Noticing initial message drops

[cv53]

Hi,
I am making a publisher in python I observe 2 things

1. if I do not send sys.argv into the intialization the ecal_rec does not immedietly see the topic
2. I need to have a small delay after creating the publisher and sending the messages as I notice that the ecal_rec drops the first few messages

I have seen the code and notice the registration process but hard to understand what is happening on the subscription side that would cause the drop in initial messages

also is there a better way in handlng this and not just by a delay?

[rex-schilasky]

Hi @cv53, what eCAL version are you using and what OS? "ecal_rec" means the ecal recorder command line version, I assume.

[cv53]

Hi I am running v5.13 and yes ecal_rec is is the command line tool

[rex-schilasky]

Hi, I double‑checked the eCAL 5.x Python API and, unfortunately, there isn’t a get_subscriber_count() (or equivalent) available to delay publishing until a subscriber connects. That call only appears in the new eCAL 6 Python bindings—using publisher.get_subscriber_count() there would let you wait for the desired number of subscribers before you start sending messages.

while publisher.get_subscriber_count() == 0:
    time.sleep(0.01)
# publish safely