struct index_def *def)
 	enum rtree_distance_type distance_type =
 		(enum rtree_distance_type)def->opts.distance;
 
-	memtx_index_arena_init();
-
 	if (!mempool_is_initialized(&memtx->rtree_iterator_pool)) {
 		mempool_create(&memtx->rtree_iterator_pool, cord_slab_cache(),
 			       sizeof(struct index_rtree_iterator));
diff --git a/src/box/memtx_tree.c b/src/box/memtx_tree.c
index 6b76e538..0911af52 100644
--- a/src/box/memtx_tree.c
+++ b/src/box/memtx_tree.c
@@ -669,8 +669,6 @@ static const struct index_vtab memtx_tree_index_vtab = {
 struct memtx_tree_index *
 memtx_tree_index_new(struct memtx_engine *memtx, struct index_def *def)
 {
-	memtx_index_arena_init();
-
 	if (!mempool_is_initialized(&memtx->tree_iterator_pool)) {
 		mempool_create(&memtx->tree_iterator_pool, cord_slab_cache(),
 			       sizeof(struct tree_iterator));
-- 
2.11.0