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diff --git a/src/lib/tcp/tcp_connection_pool.h b/src/lib/tcp/tcp_connection_pool.h
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+++ b/src/lib/tcp/tcp_connection_pool.h
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+// Copyright (C) 2022 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef TCP_CONNECTION_POOL_H
+#define TCP_CONNECTION_POOL_H
+
+#include <tcp/tcp_connection.h>
+
+#include <list>
+#include <mutex>
+
+namespace isc {
+namespace tcp {
+
+/// @brief Type of TCP connection pointer list.
+typedef std::list<TcpConnectionPtr> TcpConnectionList;
+
+/// @brief Pool of active TCP connections.
+///
+/// The TCP server is designed to handle many connections simultaneously.
+/// The communication between the client and the server may take long time
+/// and the server must be able to react on other events while the communication
+/// with the clients is in progress. Thus, the server must track active
+/// connections and gracefully close them when needed. An obvious case when the
+/// connections must be terminated by the server is when the shutdown signal
+/// is received.
+///
+/// This object is a simple container for the server connections which provides
+/// means to terminate them on request.
+class TcpConnectionPool {
+public:
+
+    /// @brief Start new connection.
+    ///
+    /// The connection is inserted to the pool and the
+    /// @ref TcpConnection::asyncAccept is invoked.
+    ///
+    /// @param connection Pointer to the new connection.
+    void start(const TcpConnectionPtr& connection);
+
+    /// @brief Removes a connection from the pool and shutdown it.
+    ///
+    /// Shutdown is specific to TLS and is a first part of graceful close
+    /// (note it is NOT the same as TCP shutdown system call).
+    ///
+    /// @note if the TLS connection stalls e.g. the peer does not try I/O
+    /// on it the connection has to be explicitly stopped.
+    ///
+    /// @param connection Pointer to the connection.
+    void shutdown(const TcpConnectionPtr& connection);
+
+    /// @brief Removes a connection from the pool and stops it.
+    ///
+    /// @param connection Pointer to the connection.
+    void stop(const TcpConnectionPtr& connection);
+
+    /// @brief Stops all connections and removes them from the pool.
+    ///
+    /// @note This function is not thread-safe so should be called
+    /// when the thread pool is stopped.
+    void stopAll();
+
+    /// @brief Returns the number of connections using a given remote IP address.
+    ///
+    /// Used to limit the number of connections when accepting a new one.
+    ///
+    /// @param remote_ip The remote IP address.
+    /// @param[out] total_connections Size of the connection pool.
+    /// @return The number of connections using a given remote IP address.
+    size_t usedByRemoteIp(const asiolink::IOAddress& remote_ip,
+                          size_t& total_connections);
+
+    /// @brief Class/static started (i.e. added to pool) connection counter.
+    static std::atomic<uint64_t> started_counter_;
+
+    /// @brief Class/static stopped (i.e. removed from pool) connection counter.
+    static std::atomic<uint64_t> stopped_counter_;
+
+    /// @brief Class/static rejected (by the accept filter) connection counter.
+    static std::atomic<uint64_t> rejected_counter_;
+
+protected:
+
+    /// @brief Stops all connections and removes them from the pool.
+    ///
+    /// Must be called from with a thread-safe context.
+    void stopAllInternal();
+
+    /// @brief Returns the number of connections using a given remote IP address.
+    ///
+    /// Used to limit the number of connections when accepting a new one.
+    /// Must be called from with a thread-safe context.
+    ///
+    /// @param remote_ip The remote IP address.
+    /// @param[out] total_connections Size of the connection pool.
+    /// @return The number of connections using a given remote IP address.
+    size_t usedByRemoteIpInternal(const asiolink::IOAddress& remote_ip,
+                                  size_t& total_connections);
+
+    /// @brief Set of connections.
+    TcpConnectionList connections_;
+
+    /// @brief Mutex to protect the internal state.
+    std::mutex mutex_;
+};
+
+}
+}
+
+#endif