bundles: store no/default/pipeline/multiplex

to allow code to act differently on the situation.

Also added some more info message for the connection re-use function to
make it clearer when connections are not re-used.

lib/conncache.c

@@ -56,7 +56,7 @@ static CURLcode bundle_create(struct SessionHandle *data,
     return CURLE_OUT_OF_MEMORY;
 
   (*cb_ptr)->num_connections = 0;
-  (*cb_ptr)->server_supports_pipelining = FALSE;
+  (*cb_ptr)->multiuse = BUNDLE_UNKNOWN;
 
   (*cb_ptr)->conn_list = Curl_llist_alloc((curl_llist_dtor) conn_llist_dtor);
   if(!(*cb_ptr)->conn_list) {
@@ -205,10 +205,8 @@ CURLcode Curl_conncache_add_conn(struct conncache *connc,
       return result;
 
     key = hashkey(conn);
-    if(!key) {
-      bundle_destroy(new_bundle);
+    if(!key)
       return CURLE_OUT_OF_MEMORY;
-    }
 
     rc = conncache_add_bundle(data->state.conn_cache, key, new_bundle);
     free(key);

lib/conncache.h

@@ -30,9 +30,13 @@ struct conncache {
   struct timeval last_cleanup;
 };
 
+#define BUNDLE_NO_MULTIUSE -1
+#define BUNDLE_UNKNOWN     0  /* initial value */
+#define BUNDLE_PIPELINING  1
+#define BUNDLE_MULTIPLEX   2
+
 struct connectbundle {
-  bool server_supports_pipelining; /* TRUE if server supports pipelining,
-                                      set after first response */
+  int multiuse;                 /* supports multi-use */
   size_t num_connections;       /* Number of connections in the bundle */
   struct curl_llist *conn_list; /* The connectdata members of the bundle */
 };

lib/http.c

@@ -3375,7 +3375,7 @@ CURLcode Curl_http_readwrite_headers(struct SessionHandle *data,
 
           /* HTTP/2 cannot blacklist multiplexing since it is a core
              functionality of the protocol */
-          conn->bundle->server_supports_pipelining = TRUE;
+          conn->bundle->multiuse = BUNDLE_MULTIPLEX;
         }
         else if(conn->httpversion >= 11 &&
                 !conn->bits.close) {
@@ -3390,7 +3390,7 @@ CURLcode Curl_http_readwrite_headers(struct SessionHandle *data,
           cb_ptr = conn->bundle;
           if(cb_ptr) {
             if(!Curl_pipeline_site_blacklisted(data, conn))
-              cb_ptr->server_supports_pipelining = TRUE;
+              cb_ptr->multiuse = BUNDLE_PIPELINING;
           }
         }
 
@@ -3474,9 +3474,9 @@ CURLcode Curl_http_readwrite_headers(struct SessionHandle *data,
         char *server_name = Curl_copy_header_value(k->p);
 
         /* Turn off pipelining if the server version is blacklisted  */
-        if(conn->bundle && conn->bundle->server_supports_pipelining) {
+        if(conn->bundle && (conn->bundle->multiuse == BUNDLE_PIPELINING)) {
           if(Curl_pipeline_server_blacklisted(data, server_name))
-            conn->bundle->server_supports_pipelining = FALSE;
+            conn->bundle->multiuse = BUNDLE_NO_MULTIUSE;
         }
         free(server_name);
       }

lib/http2.c

@@ -32,7 +32,7 @@
 #include "curl_base64.h"
 #include "rawstr.h"
 #include "multiif.h"
-#include "bundles.h"
+#include "conncache.h"
 
 /* The last #include files should be: */
 #include "curl_memory.h"
@@ -1196,7 +1196,7 @@ CURLcode Curl_http2_setup(struct connectdata *conn)
 
   conn->bits.multiplex = TRUE; /* at least potentially multiplexed */
   conn->httpversion = 20;
-  conn->bundle->server_supports_pipelining = TRUE;
+  conn->bundle->multiuse = BUNDLE_MULTIPLEX;
 
   return CURLE_OK;
 }

lib/multi.c

@@ -2730,11 +2730,6 @@ size_t Curl_multi_max_total_connections(struct Curl_multi *multi)
   return multi ? multi->max_total_connections : 0;
 }
 
-size_t Curl_multi_max_pipeline_length(struct Curl_multi *multi)
-{
-  return multi ? multi->max_pipeline_length : 0;
-}
-
 curl_off_t Curl_multi_content_length_penalty_size(struct Curl_multi *multi)
 {
   return multi ? multi->content_length_penalty_size : 0;

lib/multiif.h

@@ -59,9 +59,6 @@ void Curl_multi_process_pending_handles(struct Curl_multi *multi);
 /* Return the value of the CURLMOPT_MAX_HOST_CONNECTIONS option */
 size_t Curl_multi_max_host_connections(struct Curl_multi *multi);
 
-/* Return the value of the CURLMOPT_MAX_PIPELINE_LENGTH option */
-size_t Curl_multi_max_pipeline_length(struct Curl_multi *multi);
-
 /* Return the value of the CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE option */
 curl_off_t Curl_multi_content_length_penalty_size(struct Curl_multi *multi);
 

lib/url.c

@@ -3081,6 +3081,13 @@ static void prune_dead_connections(struct SessionHandle *data)
   }
 }
 
+
+static size_t max_pipeline_length(struct Curl_multi *multi)
+{
+  return multi ? multi->max_pipeline_length : 0;
+}
+
+
 /*
  * Given one filled in connection struct (named needle), this function should
  * detect if there already is one that has all the significant details
@@ -3120,7 +3127,7 @@ ConnectionExists(struct SessionHandle *data,
      particular host */
   bundle = Curl_conncache_find_bundle(needle, data->state.conn_cache);
   if(bundle) {
-    size_t max_pipe_len = Curl_multi_max_pipeline_length(data->multi);
+    size_t max_pipe_len = max_pipeline_length(data->multi);
     size_t best_pipe_len = max_pipe_len;
     struct curl_llist_element *curr;
 
@@ -3128,7 +3135,7 @@ ConnectionExists(struct SessionHandle *data,
           needle->host.name, (void *)bundle);
 
     /* We can't pipe if we don't know anything about the server */
-    if(canPipeline && !bundle->server_supports_pipelining) {
+    if(canPipeline && (bundle->multiuse <= BUNDLE_UNKNOWN)) {
       infof(data, "Server doesn't support multi-use (yet)\n");
       canPipeline = FALSE;
     }
@@ -3154,16 +3161,19 @@ ConnectionExists(struct SessionHandle *data,
       pipeLen = check->send_pipe->size + check->recv_pipe->size;
 
       if(canPipeline) {
-        /* Make sure the pipe has only GET requests */
-        struct SessionHandle* sh = gethandleathead(check->send_pipe);
-        struct SessionHandle* rh = gethandleathead(check->recv_pipe);
-        if(sh) {
-          if(!IsPipeliningPossible(sh, check))
-            continue;
-        }
-        else if(rh) {
-          if(!IsPipeliningPossible(rh, check))
-            continue;
+
+        if(!check->bits.multiplex) {
+          /* If not multiplexing, make sure the pipe has only GET requests */
+          struct SessionHandle* sh = gethandleathead(check->send_pipe);
+          struct SessionHandle* rh = gethandleathead(check->recv_pipe);
+          if(sh) {
+            if(!IsPipeliningPossible(sh, check))
+              continue;
+          }
+          else if(rh) {
+            if(!IsPipeliningPossible(rh, check))
+              continue;
+          }
         }
       }
       else {
@@ -3342,8 +3352,10 @@ ConnectionExists(struct SessionHandle *data,
           }
 
           /* We can't use the connection if the pipe is full */
-          if(pipeLen >= max_pipe_len)
+          if(pipeLen >= max_pipe_len) {
+            infof(data, "Pipe is full, skip (%d)\n", pipeLen);
             continue;
+          }
 
           /* We can't use the connection if the pipe is penalized */
           if(Curl_pipeline_penalized(data, check))
@@ -5715,8 +5727,11 @@ static CURLcode create_conn(struct SessionHandle *data,
         conn_candidate->data = data;
         (void)Curl_disconnect(conn_candidate, /* dead_connection */ FALSE);
       }
-      else
+      else {
+        infof(data, "No more connections allowed to host: %d\n",
+              max_host_connections);
         no_connections_available = TRUE;
+      }
     }
 
     if(max_total_connections > 0 &&
@@ -5731,8 +5746,10 @@ static CURLcode create_conn(struct SessionHandle *data,
         conn_candidate->data = data;
         (void)Curl_disconnect(conn_candidate, /* dead_connection */ FALSE);
       }
-      else
+      else {
+        infof(data, "No connections available in cache\n");
         no_connections_available = TRUE;
+      }
     }