Commit 164a0936 authored by Brad Spencer's avatar Brad Spencer Committed by Daniel Stenberg
Browse files

multi: fix request timer management 

There are some bugs in how timers are managed for a single easy handle
that causes the wrong "next timeout" value to be reported to the
application when a new minimum needs to be recomputed and that new
minimum should be an existing timer that isn't currently set for the
easy handle.  When the application drives a set of easy handles via the
`curl_multi_socket_action()` API (for example), it gets told to wait the
wrong amount of time before the next call, which causes requests to
linger for a long time (or, it is my guess, possibly forever).

Bug: https://curl.haxx.se/mail/lib-2017-07/0033.html
parent 53d137d9

lib/multi.c

+13 −14
Original line number Diff line number Diff line
@@ -2532,10 +2532,8 @@ static CURLMcode add_next_timeout(struct curltime now, 
    /* copy the first entry to 'tv' */

    memcpy(tv, &node->time, sizeof(*tv));



    /* remove first entry from list */

    Curl_llist_remove(list, e, NULL);



    /* insert this node again into the splay */

    /* Insert this node again into the splay.  Keep the timer in the list in

       case we need to recompute future timers. */

    multi->timetree = Curl_splayinsert(*tv, multi->timetree,

                                       &d->state.timenode);

  }
@@ -2952,26 +2950,25 @@ void Curl_expire(struct Curl_easy *data, time_t milli, expire_id id) 
    set.tv_usec -= 1000000;

  }



  /* Remove any timer with the same id just in case. */

  multi_deltimeout(data, id);



  /* Add it to the timer list.  It must stay in the list until it has expired

     in case we need to recompute the minimum timer later. */

  multi_addtimeout(data, &set, id);



  if(nowp->tv_sec || nowp->tv_usec) {

    /* This means that the struct is added as a node in the splay tree.

       Compare if the new time is earlier, and only remove-old/add-new if it

       is. */

    time_t diff = curlx_tvdiff(set, *nowp);



    /* remove the previous timer first, if there */

    multi_deltimeout(data, id);



    if(diff > 0) {

      /* the new expire time was later so just add it to the queue

         and get out */

      multi_addtimeout(data, &set, id);

      /* The current splay tree entry is sooner than this new expiry time.

         We don't need to update our splay tree entry. */

      return;

    }



    /* the new time is newer than the presently set one, so add the current

       to the queue and update the head */

    multi_addtimeout(data, nowp, id);



    /* Since this is an updated time, we must remove the previous entry from

       the splay tree first and then re-add the new value */

    rc = Curl_splayremovebyaddr(multi->timetree,
@@ -2981,6 +2978,8 @@ void Curl_expire(struct Curl_easy *data, time_t milli, expire_id id) 
      infof(data, "Internal error removing splay node = %d\n", rc);

  }



  /* Indicate that we are in the splay tree and insert the new timer expiry

     value since it is our local minimum. */

  *nowp = set;

  data->state.timenode.payload = data;

  multi->timetree = Curl_splayinsert(*nowp, multi->timetree,