There are no exceptions with run_async()

[fliiiix]

Somehow config errors are suppressed if the the server runs in async mode.

For example if i'm using a invalid .bindaddr("127.0.0"). If used with .run() i get a exception

(2024-09-03 14:35:15) [INFO    ] Before Init
terminate called after throwing an instance of 'std::system_error'
  what():  Invalid argument

(maybe not the greatest exception but good enough)

If i do the same with .run_async() it just hangs on wait_for_server_start() with out any exceptions.

Is that on purpose? Is there a way to wait or crash or maybe find out if the server crashed? Am i holding it wrong? :sweat_smile:

Full example:

#include <crow.h>

#include <chrono>
#include <thread>

int main(int /*ac*/, char ** /*av*/) {
  crow::SimpleApp app;

  CROW_ROUTE(app, "/")
  ([]() {
    return "foo";
  });

  CROW_LOG_INFO << "Before Init";
  // async example
  auto f = app.bindaddr("127.0.0").port(8001).run_async();
  app.wait_for_server_start();

  // sync example
  // app.bindaddr("127.0.0").port(8001).run();

  CROW_LOG_INFO << "After Init";
  using namespace std::chrono_literals;
  std::this_thread::sleep_for(5s);
  app.stop();
}

[gittiver]

It fails in the constructor of the server due to asio::ip::address::from_string and throws an exception, therefore never a notification will be sent in run() and wait_for_server_start() waits forever.

[fliiiix]

In general I think a overload for wait_for_server_start(1s) with a overload for a timeout would be useful, i think there are a lot of cases where one would like to fail if it does not become ready in a certain time

Is there a way to achieve something with the current crow implementation?

[gittiver]

I agree, a timeout would be generally useful. I would assume that it is easily possible.