Function main

unit_test/MPICatchMain.cpp:54–121

// Just stand up MPI before running all tests; teardown after.
using namespace unit_test::utilities;
int main(int argc, char* argv[])
{
  lbann::construct_all_options();

  // Set up the communication domain
  auto world_comm = lbann::initialize(argc, argv);
  lbann::init_random(13);
  expert::register_world_comm(*world_comm);

  // Initialize Catch2
  Catch::Session session;

  int hang_rank = -1;
  auto cli =
    session.cli() | Opt(hang_rank, "Rank to hang")["--hang-rank"](
                      "Hang this rank to attach a debugger.");
  session.cli(cli);

  // Parse the command line
  int return_code = session.applyCommandLine(argc, argv);
  if (return_code != 0) // Indicates a command line error
    return return_code;

  // Handle a debugger hang.
  //
  // Note (trb 02/10/2022): We should NOT use the default Catch2 flag
  // for this as that will hang every rank. I personally find it more
  // effective when using GDB in a parallel setting to just attach to
  // one rank. It's rare that I need more than one rank to run in GDB,
  // but this block does not preclude that. If that's the intention,
  // only the hang_rank needs to release the spin lock.
  if (world_comm->get_rank_in_world() == hang_rank) {
#ifdef LBANN_HAS_UNISTD_H
    char hostname[1024];
    gethostname(hostname, 1024);
    std::cerr << "[hang]: (hostname: " << hostname << ", pid: " << getpid()
              << ")" << std::endl;
#endif
    int volatile wait = 1;
    while (wait) {
    }
  }
  // This should hang the other ranks
  world_comm->global_barrier();

  // Manipulate output file if needed.
  auto& config_data = session.configData();
#ifdef LBANN_USE_CATCH2_V3
  auto& output_file = config_data.defaultOutputFilename;
#else
  auto& output_file = config_data.outputFilename;
#endif
  if (output_file.size() > 0) {
    lbann::utils::SystemInfo sys_info;
    output_file = replace_escapes(output_file, sys_info);
  }

  // Run the catch tests, outputting to the given file.