线程未join退出

背景

工作线程创建后，主线程退出，未join工作线程，进程收到abort信号产生core文件

原因

~thread()
{
	if (joinable())
std::terminate();
}

任何情况下， std::terminate 调用当前安装的 std::terminate_handler 。默认的 std::terminate_handler 调用 std::abort 。

// gcc-9.1.0/c/libsupc++/eh_terminate.cc
void
__cxxabiv1::__terminate (std::terminate_handler handler) throw ()
{
  __try 
    {
      handler ();
      std::abort ();
    } 
  __catch(...) 
    { std::abort (); }
}

void
std::terminate () throw()
{
  __terminate (get_terminate ());
}

/// If you write a replacement %terminate handler, it must be of this type.
// typedef void (*terminate_handler) ();
std::terminate_handler
std::set_terminate (std::terminate_handler func) throw()
{
  std::terminate_handler old;
#if ATOMIC_POINTER_LOCK_FREE > 1
  __atomic_exchange (&__terminate_handler, &func, &old, __ATOMIC_ACQ_REL);
#else
  __gnu_cxx::__scoped_lock l(mx);
  old = __terminate_handler;
  __terminate_handler = func;
#endif
  return old;
}

std::terminate_handler
std::get_terminate () noexcept
{
  std::terminate_handler func;
#if ATOMIC_POINTER_LOCK_FREE > 1
  __atomic_load (&__terminate_handler, &func, __ATOMIC_ACQUIRE);
#else
  __gnu_cxx::__scoped_lock l(mx);
  func = __terminate_handler;
#endif
  return func;
}