Re: [Discuss-gnuradio] About closing flowgraph automatically

[Piotr Krysik]

Hi Simone and all,

Can you provide your GRC flow-graph? I think that source of the problem
might be somewhere in this part
"PMT MESSAGE TO FILE SOURCE" as there is message to samples stream
conversion involved here. But it's not clear for me what it actually is
as you described it.

I have problems with automatic closing of a flow-graph that uses a block
that converts messages to samples. In my case it is PDU to Tagged Stream
block that caused problems with automatic exiting of the flow-graph.

The constant problems with exiting of flow-graphs lead me to think if
these problems can be solved once for all with some change in gnuradio's
internals.

Maybe it can be some "exit" tag that would be propagated to all blocks
in a flowgraph. This tag would be processed by all blocks and would
cause them to be marked as ready for the program exit. Blocks that have
stream inputs and message outputs would convert the tag to an "exit"
message, which would be propagated through the outputs.
Blocks with message inputs ans stream outputs would convert "exit"
message to an "exit" tag. When all blocks would be marked as ready for
closing the program would end.

In this concept there is problem how to propagate the information to
blocks upstream, that might not have information about ending of a
flow-graph. So the method I described might be used as an addition to
current method of ending flowgraphs.

What do you think?

Best Regards,
Piotr Krysik

W dniu 22.07.2016 o 18:40, Martin Braun pisze:
> Simone,
>
> a file source *will* terminate the flow graph once its read the file
> (unless you specify 'repeat').
>
> M
>
> On 07/21/2016 12:32 AM, Simone Ciccia S210664 wrote:
>> 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
>>