tcp-handler: store max TCP clients configuration to handler context

diff --git a/src/knot/server/tcp-handler.c b/src/knot/server/tcp-handler.c
index e31039781c38a7ee6077b4a8593e949452cdcc1d..dabb8e33b8d319ddb0e0f8018c359f8ac499661b 100644 (file)
--- a/src/knot/server/tcp-handler.c
+++ b/src/knot/server/tcp-handler.c
@@ -51,10 +51,19 @@ typedef struct tcp_context {
        bool is_throttled;               /*!< TCP connections throttling switch. */
        fdset_t set;                     /*!< Set of server/client sockets. */
        unsigned thread_id;              /*!< Thread identifier. */
+       unsigned max_clients;            /*!< Max TCP clients per worker configuration. */
 } tcp_context_t;
 
 #define TCP_SWEEP_INTERVAL 2 /*!< [secs] granularity of connection sweeping. */
 
+static void update_tcp_conf(tcp_context_t *tcp)
+{
+       rcu_read_lock();
+       unsigned clients = conf()->cache.srv_max_tcp_clients;
+       tcp->max_clients = MAX(clients / conf_tcp_threads(conf()), 1);
+       rcu_read_unlock();
+}
+
 /*! \brief Sweep TCP connection. */
 static enum fdset_sweep_state tcp_sweep(fdset_t *set, int i, void *data)
 {
@@ -226,13 +235,8 @@ static int tcp_wait_for_events(tcp_context_t *tcp)
 {
        fdset_t *set = &tcp->set;
 
-       /* Configuration limit, infer maximal pool size. */
-       rcu_read_lock();
-       int clients = conf()->cache.srv_max_tcp_clients;
-       unsigned max_per_set = MAX(clients / conf_tcp_threads(conf()), 1);
-       rcu_read_unlock();
-       /* Subtract master sockets check limits. */
-       tcp->is_throttled = (set->n - tcp->client_threshold) >= max_per_set;
+       /* Check if throttled with many open TCP connections. */
+       tcp->is_throttled = (set->n - tcp->client_threshold) >= tcp->max_clients;
 
        /* If throttled, temporarily ignore new TCP connections. */
        unsigned i = tcp->is_throttled ? tcp->client_threshold : 0;
@@ -310,9 +314,10 @@ int tcp_master(dthread_t *thread)
                }
        }
 
-       /* Initialize sweep interval. */
+       /* Initialize sweep interval and TCP configuration. */
        struct timespec next_sweep = time_now();
        next_sweep.tv_sec += TCP_SWEEP_INTERVAL;
+       update_tcp_conf(&tcp);
 
        for(;;) {
 
@@ -342,11 +347,12 @@ int tcp_master(dthread_t *thread)
                /* Serve client requests. */
                tcp_wait_for_events(&tcp);
 
-               /* Sweep inactive clients. */
+               /* Sweep inactive clients and refresh TCP configuration. */
                if (tcp.last_poll_time.tv_sec >= next_sweep.tv_sec) {
                        fdset_sweep(&tcp.set, &tcp_sweep, NULL);
                        next_sweep = time_now();
                        next_sweep.tv_sec += TCP_SWEEP_INTERVAL;
+                       update_tcp_conf(&tcp);
                }
        }