[boost] [thread] Passing function with parameters to boost::barrier

Subject: [boost] [thread] Passing function with parameters to boost::barrier
From: André Offringa (offringa_at_[hidden])
Date: 2019-01-31 14:08:21

Hi Boost developers,

I'm having a problem with passing a completion function to a 
boost::barrier, causing a segfault, and I suspect it is a bug in the 
barrier code. The following is a minimal example that shows the problem:

#include <boost/thread/barrier.hpp>

void func(int)
{
}

int main()
{
 Â  boost::barrier b(1, std::bind(func, 42));
 Â  b.wait();
}

Running inside gdb and doing a bt shows some infinite recursion 
happening, starting with:
#0Â  0x000055555555e41a in 
boost::thread_detail::decay_copy<boost::detail::nullary_function<void 
()>&>(boost::detail::nullary_function<void ()>&) (
 Â Â Â  t=<error reading variable: Cannot access memory at address 
0x7fffff7feff0>) at /usr/include/boost/thread/detail/move.hpp:355
#1Â  0x000055555555d814 in boost::detail::nullary_function<void 
()>::nullary_function<boost::detail::nullary_function<void 
()>&>(boost::detail::nullary_function<void ()>&) (
 Â Â Â  this=0x7fffff7ff0c0, f=...) at 
/usr/include/boost/thread/detail/nullary_function.hpp:81
...

When I change "std::bind(func, 42)" to just "func" (and declare func 
without parameters), it does work and the program exits normally. 
Passing a lambda to barrier (e.g. barrier(1, [&]() { func(0); } ) ) 
causes the same segfault, and the same holds when I change std::bind to 
boost::bind. I'm using Boost 1.67 on Debian Linux, amd64, gcc 8.2.0. Is 
this a bug?

Cheers,
André