Query on api nc_client_monitoring_thread_start

[srikanthsubbaramu]

Hi Michal,

I have a query on the api nc_client_monitoring_thread_start,
We are trying to use this api to get callback on session disconnect, our server resides in a differnt system , we initially keep trying to connect to server, and we may not connect to netopeer2-server at initial attempts,

i went through documentation of the api, as per documentation we only need to call the api once, so any session established later would get monitored, but what i am seeing is certain times the monitoring thread is not started, so i added stop and start for connection attempt,

// Stop first in case it was running (ignore error if not running)
nc_client_monitoring_thread_stop();

int mret = nc_client_monitoring_thread_start(
    on_nc_session_disconnect, this, nullptr);
if (mret != 0) {
    LOG("WARNING: monitoring thread start failed");
} else {
    LOG("monitoring thread started on connect thread");
}

We try connecting to server in a loop until connection succeeds, but what i observed is thread stop happend in third attempt, ie first api never started monitoring thread,

Attempt1:
257:[ERR]: nc_client_monitoring_thread_stop: start
258-[ERR]: Client monitoring thread is not running.
259-[ERR]: nc_client_monitoring_thread_start: start
[2026-07-01 05:14:39.676690] [INFO] monitoring thread started on connect thread
Attempt2:
13405:[ERR]: nc_client_monitoring_thread_stop: start
13406-[ERR]: Client monitoring thread is not running.
13407-[ERR]: nc_client_monitoring_thread_start: start
[2026-07-01 05:14:40.230002] [INFO] monitoring thread started on connect thread

Attempt3:
13425:[ERR]: nc_client_monitoring_thread_stop: start
13426-[ERR]: Client monitoring thread exit.
13427:[ERR]: nc_client_monitoring_thread_stop: end
13428-[ERR]: nc_client_monitoring_thread_start: start

Although we have recieved successful return code for attempt1, the monitoring thread never started, i want to understand if there any other apis that i need to call before using this api.

Thanks,
Srikanth

[srikanthsubbaramu]

Please ignore the question as i have called from different threads, i will go through thread_contexts and update,
thanks,
Srikanth

[Roytak]

Hi Srikanth,
I was about to answer this is most likely due to using different threads, but anyway I updated the docs of this API because it felt unclear.

Although we have recieved successful return code for attempt1, the monitoring thread never started, i want to understand if there any other apis that i need to call before using this api.

The way this is intended is that:

• Call nc_client_monitoring_thread_start() once at application startup.
• Call e.g. nc_connect_ssh() from the same thread (or a thread sharing the same context via nc_client_set_thread_context()).
• Call nc_client_monitoring_thread_stop() only at shutdown.

[srikanthsubbaramu]

Thank you @Roytak , i will use nc_client_set_thread_context and try