[core] clear request,connection pools every 64 sec (#3084)

x-ref:
  "Memory fragmentation with HTTP/2 enabled"
  https://redmine.lighttpd.net/issues/3084

src/connections.c

@@ -57,8 +57,6 @@ static connection *connections_get_new_connection(server *srv) {
     else {
         con = connection_init(srv);
         connection_reset(con);
-        if (srv->srvconf.h2proto)
-            request_pool_extend(srv, 8);
     }
     /*con->prev = NULL;*//*(already set)*/
     if ((con->next = srv->conns))

src/reqpool.c

@@ -232,21 +232,6 @@ request_free_data (request_st * const r)
 
 /* linked list of (request_st *) cached for reuse */
 static request_st *reqpool;
-/* max num of (request_st *) to cache */
-static uint32_t reqspace;
-
-
-void
-request_pool_extend (server *srv, const uint32_t sz)
-{
-    for (uint32_t i = 0; i < sz; ++i) {
-        request_st * const x = calloc(1, sizeof(request_st));
-        force_assert(x);
-        request_init_data(x, NULL, srv);
-        x->con = (connection *)reqpool; /*(reuse r->con as next ptr)*/
-        reqpool = x;
-    }
-}
 
 
 void
@@ -257,7 +242,6 @@ request_pool_free (void)
         reqpool = (request_st *)r->con; /*(reuse r->con as next ptr)*/
         request_free_data(r);
         free(r);
-        ++reqspace;
     }
 }
 
@@ -279,15 +263,8 @@ request_release (request_st * const r)
     request_reset_ex(r);
     r->state = CON_STATE_CONNECT;
 
-    if (reqspace) {
-        --reqspace;
-        r->con = (connection *)reqpool; /*(reuse r->con as next ptr)*/
-        reqpool = r;
-    }
-    else {
-        request_free_data(r);
-        free(r);
-    }
+    r->con = (connection *)reqpool; /*(reuse r->con as next ptr)*/
+    reqpool = r;
 }
 
 
@@ -297,7 +274,6 @@ request_acquire (connection * const con)
     request_st *r = reqpool;
     if (r) {
         reqpool = (request_st *)r->con; /*(reuse r->con as next ptr)*/
-        ++reqspace;
     }
     else {
         r = calloc(1, sizeof(request_st));

src/reqpool.h

@@ -22,9 +22,6 @@ request_st * request_acquire (connection *con);
 __attribute_cold__
 void request_free_data (request_st *r);
 
-__attribute_cold__
-void request_pool_extend (server *srv, uint32_t sz);
-
 __attribute_cold__
 void request_pool_free (void);
 

src/server.c

@@ -1882,6 +1882,9 @@ static void server_handle_sigalrm (server * const srv, unix_time64_t mono_ts, un
 				if (0 == (mono_ts & 0x3f)) { /*(once every 64 secs)*/
 					/* free excess chunkqueue buffers every 64 secs */
 					chunkqueue_chunk_pool_clear();
+					/* clear request and connection pools every 64 secs */
+					request_pool_free();
+					connections_pool_clear(srv);
 					/* attempt to restart dead piped loggers every 64 secs */
 					if (0 == srv->srvconf.max_worker)
 						fdevent_restart_logger_pipes(mono_ts);