Introduced a new Timeout class that can be used to trigger a timeout.

Also fixed a bunch of issues:
    - Flags<T> now works correctly and correctly zero-initializes the
      value in the default constructor
    - Fixed a nasty bug in Poller that went unnoticed because the Tag
      constructor was not marked explicit

main.cc

@@ -18,7 +18,11 @@ struct ExceptionPrinter {
 };
 
 class MyHandler : public Net::Http::Handler {
-    void onRequest(const Net::Http::Request& req, Net::Http::Response response) {
+    void onRequest(
+            const Net::Http::Request& req,
+            Net::Http::Response response,
+            Net::Http::Timeout timeout) {
+
         if (req.resource() == "/ping") {
             if (req.method() == Net::Http::Method::Get) {
 
@@ -28,12 +32,10 @@ class MyHandler : public Net::Http::Handler {
                     .add<Header::Server>("lys")
                     .add<Header::ContentType>(MIME(Text, Plain));
 
-                auto w = response.beginWrite(Net::Http::Code::Ok);
-
-                std::ostream os(w);
+                std::ostream os(response.rdbuf());
                 os << "PONG";
 
-                w.send().then([](ssize_t bytes) {
+                response.send(Net::Http::Code::Ok).then([](ssize_t bytes) {
                     std::cout << "Sent total of " << bytes << " bytes" << std::endl;
                 }, Async::IgnoreException);
 
@@ -48,13 +50,15 @@ class MyHandler : public Net::Http::Handler {
             throw std::runtime_error("Exception thrown in the handler");
         }
         else if (req.resource() == "/timeout") {
-            response
-                .timeoutAfter(std::chrono::seconds(1))
-                .then([=](Net::Http::Response *response) {
-                    response->send(Net::Http::Code::Bad_Request, "Timeout occured");
-            }, Async::NoExcept);
+            timeout.arm(std::chrono::seconds(5));
         }
     }
+
+    void onTimeout(const Net::Http::Request& req, Net::Http::Response response) {
+        response
+            .send(Net::Http::Code::Request_Timeout, "Timeout")
+            .then([=](ssize_t) { }, ExceptionPrinter());
+    }
 };
 
 int main(int argc, char *argv[]) {

src/async.h

@@ -440,7 +440,7 @@ namespace Async {
         { }
 
         template<typename Arg>
-        bool operator()(Arg&& arg) {
+        bool operator()(Arg&& arg) const {
             typedef typename std::remove_reference<Arg>::type Type;
 
             if (core_->state != State::Pending)
@@ -461,7 +461,7 @@ namespace Async {
             return true;
         }
 
-        bool operator()() {
+        bool operator()() const {
             if (core_->state != State::Pending)
                 throw Error("Attempt to resolve a fulfilled promise");
 
@@ -488,7 +488,7 @@ namespace Async {
 
 
         template<typename Exc>
-        bool operator()(Exc exc) {
+        bool operator()(Exc exc) const {
             if (core_->state != State::Pending)
                 throw Error("Attempt to reject a fulfilled promise");
 

src/flags.h

@@ -6,6 +6,7 @@
 
 #pragma once
 #include <type_traits>
+#include <climits>
 #include <iostream>
 
 // Looks like gcc 4.6 does not implement std::underlying_type
@@ -28,15 +29,31 @@ namespace detail {
     template<typename T> struct UnderlyingType {
         typedef typename TypeStorage<sizeof(T)>::Type Type;
     };
+
+    template<typename Enum>
+    struct HasNone {
+        template<typename U>
+        static auto test(U *) -> decltype(U::None, std::true_type());
+
+        template<typename U>
+        static auto test(...) -> std::false_type;
+
+        static constexpr bool value =
+            std::is_same<decltype(test<Enum>(0)), std::true_type>::value;
+    };
 }
 
 template<typename T>
 class Flags {
 public:
-    static_assert(std::is_enum<T>::value, "Flags only works with enumerations");
     typedef typename detail::UnderlyingType<T>::Type Type;
 
-    Flags() { }
+    static_assert(std::is_enum<T>::value, "Flags only works with enumerations");
+    static_assert(detail::HasNone<T>::value, "The enumartion needs a None value");
+    static_assert(static_cast<Type>(T::None) == 0, "None should be 0");
+
+    Flags() : val(T::None) {
+    }
 
     Flags(T val) : val(val)
     {
@@ -83,13 +100,12 @@ public:
 #undef DEFINE_BITWISE_OP
 
     bool hasFlag(T flag) const {
-        return static_cast<T>(
-                    static_cast<Type>(val) & static_cast<Type>(flag)
-               ) == flag;
+        return static_cast<Type>(val) & static_cast<Type>(flag);
     }
 
     Flags<T>& setFlag(T flag) {
-        return *this &= flag;
+        *this |= flag;
+        return *this;
     }
 
     Flags<T>& toggleFlag(T flag) {
@@ -115,3 +131,15 @@ private:
 #define DECLARE_FLAGS_OPERATORS(T) \
     DEFINE_BITWISE_OP(&, T) \
     DEFINE_BITWISE_OP(|, T)
+
+template<typename T>
+std::ostream& operator<<(std::ostream& os, Flags<T> flags) {
+    typedef typename detail::UnderlyingType<T>::Type UnderlyingType;
+
+    auto val = static_cast<UnderlyingType>(static_cast<T>(flags));
+    for (ssize_t i = (sizeof(UnderlyingType) * CHAR_BIT) - 1; i >= 0; --i) {
+        os << ((val >> i) & 0x1);
+    }
+
+    return os;
+}

src/http.cc

@@ -348,67 +348,60 @@ Request::query() const {
     return query_;
 }
 
-Async::Promise<Response *>
-Response::timeoutAfter(std::chrono::milliseconds timeout)
-{
-#if 0
-    Async::Promise<uint64_t> promise([=](Async::Resolver& resolve, Async::Rejection& reject) {
-       peer()->io()->setTimeout(timeout, resolve, reject);
-   }); 
-
-    promise.then([=](uint64_t) {
-        send(Code::Bad_Request, "A timeout occured");
-    }, Async::NoExcept);
-
-    return promise;
-#endif
-    Async::Promise<uint64_t> promise([=](Async::Resolver& resolve, Async::Rejection& reject) {
-       peer()->io()->setTimeout(timeout, resolve, reject);
-   }); 
-
-    return promise.then([=](uint64_t) {
-        auto p = Async::Promise<Response *>::resolved(this);
-
-        return p;
-    }, Async::NoExcept);
+std::shared_ptr<Tcp::Peer>
+Request::peer() const {
+    auto p = peer_.lock();
+
+    if (!p) throw std::runtime_error("Failed to retrieve peer: Broken pipe");
+
+    return p;
 }
 
 Async::Promise<ssize_t>
-ResponseWriter::send() const
+Response::putOnWire() const
 {
-    auto body = stream_.buffer();
+    try {
+        auto body = stream_.buffer();
 
-    NetworkStream stream(512 + body.len);
-    std::ostream os(&stream);
+        NetworkStream stream(512 + body.len);
+        std::ostream os(&stream);
 
 #define OUT(...) \
-    do { \
-        __VA_ARGS__; \
-        if (!os) { \
-            return Async::Promise<ssize_t>::rejected(Error("Response exceeded buffer size")); \
-        } \
-    } while (0);
-
-    OUT(os << "HTTP/1.1 ");
-    OUT(os << static_cast<int>(code_));
-    OUT(os << ' ');
-    OUT(os << code_);
-    OUT(os << crlf);
-
-    for (const auto& header: headers_.list()) {
-        OUT(os << header->name() << ": ");
-        OUT(header->write(os));
+        do { \
+            __VA_ARGS__; \
+            if (!os) { \
+                return Async::Promise<ssize_t>::rejected(Error("Response exceeded buffer size")); \
+            } \
+        } while (0);
+
+        OUT(os << "HTTP/1.1 ");
+        OUT(os << static_cast<int>(code_));
+        OUT(os << ' ');
+        OUT(os << code_);
         OUT(os << crlf);
-    }
 
-    OUT(writeHeader<Header::ContentLength>(os, body.len));
-    OUT(os << crlf);
+        for (const auto& header: headers_.list()) {
+            OUT(os << header->name() << ": ");
+            OUT(header->write(os));
+            OUT(os << crlf);
+        }
 
-    OUT(os.write(static_cast<const char *>(body.data), body.len));
+        OUT(writeHeader<Header::ContentLength>(os, body.len));
+        OUT(os << crlf);
+
+        OUT(os.write(static_cast<const char *>(body.data), body.len));
+
+        auto buf = stream.buffer();
+
+        if (io_) {
+            io_->disarmTimer();
+        }
 
-    auto buf = stream.buffer();
+        return peer()->send(buf.data, buf.len);
 
-    return peer()->send(buf.data, buf.len);
+    } catch (const std::runtime_error& e) {
+        return Async::Promise<ssize_t>::rejected(e);
+    }
 }
 
 void
@@ -422,19 +415,23 @@ Handler::onInput(const char* buffer, size_t len, const std::shared_ptr<Tcp::Peer
 
         auto state = parser.parse();
         if (state == Private::State::Done) {
-            Response response;
+            Response response(io());
             response.associatePeer(peer);
-            onRequest(parser.request, std::move(response));
+
+            Timeout timeout(io(), this, peer, parser.request);
+
+            parser.request.associatePeer(peer);
+            onRequest(parser.request, std::move(response), std::move(timeout));
             parser.reset();
         }
     } catch (const HttpError &err) {
-        Response response;
+        Response response(io());
         response.associatePeer(peer);
         response.send(static_cast<Code>(err.code()), err.reason());
         getParser(peer).reset();
     }
     catch (const std::exception& e) {
-        Response response;
+        Response response(io());
         response.associatePeer(peer);
         response.send(Code::Internal_Server_Error, e.what());
         getParser(peer).reset();
@@ -450,6 +447,20 @@ void
 Handler::onDisconnection(const shared_ptr<Tcp::Peer>& peer) {
 }
 
+void
+Handler::onTimeout(const Request& request, Response response) {
+}
+
+void
+Timeout::onTimeout(uint64_t numWakeup) {
+    if (!peer.lock()) return;
+
+    Response response(io);
+    response.associatePeer(peer);
+
+    handler->onTimeout(request, std::move(response));
+}
+
 Private::Parser&
 Handler::getParser(const std::shared_ptr<Tcp::Peer>& peer) const {
     return *peer->getData<Private::Parser>(ParserData);

src/http.h

@@ -71,7 +71,7 @@ public:
     friend class Private::BodyStep;
     friend class Private::Parser;
 
-    Request();
+    friend class Handler;
 
     Version version() const;
     Method method() const;
@@ -82,88 +82,33 @@ public:
     const Header::Collection& headers() const;
     const Uri::Query& query() const;
 
-private:
-    Method method_;
-    std::string resource_;
-    Uri::Query query_;
-};
-
-class Handler;
-
-class ResponseWriter : private Message {
-public:
-    ResponseWriter(const ResponseWriter& other) = delete;
-    ResponseWriter& operator=(const ResponseWriter& other) = delete;
-
-    ResponseWriter(ResponseWriter&& other)
-        : Message(std::move(other))
-        , peer_(std::move(other.peer_))
-        , stream_(std::move(other.stream_))
-    { }
-
-    ResponseWriter& operator=(ResponseWriter&& other) {
-        Message::operator=(std::move(other));
-        peer_ = std::move(other.peer_);
-        stream_ = std::move(other.stream_);
-
-        return *this;
-    }
-
-    friend class Response;
-
-    const Header::Collection& headers() const {
-        return headers_;
-    }
-
-    Code code() const {
-        return code_;
-    }
-
-    void setCode(Code code) {
-        code_ = code;
-    }
-
-    std::streambuf* rdbuf() {
-        return &stream_;
-    }
-
-    operator std::streambuf*() {
-        return &stream_;
-    }
-
-    Async::Promise<ssize_t> send() const;
+    std::shared_ptr<Tcp::Peer> peer() const;
 
 private:
-    ResponseWriter(Message&& other, size_t size, std::weak_ptr<Tcp::Peer> peer)
-        : Message(std::move(other))
-        , stream_(size)
-        , peer_(peer)
-    {
-    }
-
-    ResponseWriter(const Message& other, size_t size, std::weak_ptr<Tcp::Peer> peer)
-        : Message(other)
-        , stream_(size)
-        , peer_(peer)
-    {
-    }
+    Request();
 
-    std::shared_ptr<Tcp::Peer> peer() const {
-        if (peer_.expired()) {
-            throw std::runtime_error("Broken pipe");
-        }
+    void associatePeer(const std::shared_ptr<Tcp::Peer>& peer) {
+        if (peer_.use_count() > 0)
+            throw std::runtime_error("A peer was already associated to the response");
 
-        return peer_.lock();
+        peer_ = peer;
     }
 
-    NetworkStream stream_;
+    Method method_;
+    std::string resource_;
+    Uri::Query query_;
+
     std::weak_ptr<Tcp::Peer> peer_;
 };
 
+class Handler;
+class Timeout;
+
 // 6. Response
 class Response : private Message {
 public:
     friend class Handler;
+    friend class Timeout;
 
     static constexpr size_t DefaultStreamSize = 512;
 
@@ -173,9 +118,13 @@ public:
     Response(Response&& other)
         : Message(std::move(other))
         , peer_(other.peer_)
+        , stream_(512)
+        , io_(other.io_)
     { }
     Response& operator=(Response&& other) {
+        Message::operator=(std::move(other));
         peer_ = other.peer_;
+        io_ = other.io_;
         return *this;
     }
 
@@ -202,7 +151,8 @@ public:
     }
 
     Async::Promise<ssize_t> send(Code code) {
-        return send(code, "");
+        code_ = code;
+        return putOnWire();
     }
     Async::Promise<ssize_t> send(
             Code code,
@@ -219,44 +169,92 @@ public:
                 headers_.add(std::make_shared<Header::ContentType>(mime));
         }
 
-        ResponseWriter w(*this, body.size(), peer_);
-        std::ostream os(w);
+        std::ostream os(&stream_);
         os << body;
+
         if (!os)
             return Async::Promise<ssize_t>::rejected(Error("Response exceeded buffer size"));
-        return w.send();
-    }
 
-    /* @Revisit: not sure about the name yet */
-    ResponseWriter
-    beginWrite(Code code = Code::Ok, size_t size = DefaultStreamSize) {
-        code_ = code;
-        return ResponseWriter(std::move(*this), size, peer_);
+        return putOnWire();
     }
 
-    Async::Promise<Response *> timeoutAfter(std::chrono::milliseconds timeout);
+
+    std::streambuf *rdbuf() {
+        return &stream_;
+    }
 
 private:
-    Response()
+    Response(Tcp::IoWorker* io)
         : Message()
+        , stream_(512)
+        , io_(io)
     { }
 
     std::shared_ptr<Tcp::Peer> peer() const {
-        if (peer_.expired()) {
-            throw std::runtime_error("Broken pipe");
-        }
+        if (peer_.expired())
+            throw std::runtime_error("Write failed: Broken pipe");
 
         return peer_.lock();
     }
 
-    void associatePeer(const std::shared_ptr<Tcp::Peer>& peer) {
+    template<typename Ptr>
+    void associatePeer(const Ptr& peer) {
         if (peer_.use_count() > 0)
             throw std::runtime_error("A peer was already associated to the response");
 
         peer_ = peer;
     }
 
+    Async::Promise<ssize_t> putOnWire() const;
+
     std::weak_ptr<Tcp::Peer> peer_;
+    NetworkStream stream_;
+    Tcp::IoWorker *io_;
+};
+
+class Timeout {
+public:
+
+    friend class Handler;
+
+    template<typename Duration>
+    void arm(Duration duration) {
+        Async::Promise<uint64_t> p([=](Async::Resolver& resolve, Async::Rejection& reject) {
+            io->armTimer(duration, resolve, reject);
+        });
+
+        p.then(
+            [=](uint64_t numWakeup) {
+                this->onTimeout(numWakeup);
+        },
+        [=](std::exception_ptr exc) {
+            std::rethrow_exception(exc);
+        });
+    }
+
+    void disarm() {
+        io->disarmTimer();
+    }
+
+private:
+    Timeout(Tcp::IoWorker* io,
+            Handler* handler,
+            const std::shared_ptr<Tcp::Peer>& peer,
+            const Request& request)
+        : io(io)
+        , handler(handler)
+        , peer(peer)
+        , request(request)
+    { }
+
+
+    void onTimeout(uint64_t numWakeup);
+
+    Handler* handler;
+    std::weak_ptr<Tcp::Peer> peer;
+    Request request;
+
+    Tcp::IoWorker *io;
 };
 
 namespace Private {
@@ -358,7 +356,9 @@ public:
     void onConnection(const std::shared_ptr<Tcp::Peer>& peer);
     void onDisconnection(const std::shared_ptr<Tcp::Peer>& peer);
 
-    virtual void onRequest(const Request& request, Response response) = 0;
+    virtual void onRequest(const Request& request, Response response, Timeout timeout) = 0;
+
+    virtual void onTimeout(const Request& request, Response response);
 
 private:
     Private::Parser& getParser(const std::shared_ptr<Tcp::Peer>& peer) const;

src/io.cc

@@ -49,6 +49,8 @@ IoWorker::~IoWorker() {
 void
 IoWorker::start(const std::shared_ptr<Handler>& handler, Flags<Options> options) {
     handler_ = handler;
+    handler_->io_ = this;
+
     options_ = options;
 
     thread.reset(new std::thread([this]() {
@@ -74,7 +76,7 @@ IoWorker::pin(const CpuSet& set) {
 }
 
 void
-IoWorker::setTimeoutMs(
+IoWorker::armTimer(
         std::chrono::milliseconds value,
         Async::Resolver resolve, Async::Rejection reject)
 {
@@ -99,8 +101,23 @@ IoWorker::setTimeoutMs(
         return;
     }
 
-    timeout = Some(Timeout(value, std::move(resolve), std::move(reject)));
+    timer = Some(Timer(value, std::move(resolve), std::move(reject)));
+
+}
+
+void
+IoWorker::disarmTimer()
+{
+    itimerspec spec;
+    spec.it_value.tv_sec = spec.it_value.tv_nsec = 0;
+    spec.it_interval.tv_sec = spec.it_interval.tv_nsec = 0;
+
+    int res = timerfd_settime(timerFd, 0, &spec, 0);
+
+    if (res == -1)
+        throw Error::system("Could not set timer time");
 
+    timer = None();
 }
 
 void
@@ -147,8 +164,7 @@ IoWorker::handleIncoming(const std::shared_ptr<Peer>& peer) {
                 }
             } else {
                 if (errno == ECONNRESET) {
-                    handler_->onDisconnection(peer);
-                    close(fd);
+                    handlePeerDisconnection(peer);
                 }
                 else {
                     throw std::runtime_error(strerror(errno));
@@ -157,8 +173,7 @@ IoWorker::handleIncoming(const std::shared_ptr<Peer>& peer) {
             break;
         }
         else if (bytes == 0) {
-            handler_->onDisconnection(peer);
-            close(fd);
+            handlePeerDisconnection(peer);
             break;
         }
 
@@ -185,9 +200,26 @@ IoWorker::handleNewPeer(const std::shared_ptr<Peer>& peer)
     peer->io_ = this;
 
     handler_->onConnection(peer);
-    poller.addFd(fd, NotifyOn::Read, Polling::Tag(fd), Polling::Mode::Edge);
+    poller.addFd(fd, NotifyOn::Read | NotifyOn::Shutdown, Polling::Tag(fd), Polling::Mode::Edge);
 }
 
+void
+IoWorker::handlePeerDisconnection(const std::shared_ptr<Peer>& peer)
+{
+    handler_->onDisconnection(peer);
+
+    int fd = peer->fd();
+    {
+        std::unique_lock<std::mutex> guard(peersMutex);
+        auto it = peers.find(fd);
+        if (it == std::end(peers))
+            throw std::runtime_error("Could not find peer to erase");
+
+        peers.erase(it);
+    }
+
+    close(fd);
+}
 
 void
 IoWorker::run() {
@@ -226,6 +258,9 @@ IoWorker::run() {
                             handleIncoming(peer);
                         }
                     }
+                    else if (event.flags.hasFlag(NotifyOn::Shutdown)) {
+                        handlePeerDisconnection(getPeer(event.tag));
+                    }
                     else if (event.flags.hasFlag(NotifyOn::Write)) {
                         auto fd = event.tag.value();
                         auto it = toWrite.find(fd);
@@ -257,24 +292,24 @@ IoWorker::run() {
 void
 IoWorker::handleTimeout() {
 
-    auto& entry = timeout.unsafeGet();
-
-    uint64_t numWakeups;
-    int res = ::read(timerFd, &numWakeups, sizeof numWakeups);
-    if (res == -1) {
-        if (errno == EAGAIN || errno == EWOULDBLOCK)
-            return;
-        else
-            entry.reject(Error::system("Could not read timerfd"));
-    } else {
-        if (res != sizeof(numWakeups)) {
-            entry.reject(Error("Read invalid number of bytes for timer fd: "
-                        + std::to_string(timerFd)));
-        }
-        else {
-            entry.resolve(numWakeups);
+    optionally_do(timer, [=](const Timer& entry) {
+        uint64_t numWakeups;
+        int res = ::read(timerFd, &numWakeups, sizeof numWakeups);
+        if (res == -1) {
+            if (errno == EAGAIN || errno == EWOULDBLOCK)
+                return;
+            else
+                entry.reject(Error::system("Could not read timerfd"));
+        } else {
+            if (res != sizeof(numWakeups)) {
+                entry.reject(Error("Read invalid number of bytes for timer fd: "
+                            + std::to_string(timerFd)));
+            }
+            else {
+                entry.resolve(numWakeups);
+            }
         }
-    }
+    });
 }
 
 Async::Promise<ssize_t>

src/io.h

@@ -40,12 +40,14 @@ public:
 
     void shutdown();
     template<typename Duration>
-    void setTimeout(Duration timeout, Async::Resolver resolve, Async::Rejection reject) {
-        setTimeoutMs(std::chrono::duration_cast<std::chrono::milliseconds>(timeout), 
+
+    void armTimer(Duration timeout, Async::Resolver resolve, Async::Rejection reject) {
+        armTimer(std::chrono::duration_cast<std::chrono::milliseconds>(timeout), 
                    std::move(resolve),
                    std::move(reject));
     }
 
+    void disarmTimer();
 
 private:
     struct OnHoldWrite {
@@ -65,10 +67,10 @@ private:
     };
 
     void
-    setTimeoutMs(std::chrono::milliseconds value, Async::Resolver, Async::Rejection reject);
+    armTimer(std::chrono::milliseconds value, Async::Resolver, Async::Rejection reject);
 
-    struct Timeout {
-        Timeout(std::chrono::milliseconds value,
+    struct Timer {
+        Timer(std::chrono::milliseconds value,
                 Async::Resolver resolve,
                 Async::Rejection reject)
           : value(value)
@@ -88,7 +90,7 @@ private:
     std::unordered_map<Fd, std::shared_ptr<Peer>> peers;
     std::unordered_map<Fd, OnHoldWrite> toWrite;
 
-    Optional<Timeout> timeout;
+    Optional<Timer> timer;
     Fd timerFd;
 
     std::shared_ptr<Handler> handler_;
@@ -101,6 +103,8 @@ private:
 
     Async::Promise<ssize_t> asyncWrite(Fd fd, const void *buf, size_t len);
 
+    void handlePeerDisconnection(const std::shared_ptr<Peer>& peer);
+
     void handleIncoming(const std::shared_ptr<Peer>& peer);
     void handleTimeout();
     void run();

src/os.cc

@@ -195,7 +195,7 @@ namespace Polling {
 
                 Event event(tag);
                 event.flags = toNotifyOn(ev->events);
-                events.push_back(tag);
+                events.push_back(event);
             }
         }
 
@@ -212,6 +212,8 @@ namespace Polling {
             events |= EPOLLOUT;
         if (interest.hasFlag(NotifyOn::Hangup))
             events |= EPOLLHUP;
+        if (interest.hasFlag(NotifyOn::Shutdown))
+            events |= EPOLLRDHUP;
 
         return events;
     }
@@ -226,6 +228,9 @@ namespace Polling {
             flags.setFlag(NotifyOn::Write);
         if (events & EPOLLHUP)
             flags.setFlag(NotifyOn::Hangup);
+        if (events & EPOLLRDHUP) {
+            flags.setFlag(NotifyOn::Shutdown);
+        }
 
         return flags;
     }

src/os.h

@@ -52,9 +52,12 @@ enum class Mode {
 };
 
 enum class NotifyOn {
-    Read,
-    Write,
-    Hangup
+    None = 0,
+
+    Read = 1,
+    Write = Read << 1,
+    Hangup = Write << 1,
+    Shutdown = Hangup << 1
 };
 
 DECLARE_FLAGS_OPERATORS(NotifyOn);
@@ -79,7 +82,7 @@ inline constexpr bool operator==(Tag lhs, Tag rhs) {
 }
 
 struct Event {
-    Event(Tag tag) :
+    explicit Event(Tag tag) :
         tag(tag)
     { }
 

src/peer.h

@@ -52,10 +52,6 @@ public:
 
     Async::Promise<ssize_t> send(const void* buf, size_t len);
 
-    IoWorker *io() {
-        return io_;
-    }
-
 private:
     IoWorker* io_;
 

src/tcp.h

@@ -28,8 +28,12 @@ enum class Options : uint64_t {
 
 DECLARE_FLAGS_OPERATORS(Options)
 
+class IoWorker;
+
 class Handler {
 public:
+    friend class IoWorker;
+
     Handler();
     ~Handler();
 
@@ -38,6 +42,11 @@ public:
     virtual void onConnection(const std::shared_ptr<Tcp::Peer>& peer);
     virtual void onDisconnection(const std::shared_ptr<Tcp::Peer>& peer);
 
+protected:
+    IoWorker *io() { return io_; }
+
+private:
+    IoWorker *io_;
 };
 
 } // namespace Tcp