tree 14ac299efe395fc4a0d6a78f2e13a595181edd8b
parent eda8b7b23d97994f7e9d1d6554ba4657b6531ad8
author Pau Espin Pedrol <pespin@sysmocom.de> 1568738338 +0200
committer Pau Espin Pedrol <pespin@sysmocom.de> 1570623592 +0200

logging: Introduce mutex API to manage log_target in multi-thread envs

log_enable_multithread() enables use of locks inside the
implementation. Lock use is disabled by default, this way only
multi-thread processes need to enable it and suffer related
complexity/performance penalties.

Locks are required around osmo_log_target_list and items inside it,
since targets can be used, modified and deleted by different threads
concurrently (for instance, user writing "logging disable" in VTY while
another thread is willing to write into that target).

Multithread apps and libraries aiming at being used in multithread apps
should update their code to use the locks introduced here when
containing code iterating over osmo_log_target_list explictly or
implicitly by obtaining a log_target (eg. osmo_log_vty2tgt()).

Related: OS#4088
Change-Id: Id7711893b34263baacac6caf4d489467053131bb