It makes the helper a bit more convenient to use it tests.

NO_DOC=testing helper
NO_TEST=see NO_DOC
NO_CHANGELOG=see NO_DOC

This patch implements broadcastion of the current statusi.

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This patch introduces the "config" module. This module allows you to
access the configuration, apply it, and reload.

Part of #8789

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This patch introduces the env configuration source. This is the instance
source that can be used to describe configuration options for a single
instance.

Part of #8789

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This patch introduces the file configuration source. This is the cluster
source that can be used to describe all configuration options for
cluster instances.

Part of #8789

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This patch introduces the application applier. This applier is used to
set user application options.

Part of #8789

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This patch introduces the fiber applier. This applier is used to set
fiber options.

Part of #8789

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This patch introduces the console applier. This applier is used to set
console options.

Part of #8789

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This patch introduces the credentials applier. This applier is used to
create roles and users, set roles to users and roles, set password to
users, set any privileges for users and roles for universe.

Part of #8789

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This patch introduces the box_cfg applier. This applier is used to
process box options. This appliers is called after mkdir applier because
we need all necessary directories to exist by the time the box options
are processed.

Part of #8789

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This patch introduces the mkdir applier. This appliers is used to create
all required directories. This applier is called before all other
appliers.

Part of #8789

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This patch introduces the configdata module, which prepares data from
configuration sources before it is provided to appliers.

Part of #8789

NO_DOC=will be added later
NO_CHANGELOG=will be added later

<luaT_pushtuple> function created a new GCfunc object for a tuple __gc
handler (i.e. <lbox_tuple_gc>), having no upvalues, on each call when
tuple object for Lua world is created.

The change introduces the reference to the single GCfunc object created
on Tarantool startup and stored to Lua registry. Using this approach in
scope of <luaT_pushtuple> is aimed to reduce Lua GC memory usage.

Part of #5201

NO_DOC=refactoring
NO_TEST=refactoring
NO_CHANGELOG=refactoring

Reviewed-by: Vladimir Davydov <vdavydov@tarantool.org>
Reviewed-by: Sergey Kaplun <skaplun@tarantool.org>
Signed-off-by: Igor Munkin <imun@tarantool.org>

We are going to introduce universal triggers registry and use it for
tarantool triggers (e.g. space.on_replace). However, when trigger is set
to the registry, we do not know which arguments will be passed there
from C. That is why current implementation of triggers in tarantool is not
suitable for use in universal registry.

We decided to introduce func_adapter interface which allows to call
functions from any programming language. Now we support only one
language, which is Lua, so for the most part this interface is needed
to invert dependencies.

The patch introduces func_adapter interface and its implementation for
Lua functions.

Part of #8657

NO_CHANGELOG=internal
NO_DOC=internal

`cord_slab_cache` was not designed to offer a backward compatible API, and
leaving it exposed inevitably leads to errors like those highlighted in
#7124 and tarantool/memcached#96: hence, remove it from the public API
export.

Closes #7124

@TarantoolBot document
Title: `cord_slab_cache` was removed from public API export

The `cord_slab_cache` needs to be removed from the C API reference of the
fiber module.

Space index build and space format checking operations don't destroy space
iterator on `txn_check_singlestatement` failure — fix this.

Closes #8773

NO_DOC=bugfix
NO_TEST=<leak happens in small, cannot be detected by sanitizer>

The procedure name cache uses a region for hash table entry allocation, but
the cache is a thread local variable, while the `region` uses a `slab`
allocator the lifetime of which is bounded by `main`, while thread locals
are destroyed after `main`: use the `malloc` allocator instead.

Benchmark from #7207 shows that this change does not effect performance.

Closes #8777

NO_CHANGELOG=<leak does not affect users>
NO_DOC=bugfix
NO_TEST=<detected by ASAN>

This patch removes some deprecated code. This code had no user-visible
effect, but caused problems when running the test with ASAN enabled.

Closes #8761

NO_DOC=refactoring
NO_TEST=refactoring
NO_CHANGELOG=refactoring

Before a commit ec1af129 ("box: do not close xlog file descriptors in
the atfork handler") there was a bug when Tarantool with enabled
background mode via environment variable could lead a crash:

NO_WRAP
```
$ TT_PID_FILE=tarantool.pid TT_LOG=tarantool.log TT_BACKGROUND=true TT_LISTEN=3301 tarantool -e 'box.cfg{}'
$ tail -3 tarantool.log
2021-11-02 16:05:43.672 [2341202] main init.c:696 E> LuajitError: cannot read stdin: Resource temporarily unavailable
2021-11-02 16:05:43.672 [2341202] main F> fatal error, exiting the event loop
2021-11-02 16:05:43.672 [2341202] main F> fatal error, exiting the event loop
```
NO_WRAP

With commit ec1af129 ("box: do not close xlog file descriptors in
the atfork handler") described bug could not be reproduced.

Proposed patch adds a test that starts Tarantool in background mode
enabled via box.cfg option and via environment variable TT_BACKGROUND to
make sure this behaviour will not be broken in a future.

Closes #6128

NO_DOC=test

This patch adds configuration examples. Although the configuration
module will be introduced later, the examples can already be tested
using the instance_config and cluster_config modules.

Closes #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This patch introduces the cluster_config module. This module contains
the cluster configuration schema.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This patch instroduces instance EE options.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance application configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance credentials configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance replication configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance snapshot configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance WAL configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance vinyl engine configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance memtx engine configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance SQL configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance database configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance iproto configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance log configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance fiber configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance console configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes the instance process configuration.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This section describes general instance configuration options.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

This patch introduces the instance_config module. This module will
contain the instance configuration schema.

Part of #8778

NO_DOC=will be added later
NO_CHANGELOG=will be added later

The msgpack module can't lack `msgpack.NULL`, because it leads to the
'Please call box.cfg{} first' error at access to `box.NULL`.

An upcoming patch regarding schemas for tarantool's new hierarchical
configuration uses `box.NULL` during tarantool's initialization.

The override feature is tested on a set of modules, which are easy to
replace with an arbitrary table without losing an ability to pass
tarantool's initialization. The msgpack module will not meet the
criteria after the mentioned patch.

The test doesn't attempt to hold a precise list of modules available for
overriding. It rather checks the overall mechanics. So it is OK to
adjust the list.

NO_DOC=testing code change
NO_CHANGELOG=see NO_DOC

There are sporadic segfaults in libunwind during backtrace_collect().
Reproducible with the latest version, and there are open issues with
similar stacks:

https://github.com/libunwind/libunwind/issues/150
https://github.com/libunwind/libunwind/issues/260
https://github.com/libunwind/libunwind/issues/473

Let's disable ENABLE_BACKTRACE for AArch64 Linux until these issues are
resolved in libunwind.

Closes #8572
Part of #8791

NO_DOC=bugfix