Adding upstream version 2.2.0.upstream/2.2.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 78 insertions, 0 deletions

diff --git a/src/lib/http/connection_pool.h b/src/lib/http/connection_pool.h
new file mode 100644
index 0000000..a9110bc
--- /dev/null
+++ b/src/lib/http/connection_pool.h
@@ -0,0 +1,78 @@
+// Copyright (C) 2017-2021 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 HTTP_CONNECTION_POOL_H
+#define HTTP_CONNECTION_POOL_H
+
+#include <http/connection.h>
+
+#include <list>
+#include <mutex>
+
+namespace isc {
+namespace http {
+
+/// @brief Pool of active HTTP connections.
+///
+/// The HTTP 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 HttpConnectionPool {
+public:
+
+    /// @brief Start new connection.
+    ///
+    /// The connection is inserted to the pool and the
+    /// @ref HttpConnection::asyncAccept is invoked.
+    ///
+    /// @param connection Pointer to the new connection.
+    void start(const HttpConnectionPtr& 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 HttpConnectionPtr& connection);
+
+    /// @brief Removes a connection from the pool and stops it.
+    ///
+    /// @param connection Pointer to the connection.
+    void stop(const HttpConnectionPtr& connection);
+
+    /// @brief Stops all connections and removes them from the pool.
+    void stopAll();
+
+protected:
+
+    /// @brief Stops all connections and removes them from the pool.
+    ///
+    /// Must be called from with a thread-safe context.
+    void stopAllInternal();
+
+    /// @brief Set of connections.
+    std::list<HttpConnectionPtr> connections_;
+
+    /// @brief Mutex to protect the internal state.
+    std::mutex mutex_;
+};
+
+}
+}
+
+#endif
+