[Discuss-gnuradio] About closing flowgraph automatically

[Simone Ciccia S210664]

Goodmorning,
I would like to Know some methods to Close flowgraph automatically when 
it has finished. Some example, stop when USRP has no more samples to 
transmits, or a file source has read until EOF.
The Run of completion option works when (for instance) you have a file 
source connected to other non-PMT Message block and a sink (USRP or null 
sink...). However, when the file source output is converted to pmt 
Message, then the flowgraph does not stop anymore when rhe file source 
has finished. Probably because the PMT Message block continue to waits 
for messages. In this case, How I can stop automatically the flowgraph? 
I would like to Close the flowgraph when EOF or USRP has no more sample 
to transmit, for example, in a situation like the following:

FILE SOURCE -> STREAM TO PMT MESSAGE -> PROCESSING BLOCKS -> PMT MESSAGE 
TO FILE SOURCE -> USRP SINK

Thank for yours support and for the great utility of the list 😊
simone