Commit 3c8c8732 authored by Daniel Stenberg's avatar Daniel Stenberg
Browse files

multi: convert CURLM_STATE_CONNECT_PEND handling to a list 

... instead of scanning through all handles, stash only the actual
handles that are in that state in the new ->pending list and scan that
list only. It should be mostly empty or very short. And only used for
pipelining.

This avoids a rather hefty slow-down especially notable if you add many
handles to the same multi handle. Regression introduced in commit
0f147887 (version 7.30.0).

Bug: http://curl.haxx.se/mail/lib-2014-07/0206.html
Reported-by: David Meyer
parent 4901ec23

lib/multi.c

+21 −6
Original line number Diff line number Diff line
@@ -309,6 +309,10 @@ struct Curl_multi *Curl_multi_handle(int hashsize, /* socket hash */ 
  if(!multi->msglist)

    goto error;



  multi->pending = Curl_llist_alloc(multi_freeamsg);

  if(!multi->pending)

    goto error;



  /* allocate a new easy handle to use when closing cached connections */

  multi->closure_handle = curl_easy_init();

  if(!multi->closure_handle)
@@ -334,6 +338,7 @@ struct Curl_multi *Curl_multi_handle(int hashsize, /* socket hash */ 
  Curl_close(multi->closure_handle);

  multi->closure_handle = NULL;

  Curl_llist_destroy(multi->msglist, NULL);

  Curl_llist_destroy(multi->pending, NULL);



  free(multi);

  return NULL;
@@ -1046,6 +1051,11 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi, 
        /* There was no connection available. We will go to the pending

           state and wait for an available connection. */

        multistate(data, CURLM_STATE_CONNECT_PEND);



        /* add this handle to the list of connect-pending handles */

        if(!Curl_llist_insert_next(multi->pending, multi->pending->tail, data))

          data->result = CURLM_OUT_OF_MEMORY;

        else

          data->result = CURLE_OK;

        break;

      }
@@ -1884,6 +1894,10 @@ CURLMcode curl_multi_cleanup(CURLM *multi_handle) 
    Curl_llist_destroy(multi->msglist, NULL);

    multi->msglist = NULL;



    /* remove the pending handles queue */

    Curl_llist_destroy(multi->pending, NULL);

    multi->msglist = NULL;



    /* remove all easy handles */

    data = multi->easyp;

    while(data) {
@@ -2776,16 +2790,17 @@ struct curl_llist *Curl_multi_pipelining_server_bl(struct Curl_multi *multi) 


void Curl_multi_process_pending_handles(struct Curl_multi *multi)

{

  struct SessionHandle *data;

  struct curl_llist_element *e;



  data=multi->easyp;

  while(data) {

  for(e = multi->pending->head; e; e = e->next) {

    struct SessionHandle *data = e->ptr;

    if(data->mstate == CURLM_STATE_CONNECT_PEND) {

      multistate(data, CURLM_STATE_CONNECT);

      /* Remove this node from the list */

      Curl_llist_remove(multi->pending, e, NULL);

      /* Make sure that the handle will be processed soonish. */

      Curl_expire(data, 1);

      Curl_expire_latest(data, 1);

    }

    data = data->next; /* operate on next handle */

  }

}

lib/multihandle.h

+4 −1
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ 
 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.

 * Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.

 *

 * This software is licensed as described in the file COPYING, which

 * you should have received as part of this distribution. The terms
@@ -75,6 +75,9 @@ struct Curl_multi { 


  struct curl_llist *msglist; /* a list of messages from completed transfers */



  struct curl_llist *pending; /* SessionHandles that are in the

                                 CURLM_STATE_CONNECT_PEND state */



  /* callback function and user data pointer for the *socket() API */

  curl_socket_callback socket_cb;

  void *socket_userp;