Finish std::shared_ptr -> Ref migration

src/connection.cpp

@@ -38,10 +38,14 @@ static thread_local std::vector<struct iovec> g_iovec_buffer{IOV_MAX};
 
 Connection::Connection(struct sockaddr_storage addr, int fd, int64_t id,
                        size_t epoll_index, ConnectionHandler *handler,
-                       Server &server)
+                       WeakRef<Server> server)
     : fd_(fd), id_(id), epoll_index_(epoll_index), addr_(addr), arena_(),
-      handler_(handler), server_(server.weak_from_this()) {
-  server.active_connections_.fetch_add(1, std::memory_order_relaxed);
+      handler_(handler), server_(std::move(server)) {
+  auto server_ref = server_.lock();
+  // This should only be called from a member of Server itself, so I should
+  // hope it's alive.
+  assert(server_ref);
+  server_ref->active_connections_.fetch_add(1, std::memory_order_relaxed);
 
   // Increment connection metrics using thread-local instances
   connections_total.inc();
@@ -55,6 +59,7 @@ Connection::~Connection() {
   if (handler_) {
     handler_->on_connection_closed(*this);
   }
+  // Server may legitimately be gone now
   if (auto server_ptr = server_.lock()) {
     server_ptr->active_connections_.fetch_sub(1, std::memory_order_relaxed);
   }

src/connection.hpp

@@ -3,13 +3,13 @@
 #include <cassert>
 #include <cstring>
 #include <deque>
-#include <memory>
 #include <sys/socket.h>
 #include <sys/uio.h>
 #include <unistd.h>
 
 #include "arena.hpp"
 #include "connection_handler.hpp"
+#include "reference.hpp"
 
 #ifndef __has_feature
 #define __has_feature(x) 0
@@ -330,7 +330,8 @@ private:
    * @param server Reference to server associated with this connection
    */
   Connection(struct sockaddr_storage addr, int fd, int64_t id,
-             size_t epoll_index, ConnectionHandler *handler, Server &server);
+             size_t epoll_index, ConnectionHandler *handler,
+             WeakRef<Server> server);
 
   // Networking interface - only accessible by Server
   int readBytes(char *buf, size_t buffer_size);
@@ -347,7 +348,7 @@ private:
   struct sockaddr_storage addr_; // sockaddr_storage handles IPv4/IPv6
   Arena arena_;
   ConnectionHandler *handler_;
-  std::weak_ptr<Server> server_; // Weak reference to server for safe cleanup
+  WeakRef<Server> server_; // Weak reference to server for safe cleanup
 
   std::deque<std::string_view, ArenaStlAllocator<std::string_view>> messages_{
       ArenaStlAllocator<std::string_view>{&arena_}};

src/reference.hpp

@@ -318,7 +318,7 @@ template <typename T> struct WeakRef {
    * @brief Attempt to promote WeakRef to Ref
    * @return Valid Ref if object still alive, empty Ref otherwise
    */
-  Ref<T> lock() {
+  Ref<T> lock() const {
     if (!control_block) {
       return Ref<T>();
     }

src/server.cpp

@@ -21,12 +21,12 @@
 // Static thread-local storage for read buffer (used across different functions)
 static thread_local std::vector<char> g_read_buffer;
 
-std::shared_ptr<Server> Server::create(const weaseldb::Config &config,
+Ref<Server> Server::create(const weaseldb::Config &config,
                            ConnectionHandler &handler,
                            const std::vector<int> &listen_fds) {
-  // Use std::shared_ptr constructor with private access
-  // We can't use make_shared here because constructor is private
-  return std::shared_ptr<Server>(new Server(config, handler, listen_fds));
+  auto result = make_ref<Server>(config, handler, listen_fds);
+  result->self_ = result;
+  return result;
 }
 
 Server::Server(const weaseldb::Config &config, ConnectionHandler &handler,
@@ -218,7 +218,7 @@ int Server::create_local_connection() {
   // Create Connection object
   auto connection = std::unique_ptr<Connection>(new Connection(
       addr, server_fd, connection_id_.fetch_add(1, std::memory_order_relaxed),
-      epoll_index, &handler_, *this));
+      epoll_index, &handler_, self_));
 
   // Store in registry
   connection_registry_.store(server_fd, std::move(connection));
@@ -422,7 +422,7 @@ void Server::start_io_threads(std::vector<std::thread> &threads) {
             batch[batch_count] = std::unique_ptr<Connection>(new Connection(
                 addr, fd,
                 connection_id_.fetch_add(1, std::memory_order_relaxed),
-                epoll_index, &handler_, *this));
+                epoll_index, &handler_, self_));
             batch_events[batch_count] =
                 EPOLLIN; // New connections always start with read
             batch_count++;

src/server.hpp

@@ -29,18 +29,18 @@
  *
  * IMPORTANT: Server uses a factory pattern and MUST be created via
  * Server::create(). This ensures:
- * - Proper shared_ptr semantics for enable_shared_from_this
- * - Safe weak_ptr references from Connection objects
+ * - Proper Ref<Server> semantics for reference counting
+ * - Safe WeakRef<Server> references from Connection objects
  * - Prevention of accidental stack allocation that would break safety
  * guarantees
  */
-struct Server : std::enable_shared_from_this<Server> {
+struct Server {
   /**
    * Factory method to create a Server instance.
    *
-   * This is the only way to create a Server - ensures proper shared_ptr
+   * This is the only way to create a Server - ensures proper Ref<Server>
    * semantics and prevents accidental stack allocation that would break
-   * weak_ptr safety.
+   * WeakRef<Server> safety.
    *
    * @param config Server configuration (threads, ports, limits, etc.)
    * @param handler Protocol handler for processing connection data
@@ -48,9 +48,9 @@ struct Server : std::enable_shared_from_this<Server> {
    *                   Server takes ownership and will close them on
    * destruction. Server will set these to non-blocking mode for safe epoll
    * usage. Empty vector means no listening sockets.
-   * @return shared_ptr to the newly created Server
+   * @return Ref to the newly created Server
    */
-  static std::shared_ptr<Server> create(const weaseldb::Config &config,
+  static Ref<Server> create(const weaseldb::Config &config,
                             ConnectionHandler &handler,
                             const std::vector<int> &listen_fds);
 
@@ -122,6 +122,10 @@ private:
    */
   explicit Server(const weaseldb::Config &config, ConnectionHandler &handler,
                   const std::vector<int> &listen_fds);
+  friend Ref<Server> make_ref<Server>(const weaseldb::Config &config,
+                                      ConnectionHandler &handler,
+                                      const std::vector<int> &listen_fds);
+  WeakRef<Server> self_;
 
   const weaseldb::Config &config_;
   ConnectionHandler &handler_;