Re: [Discuss-gnuradio] Problems passing the control between blocks - message passing

[Josh Blum]

On 10/22/2012 03:24 PM, Jose Torres Diaz wrote:
> Hi Community,
> 
> In following up this issue, we've tried different options (ie. returns 0,
> yield or returns -1 in work function). What is happening is the block are
> running exactly once. In other words, the work() function never comes back
> and run again.
> 
> Anyone can suggest a way to solve this issue?.
> 

Do you see an error when you return 0 from work? Like source block
returned 0, marking it done? If this is the case, you can update
gnuradio to get the fix.

On the other hand, its OK to block in the work function. For example,
you can block on pop_msg_queue(). Calling tb->stop() will still
interrupt this, so its safe to do.

-josh

> Thanks for your comments,
> 
> Jose.
> 
> On Mon, Oct 22, 2012 at 5:55 PM, Jose Torres Diaz <address@hidden
>> wrote:
> 
>> Hi John,
>>
>> Also, I am trying to use boost::this_thread::yield() between blocks, but
>> when I add a third block into the chain, the control passes between BLOCK 1
>> <-> BLOCK 2. When they finish, the control is passed to BLOCK 3.
>>
>> Thanks again for your suggestions,
>>
>> Jose
>>
>>
>> On Mon, Oct 22, 2012 at 9:17 AM, Jose Torres Diaz <
>> address@hidden> wrote:
>>
>>> Hi John,
>>>
>>> Please, find attached the codes (.cc) for BLOCK 1 and BLOCK 2. I'm still
>>> unable to control the correct order of them, when I generated an infinite
>>> loop.
>>>
>>> Thanks a lot for your help in this issue,
>>>
>>> Regards,
>>>
>>> Jose
>>>
>>>
>>> On Thu, Oct 18, 2012 at 9:58 AM, John Malsbury <address@hidden>wrote:
>>>
>>>> Can you send me the files?
>>>>
>>>> -John
>>>>
>>>>
>>>>
>>>>
>>>> On Wed, Oct 17, 2012 at 4:16 PM, Jose Torres Diaz <
>>>> address@hidden> wrote:
>>>>
>>>>> Hi John,
>>>>>
>>>>> Yes, I also checked the examples in your branch. In regards to your
>>>>> questions.
>>>>>
>>>>> *1.* BLOCK 2 is processing the data from BLOCK 1, but only when BLOCK
>>>>> 1 has finished the routine "N times". Let me post a piece of code from
>>>>> BLOCK 1:
>>>>>
>>>>>
>>>>>
>>>>> int work(
>>>>>         const InputItems &,
>>>>>         const OutputItems &
>>>>>     ){
>>>>>
>>>>>
>>>>>         for (int i = 0; i < d_pkt_len; i++) {
>>>>>                if (d_mode == 2)
>>>>>           { elements[i] = ((i % d_pkt_len) + d_num_pkts_output) & 0xff;
>>>>>                   }
>>>>>         else if (d_mode == 0)
>>>>>           {elements[i]=0;
>>>>>                  }
>>>>>              else // ones
>>>>>         {elements[i]=0xFF;
>>>>>         }
>>>>>         num_output++;
>>>>>       } //End of for
>>>>>       d_num_pkts_output++;
>>>>>
>>>>>       //(4.1) adding data into the dictionary
>>>>>       dictionary = pmt::pmt_dict_add(dictionary, data_key, vector_data);
>>>>>       std::cout << std::endl << "(4) Now, the dictionary is" <<
>>>>> dictionary <<std::endl;
>>>>>
>>>>>
>>>>>       //Posting a message downstream
>>>>>       this->post_msg(0, AMSG_KEY, dictionary, _d_my_unique_id);
>>>>>       std::cout << std::endl << "posting the message downstream "
>>>>> <<std::endl;
>>>>>
>>>>>       return -1;  // <--The problem seems to be here
>>>>>
>>>>>    }
>>>>>
>>>>>
>>>>> *2.* N is the number of packet that I want to transmit from BLOCK 1.
>>>>> In my code, I'm using the variable d_max_pkts. So, when d_num_pkts_output
>>>>>> = d_max_pkts, the program stops:
>>>>>
>>>>>     if (d_num_pkts_output >= d_max_pkts)
>>>>>       return 0;
>>>>>
>>>>> 3. Yes, my BLOCK 1 is as follows:
>>>>>
>>>>> block(
>>>>>           //"gr uhd amsg source",
>>>>>           "BLOCK 1",
>>>>>             gr_make_io_signature(0, 0, 0),
>>>>>             gr_make_io_signature(0, 0, 0),
>>>>>             msg_signature(false, 1)
>>>>>
>>>>>
>>>>> Thanks again for your advice,
>>>>>
>>>>> Regards,
>>>>>
>>>>> Jose
>>>>>
>>>>>
>>>>> On Wed, Oct 17, 2012 at 5:14 PM, John Malsbury <address@hidden
>>>>>> wrote:
>>>>>
>>>>>> So, block 2 is never processing the data?  What are you using to set
>>>>>> the "N"?  Does the uhd_amsg_source have the same i/o as the original 
>>>>>> block
>>>>>> - no inputs, one msg output?
>>>>>>
>>>>>> If you're looking to something to generate periodic msg's with
>>>>>> arbirtrary key and value, the heart_beat block in my pre-cog branch might
>>>>>> help...
>>>>>>
>>>>>> -John
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Tue, Oct 16, 2012 at 11:34 PM, Jose Torres Diaz <
>>>>>> address@hidden> wrote:
>>>>>>
>>>>>>> Hi John,
>>>>>>>
>>>>>>> I wrote the code in C++ based on UHD_AMsg_source.cc, provided in
>>>>>>> GRExtras. In my work function, I've finished it using return -1 (ie. the
>>>>>>> block has finished processing correctly) as shown below:
>>>>>>>
>>>>>>> int work(
>>>>>>>         const InputItems &,
>>>>>>>         const OutputItems &
>>>>>>>     ){
>>>>>>>       //work definition here (ie. generate a packet and post
>>>>>>> downstream)
>>>>>>>       return -1; //done running, work done status
>>>>>>>     }
>>>>>>>
>>>>>>> However, in that way the block in GNU Radio Companion runs only once.
>>>>>>> The other possibility is not to use "return" at all, but in that case 
>>>>>>> what
>>>>>>> I have is:
>>>>>>>
>>>>>>> 1. BLOCK 1 generates a packet
>>>>>>> 2. BLOCK 1 post the packet downstream
>>>>>>>
>>>>>>> Step 1 and 2 repeats "N times". When finishes, it gives the control
>>>>>>> to BLOCK 2 to process the message. However, I need a sequence as 
>>>>>>> follows:
>>>>>>>
>>>>>>> 1. BLOCK 1 generates a packet
>>>>>>> 2. BLOCK 1 post the packet downstream
>>>>>>> 3. BLOCK 2 process the packet
>>>>>>> 4. BLOCK 2 post the message again downstream and so on...
>>>>>>>
>>>>>>> Step 1 to 4 should repeat "N times".
>>>>>>>
>>>>>>> Thanks again for your help,
>>>>>>>
>>>>>>> Jose
>>>>>>>
>>>>>>>
>>>>>>> On Wed, Oct 17, 2012 at 4:52 PM, John Malsbury <
>>>>>>> address@hidden> wrote:
>>>>>>>
>>>>>>>> Jose,
>>>>>>>>
>>>>>>>> Try a while(1) with a block and  a blocking call to pop msg's off
>>>>>>>> the queue:
>>>>>>>>
>>>>>>>> self.pop_msg_queue()
>>>>>>>>
>>>>>>>> Should help you avoid the return -1
>>>>>>>>
>>>>>>>> Or maybe I've misunderstood your problem...?
>>>>>>>>
>>>>>>>> -John
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Tue, Oct 16, 2012 at 11:18 PM, Jose Torres Diaz <
>>>>>>>> address@hidden> wrote:
>>>>>>>>
>>>>>>>>> Hi All,
>>>>>>>>>
>>>>>>>>> I'm working with 2 blocks that I've created using "UHD_AMsg_Source"
>>>>>>>>> as a reference model. In these blocks, I am passing pmt_dict type as
>>>>>>>>> messages, ie:
>>>>>>>>>
>>>>>>>>>  this->post_msg(0, AMSG_KEY, dictionary,_id);
>>>>>>>>>
>>>>>>>>> Where, dictionary contains data/metadata that I can read in the
>>>>>>>>> next block downstream.
>>>>>>>>>
>>>>>>>>> BLOCK 1  -- (pmt_dict included in the message) -->  BLOCK 2
>>>>>>>>>
>>>>>>>>> The blocks are working ok, but the problem is that when I want to
>>>>>>>>> generate several packets and post them downstream, BLOCK 1 runs until
>>>>>>>>> finishes and then BLOCK 2 takes the control until finishes. The 
>>>>>>>>> problem is
>>>>>>>>> the "return" sentence in my work function. I did 2 possible ways
>>>>>>>>>
>>>>>>>>> Option 1: Using -1
>>>>>>>>>
>>>>>>>>> work {
>>>>>>>>> //work here
>>>>>>>>> return -1
>>>>>>>>> }
>>>>>>>>>
>>>>>>>>> In this way BLOCK 1 stops working after one iteration and it does
>>>>>>>>> not run as many times as I want.
>>>>>>>>>
>>>>>>>>> Option 1: Not using return
>>>>>>>>>
>>>>>>>>> work {
>>>>>>>>> //work here
>>>>>>>>> }
>>>>>>>>>
>>>>>>>>> In this way BLOCK 1 runs many times and posts messages downstream
>>>>>>>>> all those times, but it gives the control to BLOCK 2 when it finishes.
>>>>>>>>> Then, BLOCK 2 takes the messages from the message queue. However, this
>>>>>>>>> implementation is not useful for me. BLOCK 1 should post a message
>>>>>>>>> downstream and then, BLOCK 2 takes the message and work with the 
>>>>>>>>> packet.
>>>>>>>>>
>>>>>>>>> Any suggestion is welcome, thanks a lot for your time,
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>>
>>>>>>>>> Jose
>>>>>>>>>
>>>>>>>>> _______________________________________________
>>>>>>>>> Discuss-gnuradio mailing list
>>>>>>>>> address@hidden
>>>>>>>>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>
>>>
>>>
>>>
>>
>>
>>
> 
> 
> 
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