Improvements to test::stream:

The behavior of the test stream when either
end is destroyed or closed is well-defined.

CHANGELOG.md

@@ -1,6 +1,7 @@
 Version 211:
 
 * close_socket is in stream_traits.hpp
+* Improvements to test::stream
 
 --------------------------------------------------------------------------------
 

include/boost/beast/_experimental/test/impl/stream.hpp

@@ -10,30 +10,146 @@
 #ifndef BOOST_BEAST_TEST_IMPL_STREAM_HPP
 #define BOOST_BEAST_TEST_IMPL_STREAM_HPP
 
+#include <boost/beast/core/bind_handler.hpp>
 #include <boost/beast/core/buffer_size.hpp>
 #include <boost/beast/core/buffers_prefix.hpp>
+#include <stdexcept>
 
 namespace boost {
 namespace beast {
 namespace test {
 
+//------------------------------------------------------------------------------
+
+template<class Handler, class Buffers>
+class stream::read_op : public stream::read_op_base
+{
+    using ex1_type =
+        net::io_context::executor_type;
+    using ex2_type
+        = net::associated_executor_t<Handler, ex1_type>;
+
+    class lambda
+    {
+        state& s_;
+        Buffers b_;
+        Handler h_;
+        net::executor_work_guard<ex2_type> wg2_;
+
+    public:
+        lambda(lambda&&) = default;
+        lambda(lambda const&) = default;
+
+        template<class DeducedHandler>
+        lambda(state& s, Buffers const& b, DeducedHandler&& h)
+            : s_(s)
+            , b_(b)
+            , h_(std::forward<DeducedHandler>(h))
+            , wg2_(net::get_associated_executor(
+                h_, s_.ioc.get_executor()))
+        {
+        }
+
+        void
+        operator()(bool cancel)
+        {
+            error_code ec;
+            std::size_t bytes_transferred = 0;
+            if(cancel)
+            {
+                ec = net::error::operation_aborted;
+            }
+            else
+            {
+                std::lock_guard<std::mutex> lock(s_.m);
+                BOOST_ASSERT(! s_.op);
+                if(s_.b.size() > 0)
+                {
+                    bytes_transferred =
+                        net::buffer_copy(
+                            b_, s_.b.data(), s_.read_max);
+                    s_.b.consume(bytes_transferred);
+                }
+                else
+                {
+                    ec = net::error::eof;
+                }
+            }
+            auto alloc = net::get_associated_allocator(h_);
+            wg2_.get_executor().dispatch(
+                beast::bind_front_handler(std::move(h_),
+                    ec, bytes_transferred), alloc);
+            wg2_.reset();
+        }
+    };
+
+    lambda fn_;
+    net::executor_work_guard<ex1_type> wg1_;
+
+public:
+    template<class Handler_>
+    read_op(state& s,
+        Buffers const& b, Handler_&& h)
+        : fn_(s, b, std::forward<Handler_>(h))
+        , wg1_(s.ioc.get_executor())
+    {
+    }
+
+    void
+    operator()(bool cancel) override
+    {
+        net::post(
+            wg1_.get_executor(),
+            bind_handler(
+                std::move(fn_),
+                cancel));
+        wg1_.reset();
+    }
+};
+
+//------------------------------------------------------------------------------
+
+stream::
+state::
+state(
+    net::io_context& ioc_,
+    fail_count* fc_)
+    : ioc(ioc_)
+    , fc(fc_)
+{
+}
+
+stream::
+state::
+~state()
+{
+    // cancel outstanding read
+    if(op != nullptr)
+        (*op)(true);
+}
+
+void
+stream::
+state::
+notify_read()
+{
+    if(op)
+    {
+        auto op_ = std::move(op);
+        op_->operator()();
+    }
+    else
+    {
+        cv.notify_all();
+    }
+}
+
+//------------------------------------------------------------------------------
+        
 stream::
 ~stream()
 {
-    {
-        std::unique_lock<std::mutex> lock{in_->m};
-        in_->op.reset();
-    }
-    auto out = out_.lock();
-    if(out)
-    {
-        std::unique_lock<std::mutex> lock{out->m};
-        if(out->code == status::ok)
-        {
-            out->code = status::reset;
-            out->on_write();
-        }
-    }
+    close();
 }
 
 stream::
@@ -50,6 +166,7 @@ stream&
 stream::
 operator=(stream&& other)
 {
+    close();
     auto in = std::make_shared<state>(
         other.in_->ioc, other.in_->fc);
     in_ = std::move(other.in_);
@@ -58,6 +175,8 @@ operator=(stream&& other)
     return *this;
 }
 
+//------------------------------------------------------------------------------
+
 stream::
 stream(net::io_context& ioc)
     : in_(std::make_shared<state>(ioc, nullptr))
@@ -103,6 +222,8 @@ connect(stream& remote)
     BOOST_ASSERT(! remote.out_.lock());
     out_ = remote.in_;
     remote.out_ = in_;
+    in_->code = status::ok;
+    remote.in_->code = status::ok;
 }
 
 string_view
@@ -138,15 +259,33 @@ void
 stream::
 close()
 {
-    BOOST_ASSERT(! in_->op);
-    auto out = out_.lock();
-    if(! out)
-        return;
-    std::lock_guard<std::mutex> lock{out->m};
-    if(out->code == status::ok)
+    // cancel outstanding read
     {
-        out->code = status::eof;
-        out->on_write();
+        std::unique_ptr<read_op_base> op;
+        {
+            std::lock_guard<std::mutex> lock(in_->m);
+            in_->code = status::eof;
+            op = std::move(in_->op);
+        }
+        if(op != nullptr)
+            (*op)(true);
+    }
+
+    // disconnect
+    {
+        auto out = out_.lock();
+        out_.reset();
+
+        // notify peer
+        if(out)
+        {
+            std::lock_guard<std::mutex> lock(out->m);
+            if(out->code == status::ok)
+            {
+                out->code = status::eof;
+                out->notify_read();
+            }
+        }
     }
 }
 
@@ -158,7 +297,7 @@ close_remote()
     if(in_->code == status::ok)
     {
         in_->code = status::eof;
-        in_->on_write();
+        in_->notify_read();
     }
 }
 
@@ -186,13 +325,20 @@ read_some(MutableBufferSequence const& buffers,
     static_assert(net::is_mutable_buffer_sequence<
             MutableBufferSequence>::value,
         "MutableBufferSequence requirements not met");
+
+    ++in_->nread;
+
+    // test failure
     if(in_->fc && in_->fc->fail(ec))
         return 0;
+
+    // 0-byte reads are no-ops
     if(buffer_size(buffers) == 0)
     {
         ec.clear();
         return 0;
     }
+
     std::unique_lock<std::mutex> lock{in_->m};
     BOOST_ASSERT(! in_->op);
     in_->cv.wait(lock,
@@ -202,25 +348,20 @@ read_some(MutableBufferSequence const& buffers,
                 in_->b.size() > 0 ||
                 in_->code != status::ok;
         });
-    std::size_t bytes_transferred;
+
+    // deliver bytes before eof
     if(in_->b.size() > 0)
     {
-        ec = {};
-        bytes_transferred = net::buffer_copy(
+        auto const n = net::buffer_copy(
             buffers, in_->b.data(), in_->read_max);
-        in_->b.consume(bytes_transferred);
+        in_->b.consume(n);
+        return n;
     }
-    else
-    {
-        BOOST_ASSERT(in_->code != status::ok);
-        bytes_transferred = 0;
-        if(in_->code == status::eof)
-            ec = net::error::eof;
-        else if(in_->code == status::reset)
-            ec = net::error::connection_reset;
-    }
-    ++in_->nread;
-    return bytes_transferred;
+
+    // deliver error
+    BOOST_ASSERT(in_->code != status::ok);
+    ec = net::error::eof;
+    return 0;
 }
 
 template<class MutableBufferSequence, class ReadHandler>
@@ -234,8 +375,18 @@ async_read_some(
     static_assert(net::is_mutable_buffer_sequence<
             MutableBufferSequence>::value,
         "MutableBufferSequence requirements not met");
+
     BOOST_BEAST_HANDLER_INIT(
         ReadHandler, void(error_code, std::size_t));
+
+    ++in_->nread;
+
+    std::unique_lock<std::mutex> lock(in_->m);
+    if(in_->op != nullptr)
+        throw std::logic_error(
+            "in_->op != nullptr");
+
+    // test failure
     error_code ec;
     if(in_->fc && in_->fc->fail(ec))
     {
@@ -243,51 +394,55 @@ async_read_some(
             in_->ioc.get_executor(),
             beast::bind_front_handler(
                 std::move(init.completion_handler),
-                ec,
-                0));
+                ec, std::size_t{0}));
+        return init.result.get();
     }
-    else
+
+    // 0-byte reads are no-ops
+    if(buffer_size(buffers) == 0)
     {
-        std::unique_lock<std::mutex> lock{in_->m};
-        BOOST_ASSERT(! in_->op);
-        if( buffer_size(buffers) == 0 ||
-            buffer_size(in_->b.data()) > 0)
-        {
-            auto const bytes_transferred = net::buffer_copy(
-                buffers, in_->b.data(), in_->read_max);
-            in_->b.consume(bytes_transferred);
-            lock.unlock();
-            ++in_->nread;
-            net::post(
-                in_->ioc.get_executor(),
-                beast::bind_front_handler(
-                    std::move(init.completion_handler),
-                    error_code{},
-                    bytes_transferred));
-        }
-        else if(in_->code != status::ok)
-        {
-            lock.unlock();
-            ++in_->nread;
-            if(in_->code == status::eof)
-                ec = net::error::eof;
-            else if(in_->code == status::reset)
-                ec = net::error::connection_reset;
-            net::post(
-                in_->ioc.get_executor(),
-                beast::bind_front_handler(
-                    std::move(init.completion_handler),
-                    ec,
-                    0));
-        }
-        else
-        {
-            in_->op.reset(new read_op<BOOST_ASIO_HANDLER_TYPE(
-                ReadHandler, void(error_code, std::size_t)),
-                    MutableBufferSequence>{*in_, buffers,
-                        std::move(init.completion_handler)});
-        }
+        lock.unlock();
+        net::post(
+            in_->ioc.get_executor(),
+            beast::bind_front_handler(
+                std::move(init.completion_handler),
+                ec, std::size_t{0}));
+        return init.result.get();
     }
+
+    // deliver bytes before eof
+    if(buffer_size(in_->b.data()) > 0)
+    {
+        auto n = net::buffer_copy(
+            buffers, in_->b.data(), in_->read_max);
+        in_->b.consume(n);
+        lock.unlock();
+        net::post(
+            in_->ioc.get_executor(),
+            beast::bind_front_handler(
+                std::move(init.completion_handler),
+                ec, n));
+        return init.result.get();
+    }
+
+    // deliver error
+    if(in_->code != status::ok)
+    {
+        lock.unlock();
+        ec = net::error::eof;
+        net::post(
+            in_->ioc.get_executor(),
+            beast::bind_front_handler(
+                std::move(init.completion_handler),
+                ec, std::size_t{0}));
+        return init.result.get();
+    }
+
+    // complete when bytes available or closed
+    in_->op.reset(new read_op<BOOST_ASIO_HANDLER_TYPE(
+        ReadHandler, void(error_code, std::size_t)),
+            MutableBufferSequence>{*in_, buffers,
+                std::move(init.completion_handler)});
     return init.result.get();
 }
 
@@ -316,26 +471,31 @@ write_some(
     static_assert(net::is_const_buffer_sequence<
             ConstBufferSequence>::value,
         "ConstBufferSequence requirements not met");
+
+    ++in_->nwrite;
+
+    // connection closed
     auto out = out_.lock();
     if(! out)
     {
         ec = net::error::connection_reset;
         return 0;
     }
-    BOOST_ASSERT(out->code == status::ok);
+
+    // test failure
     if(in_->fc && in_->fc->fail(ec))
         return 0;
-    auto const n = std::min<std::size_t>(
+
+    // copy buffers
+    auto n = std::min<std::size_t>(
         buffer_size(buffers), in_->write_max);
-    std::unique_lock<std::mutex> lock{out->m};
-    auto const bytes_transferred =
-        net::buffer_copy(out->b.prepare(n), buffers);
-    out->b.commit(bytes_transferred);
-    out->on_write();
-    lock.unlock();
-    ++in_->nwrite;
-    ec = {};
-    return bytes_transferred;
+    {
+        std::lock_guard<std::mutex> lock(out->m);
+        n = net::buffer_copy(out->b.prepare(n), buffers);
+        out->b.commit(n);
+        out->notify_read();
+    }
+    return n;
 }
 
 template<class ConstBufferSequence, class WriteHandler>
@@ -350,6 +510,10 @@ async_write_some(ConstBufferSequence const& buffers,
         "ConstBufferSequence requirements not met");
     BOOST_BEAST_HANDLER_INIT(
         WriteHandler, void(error_code, std::size_t));
+
+    ++in_->nwrite;
+
+    // connection closed
     auto out = out_.lock();
     if(! out)
     {
@@ -358,49 +522,46 @@ async_write_some(ConstBufferSequence const& buffers,
             beast::bind_front_handler(
                 std::move(init.completion_handler),
                 net::error::connection_reset,
-                0));
+                std::size_t{0}));
+        return init.result.get();
     }
-    else
+
+    // test failure
+    error_code ec;
+    if(in_->fc && in_->fc->fail(ec))
     {
-        BOOST_ASSERT(out->code == status::ok);
-        error_code ec;
-        if(in_->fc && in_->fc->fail(ec))
-        {
-            net::post(
-                in_->ioc.get_executor(),
-                beast::bind_front_handler(
-                    std::move(init.completion_handler),
-                    ec,
-                    0));
-        }
-        else
-        {
-            auto const n = std::min<std::size_t>(
-                buffer_size(buffers), in_->write_max);
-            std::unique_lock<std::mutex> lock{out->m};
-            auto const bytes_transferred =
-                net::buffer_copy(out->b.prepare(n), buffers);
-            out->b.commit(bytes_transferred);
-            out->on_write();
-            lock.unlock();
-            ++in_->nwrite;
-            net::post(
-                in_->ioc.get_executor(),
-                beast::bind_front_handler(
-                    std::move(init.completion_handler),
-                    error_code{},
-                    bytes_transferred));
-        }
+        net::post(
+            in_->ioc.get_executor(),
+            beast::bind_front_handler(
+                std::move(init.completion_handler),
+                ec,
+                std::size_t{0}));
+        return init.result.get();
     }
 
+    // copy buffers
+    auto n = std::min<std::size_t>(
+        buffer_size(buffers), in_->write_max);
+    {
+        std::lock_guard<std::mutex> lock(out->m);
+        n = net::buffer_copy(out->b.prepare(n), buffers);
+        out->b.commit(n);
+        out->notify_read();
+    }
+    net::post(
+        in_->ioc.get_executor(),
+        beast::bind_front_handler(
+            std::move(init.completion_handler),
+            error_code{}, n));
+
     return init.result.get();
 }
 
 void
 teardown(
-websocket::role_type,
-stream& s,
-boost::system::error_code& ec)
+    websocket::role_type,
+    stream& s,
+    boost::system::error_code& ec)
 {
     if( s.in_->fc &&
         s.in_->fc->fail(ec))
@@ -412,15 +573,15 @@ boost::system::error_code& ec)
         s.in_->fc->fail(ec))
         ec = net::error::eof;
     else
-        ec = {};
+        ec.clear();
 }
 
 template<class TeardownHandler>
 void
 async_teardown(
-websocket::role_type,
-stream& s,
-TeardownHandler&& handler)
+    websocket::role_type,
+    stream& s,
+    TeardownHandler&& handler)
 {
     error_code ec;
     if( s.in_->fc &&
@@ -434,7 +595,7 @@ TeardownHandler&& handler)
         s.in_->fc->fail(ec))
         ec = net::error::eof;
     else
-        ec = {};
+        ec.clear();
 
     net::post(
         s.get_executor(),
@@ -442,95 +603,6 @@ TeardownHandler&& handler)
             std::move(handler), ec));
 }
 
-//------------------------------------------------------------------------------
-
-template<class Handler, class Buffers>
-class stream::read_op : public stream::read_op_base
-{
-    using ex1_type =
-        net::io_context::executor_type;
-    using ex2_type
-        = net::associated_executor_t<Handler, ex1_type>;
-
-    class lambda
-    {
-        state& s_;
-        Buffers b_;
-        Handler h_;
-        net::executor_work_guard<ex2_type> wg2_;
-
-    public:
-        lambda(lambda&&) = default;
-        lambda(lambda const&) = default;
-
-        template<class DeducedHandler>
-        lambda(state& s, Buffers const& b, DeducedHandler&& h)
-            : s_(s)
-            , b_(b)
-            , h_(std::forward<DeducedHandler>(h))
-            , wg2_(net::get_associated_executor(
-                h_, s_.ioc.get_executor()))
-        {
-        }
-
-        void
-        operator()()
-        {
-            std::unique_lock<std::mutex> lock{s_.m};
-            error_code ec;
-            std::size_t bytes_transferred = 0;
-            BOOST_ASSERT(! s_.op);
-            if(s_.b.size() > 0)
-            {
-                bytes_transferred =
-                    net::buffer_copy(
-                        b_, s_.b.data(), s_.read_max);
-                s_.b.consume(bytes_transferred);
-                ++s_.nread;
-            }
-            else
-            {
-                BOOST_ASSERT(s_.code != status::ok);
-                auto& s = s_;
-                ++s.nread;
-                if(s.code == status::eof)
-                    ec = net::error::eof;
-                else if(s.code == status::reset)
-                    ec = net::error::connection_reset;
-
-            }
-            lock.unlock();
-            auto alloc = net::get_associated_allocator(h_);
-            wg2_.get_executor().dispatch(
-                beast::bind_front_handler(
-                    std::move(h_),
-                    ec,
-                    bytes_transferred), alloc);
-            wg2_.reset();
-        }
-    };
-
-    lambda fn_;
-    net::executor_work_guard<ex1_type> wg1_;
-
-public:
-    template<class DeducedHandler>
-    read_op(state& s, Buffers const& b, DeducedHandler&& h)
-        : fn_(s, b, std::forward<DeducedHandler>(h))
-        , wg1_(s.ioc.get_executor())
-    {
-    }
-
-    void
-    operator()() override
-    {
-        net::post(
-            wg1_.get_executor(),
-            std::move(fn_));
-        wg1_.reset();
-    }
-};
-
 stream
 connect(stream& to)
 {

include/boost/beast/_experimental/test/stream.hpp

@@ -98,7 +98,7 @@ class stream
     struct read_op_base
     {
         virtual ~read_op_base() = default;
-        virtual void operator()() = 0;
+        virtual void operator()(bool cancel = false) = 0;
     };
 
     template<class Handler, class Buffers>
@@ -108,7 +108,6 @@ class stream
     {
         ok,
         eof,
-        reset
     };
 
     struct state
@@ -129,33 +128,16 @@ class stream
         std::size_t write_max =
             (std::numeric_limits<std::size_t>::max)();
 
-        ~state()
-        {
-            BOOST_ASSERT(! op);
-        }
-
+        BOOST_BEAST_DECL
         explicit
-        state(
-            net::io_context& ioc_,
-            fail_count* fc_)
-            : ioc(ioc_)
-            , fc(fc_)
-        {
-        }
+        state(net::io_context& ioc_, fail_count* fc_);
 
+        BOOST_BEAST_DECL
+        ~state();
+        
+        BOOST_BEAST_DECL
         void
-        on_write()
-        {
-            if(op)
-            {
-                std::unique_ptr<read_op_base> op_ = std::move(op);
-                op_->operator()();
-            }
-            else
-            {
-                cv.notify_all();
-            }
-        }
+        notify_read();
     };
 
     std::shared_ptr<state> in_;

test/beast/experimental/stream.cpp

@@ -9,3 +9,126 @@
 
 // Test that header file is self-contained.
 #include <boost/beast/_experimental/test/stream.hpp>
+
+#include <boost/beast/_experimental/unit_test/suite.hpp>
+
+namespace boost {
+namespace beast {
+
+class test_stream_test
+    : public unit_test::suite
+{
+public:
+    void
+    testTestStream()
+    {
+        net::io_context ioc;
+        char buf[1] = {};
+        net::mutable_buffer m0;
+        net::mutable_buffer m1(buf, sizeof(buf));
+
+        {
+            {
+                test::stream ts(ioc);
+            }
+            {
+                test::stream ts(ioc);
+                ts.close();
+            }
+            {
+                test::stream t1(ioc);
+                auto t2 = connect(t1);
+            }
+            {
+                test::stream t1(ioc);
+                auto t2 = connect(t1);
+                t2.close();
+            }
+            {
+#if 0
+                test::stream ts(ioc);
+                error_code ec;
+                ts.read_some(net::mutable_buffer{}, ec);
+                log << ec.message();
+#endif
+            }
+            {
+                error_code ec;
+                {
+                    test::stream ts(ioc);
+                    ts.async_read_some(m1,
+                        [&](error_code ec_, std::size_t)
+                        {
+                            ec = ec_;
+                        });
+                }
+                ioc.run();
+                ioc.restart();
+                BEAST_EXPECTS(
+                    //ec == net::error::eof,
+                    ec == net::error::operation_aborted,
+                    ec.message());
+            }
+            {
+                error_code ec;
+                test::stream ts(ioc);
+                ts.async_read_some(m1,
+                    [&](error_code ec_, std::size_t)
+                    {
+                        ec = ec_;
+                    });
+                ts.close(); 
+                ioc.run();
+                ioc.restart();
+                BEAST_EXPECTS(
+                    //ec == net::error::eof,
+                    ec == net::error::operation_aborted,
+                    ec.message());
+            }
+            {
+                error_code ec;
+                test::stream t1(ioc);
+                auto t2 = connect(t1);
+                t1.async_read_some(m1,
+                    [&](error_code ec_, std::size_t)
+                    {
+                        ec = ec_;
+                    });
+                t2.close();
+                ioc.run();
+                ioc.restart();
+                BEAST_EXPECTS(
+                    ec == net::error::eof,
+                    ec.message());
+            }
+            {
+                error_code ec;
+                test::stream t1(ioc);
+                auto t2 = connect(t1);
+                t1.async_read_some(m1,
+                    [&](error_code ec_, std::size_t)
+                    {
+                        ec = ec_;
+                    });
+                t1.close();
+                ioc.run();
+                ioc.restart();
+                BEAST_EXPECTS(
+                    ec == net::error::operation_aborted,
+                    ec.message());
+            }
+        }
+    }
+
+    void
+    run() override
+    {
+        testTestStream();
+        pass();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(beast,test,test_stream);
+
+} // beast
+} // boost