io_object: move execution context to base class

- Add ctx_ member and context() accessor to io_object
- Add explicit constructor taking execution_context&
- Update io_stream to derive with context parameter
- Update socket, acceptor, wolfssl_stream to use base class
- Move io_stream_impl to public section for visibility

Author: vinniefalco

include/boost/corosio/acceptor.hpp

@@ -154,7 +154,7 @@ class acceptor : public io_object
         @param other The acceptor to move from.
     */
     acceptor(acceptor&& other) noexcept
-        : ctx_(other.ctx_)
+        : io_object(other.context())
     {
         impl_ = other.impl_;
         other.impl_ = nullptr;

include/boost/corosio/io_object.hpp

@@ -11,6 +11,7 @@
 #define BOOST_COROSIO_IO_OBJECT_HPP
 
 #include <boost/corosio/detail/config.hpp>
+#include <boost/capy/execution_context.hpp>
 
 namespace boost {
 namespace corosio {
@@ -40,10 +41,28 @@ class io_object
         virtual void release() = 0;
     };
 
+    /** Return the execution context.
+
+        @return Reference to the execution context that owns this socket.
+    */
+    auto
+    context() const noexcept ->
+        capy::execution_context&
+    {
+        return *ctx_;
+    }
+
 protected:
     virtual ~io_object() = default;
-    io_object() = default;
-    
+
+    explicit
+    io_object(
+        capy::execution_context& ctx) noexcept
+        : ctx_(&ctx)
+    {
+    }
+
+    capy::execution_context* ctx_ = nullptr;
     io_object_impl* impl_ = nullptr;
 };
 

include/boost/corosio/io_stream.hpp

@@ -27,25 +27,6 @@ namespace corosio {
 class io_stream : public io_object
 {
 public:
-    struct io_stream_impl : io_object_impl
-    {
-        virtual void read_some(
-            std::coroutine_handle<>,
-            capy::any_dispatcher,
-            any_bufref&,
-            std::stop_token,
-            system::error_code*,
-            std::size_t*) = 0;
-
-        virtual void write_some(
-            std::coroutine_handle<>,
-            capy::any_dispatcher,
-            any_bufref&,
-            std::stop_token,
-            system::error_code*,
-            std::size_t*) = 0;
-    };
-
     /** Initiate an asynchronous read operation.
 
         Reads available data into the provided buffer sequence. The
@@ -213,6 +194,34 @@ class io_stream : public io_object
         }
     };
 
+public:
+    struct io_stream_impl : io_object_impl
+    {
+        virtual void read_some(
+            std::coroutine_handle<>,
+            capy::any_dispatcher,
+            any_bufref&,
+            std::stop_token,
+            system::error_code*,
+            std::size_t*) = 0;
+
+        virtual void write_some(
+            std::coroutine_handle<>,
+            capy::any_dispatcher,
+            any_bufref&,
+            std::stop_token,
+            system::error_code*,
+            std::size_t*) = 0;
+    };
+
+protected:
+    explicit
+    io_stream(
+        capy::execution_context& ctx) noexcept
+        : io_object(ctx)
+    {
+    }
+
 private:
     io_stream_impl& get() const noexcept
     {

include/boost/corosio/socket.hpp

@@ -72,6 +72,26 @@ namespace corosio {
 */
 class socket : public io_stream
 {
+    friend class acceptor;
+
+    struct socket_impl;
+
+    inline socket_impl& get() const noexcept
+    {
+        return *static_cast<socket_impl*>(impl_);
+    }
+
+public:
+    struct socket_impl : io_stream_impl
+    {
+        virtual void connect(
+            std::coroutine_handle<>,
+            capy::any_dispatcher,
+            endpoint,
+            std::stop_token,
+            system::error_code*) = 0;
+    };
+
     struct connect_awaitable
     {
         socket& s_;
@@ -154,7 +174,7 @@ class socket : public io_stream
         @param other The socket to move from.
     */
     socket(socket&& other) noexcept
-        : ctx_(other.ctx_)
+        : io_stream(other.context())
     {
         impl_ = other.impl_;
         other.impl_ = nullptr;
@@ -261,37 +281,6 @@ class socket : public io_stream
     */
     BOOST_COROSIO_DECL
     void cancel();
-
-    /** Return the execution context.
-
-        @return Reference to the execution context that owns this socket.
-    */
-    auto
-    context() const noexcept ->
-        capy::execution_context&
-    {
-        return *ctx_;
-    }
-
-    struct socket_impl : io_stream_impl
-    {
-        virtual void connect(
-            std::coroutine_handle<>,
-            capy::any_dispatcher,
-            endpoint,
-            std::stop_token,
-            system::error_code*) = 0;
-    };
-    
-private:
-    friend class acceptor;
-
-    inline socket_impl& get() const noexcept
-    {
-        return *static_cast<socket_impl*>(impl_);
-    }
-
-    capy::execution_context* ctx_;
 };
 
 } // namespace corosio

src/src/acceptor.cpp

@@ -39,7 +39,7 @@ acceptor::
 acceptor::
 acceptor(
     capy::execution_context& ctx)
-    : ctx_(&ctx)
+    : io_object(ctx)
 {
 }
 

src/src/detail/win_iocp_sockets.hpp

@@ -95,19 +95,22 @@ class win_socket_impl
     explicit win_socket_impl(win_iocp_sockets& svc) noexcept;
 
     void release() override;
+
     void connect(
         std::coroutine_handle<>,
         capy::any_dispatcher,
         endpoint,
         std::stop_token,
         system::error_code*) override;
+
     void read_some(
         std::coroutine_handle<>,
         capy::any_dispatcher,
         any_bufref&,
         std::stop_token,
         system::error_code*,
         std::size_t*) override;
+
     void write_some(
         std::coroutine_handle<>,
         capy::any_dispatcher,
@@ -150,6 +153,7 @@ class win_acceptor_impl
     explicit win_acceptor_impl(win_iocp_sockets& svc) noexcept;
 
     void release() override;
+
     void accept(
         std::coroutine_handle<>,
         capy::any_dispatcher,

src/src/socket.cpp

@@ -39,7 +39,7 @@ socket::
 socket::
 socket(
     capy::execution_context& ctx)
-    : ctx_(&ctx)
+    : io_stream(ctx)
 {
 }
 

src/wolfssl/src/wolfssl_stream.cpp

@@ -678,7 +678,8 @@ struct wolfssl_stream_impl_
 
 wolfssl_stream::
 wolfssl_stream(io_stream& stream)
-    : s_(stream)
+    : io_stream(stream.context())
+    , s_(stream)
 {
     construct();
 }