I can’t explain it, but I found what’s wrong. My failing Test class that
derives from gr::block called the default ctor. That’s bad. If instead, Test
calls the “real” ctor, with io_signature and everything, it works. Note that
the example that derives from gr::sync_block does call the “real” ctor; if I
use the default gr::sync_block ctor, it still fails.
I didn’t think I was calling the default ctor, but apparently I was.
The interface class:
class CYBERRADIO_API vita_udp_rx : virtual public gr::block
{
…
protected:
using gr::block::block; // "inherit" base class ctor
};
Since this interface doesn’t really do anything, I thought I could just
pass-through to the gr::block constructor(s).
The impl class:
class vita_udp_rx_impl : public vita_udp_rx
{
using Base = vita_udp_rx;
…
};
The impl ctor:
vita_udp_rx_impl::vita_udp_rx_impl(Cfg const& cfg)
: Base("vita_udp_rx",
gr::io_signature::make(0, 0, 0),
gr::io_signature::make(1, 1, sizeof(gr_complex))),
…
{
…
}
What this should do is pass through to the gr::block constructor. But it
doesn’t appear to do so. If instead, I write
vita_udp_rx_impl::vita_udp_rx_impl(Cfg const& cfg)
: gr::block("vita_udp_rx",
gr::io_signature::make(0, 0, 0),
gr::io_signature::make(1, 1, sizeof(gr_complex))),
…
{
…
}
Then it works.
---
Jim Melton
From: Discuss-gnuradio <[email protected]>
On Behalf Of Jeff Long
Sent: Wednesday, September 15, 2021 16:23
To: GNURadio Discussion List <[email protected]>
Subject: [EXTERNAL] Re: Re: Why does this dump core?
The Message Strobe block:
gr-blocks/include/gnuradio/blocks/message_strobe.h
gr-blocks/lib/message_strobe_impl.h
gr-blocks/lib/message_strobe_impl.cc
looks like the simplest builtin block that has a message out port. It
subclasses gr::block, so that should work.
Instantiating gr::block directly, and on the stack, is not something I've
tried. Your longer bit of code shows you're using sptrs.
On Wed, Sep 15, 2021 at 5:57 PM Jim Melton
<[email protected]<mailto:[email protected]>> wrote:
If I derived from a different block, it doesn’t crash:
class Test : public gr::sync_block
{
public:
Test();
int work(int, gr_vector_const_void_star&, gr_vector_void_star&) override {
return 0;};
};
Test::Test() : gr::sync_block("test",
gr::io_signature::make(0, 0, 0),
gr::io_signature::make(1, 1, sizeof(gr_complex)))
{
}
---
Jim Melton
From: Jim Melton
Sent: Wednesday, September 15, 2021 14:57
To: 'Jeff Long' <[email protected]<mailto:[email protected]>>
Cc: GNURadio Discussion List
<[email protected]<mailto:[email protected]>>
Subject: RE: [EXTERNAL] Re: Why does this dump core?
Simpler example. This still dumps core. Please explain what is wrong with the
argument:
class Test : public gr::block
{
public:
Test();
};
Test::Test() : gr::block() {
message_port_register_out(pmt::mp("test"));
}
int main(int argc, char** argv)
{
Test test; // dumps core
Return 0;
}
---
Jim Melton
From: Jeff Long <[email protected]<mailto:[email protected]>>
Sent: Tuesday, September 14, 2021 14:10
To: Jim Melton <[email protected]<mailto:[email protected]>>
Cc: GNURadio Discussion List
<[email protected]<mailto:[email protected]>>
Subject: [EXTERNAL] Re: Why does this dump core?
gr::CyberRadio::vita_udp_rx_impl::vita_udp_rx_impl() is calling
gr::basic_block::message_port_register_out() with a bad argument most likely.
On Tue, Sep 14, 2021 at 2:40 PM Jim Melton
<[email protected]<mailto:[email protected]>> wrote:
As briefly discussed on IRC last night, I am trying to modify someone else’s
block to be more robust (detect or eliminate packet drops). In the ctor, I call
message_port_register_out() and it dumps core. The offending call is here:
https://github.com/jwmelto/gr-cyberradio/blob/7b048a14f76b140f5cd3edd7d8dfa533e1f892a7/gr-CyberRadio/lib/vita_udp_rx_impl.cc#L427
The stack trace from the core is
#0 0x00007ffff4b04973 in pmt::is_pair(boost::shared_ptr<pmt::pmt_base> const&)
() from /usr/local/lib64/libgnuradio-pmt.so.3.8.2
#1 0x00007ffff4b07328 in pmt::assv(boost::shared_ptr<pmt::pmt_base>,
boost::shared_ptr<pmt::pmt_base>) () from
/usr/local/lib64/libgnuradio-pmt.so.3.8.2
#2 0x00007ffff4b075fd in pmt::dict_has_key(boost::shared_ptr<pmt::pmt_base>
const&, boost::shared_ptr<pmt::pmt_base> const&) () from
/usr/local/lib64/libgnuradio-pmt.so.3.8.2
#3 0x00007ffff73b72e2 in
gr::basic_block::message_port_register_out(boost::shared_ptr<pmt::pmt_base>) ()
from /usr/local/lib64/libgnuradio-runtime.so.3.8.2
#4 0x00007ffff7b58d73 in gr::CyberRadio::vita_udp_rx_impl::vita_udp_rx_impl
(this=0x622800, cfg=..., __in_chrg=<optimized out>, __vtt_parm=<optimized out>)
at /tmp/gr-cyberradio/gr-CyberRadio/lib/vita_udp_rx_impl.cc:427
#5 0x00007ffff7b56cb3 in gr::CyberRadio::vita_udp_rx::make (cfg=...) at
/tmp/gr-cyberradio/gr-CyberRadio/lib/vita_udp_rx_impl.cc:111
#6 0x000000000040c51d in main (argc=1, argv=0x7fffffffdf18) at
/usr/src/project/main.cc:23
My minimal test program is here:
#include <CyberRadio/vita_udp_rx.h>
#include <gnuradio/top_block.h>
#include <gnuradio/blocks/file_sink.h>
int main(int argc, char** argv)
{
gr::CyberRadio::vita_udp_rx::Cfg cfg;
cfg.src_ip = "192.168.110.10";
cfg.port = 8010;
cfg.header_byte_offset = 48;
cfg.samples_per_packet = 1024;
cfg.bytes_per_packet = 4152;
cfg.swap_bytes = true;
cfg.swap_iq = false;
cfg.tag_packets = true;
cfg.uses_v49_1 = false;
cfg.debug = true;
auto v49 = gr::CyberRadio::vita_udp_rx::make(cfg); // core dump
auto sink = gr::blocks::file_sink::make(sizeof(gr_complex), "test.dat");
auto top = gr::make_top_block("Test");
top->connect(v49, 0, sink, 0);
return 0;
}
According to all that I know, this should work. It clearly does not. I would
appreciate any pointers on how to get past this roadblock.
---
Jim Melton
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