[vz-dev] [volkszaehler/vzlogger] c5bcd3: Add lock/unlock before iterating buffer (#429)

[Matthias Behr]

  Branch: refs/heads/master
  Home:   https://github.com/volkszaehler/vzlogger
  Commit: c5bcd3296a4400ddf041db21c67a17f4e526f71e
      https://github.com/volkszaehler/vzlogger/commit/c5bcd3296a4400ddf041db21c67a17f4e526f71e
  Author: Matthias Behr <mbehr at mcbehr.de>
  Date:   2020-07-25 (Sat, 25 Jul 2020)

  Changed paths:
    M src/threads.cpp

  Log Message:
  -----------
  Add lock/unlock before iterating buffer (#429)

As *it was 0 (see #427) it seems either an
nulptr was casted wrongly or
the buffer was modified in between the iterations.
Avoid this with the lock/unlock and additional check.
Issue: #427