[PATCH 0/8] Follow-up on async memtx index cleanup

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

Turned out that after commit 2a1482f33fa0 ("memtx: free tuples
asynchronously when primary index is dropped"), we can't merge
1.10 to 2.0 without breaking tests, because one of the tests
(namely sql-tap/gh-3083-ephemeral-unref-tuples) executes a lot
of SQL SELECT statements without yielding. Those statements
in turn create a lot of ephemeral spaces that consume all
available memory since memtx garbage collection doesn't have
a chance to clean up. To fix that, this patch set improves
the garbage collection procedure: now it is invoked not only
by a background fiber, but also on demand, i.e. when any of
memtx functions fails to allocate memory.

https://github.com/tarantool/tarantool/issues/3408
https://github.com/tarantool/tarantool/commits/memtx-run-gc-on-demand

Vladimir Davydov (8):
  memtx: init index extent allocator in engine constructor
  memtx: fold memtx_tuple.cc into memtx_engine.c
  memtx: pass engine to memory allocation functions
  memtx: move all global variables to engine
  memtx: destroy slab arena on engine shutdown
  memtx: embed light hash into memtx_hash_index
  memtx: rework background garbage collection procedure
  memtx: run garbage collection on demand

 src/box/CMakeLists.txt |   1 -
 src/box/alter.cc       |   1 -
 src/box/index.cc       |   7 +-
 src/box/lua/slab.c     |  35 ++++---
 src/box/lua/tuple.c    |   1 -
 src/box/lua/xlog.c     |   1 -
 src/box/memtx_bitset.c |   4 +-
 src/box/memtx_engine.c | 257 ++++++++++++++++++++++++++++++++++---------------
 src/box/memtx_engine.h |  67 ++++++++++---
 src/box/memtx_hash.c   |  93 ++++++------------
 src/box/memtx_hash.h   |  35 ++++++-
 src/box/memtx_rtree.c  |   4 +-
 src/box/memtx_space.c  |   7 +-
 src/box/memtx_tree.c   |  33 +++----
 src/box/memtx_tree.h   |   1 +
 src/box/memtx_tuple.cc | 193 -------------------------------------
 src/box/memtx_tuple.h  | 100 -------------------
 src/box/tuple_format.c |   1 +
 src/box/tuple_format.h |   2 +
 19 files changed, 349 insertions(+), 494 deletions(-)
 delete mode 100644 src/box/memtx_tuple.cc
 delete mode 100644 src/box/memtx_tuple.h

-- 
2.11.0