2
0
mirror of https://github.com/boostorg/asio.git synced 2026-02-27 15:12:12 +00:00
Files
asio/test/experimental/coro/cancel.cpp
klemens-morgenstern ecca8406c0 Added experimental::coro class template.
The coro type is a C++20 coroutine primitive for resumable functions,
with the ability to combine both asynchronous waiting (co_await) and
yielding (co_yield) into a single, stateful control flow. For example:

    #include <boostasio.hpp>
    #include <boostasio/experimental/coro.hpp>

    using boost::asio::ip::tcp;

    boost::asio::experimental::coro<std::string> reader(tcp::socket& sock)
    {
      std::string buf;
      while (sock.is_open())
      {
        std::size_t n = co_await boost::asio::async_read_until(
            sock, boost::asio::dynamic_buffer(buf), '\n',
            boost::asio::experimental::use_coro);
        co_yield buf.substr(0, n);
        buf.erase(0, n);
      }
    }

    boost::asio::awaitable<void> consumer(tcp::socket sock)
    {
      auto r = reader(sock);
      auto msg1 = co_await r.async_resume(boost::asio::use_awaitable);
      std::cout << "Message 1: " << msg1.value_or("\n");
      auto msg2 = co_await r.async_resume(boost::asio::use_awaitable);
      std::cout << "Message 2: " << msg2.value_or("\n");
    }

    boost::asio::awaitable<void> listen(tcp::acceptor& acceptor)
    {
      for (;;)
      {
        co_spawn(
            acceptor.get_executor(),
            consumer(co_await acceptor.async_accept(boost::asio::use_awaitable)),
            boost::asio::detached);
      }
    }

    int main()
    {
      boost::asio::io_context ctx;
      tcp::acceptor acceptor(ctx, {tcp::v4(), 54321});
      co_spawn(ctx, listen(acceptor), boost::asio::detached);
      ctx.run();
    }
2021-07-01 21:34:51 +10:00

158 lines
4.0 KiB
C++

//
// experimental/coro/cancel.cpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2021 Klemens D. Morgenstern
// (klemens dot morgenstern at gmx dot net)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Disable autolinking for unit tests.
#if !defined(BOOST_ALL_NO_LIB)
#define BOOST_ALL_NO_LIB 1
#endif // !defined(BOOST_ALL_NO_LIB)
// Test that header file is self-contained.
#include <boost/asio/experimental/coro.hpp>
#include <iostream>
#include <boost/asio/io_context.hpp>
#include <boost/asio/steady_timer.hpp>
#include <boost/scope_exit.hpp>
#include "../../unit_test.hpp"
using namespace boost::asio::experimental;
namespace this_coro = boost::asio::this_coro;
namespace coro {
void coro_simple_cancel()
{
boost::asio::io_context ctx;
auto k =
[](boost::asio::io_context& ) noexcept
-> boost::asio::experimental::coro<
void() noexcept, boost::system::error_code>
{
boost::asio::steady_timer timer{
co_await this_coro::executor,
std::chrono::seconds(1)};
BOOST_ASIO_CHECK(
!(co_await this_coro::cancellation_state).cancelled());
auto ec = co_await timer;
BOOST_ASIO_CHECK(
(co_await this_coro::cancellation_state).cancelled());
co_return ec;
}(ctx);
boost::system::error_code res_ec;
k.async_resume([&](boost::system::error_code ec) {res_ec = ec;});
boost::asio::post(ctx, [&]{k.cancel();});
BOOST_ASIO_CHECK(!res_ec);
ctx.run();
BOOST_ASIO_CHECK(res_ec == boost::asio::error::operation_aborted);
}
void coro_throw_cancel()
{
boost::asio::io_context ctx;
auto k = [](boost::asio::io_context& )
-> boost::asio::experimental::coro<void() , void>
{
boost::asio::steady_timer timer{
co_await this_coro::executor,
std::chrono::seconds(1)};
co_await timer;
}(ctx);
std::exception_ptr res_ex;
k.async_resume([&](std::exception_ptr ex) {res_ex = ex;});
boost::asio::post(ctx, [&]{k.cancel();});
BOOST_ASIO_CHECK(!res_ex);
ctx.run();
BOOST_ASIO_CHECK(res_ex);
try
{
std::rethrow_exception(res_ex);
}
catch (boost::system::system_error& se)
{
BOOST_ASIO_CHECK(se.code() == boost::asio::error::operation_aborted);
}
}
void coro_simple_cancel_nested()
{
boost::asio::io_context ctx;
auto k = [](boost::asio::io_context&, int& cnt) noexcept
-> boost::asio::experimental::coro<
void() noexcept, boost::system::error_code>
{
boost::asio::steady_timer timer{
co_await this_coro::executor,
std::chrono::milliseconds(100)};
BOOST_ASIO_CHECK(!(co_await this_coro::cancellation_state).cancelled());
auto ec = co_await timer;
cnt++;
BOOST_ASIO_CHECK((co_await this_coro::cancellation_state).cancelled());
co_return ec;
};
int cnt = 0;
auto kouter = [&](boost::asio::io_context& ctx, int& cnt) noexcept
-> boost::asio::experimental::coro<
boost::system::error_code() noexcept,
boost::system::error_code>
{
BOOST_ASIO_CHECK(cnt == 0);
co_yield co_await k(ctx, cnt);
BOOST_ASIO_CHECK(cnt == 1);
auto ec = co_await k(ctx, cnt);
BOOST_ASIO_CHECK(cnt == 2);
co_return ec;
}(ctx, cnt);
boost::system::error_code res_ec;
kouter.async_resume([&](boost::system::error_code ec) {res_ec = ec;});
boost::asio::post(ctx, [&]{kouter.cancel();});
BOOST_ASIO_CHECK(!res_ec);
ctx.run();
BOOST_ASIO_CHECK(res_ec == boost::asio::error::operation_aborted);
ctx.restart();
res_ec = {};
kouter.async_resume([&](boost::system::error_code ec) {res_ec = ec;});
boost::asio::post(ctx, [&]{kouter.cancel();});
BOOST_ASIO_CHECK(!res_ec);
ctx.run();
BOOST_ASIO_CHECK(res_ec == boost::asio::error::operation_aborted);
BOOST_ASIO_CHECK(cnt == 2);
}
} // namespace coro
BOOST_ASIO_TEST_SUITE
(
"coro/cancel",
BOOST_ASIO_TEST_CASE(::coro::coro_simple_cancel)
BOOST_ASIO_TEST_CASE(::coro::coro_throw_cancel)
BOOST_ASIO_TEST_CASE(::coro::coro_simple_cancel_nested)
)