network plugin: Make the receive thread even faster.

[collectd.git] / src / network.c

diff --git a/src/network.c b/src/network.c
index 9e391bb..34f89d9 100644 (file)
--- a/src/network.c
+++ b/src/network.c
@@ -1279,6 +1279,9 @@ static int network_receive (void)
        int i;
        int status;
 
+       receive_list_entry_t *private_list_head;
+       receive_list_entry_t *private_list_tail;
+
        if (listen_sockets_num == 0)
                network_add_listen_socket (NULL, NULL);
 
@@ -1288,6 +1291,9 @@ static int network_receive (void)
                return (-1);
        }
 
+       private_list_head = NULL;
+       private_list_tail = NULL;
+
        while (listen_loop == 0)
        {
                status = poll (listen_sockets, listen_sockets_num, -1);
@@ -1328,7 +1334,8 @@ static int network_receive (void)
                                ERROR ("network plugin: malloc failed.");
                                return (-1);
                        }
-                       memset (ent, '\0', sizeof (receive_list_entry_t));
+                       memset (ent, 0, sizeof (receive_list_entry_t));
+                       ent->next = NULL;
 
                        /* Hopefully this be optimized out by the compiler. It
                         * might help prevent stupid bugs in the future though.
@@ -1338,22 +1345,49 @@ static int network_receive (void)
                        memcpy (ent->data, buffer, buffer_len);
                        ent->data_len = buffer_len;
 
-                       pthread_mutex_lock (&receive_list_lock);
-                       if (receive_list_head == NULL)
-                       {
-                               receive_list_head = ent;
-                               receive_list_tail = ent;
-                       }
+                       if (private_list_head == NULL)
+                               private_list_head = ent;
                        else
+                               private_list_tail->next = ent;
+                       private_list_tail = ent;
+
+                       /* Do not block here. Blocking here has led to
+                        * insufficient performance in the past. */
+                       if (pthread_mutex_trylock (&receive_list_lock) == 0)
                        {
-                               receive_list_tail->next = ent;
-                               receive_list_tail = ent;
+                               if (receive_list_head == NULL)
+                                       receive_list_head = private_list_head;
+                               else
+                                       receive_list_tail->next = private_list_head;
+                               receive_list_tail = private_list_tail;
+
+                               private_list_head = NULL;
+                               private_list_tail = NULL;
+
+                               pthread_cond_signal (&receive_list_cond);
+                               pthread_mutex_unlock (&receive_list_lock);
                        }
-                       pthread_cond_signal (&receive_list_cond);
-                       pthread_mutex_unlock (&receive_list_lock);
                } /* for (listen_sockets) */
        } /* while (listen_loop == 0) */
 
+       /* Make sure everything is dispatched before exiting. */
+       if (private_list_head != NULL)
+       {
+               pthread_mutex_lock (&receive_list_lock);
+
+               if (receive_list_head == NULL)
+                       receive_list_head = private_list_head;
+               else
+                       receive_list_tail->next = private_list_head;
+               receive_list_tail = private_list_tail;
+
+               private_list_head = NULL;
+               private_list_tail = NULL;
+
+               pthread_cond_signal (&receive_list_cond);
+               pthread_mutex_unlock (&receive_list_lock);
+       }
+
        return (0);
 }