C++11 and threading on BeagleBone Black

[J Adam Crain]

All,

I'm starting a new thread to focus on the threading issues with BBB.

I keep getting the same results as Cornel and others, pure virtual method calls.

I decided to test the most basic C++11 threading program:

-----------------------------------------

#include <iostream>

#include <thread>

using namespace std;

int main(int argc, char** argv)

{

  cout << "hello world" << endl;

  thread t([](){ cout << "hello from thread!" << endl; });

  t.join();

  return 0;

}

-----------------------------------------

On Unbuntu 13 w/ G++ 4.7.3:

> g++ --std=c++11 Test.cpp -lpthread

> ./a.out 

hello world

hello from thread!

>

On BeagleBone black:

root@beaglebone:~/test# ./a.out 

hello world

pure virtual method called

terminate called without an active exception

Aborted

root@beaglebone:~/test#

So, we have to solve this basic issue before we can proceed. Time to start hitting the BBB mailing lists!

-Adam

[J Adam Crain]

Ok, I have an answer. It involves some deep, dark black magic that I will never understand:

http://stackoverflow.com/questions/16171401/why-does-this-simple-c11-threading-example-fail-when-compiled-with-clang-3-2

Add the following pre-processor declarations to the build:

-D__GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 -D__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 -D__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 -D__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8

This fixed the issue with the example program.  To do this for opendnp3, add this stuff to the configure step, i.e.:

> ./configure CXXFLAGS="--std=c++11 -pthread -D__GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 -D__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 -D__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 -D__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8"

I am rebuilding opendnp3 in the background this morning on the BBB. I'll report when I have the tests passing.

-Adam

[J Adam Crain]

Kazaa!

-----------------------

root@beaglebone:~/dnp3# ./dnp3test --show_progress

0%   10   20   30   40   50   60   70   80   90   100%

|----|----|----|----|----|----|----|----|----|----|

Running 461 test cases...

****************************************************** No errors detected

------------------------------

root@beaglebone:~/dnp3/cpp/demos/outstation# ./outstationdemo

Server state: CLOSED

Wed Jul 31 15:18:30.855664 - INFO - tcpserver.outstation.outstation - StackState: COMMS_DOWN

Server state: OPENING

outstation state: COMMS_DOWN

Enter something to increment a counter or type exit

-------------------------------

-Adam

[J Adam Crain]

All in all, a very nice little hobby board. I am impressed with the out-of-the-box functionality.

It has some impressive I/O capabilities and the realtime MCU functionality looks interesting too.

Daniel and Cornel:

Please let me know if those pre-processor defines resolve your issues.

-Adam

[Daniel]

Hi Adam,

Thanks for the update. I haven't had time recently to play with the BBB debugging. I will do a test over the weekend and post my results.

Thanks Adam and Cornel!

Regards

[Cornel Verster]

Tested it and my code works :)

Thanks so much for the help Adam, it is greatly appreciated!

Cornel