strings/json_lib.c added as a JSON library.
        SQL frunction added with sql/item_jsonfunc.h/cc

On PPC64 high-loaded server may crash due to assertion failure in InnoDB
rwlocks code.

This happened because load order between "recursive" and "writer_thread"
wasn't properly enforced.

Clean-up periodic mutex/rwlock waiters wake up. This was a hack needed to
workaround broken mutexes/rwlocks implementation. We must have sane
implementations now and don't need these anymore: release thread is
guaranteed to wake up waiters.

Removed redundant ifdef that has equivalent code in both branches.

Removed os0atomic.h and os0atomic.ic: not used anymore.

Clean-up unused cmake checks.

No point to issue RELEASE memory barrier in os_thread_create_func(): thread
creation is full memory barrier.

No point to issue os_wmb in rw_lock_set_waiter_flag() and
rw_lock_reset_waiter_flag(): this is deadcode and it is unlikely operational
anyway. If atomic builtins are unavailable - memory barriers are most certainly
unavailable too.

RELEASE memory barrier is definitely abused in buf_pool_withdraw_blocks(): most
probably it was supposed to commit volatile variable update, which is not what
memory barriers actually do. To operate properly it needs corresponding ACQUIRE
barrier without an associated atomic operation anyway.

ACQUIRE memory barrier is definitely abused in log_write_up_to(): most probably
it was supposed to synchronize dirty read of log_sys->write_lsn. To operate
properly it needs corresponding RELEASE barrier without an associated atomic
operation anyway.

Removed a bunch of ACQUIRE memory barriers from InnoDB rwlocks. They're
meaningless without corresponding RELEASE memory barriers.

Valid usage example of memory barriers without an associated atomic operation:
http://en.cppreference.com/w/cpp/atomic/atomic_thread_fence

Replaced InnoDB atomic operations with server atomic operations.

Moved INNODB_RW_LOCKS_USE_ATOMICS - it is always defined (code won't compile
otherwise).

NOTE: InnoDB uses thread identifiers as a target for atomic operations.
Thread identifiers should be considered opaque: any attempt to use a
thread ID other than in pthreads calls is nonportable and can lead to
unspecified results.

Simplified InnoDB mutex implementations, corrected memory barriers usage, use
server atomic builtins.

In 10.2, use the thd_rpl_deadlock_check() API. This way, all the
locking hacks around thd_report_wait_for() can be removed. Now
parallel replication deadlock kill happens asynchroneously, from the
slave background thread.

In InnoDB, remove also the buffering of wait reports, to simplify the
code, as this is no longer needed when the locking issues are gone.

In XtraDB, the buffering is kept for now. This is just because
presumably XtraDB will eventually be updated to MySQL 5.7-based InnoDB
as well, so there is little need to modify the existing code only for
clean-up purposes.

The old synchronous function thd_report_wait_for() is no longer used
and removed in this patch.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Merge feature into 10.2 from feature branch.

Delayed replication adds an option

  CHANGE MASTER TO master_delay=<seconds>

Replication will then delay applying events with that many
seconds. This creates a replication slave that reflects the state of
the master some time in the past.

Feature is ported from MySQL source tree.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

MDEV-10943 . Workaround linker error on Linux. Linux does not actually use __bss_start,  put __bss_start into #ifndef __linux__ section

Add test cases for delayed slave with parallel replication.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Extend to work also for parallel replication.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Only run testcase in --big. It takes a long time due to excessive sleeps.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Problem:
When using the delayed slave feature, and the SQL thread is delaying,
and the user issues STOP SLAVE, the event we wait for was executed.
It should not be executed.
Fix:
Check the return value from the delay function,
slave.cc:slave_sleep(). If the return value is 1, it means the thread
has been stopped, in this case we don't execute the statement.

Also, refactored the test case for delayed slave a little: added the
test script include/rpl_assert.inc, which asserts that a condition holds
and prints a message if not. Made rpl_delayed_slave.test use this. The
advantage is that the test file is much easier to read and maintain,
because it is clear what is an assertion and what is not, and also the
expected result can be found in the test file, you don't have to compare
it to the result file.

Manually merged into MariaDB from MySQL commit
fd2b210383358fe7697f201e19ac9779879ba72a
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

The original MySQL patch left some refactoring todo's, possibly
because of known conflicts with other parallel development (like
info-repository feature perhaps).

This patch fixes those todos/refactorings.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Two merge error fixed, and testsuite updated to removed some other
test failues.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Initial merge of delayed replication from MySQL git.

The code from the initial push into MySQL is merged, and the
associated test case passes. A number of tasks are still pending:

1. Check full test suite run for any regressions or .result file updates.

2. Extend the feature to also work for parallel replication.

3. There are some todo-comments about future refactoring left from
MySQL, these should be located and merged on top.

4. There are some later related MySQL commits, these should be checked
and merged. These include:
    e134b9362ba0b750d6ac1b444780019622d14aa5
    b38f0f7857c073edfcc0a64675b7f7ede04be00f
    fd2b210383358fe7697f201e19ac9779879ba72a
    afc397376ec50e96b2918ee64e48baf4dda0d37d

5. The testcase from MySQL relies heavily on sleep and timing for
testing, and seems likely to sporadically fail on heavily loaded test
servers in buildbot or distro build farms.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

The function apply_event_and_update_pos() is called with the
rli->data_lock mutex held. However, there seems to be nothing in the
function actually needing the mutex to be held. Certainly not in the
parallel replication case, where sql_slave_skip_counter is always 0
since the non-zero case is handled by the SQL driver thread.

So this patch makes parallel replication use a variant of
apply_event_and_update_pos() without the need to take the
rli->data_lock mutex. This avoids one contended global mutex for each
event executed, which might improve performance on CPU-bound workloads
somewhat.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Part 3 (final): removing MY_CHARSET_HANDLER::well_formed_len().

The result of binlog_{row|stm}_ctype_ucs.test depended on the machine
time zone setting. Making the test timzone independent.

MDEV-10867 PREPARE..EXECUTE is not consistent about non-ASCII characters

Previously Travis-CI stated that cracklib is forbidden, but it does
not longer seem to be the case.

Now we check if a dependency is available and not just if older versions
are available. Also use correct name of libcrack2 to actually detect it.

Use sed to inject dependency at the end of the dependency list.
Otherwise keep the control line clean and parseable by Debian tools.

- All build-depends should be in one place.
- Library packages should depend on their main package using strict version.
- Most packages should depend on the misc variable, so that debhelper
  can fill in it with various calculated dependencies automatically.
- All packages using dynamic libraries should depend on the shlibs variable
  to include shared libraries as dependencies automatically.
- Essential tools like bsdutils, grep and tar shall not be defined in vain.