Attention is currently required from: fixeria, pespin.

Hello Jenkins Builder, fixeria,

I'd like you to reexamine a change. Please visit

https://gerrit.osmocom.org/c/libosmocore/+/36538?usp=email

to look at the new patch set (#2).

The following approvals got outdated and were removed: Code-Review+1 by fixeria, Verified+1 by Jenkins Builder

Change subject: add osmo_stats_report_lock api ......................................................................

add osmo_stats_report_lock api

Allow multi-threaded access to reported stats: - enable use of a stats mutex with osmo_stats_report_use_lock(true). - lock/unlock externally with osmo_stats_report_lock(true/false).

Rationale:

In osmo-hnbgw, we would like to collect stats from nftables, and do so in a separate thead. The most efficient way is to write the parsing results from nft directly to the rate_ctr destination.

But what if the main thread reports rate counters at exactly that time? - is writing to stats atomic on a data type level? - do applications need stats to be "atomic" as a whole?

In osmo-hnbgw in particular, there are two counters, 'packets' and 'total_bytes'. These correspond, and it would skew statistics if we reported them out of sync to each other.

The simplest way to ensure correctness in all cases is a mutex around the stats reporting.

But this mutex isn't needed in most of our programs. To completely avoid any overhead the mutex may bring, make use of it optional with a global flag.

This use case is likely to also show up in other programs that would like to collect and report stats from a separate thread.

Related: SYS#6773 Related: osmo-hnbgw I9dc54e6bc94c553f45adfa71ae8ad70be4afbc8f Change-Id: Ib335bea7d2a440ca284e6c439066f96456bf2c2d --- M include/osmocom/core/stats.h M src/core/libosmocore.map M src/core/stats.c M src/vty/stats_vty.c 4 files changed, 128 insertions(+), 0 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/38/36538/2