Sounds good. Only look at the C++ to figure out the general idea. I'd learn
Python threading first in a standalone program so you're not learning
(debugging) GR and python threading at the same time. Good luck - let us
know how it goes.
Also, please respond to the mailing list so everyone can benefit from the
conversation.
On Mon, Nov 29, 2021 at 5:11 PM Michelle <mkprojects...@gmail.com> wrote:
> Hi Jeff,
>
> thank you for your help and sorry for the delay, I was in class.
>
> it is now that I start to work on it. My first step is to master how the
> c++ code of the strobe message block work, specially the functions:
>
> -bool message_strobe_impl::start()
>
> -bool message_strobe_impl::stop()
>
> -void message_strobe_impl::run()
>
> Then I will implement the python version following your advice. I will
> write to you to show you the result.
>
> Once again thank you, I was really lost.
>
> Have a good afternoon.
>
> OK, it does work, as long as there is a message port defined and connected
> in a flowgraph. I was trying too simple an example. You would do your
> thread management in the start() and stop() functions.
>
> """
> Embedded Python Blocks:
>
> Each time this file is saved, GRC will instantiate the first class it finds
> to get ports and parameters of your block. The arguments to __init__ will
> be the parameters. All of them are required to have default values!
> """
>
> import numpy as np
> from gnuradio import gr
> import pmt
>
> class blk(gr.sync_block): # other base classes are basic_block,
> decim_block, interp_block
> """Embedded Python Block example - a simple multiply const"""
>
> def __init__(self): # only default arguments here
> """arguments to this function show up as parameters in GRC"""
> gr.sync_block.__init__(
> self,
> name='Embedded Python Block', # will show up in GRC
> in_sig=[],
> out_sig=[]
> )
> self.message_port_register_out(pmt.intern("msgout"))
> print('init')
>
> def start(self):
> print('start')
> return True
>
> def stop(self):
> print('stop')
> return True
>
> On Mon, Nov 29, 2021 at 2:13 PM Jeff Long <willco...@gmail.com> wrote:
>
>> Issue submitted: https://github.com/gnuradio/gnuradio/issues/5358
>>
>> On Mon, Nov 29, 2021 at 1:58 PM Jeff Long <willco...@gmail.com> wrote:
>>
>>> It does not seem that python blocks can override start() and stop(),
>>> which they should be able to do. So, don't go too far down that path. I do
>>> not see anywhere in the code where this is used or would have been caught.
>>>
>>> The embedded blocks are easier, be beware that GRC calls the init
>>> function to learn about the block. Therefore, you don't want any action
>>> taken as a result of a call to init, for instance spawning a thread and
>>> starting to send messages. Embedded python block are sort of a toy that
>>> turned out to be useful. In general, an OOT is a better idea, but an
>>> embedded block can work if it's simple enough.
>>>
>>> Maybe someone else has figured this out. With just a quick look, I don't
>>> see how a Message Strobe kind of block can be implemented in python without
>>> start() and stop().
>>>
>>> Here's kind of a hack: make a python block with a message handler that
>>> gets a periodic strobe from the existing Message Strobe block. In the
>>> handler, send out the message that you would have sent in the thread.
>>>
>>
