[OpenSIPS-Devel] [OpenSIPS/opensips] 3a994c: tm: prevent concurrency between different cleanup

[Răzvan Crainea]

  Branch: refs/heads/2.4
  Home:   https://github.com/OpenSIPS/opensips
  Commit: 3a994ceeafc6830a1c3b3f2699a7dc1ea915c83a
      https://github.com/OpenSIPS/opensips/commit/3a994ceeafc6830a1c3b3f2699a7dc1ea915c83a
  Author: Razvan Crainea <razvan at opensips.org>
  Date:   2019-05-09 (Thu, 09 May 2019)

  Changed paths:
    M modules/tm/tm.c

  Log Message:
  -----------
  tm: prevent concurrency between different cleanup

This fixes a problem that was happening when having a transaction that
wasn't fully updated, for example in a Push Nofitication scenario where
no t_relay() was made, multiple messages may have reached the
do_t_cleanup() function in parallel, both updating the transaction.

Reported by 46Labs

(cherry picked from commit deafdb7f4b474701289a8086fbf44a05e19feca6)