Hi~
I am getting the trace data using lttng-live mode via babeltrace2. In the final
step, I borrowed the code in doc/api/libbabeltrace2/examples/epitome.c.
The difference is that in print_message(line 172) in function
epitome_out_consume, instead of printing the data directly to the console, I
send it out using the socket.
Of course, I can get the parsed results, such as timestamp, event->name, etc.,
through the socket's recv function on the other end.
However, we know that LTTng is continuously generating CTF data, and
BabelTrace2 will continuously parse CTF data. Babeltrace2 then continuously
sends parsed CTF data over the socket(in my code) or prints it directly to the
console(in the example "epitome" given).
I wonder if my socket recv function is blocked on the other end, causing the
socket send function to block in print_message function in babeltrace2;or when
printing to the console, the printing speed can't keep up with the parsed CTF
data generation speed and the print buffer is also full.
In this case, how will Babeltrace2 handle the parsed CTF data that has not been
sent yet, store them in a buffer, a queue or just discard them? Or would the
blocking directly cause LTTng to discard the original CTF data at the ring
buffer before LTTng Consumer daemon?
I thought I can find the reason in the bt_message_iterator_next function(line
144),but I failed.So I wrote this email hoping to find out why.
Looking forward to your reply.It would be better if you could help me point it
out in the code.
thanks,
Yuhua.
_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
