timeout_context.cpp

/*
 * The function `bongo::context::with_timeout` returns a cancelable context
 * that is automatically canceled after the specified duration.
 */

#include <chrono>
#include <iostream>
#include <optional>
#include <variant>

#include <bongo/bongo.h>
#include <bongo/context.h>

using namespace std::chrono_literals;

int main() try {
  // Pass a context with a timeout to tell a blocking function that should
  // abandon its work after the timeout elapses.
  auto [ctx, cancel] = bongo::context::with_timeout(bongo::context::background(), 1ms);
  auto t = bongo::time::timer{1s};

  decltype(t)::recv_type v0;
  std::optional<std::monostate> v1;
  switch (bongo::select(
    bongo::recv_select_case(t.c(), v0),
    bongo::recv_select_case(ctx->done(), v1)
  )) {
  case 0:
    std::cout << "overslept\n";
    break;
  case 1:
    std::cerr << ctx->err() << "\n";
    break;
  }

  cancel();
  return 0;
} catch (std::exception const& e) {
  std::cerr << e.what() << "\n";
  return 1;
}