The graceful shutdown protocol works as follows:

 1. The server sends a shutdown request (the box.shutdown event) to all
    its clients that subscribed to it.
 2. Upon receiving a shutdown request, a client is supposed to close its
    connection.
 3. The server waits for all clients subscribed to box.shutdown event to
    exit.
 4. The server exits.

In net.box, the box.shutdown event is processed by `remote._callback`.
The problem is it may occur that `remote._callback` is garbage collected
while the `remote` object isn't. If this happens, the shutdown request
will never get processed, and the server won't exit until the `remote`
object is garbage collected, which may take forever.

Let's fix this issue by breaking the worker loop if we see that the
callback was garbage collected.

Closes #7225

NO_DOC=bug fix

nixos (and probably some other distributives) place zoneinfo directory
not in /usr/share (in /etc for example). TZDIR is set accordingly.
Currently zoneinfo is looked for in /usr/share, disregarding TZDIR env
variable.

This commit adds compile definition for TZDIR if such env variable is
defined. This fixes zoneinfo lookup for nixos.

NO_CHANGELOG=build
NO_DOC=build
NO_TEST=build

This reverts commit 33830978.

Follow-up #6477

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

This reverts commit 9d1f9f0e.

Follow-up #6477

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

Two things we need to do to fix build with OpenSSL 3.0:

1. Use EVP_MAC_* functions instead of HMAC_*
   https://www.openssl.org/docs/man3.0/man3/HMAC_CTX_new.html

2. Load the Legacy provider to enable legacy algorithms, such as MD4
   https://wiki.openssl.org/index.php/OpenSSL_3.0#Programming_in_OpenSSL_3.0

Closes #6477

NO_DOC=build fix
NO_TEST=build fix
NO_CHANGELOG=build fix

We redefine ssl_init and ssl_free in the EE build, because we need to do
some extra work there. Currently, it's fine to duplicate the bulk of the
OpenSSL library initialization code between EE and CE repositories, but
with the introduction of OpenSSL 3.0 it's going to become more
complicated so duplicating would look bad. Let's move the common code to
ssl_init_impl() and ssl_free_impl() helper functions.

Needed for #6477

NO_DOC=refactoring
NO_TEST=refactoring
NO_CHANGELOG=refactoring

ERR_error_string adds some extra information that depends on the OpenSSL
library version (code, module, method). This information says nothing to
the end user, and it results in different test results after updating to
OpenSSL 3.0. Let's use ERR_reason_error_string instead, which just
prints a human-readable error message.

Part of #6477

NO_DOC=minor change in error message
NO_CHANGELOG=minor change in error message

openssl_err_str is used for reporting OpenSSL errors. It calls
crypto_ERR_* functions using FFI. There's a typo in the code:
ffi.crypto_ERR_error_string is used instead of ffi.C.*.

We don't normally step on this, because OpenSSL doesn't return errors
in our configuration, but if it did for some reason (e.g. a cipher was
disabled in the library), we'd get a confusing error message.

NO_DOC=bug fix
NO_TEST=occur only on internal error
NO_CHANGELOG=occur only on internal error

Added 'tarantool/actions/cleanup' action to each job which uses
self-hosted runners.

The action cleans workspace directory of self-hosted runner after
previous run. The main reason to add this action is 'Need a single
revision' error [1] caused by a conflict of submodule versions,
the standard 'actions/checkout' action fails with this error. It's a
well-known problem and related issue [2] is still opened.

[1] https://github.com/tarantool/tarantool-qa/issues/145
[2] https://github.com/actions/checkout/issues/418

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

Closes tarantool/tarantool-qa#145

This patch introduces not thread-safe low resolution
monotonic clock, based on interval timer. It should
be used only by thread that initialized it.

Part of #6085

NO_CHANGELOG=internal feature
NO_DOC=internal feature

Since the use of sigprocmask() is unspecified in a multithreaded
process we should use pthread_sigmask() instead. This patch
replaces all the sigprocmask calls with pthread analogue.

NO_TEST=refactoring
NO_CHANGELOG=refactoring
NO_DOC=refactoring

To ensure that regular and GC64 jobs in packaging workflows don't
overwrite artifacts of each other, we need to use a different artifact
name per job.

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

In PR #7090 we forgot to update the path to gather failure artifacts for
many packaging workflows. Now it is fixed.

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

GitHub suggests to look on the document, when it is present. The banner
is shown for visitors of issues and pull requests pages. We can use this
feature to highlight typical stones on the contributor's road.

My goal is to leave suggestions for typical points of a confusion in a
short document (don't bury into details) and leave links for further
reading.

I hope we should move most of content of the 'open a pull request'
section to a wiki page and possibly merge it with [1] and [2]. It
requires more work and I would consider it as a future step toward good
developer guidelines.

[1]: https://github.com/tarantool/tarantool/wiki/Code-review-procedure
[2]: https://www.tarantool.io/en/doc/latest/dev_guide/developer_guidelines

NO_CHANGELOG=not a user visible change
NO_DOC=nothing requires an update on the website
NO_TEST=it is purely documentation change

Introduce helpers for each of our custom extension types.
The helpers will be used by mp_check() to validate extension contents
and make sure no malformed data is accepted by tarantool.

Closes #6857

NO_DOC=no user visible changes

The inject remote method is used in testing quite a lot. For example,
when someone needs to pass arbitrary MsgPack to Tarantool.

The current way to use it is:
conn:_request(netbox._method.inject, opts, nil, nil, custom_msgpack)

This is quite long and ugly, so let's add a helper:
conn:_inject(custom_msgpack, opts)

Also, while we're at it, lets fix the following issue.
The _inject remote method is barely usable without knowing which sync
net.box will use for the next request.

On the one hand, the user has to encode some custom sync to the request
he's injecting.
On the other hand, net.box doesn't parse the custom sync and always uses
its own pre-generated one to wait for the request response.

So the user has to pick the correct sync value, which net.box uses
internally.

Let's make life simpler and introduce _next_sync method, which returns
the next sync, which will be used by net.box.

In-scope-of #6857
Closes #7177

NO_DOC=internal change
NO_CHANGELOG=internal change
NO_TEST=tested implicitly in next commit

A Tarantool server is supposed to send a greeting message right after
accepting a new client so the first thing an applier does after
connecting to the master is reads the greeting. It does this without
timeouts. The problem is that if by mistake we connect to a wrong
instance, which doesn't send anything to clients, the applier will hang
forever (until the remote closes the socket), without logging any
errors.

This may happen even with a valid Tarantool instance - if SSL encryption
is enabled on the master, but not on the client, because the SSL
protocol assumes that the client initiates a connection by writing to
the socket first (before the server).

Let's add a timeout to the operation reading the greeting. The timeout
is set to replication_disconnect_timeout(), after which a connection is
broken if the master doesn't send heartbeats for that long. Note, we
don't add a timeout to other read/write operations issued to initiate a
replication connection, because if we received a greeting and it's
valid, then the master is likely to be fine.

Closes #7204

NO_DOC=bug

The upgrade test worked incorrectly: the instances WAL directory contained
xlog with the latest schema version and the snapshot contained an older
schema version (2.7.1) than required (2.9.1), whereas there only need to
be a snapshot with 2.9.1 schema version — fix this descrepancy.

Also, schema upgrade is performed automatically: remove the redundant
`box.schema.upgrade` call.

NO_CHANGELOG=test fix
NO_DOC=test fix
NO_DOC=test fix

Commit b18dd47f ("Introduce backtrace=true option to fiber.info()")
introduced a way to skip backtraces in fiber.info() calls.
Commit 9da7e03e ("fiber: introduce fiber_o:info() and fiber_o:csw()")
introduced `options` function for fiber object however it ignored
passed options.
This patch fixed it. Currently fiber:info({backtrace = false})
returns info without backtrace.

Closes #7210

NO_DOC=bugfix

- Ubuntu Groovy Gorilla (20.10)
- Ubuntu Hirsute Hippo (21.04)

See for details: https://wiki.ubuntu.com/Releases

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

- Fedora 30
- Fedora 31
- Fedora 32
- Fedora 33

See for details: https://docs.fedoraproject.org/en-US/releases/eol

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

FreeBSD Tarantool port has some problems if build uses cmake'
ExternalProject_Add which refers to the github repository.
Sumodule works better - so switching to using it.

NO_CHANGELOG=build
NO_DOC=build
NO_TEST=build

Previous version of tzcode/CMakeLists.txt leaves untracked files under
source directory src/lib/tzcode/tz/. We have changed slightly an approach
used to checkout and build IANA github sources under build/ directory,
not in ${PROJECT_BINARY_DIR} (which may be pointing not to out-of-source
build directory, but rather to the repository root itself, if insource
build used).

Closes #7173

NO_CHANGELOG=infra
NO_DOC=infra
NO_TEST=infra

By a mistake it was marked as API_EXPORT but was forgotten to
be added to exports.

Closes #7125

NO_DOC=bugfix

This client error assumes two arguments: space's name and index's name.
Since from the context it's clear that primary index is affected,
let's drop index name from error message. It's quite handy for space
upgrade case, since in such situation we have lack of information
concerning space.

NO_CHANGELOG=<Minor change>
NO_DOC=<No functional changes>

We are going to utilize primary key definition during space upgrade in
order to verify primary key invariant. So we need it to be stored in
space_upgrade metadata. Let's extend space_upgrade_new() signature and
pass there primary key definition. Also patch moves space_upgrade_new()
call a bit lower through code - now it's called after all indexes are
assigned (to simplify extraction of primary key definition).
Moreover, in order to print pretty error message during space upgrade
we should keep space in struct space_upgrade.

NO_DOC=ee
NO_TEST=ee
NO_CHANGELOG=ee

box.error() expects first argument to be numeric or table; passing
string to it is wrong. Accidentally in net.box module two places where
string is passed to box.error() as first argument: in :unprepare() and
:connect() methods. Let's fix them and pass error code ER_ILLEGAL_PARAMS.

NO_DOC=<bugfix>
NO_CHANGELOG=<Minor>

Fix wording, punctuation, and formatting.

NO_DOC=changelog
NO_TEST=changelog

Previously SQL didn't validate for all cases, that the amount of the
source and destination columns during insertion is equal. The problem
was detected when we insert an incorrect amount of values into the
table. For example, the query

insert into t(a) select a, b from t

produced an instance crash. Fixed.

Closes #7132

NO_DOC=bug fix

Co-authored-by: Mergen Imeev <imeevma@gmail.com>

We used to not implement comparison operators for interval
objects, thus any compare (even of equal) objects returned false:

	```
	tarantool> dt1 = datetime.new()
	---
	...

	tarantool> dt2 = datetime.now()
	---
	...

	tarantool> dt1 - dt1 == dt2 - dt2
	---
	- false
	...
	```

Now we implemented comparison for interval objects, where we compare
field by field starting from highest attribute (e.g. `year`) to
smallest attribute (e.g. `nsec`) and if any of comparison
returned non zero value then we return this result.

NO_DOC=bugfix
NO_CHANGELOG=bugfix

Use Olson/IANA tzdata for timezone handling in datetime string.

Closes of #6751

NO_TEST=doc

@TarantoolBot document
Title: Document timezone support

Timezones support
-----------------

Tarantool uses IANA tzdata aka Olson DB facilities for timezone
resolution at the moment of parsing of datetime literals or while
parsing `tz` attribute in constructor, or `:set{}` method call.

In addition to the `tzoffset` we provided before, we now define
`tzindex`, the unique index assigned by Tarantool to each known IANA
timezone.

```lua
date = require 'datetime'

tarantool> T = date.parse '2022-01-01T00:00 Europe/Moscow'

tarantool> T.tzindex
---
- 947
...

tarantool> T.tzoffset
---
- 180
...

tarantool> T.tz
---
- Europe/Moscow
...
```

Now `date.isdst` field (alone and as part of `:totable()` table) is
correctly calculated using `tzindex` and attributes of the selected
timezone in the Olson DB timezone.

```
tarantool> date.parse('2004-06-01T00:00 Europe/Moscow').isdst
---
- true
...

tarantool> date.parse('2004-12-01T00:00 Europe/Moscow'):totable()
---
- sec: 0
  min: 0
  yday: 336
  day: 1
  nsec: 0
  isdst: false
  wday: 4
  tzoffset: 180
  month: 12
  year: 2004
  hour: 0
...

```

All timezone names and abbreviations, known to the current Tarantool
version are available via `datetime.TZ` bidirectional array.

```lua
print(date.TZ['Europe/Moscow']) -- 947
print(date.TZ[947]) -- Europe/Moscow
```

Limitations
-----------

There were moments in past history, when local mean time in some
partcular zone used timezone offset not representable in whole
minutes, but rather in seconds, i.e. in Moscow before 1918 there
used to be offset +2 hours 31 minutes and 19 seconds. Please see
Olson dump for this period

```
$ ./src/lib/tzcode/install/usr/bin/zdump -c1880,1918 -i Europe/Moscow

TZ="Europe/Moscow"
-       -       +023017 MMT
1916-07-03      00:01:02        +023119 MMT
1917-07-02      00      +033119 MST     1
1917-12-27      23      +023119 MMT
```

Modern tzdata rules do not use such tiny fraction, and all timezones differ
to UTC in units measured in minutes, not seconds. Tarantool datetime uses
minutes internally as units for `tzoffset` so there is some loss of
precision if you try to operate with such ancient timestamps.

For performance reasons try to reuse previously
allocated structure across calls to tzalloc() if
zone appears to be the same.

NO_DOC=refactoring
NO_CHANGELOG=refactoring
NO_TEST=refactoring

Fixed incorrect interval initialization for case of `()` used
while it was correct for `{}` arguments.

NO_DOC=bugfix
NO_CHANGELOG=bugfix
NO_TEST=bugfix

```
tarantool> itv = require('datetime').interval.new{}
---
...

tarantool> itv
---
- 0 seconds
...

tarantool> itv = require('datetime').interval.new()
---
...

tarantool> itv
---
- +0.000000001 seconds
...
```

Extended gen-zone-abbrevs.pl script with capability to generate
timezones.lua in addition to timezones.h.

That's bidirectional Lua translation table for resolution of
timezone name by it's index and vice versa. Exported to Lua
world via `datetime.TZ`

NO_DOC=next commit

Properly calculate `isdst` field in datetime Lua object and
for attribute returned by `:totable()` function.

NO_DOC=next commit

* Modified localtime.c to use tnt_tm instead of tm structure;
* Use this structure for passing data to tnt_localtime_rz at
  the moment of time-zone resolution;
* As a side-effect of refactoring - simplified singleton we
  used to use for automagical sorting of array with timezone
  abbreviations

NO_DOC=internal
NO_CHANGELOG=internal

Using our own `tnt_tm` allows to properly pass `tm_tzindex`.

NO_DOC=refactoring
NO_CHANGELOG=refactoring
NO_TEST=refactoring

* localtime.c refactored to make tzalloc/tzfree public;
* Modified Perl script to generate primary Olson timezones and aliases.
  Get rid of NYI;

NO_DOC=refactoring
NO_CHANGELOG=refactoring
NO_TEST=refactoring

- localtime.c, tzfile.h added to build

NO_DOC=build
NO_CHANGELOG=build
NO_TEST=build

A certificate used for an encrypted replication connection may expire,
in which case the user will be forced to reconfigure the connection both
on the master and on the replica to use the new certificate. If the
replica completes the reconfiguration first, it will fail to connect to
the master and never retry, even though the master should complete its
reconfiguration in a moment.

To avoid that, we should make the applier retry to connect on SSLError,
just like it does on SocketError.

Needed for https://github.com/tarantool/tarantool-ee/issues/107

NO_DOC=ee
NO_TEST=ee
NO_CHANGELOG=ee