Strange enough, pthread_setname_np() produces a warning for not defined
function even if pthread is included. Moreover the MacOS documentation
claims the return value for the function is void, but actually is int.

Related to #7089.

Set thread name for each thread of redis-server, this helps us to
monitor the utilization and optimise the performance.

And suggested-by Salvatore, implement this feature for multi
platforms. Currently support linux and bsd, ignore other OS.

An exmaple on Linux:
 # top -d 5 -p `pidof redis-server ` -H

    PID USER      PR  NI    VIRT    RES    SHR S %CPU %MEM     TIME+ COMMAND
3682671 root      20   0  227744   8248   3836 R 99.2  0.0   0:19.53 redis-server
3682677 root      20   0  227744   8248   3836 S 26.4  0.0   0:04.15 io_thd_3
3682675 root      20   0  227744   8248   3836 S 23.6  0.0   0:03.98 io_thd_1
3682676 root      20   0  227744   8248   3836 S 23.6  0.0   0:03.97 io_thd_2
3682672 root      20   0  227744   8248   3836 S  0.2  0.0   0:00.02 bio_close_file
3682673 root      20   0  227744   8248   3836 S  0.2  0.0   0:00.02 bio_aof_fsync
3682674 root      20   0  227744   8248   3836 S  0.0  0.0   0:00.00 bio_lazy_free
3682678 root      20   0  227744   8248   3836 S  0.0  0.0   0:00.00 jemalloc_bg_thd
3682682 root      20   0  227744   8248   3836 S  0.0  0.0   0:00.00 jemalloc_bg_thd
3682683 root      20   0  227744   8248   3836 S  0.0  0.0   0:00.00 jemalloc_bg_thd
3682684 root      20   0  227744   8248   3836 S  0.0  0.0   0:00.00 jemalloc_bg_thd
3682685 root      20   0  227744   8248   3836 S  0.0  0.0   0:00.00 jemalloc_bg_thd
3682687 root      20   0  227744   8248   3836 S  0.0  0.0   0:00.00 jemalloc_bg_thd

Another exmaple on FreeBSD-12.1:
  PID USERNAME    PRI NICE   SIZE    RES STATE    C   TIME    WCPU COMMAND
 5212 root        100    0    48M  7280K CPU2     2   0:26  99.52% redis-server{redis-server}
 5212 root         38    0    48M  7280K umtxn    4   0:06  26.94% redis-server{io_thd_3}
 5212 root         36    0    48M  7280K umtxn    6   0:06  26.84% redis-server{io_thd_1}
 5212 root         39    0    48M  7280K umtxn    1   0:06  25.30% redis-server{io_thd_2}
 5212 root         20    0    48M  7280K uwait    3   0:00   0.00% redis-server{redis-server}
 5212 root         21    0    48M  7280K uwait    2   0:00   0.00% redis-server{bio_close_file}
 5212 root         21    0    48M  7280K uwait    3   0:00   0.00% redis-server{bio_aof_fsync}
 5212 root         21    0    48M  7280K uwait    0   0:00   0.00% redis-server{bio_lazy_free}
Signed-off-by: Nzhenwei pi <pizhenwei@bytedance.com>

Related to #7113.

when trigger a always fail scripts, sentinel.running_scripts will increase ten times, however it
only decrease one times onretry the maximum. and it will't reset, when it become
SENTINEL_SCRIPT_MAX_RUNNING, sentinel don't trigger scripts.

this test is time sensitive and it sometimes fail to pass below the
latency threshold, even on strong machines.

this test was the reson we're running just 2 parallel tests in the
github actions CI, revering this.

While playing with ACLs I noticed that acllog-max-len wasn't in the redis.conf, but was a supported config. 

This PR documents and adds the directive to the redis.conf file.

See issue #7105.

See #6160.

Fixes issue #6418.

Fixes issue #6418.

Streams items are similar to dictionaries, however they preserve both
the order, and allow for duplicated field names. So a map is not a
semantically sounding way to deal with this.

https://twitter.com/antirez/status/1248261087553880069

Related to #3243.

Reloading of the RDB generated by

    DEBUG POPULATE 5000000
    SAVE

is now 25% faster.

This commit also prepares the ability to have more flexibility when
loading stuff from the RDB, since we no longer use dbAdd() but can
control exactly how things are added in the database.

See #7071.

Related to #5145.

Design note: clients may change type when they turn into replicas or are
moved into the Pub/Sub category and so forth. Moreover the recomputation
of the bytes used is problematic for obvious reasons: it changes
continuously, so as a conservative way to avoid accumulating errors,
each client remembers the contribution it gave to the sum, and removes
it when it is freed or before updating it with the new memory usage.

fix comments about RESIZE DB opcode in rdb.c

Delete keys in async way when executing DEL command, if
lazyfree-lazy-user-del is yes.

Initially they needed to be at the end so that we could extend to N
strings in the future, but after further consideration I no longer
believe it's worth it.