/* * Copyright (c) 2019-Present, Redis Ltd. * All rights reserved. * * Licensed under your choice of the Redis Source Available License 2.0 * (RSALv2) or the Server Side Public License v1 (SSPLv1). */ #ifndef __REDIS_CONNHELPERS_H #define __REDIS_CONNHELPERS_H #include "connection.h" /* These are helper functions that are common to different connection * implementations (currently sockets in connection.c and TLS in tls.c). * * Currently helpers implement the mechanisms for invoking connection * handlers and tracking connection references, to allow safe destruction * of connections from within a handler. */ /* Increment connection references. * * Inside a connection handler, we guarantee refs >= 1 so it is always * safe to connClose(). * * In other cases where we don't want to prematurely lose the connection, * it can go beyond 1 as well; currently it is only done by connAccept(). */ static inline void connIncrRefs(connection *conn) { conn->refs++; } /* Decrement connection references. * * Note that this is not intended to provide any automatic free logic! * callHandler() takes care of that for the common flows, and anywhere an * explicit connIncrRefs() is used, the caller is expected to take care of * that. */ static inline void connDecrRefs(connection *conn) { conn->refs--; } static inline int connHasRefs(connection *conn) { return conn->refs; } /* Helper for connection implementations to call handlers: * 1. Increment refs to protect the connection. * 2. Execute the handler (if set). * 3. Decrement refs and perform deferred close, if refs==0. */ static inline int callHandler(connection *conn, ConnectionCallbackFunc handler) { connIncrRefs(conn); if (handler) handler(conn); connDecrRefs(conn); if (conn->flags & CONN_FLAG_CLOSE_SCHEDULED) { if (!connHasRefs(conn)) connClose(conn); return 0; } return 1; } #endif /* __REDIS_CONNHELPERS_H */