CURLOPT_MAXAGE_CONN: set the maximum allowed age for conn reuse

... and disconnect too old ones instead of trying to reuse.

Default max age is set to 118 seconds.

Ref: #3722
Closes #3782

1 files changed, 22 insertions, 1 deletions

diff --git a/lib/url.c b/lib/url.c
index 8aefd1583..ad8aa6996 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -541,6 +541,7 @@ CURLcode Curl_init_userdefined(struct Curl_easy *data)
   set->fnmatch = ZERO_NULL;
   set->upkeep_interval_ms = CURL_UPKEEP_INTERVAL_DEFAULT;
   set->maxconnects = DEFAULT_CONNCACHE_SIZE; /* for easy handles */
+  set->maxage_conn = 118;
   set->http09_allowed = TRUE;
   set->httpversion =
 #ifdef USE_NGHTTP2
@@ -958,6 +959,25 @@ static void prune_dead_connections(struct Curl_easy *data)
   }
 }
 
+/* A connection has to have been idle for a shorter time than 'maxage_conn' to
+   be subject for reuse. The success rate is just too low after this. */
+
+static bool conn_maxage(struct Curl_easy *data,
+                        struct connectdata *conn,
+                        struct curltime now)
+{
+  if(!conn->data) {
+    timediff_t idletime = Curl_timediff(now, conn->lastused);
+    idletime /= 1000; /* integer seconds is fine */
+
+    if(idletime/1000 > data->set.maxage_conn) {
+      infof(data, "Too old connection (%ld seconds), disconnect it\n",
+            idletime);
+      return TRUE;
+    }
+  }
+  return FALSE;
+}
 /*
  * Given one filled in connection struct (named needle), this function should
  * detect if there already is one that has all the significant details
@@ -981,6 +1001,7 @@ ConnectionExists(struct Curl_easy *data,
   bool foundPendingCandidate = FALSE;
   bool canmultiplex = IsMultiplexingPossible(data, needle);
   struct connectbundle *bundle;
+  struct curltime now = Curl_now();
 
 #ifdef USE_NTLM
   bool wantNTLMhttp = ((data->state.authhost.want &
@@ -1044,7 +1065,7 @@ ConnectionExists(struct Curl_easy *data,
         /* connect-only connections will not be reused */
         continue;
 
-      if(extract_if_dead(check, data)) {
+      if(conn_maxage(data, check, now) || extract_if_dead(check, data)) {
         /* disconnect it */
         (void)Curl_disconnect(data, check, /* dead_connection */TRUE);
         continue;