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### Description

Relevant modules and parameters in configuration: ``` loadmodule "presence.so" loadmodule "dialog.so" loadmodule "presence_xml.so" loadmodule "pua.so" loadmodule "presence_dialoginfo.so" loadmodule "pua_dialoginfo.so"

modparam("dialog", "db_mode", 1) modparam("presence", "subs_db_mode", 2) modparam("presence", "db_table_lock_type", 0) modparam("pua", "db_mode", 2) modparam("pua", "db_table_lock_write", 0) ```

Using 2 UDP receiver processes.

User1 is watching (has` SUBSCRIBE`d to) User2, which is called by User3 (call1). User2 doesn't answer, phone is ringing. User1 now also calls User2 (call2), but we don't support receiving a second call so, for this `INVITE`, after 183, almost immediately, a 486 "Busy Here" message is sent and the call is cancelled (call2 finished). The 183 reply generates an "**early**" state on the UDP1 process, while 486 goes to "**terminated**" on the UDP2 process. The `PUBLISH` messages are processed almost concomitantly. The problem is that "**early**" state arrives to the subscriber (User1) after the "**terminated**" one (seen with `sngrep`) so the phone button keeps blinking for a while (... and the state cannot be changed by other call while the "**early**" event is still in the `presentity` table of the database). I suspect a concurrency problem since I didn't reproduce it with only one UDP receiver process. Even if the "**terminated**" lifetime is much smaller (11s vs minutes), I strongly believe it is still there when the "**early**" state is written. Does the "**early**" event checks the database/memory for a "**terminated**" event for the same call ID? Is it because of the missing locks maybe (`db_table_lock_type`, `db_table_lock_write`) ?

### Troubleshooting

#### Reproduction

Using 2 UDP receiver processes.

User1 is watching (has `SUBSCRIBE`d to) User2, which is called by User3 (call1). User2 doesn't answer, phone is ringing. User1 now also calls User2 (call2), but we don't support receiving a second call so, for this `INVITE`, after 183, almost immediately, a 486 "Busy Here" message is sent and the call is cancelled (call2 finished).

I would not say that it is systematic, but easy enough to reproduce.

#### Debugging Data

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#### Log Messages

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#### SIP Traffic

<!-- If the issue is exposed by processing specific SIP messages, grab them with ngrep or save in a pcap file, then add them next, or attach to issue, or provide a link to download them (e.g., to a pastebin site). -->

``` (paste your sip traffic here) ```

### Possible Solutions

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### Additional Information

* **Kamailio Version** - output of `kamailio -v`

``` version: kamailio 5.5.4 (x86_64/linux) flags: , EXTRA_DEBUGUSE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MMAP, PKG_MALLOC, Q_MALLOC, F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLOCKLIST, HAVE_RESOLV_RES ADAPTIVE_WAIT_LOOPS 1024, MAX_RECV_BUFFER_SIZE 262144, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB poll method support: poll, epoll_lt, epoll_et, sigio_rt, select. id: unknown compiled with gcc 8.3.0 ```

* **Operating System**: Docker image around

``` $ lsb_release -a No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux 10 (buster) Release: 10 Codename: buster (paste your output here) ```