async_receive is not cancellable by the OR awaitable operator #209
Description
I encountered this error while developing and produced a MVE for simplification purposes below.
#include <boost/asio.hpp>
#include <boost/asio/experimental/awaitable_operators.hpp>
#include <azmq/socket.hpp>
#include <iostream>
namespace asio = boost::asio;
using namespace asio::experimental::awaitable_operators;
auto timer(std::chrono::steady_clock::duration dur) -> asio::awaitable<void> {
asio::steady_timer timer(co_await asio::this_coro::executor);
timer.expires_after(dur);
co_await timer.async_wait(asio::use_awaitable);
}
auto foo(asio::io_context& ctx) -> asio::awaitable<void> {
azmq::sub_socket socket_ = azmq::sub_socket(ctx);
std::array<std::byte, 4096> buffer{};
auto value = co_await (azmq::async_receive(socket_, asio::buffer(buffer), asio::as_tuple(asio::use_awaitable)) ||
timer(std::chrono::seconds(1)));
std::cout << "\n\n\nvalue: " << value.index() << std::endl;
}
auto main() -> int {
asio::io_context ctx{};
co_spawn(ctx, foo(ctx), asio::detached);
ctx.run();
return 0;
} The OR awaitable operator waits for one coroutine to finish and when it does it terminates the other one.
When I async_receive on a socket that doesn't contain any information this simply hangs. When the timer finishes the async_receive is not terminated.
Output (using boost asio logging feature):
@asio|1691763374.475866|0^1|in 'co_spawn_entry_point' (/home/magni-the-developer/Documents/framework/vcpkg-sysroot/x64-linux-gcc/includ:147)
@asio|1691763374.475866|0*1|[email protected]
@asio|1691763374.475906|>1|
@asio|1691763374.476192|1^2|in 'co_spawn_entry_point' (/home/magni-the-developer/Documents/framework/vcpkg-sysroot/x64-linux-gcc/includ:89)
@asio|1691763374.476192|1^2|called from 'operator||<std::tuple<boost::system::error_code, long unsigned int>, boost::asio' (/home/magni-the-developer/Documents/framework/vcpkg-sysroot/x64-linux-gcc/includ:345)
@asio|1691763374.476192|1*2|[email protected]_read_some(null_buffers)
@asio|1691763374.476204|1^3|in 'co_spawn_entry_point' (/home/magni-the-developer/Documents/framework/vcpkg-sysroot/x64-linux-gcc/includ:147)
@asio|1691763374.476204|1^3|called from 'operator||<std::tuple<boost::system::error_code, long unsigned int>, boost::asio' (/home/magni-the-developer/Documents/framework/vcpkg-sysroot/x64-linux-gcc/includ:345)
@asio|1691763374.476204|1*3|[email protected]_wait
@asio|1691763374.476211|<1|
@asio|1691763375.476231|>3|ec=system:0
@asio|1691763375.476246|3|[email protected]
@asio|1691763375.476252|<3|If it were working correctly the line
value: <index>would be printed after the timer is canceled.