multi.c

      }

      if(CURLE_OK != easy->result) {
        /* failure detected */
        disconnect_conn = TRUE;
        break;
      }
    }
    break;

#ifndef CURL_DISABLE_HTTP
    case CURLM_STATE_WAITPROXYCONNECT:
      /* this is HTTP-specific, but sending CONNECT to a proxy is HTTP... */
      easy->result = Curl_http_connect(easy->easy_conn, &protocol_connect);

      if(CURLE_OK == easy->result) {
        if(!easy->easy_conn->bits.tunnel_connecting)
          multistate(easy, CURLM_STATE_WAITCONNECT);
      }
      break;
#endif

    case CURLM_STATE_WAITCONNECT:
      /* awaiting a completion of an asynch connect */
      easy->result = Curl_is_connected(easy->easy_conn,
                                       FIRSTSOCKET,
                                       &connected);
      if(connected)
        easy->result = Curl_protocol_connect(easy->easy_conn,
                                             &protocol_connect);

      if(CURLE_OK != easy->result) {
        /* failure detected */
        /* Just break, the cleaning up is handled all in one place */
        disconnect_conn = TRUE;
        break;
      }

      if(connected) {
        if(!protocol_connect) {
          /* We have a TCP connection, but 'protocol_connect' may be false
             and then we continue to 'STATE_PROTOCONNECT'. If protocol
             connect is TRUE, we move on to STATE_DO.
             BUT if we are using a proxy we must change to WAITPROXYCONNECT
             */
#ifndef CURL_DISABLE_HTTP
          if(easy->easy_conn->bits.tunnel_connecting)
            multistate(easy, CURLM_STATE_WAITPROXYCONNECT);
          else
#endif
            multistate(easy, CURLM_STATE_PROTOCONNECT);
        }
        else {
          /* after the connect has completed, go WAITDO */
          multistate(easy, CURLM_STATE_WAITDO);

          result = CURLM_CALL_MULTI_PERFORM;
        }
      }
      break;

    case CURLM_STATE_PROTOCONNECT:
      /* protocol-specific connect phase */
      easy->result = Curl_protocol_connecting(easy->easy_conn,
                                              &protocol_connect);
      if((easy->result == CURLE_OK) && protocol_connect) {
        /* after the connect has completed, go WAITDO */
        multistate(easy, CURLM_STATE_WAITDO);
        result = CURLM_CALL_MULTI_PERFORM;
      }
      else if(easy->result) {
        /* failure detected */
        Curl_posttransfer(easy->easy_handle);
        Curl_done(&easy->easy_conn, easy->result, FALSE);
        disconnect_conn = TRUE;
      }
      break;

    case CURLM_STATE_WAITDO:
      /* Wait for our turn to DO when we're pipelining requests */
#ifdef CURLDEBUG
      infof(easy->easy_handle, "Conn %d send pipe %d inuse %d athead %d\n",
            easy->easy_conn->connectindex,
            easy->easy_conn->send_pipe->size,
            easy->easy_conn->writechannel_inuse,
            isHandleAtHead(easy->easy_handle,
                           easy->easy_conn->send_pipe));
#endif
      if(!easy->easy_conn->writechannel_inuse &&
         isHandleAtHead(easy->easy_handle,
                        easy->easy_conn->send_pipe)) {
        /* Grab the channel */
        easy->easy_conn->writechannel_inuse = TRUE;
        multistate(easy, CURLM_STATE_DO);
        result = CURLM_CALL_MULTI_PERFORM;
      }
      break;

    case CURLM_STATE_DO:
      if(easy->easy_handle->set.connect_only) {
        /* keep connection open for application to use the socket */
        easy->easy_conn->bits.close = FALSE;
        multistate(easy, CURLM_STATE_DONE);
        easy->result = CURLE_OK;
        result = CURLM_OK;
      }
      else {
        /* Perform the protocol's DO action */
        easy->result = Curl_do(&easy->easy_conn,
                               &dophase_done);

        if(CURLE_OK == easy->result) {

          if(!dophase_done) {
            /* DO was not completed in one function call, we must continue
               DOING... */
            multistate(easy, CURLM_STATE_DOING);
            result = CURLM_OK;
          }

          /* after DO, go DO_DONE... or DO_MORE */
          else if(easy->easy_conn->bits.do_more) {
            /* we're supposed to do more, but we need to sit down, relax
               and wait a little while first */
            multistate(easy, CURLM_STATE_DO_MORE);
            result = CURLM_OK;
          }
          else {
            /* we're done with the DO, now DO_DONE */
            multistate(easy, CURLM_STATE_DO_DONE);
            result = CURLM_CALL_MULTI_PERFORM;
          }
        }
        else {
          /* failure detected */
          Curl_posttransfer(easy->easy_handle);
          Curl_done(&easy->easy_conn, easy->result, FALSE);
          disconnect_conn = TRUE;
        }
      }
      break;

    case CURLM_STATE_DOING:
      /* we continue DOING until the DO phase is complete */
      easy->result = Curl_protocol_doing(easy->easy_conn,
                                         &dophase_done);
      if(CURLE_OK == easy->result) {
        if(dophase_done) {
          /* after DO, go PERFORM... or DO_MORE */
          if(easy->easy_conn->bits.do_more) {
            /* we're supposed to do more, but we need to sit down, relax
               and wait a little while first */
            multistate(easy, CURLM_STATE_DO_MORE);
            result = CURLM_OK;
          }
          else {
            /* we're done with the DO, now DO_DONE */
            multistate(easy, CURLM_STATE_DO_DONE);
            result = CURLM_CALL_MULTI_PERFORM;
          }
        } /* dophase_done */
      }
      else {
        /* failure detected */
        Curl_posttransfer(easy->easy_handle);
        Curl_done(&easy->easy_conn, easy->result, FALSE);
        disconnect_conn = TRUE;
      }
      break;

    case CURLM_STATE_DO_MORE:
      /* Ready to do more? */
      easy->result = Curl_is_connected(easy->easy_conn,
                                       SECONDARYSOCKET,
                                       &connected);
      if(connected) {
        /*
         * When we are connected, DO MORE and then go DO_DONE
         */
        easy->result = Curl_do_more(easy->easy_conn);

        /* No need to remove ourselves from the send pipeline here since that
           is done for us in Curl_done() */

        if(CURLE_OK == easy->result) {
          multistate(easy, CURLM_STATE_DO_DONE);
          result = CURLM_CALL_MULTI_PERFORM;
        }
        else {
          /* failure detected */
          Curl_posttransfer(easy->easy_handle);
          Curl_done(&easy->easy_conn, easy->result, FALSE);
          disconnect_conn = TRUE;
        }
      }
      break;

    case CURLM_STATE_DO_DONE:
      /* Move ourselves from the send to recv pipeline */
      moveHandleFromSendToRecvPipeline(easy->easy_handle, easy->easy_conn);
      /* Check if we can move pending requests to send pipe */
      checkPendPipeline(easy->easy_conn);
      multistate(easy, CURLM_STATE_WAITPERFORM);
      result = CURLM_CALL_MULTI_PERFORM;
      break;

    case CURLM_STATE_WAITPERFORM:
#ifdef CURLDEBUG
      infof(easy->easy_handle, "Conn %d recv pipe %d inuse %d athead %d\n",
            easy->easy_conn->connectindex,
            easy->easy_conn->recv_pipe->size,
            easy->easy_conn->readchannel_inuse,
            isHandleAtHead(easy->easy_handle,
                           easy->easy_conn->recv_pipe));
#endif
      /* Wait for our turn to PERFORM */
      if(!easy->easy_conn->readchannel_inuse &&
         isHandleAtHead(easy->easy_handle,
                        easy->easy_conn->recv_pipe)) {
        /* Grab the channel */
        easy->easy_conn->readchannel_inuse = TRUE;
        multistate(easy, CURLM_STATE_PERFORM);
        result = CURLM_CALL_MULTI_PERFORM;
      }
      break;

    case CURLM_STATE_TOOFAST: /* limit-rate exceeded in either direction */
      /* if both rates are within spec, resume transfer */
      Curl_pgrsUpdate(easy->easy_conn);
      if( ( ( easy->easy_handle->set.max_send_speed == 0 ) ||
             ( easy->easy_handle->progress.ulspeed <
               easy->easy_handle->set.max_send_speed ) )  &&
           ( ( easy->easy_handle->set.max_recv_speed == 0 ) ||
             ( easy->easy_handle->progress.dlspeed <
               easy->easy_handle->set.max_recv_speed ) )
        )
      multistate(easy, CURLM_STATE_PERFORM);
      break;

    case CURLM_STATE_PERFORM:
      /* check if over speed */
      if( (  ( easy->easy_handle->set.max_send_speed > 0 ) &&
              ( easy->easy_handle->progress.ulspeed >
                easy->easy_handle->set.max_send_speed ) )  ||
           (  ( easy->easy_handle->set.max_recv_speed > 0 ) &&
              ( easy->easy_handle->progress.dlspeed >
                easy->easy_handle->set.max_recv_speed ) )
        ) {
        /* Transfer is over the speed limit. Change state.  TODO: Call
         * Curl_expire() with the time left until we're targeted to be below
         * the speed limit again. */
        multistate(easy, CURLM_STATE_TOOFAST );
        break;
      }

      /* read/write data if it is ready to do so */
      easy->result = Curl_readwrite(easy->easy_conn, &done);

      k = &easy->easy_handle->req;

      if(!(k->keepon & KEEP_READ)) {
        /* We're done reading */
        easy->easy_conn->readchannel_inuse = FALSE;
      }

      if(!(k->keepon & KEEP_WRITE)) {
        /* We're done writing */
        easy->easy_conn->writechannel_inuse = FALSE;
      }

      if(easy->result)  {
        /* The transfer phase returned error, we mark the connection to get
         * closed to prevent being re-used. This is because we can't
         * possibly know if the connection is in a good shape or not now. */
        easy->easy_conn->bits.close = TRUE;
        Curl_removeHandleFromPipeline(easy->easy_handle,
                                      easy->easy_conn->recv_pipe);

        if(CURL_SOCKET_BAD != easy->easy_conn->sock[SECONDARYSOCKET]) {
          /* if we failed anywhere, we must clean up the secondary socket if
             it was used */
          sclose(easy->easy_conn->sock[SECONDARYSOCKET]);
          easy->easy_conn->sock[SECONDARYSOCKET] = CURL_SOCKET_BAD;
        }
        Curl_posttransfer(easy->easy_handle);
        Curl_done(&easy->easy_conn, easy->result, FALSE);
      }
      else if(TRUE == done) {
        char *newurl;
        bool retry = Curl_retry_request(easy->easy_conn, &newurl);

        /* call this even if the readwrite function returned error */
        Curl_posttransfer(easy->easy_handle);

        /* When we follow redirects, must to go back to the CONNECT state */
        if(easy->easy_handle->req.newurl || retry) {
          Curl_removeHandleFromPipeline(easy->easy_handle,
                                        easy->easy_conn->recv_pipe);
          /* Check if we can move pending requests to send pipe */
          checkPendPipeline(easy->easy_conn);

          if(!retry) {
            /* if the URL is a follow-location and not just a retried request
               then figure out the URL here */
            newurl = easy->easy_handle->req.newurl;
            easy->easy_handle->req.newurl = NULL;
          }
          easy->result = Curl_done(&easy->easy_conn, CURLE_OK, FALSE);
          if(easy->result == CURLE_OK)
            easy->result = Curl_follow(easy->easy_handle, newurl, retry);
          if(CURLE_OK == easy->result) {
            multistate(easy, CURLM_STATE_CONNECT);
            result = CURLM_CALL_MULTI_PERFORM;
          }
          else
            /* Since we "took it", we are in charge of freeing this on
               failure */
            free(newurl);
        }
        else {
          /* after the transfer is done, go DONE */
          multistate(easy, CURLM_STATE_DONE);
          result = CURLM_CALL_MULTI_PERFORM;
        }
      }

      break;

    case CURLM_STATE_DONE:
      /* Remove ourselves from the receive pipeline */
      Curl_removeHandleFromPipeline(easy->easy_handle,
                                    easy->easy_conn->recv_pipe);
      /* Check if we can move pending requests to send pipe */
      checkPendPipeline(easy->easy_conn);

      if(easy->easy_conn->bits.stream_was_rewound) {
          /* This request read past its response boundary so we quickly
             let the other requests consume those bytes since there is no
             guarantee that the socket will become active again */
          result = CURLM_CALL_MULTI_PERFORM;
      }

      /* post-transfer command */
      easy->result = Curl_done(&easy->easy_conn, CURLE_OK, FALSE);

      /* after we have DONE what we're supposed to do, go COMPLETED, and
         it doesn't matter what the Curl_done() returned! */
      multistate(easy, CURLM_STATE_COMPLETED);

      break;

    case CURLM_STATE_COMPLETED:
      /* this is a completed transfer, it is likely to still be connected */

      /* This node should be delinked from the list now and we should post
         an information message that we are complete. */

      /* Important: reset the conn pointer so that we don't point to memory
         that could be freed anytime */
      easy->easy_conn = NULL;
      break;

    default:
      return CURLM_INTERNAL_ERROR;
    }

    if(CURLM_STATE_COMPLETED != easy->state) {
      if(CURLE_OK != easy->result) {
        /*
         * If an error was returned, and we aren't in completed state now,
         * then we go to completed and consider this transfer aborted.
         */

        /* NOTE: no attempt to disconnect connections must be made
           in the case blocks above - cleanup happens only here */

        easy->easy_handle->state.pipe_broke = FALSE;

        if(easy->easy_conn) {
          /* if this has a connection, unsubscribe from the pipelines */
          easy->easy_conn->writechannel_inuse = FALSE;
          easy->easy_conn->readchannel_inuse = FALSE;
          Curl_removeHandleFromPipeline(easy->easy_handle,
                                        easy->easy_conn->send_pipe);
          Curl_removeHandleFromPipeline(easy->easy_handle,
                                        easy->easy_conn->recv_pipe);
          /* Check if we can move pending requests to send pipe */
          checkPendPipeline(easy->easy_conn);
        }

        if(disconnect_conn) {
          Curl_disconnect(easy->easy_conn); /* disconnect properly */

          /* This is where we make sure that the easy_conn pointer is reset.
             We don't have to do this in every case block above where a
             failure is detected */
          easy->easy_conn = NULL;
        }

        multistate(easy, CURLM_STATE_COMPLETED);
      }
    }

  } while(easy->easy_handle->change.url_changed);

  if((CURLM_STATE_COMPLETED == easy->state) && !easy->msg) {
    if(easy->easy_handle->dns.hostcachetype == HCACHE_MULTI) {
      /* clear out the usage of the shared DNS cache */
      easy->easy_handle->dns.hostcache = NULL;
      easy->easy_handle->dns.hostcachetype = HCACHE_NONE;
    }

    /* now add a node to the Curl_message linked list with this info */
    msg = (struct Curl_message *)malloc(sizeof(struct Curl_message));

    if(!msg)
      return CURLM_OUT_OF_MEMORY;

    msg->extmsg.msg = CURLMSG_DONE;
    msg->extmsg.easy_handle = easy->easy_handle;
    msg->extmsg.data.result = easy->result;
    msg->next = NULL;

    easy->msg = msg;
    easy->msg_num = 1; /* there is one unread message here */

    multi->num_msgs++; /* increase message counter */
  }

  if(CURLM_CALL_MULTI_PERFORM == result)
    /* Set the timeout for this handle to expire really soon so that it will
       be taken care of even when this handle is added in the midst of
       operation when only the curl_multi_socket() API is used. During that
       flow, only sockets that time-out or have actions will be dealt
       with. Since this handle has no action yet, we make sure it times out to
       get things to happen. Also, this makes it less important for callers of
       the curl_multi_* functions to bother about the CURLM_CALL_MULTI_PERFORM
       return code, as long as they deal with the timeouts properly. */
    Curl_expire(easy->easy_handle, 10);

  return result;
}


CURLMcode curl_multi_perform(CURLM *multi_handle, int *running_handles)
{
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
  struct Curl_one_easy *easy;
  CURLMcode returncode=CURLM_OK;
  struct Curl_tree *t;

  if(!GOOD_MULTI_HANDLE(multi))
    return CURLM_BAD_HANDLE;

  easy=multi->easy.next;
  while(easy != &multi->easy) {
    CURLMcode result;

    result = multi_runsingle(multi, easy);
    if(result)
      returncode = result;

    easy = easy->next; /* operate on next handle */
  }

  /*
   * Simply remove all expired timers from the splay since handles are dealt
   * with unconditionally by this function and curl_multi_timeout() requires
   * that already passed/handled expire times are removed from the splay.
   */
  do {
    struct timeval now = Curl_tvnow();
    int key = now.tv_sec; /* drop the usec part */

    multi->timetree = Curl_splaygetbest(key, multi->timetree, &t);
    if(t) {
      struct SessionHandle *d = t->payload;
      struct timeval* tv = &d->state.expiretime;

      /* clear the expire times within the handles that we remove from the
         splay tree */
      tv->tv_sec = 0;
      tv->tv_usec = 0;
    }

  } while(t);

  *running_handles = multi->num_alive;

  if( CURLM_OK >= returncode )
    update_timer(multi);
  return returncode;
}

/* This is called when an easy handle is cleanup'ed that is part of a multi
   handle */
void Curl_multi_rmeasy(void *multi_handle, CURL *easy_handle)
{
  curl_multi_remove_handle(multi_handle, easy_handle);
}


CURLMcode curl_multi_cleanup(CURLM *multi_handle)
{
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
  struct Curl_one_easy *easy;
  struct Curl_one_easy *nexteasy;
  int i;
  struct closure *cl;
  struct closure *n;

  if(GOOD_MULTI_HANDLE(multi)) {
    multi->type = 0; /* not good anymore */
    Curl_hash_destroy(multi->hostcache);
    Curl_hash_destroy(multi->sockhash);

    /* go over all connections that have close actions */
    for(i=0; i< multi->connc->num; i++) {
      if(multi->connc->connects[i] &&
         multi->connc->connects[i]->protocol & PROT_CLOSEACTION) {
        Curl_disconnect(multi->connc->connects[i]);
        multi->connc->connects[i] = NULL;
      }
    }
    /* now walk through the list of handles we kept around only to be
       able to close connections "properly" */
    cl = multi->closure;
    while(cl) {
      cl->easy_handle->state.shared_conn = NULL; /* no more shared */
      if(cl->easy_handle->state.closed)
        /* close handle only if curl_easy_cleanup() already has been called
           for this easy handle */
        Curl_close(cl->easy_handle);
      n = cl->next;
      free(cl);
      cl= n;
    }

    Curl_rm_connc(multi->connc);

    /* remove all easy handles */
    easy = multi->easy.next;
    while(easy != &multi->easy) {
      nexteasy=easy->next;
      if(easy->easy_handle->dns.hostcachetype == HCACHE_MULTI) {
        /* clear out the usage of the shared DNS cache */
        easy->easy_handle->dns.hostcache = NULL;
        easy->easy_handle->dns.hostcachetype = HCACHE_NONE;
      }

      /* Clear the pointer to the connection cache */
      easy->easy_handle->state.connc = NULL;

      Curl_easy_addmulti(easy->easy_handle, NULL); /* clear the association */

      if(easy->msg)
        free(easy->msg);
      free(easy);
      easy = nexteasy;
    }

    free(multi);

    return CURLM_OK;
  }
  else
    return CURLM_BAD_HANDLE;
}

CURLMsg *curl_multi_info_read(CURLM *multi_handle, int *msgs_in_queue)
{
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;

  *msgs_in_queue = 0; /* default to none */

  if(GOOD_MULTI_HANDLE(multi)) {
    struct Curl_one_easy *easy;

    if(!multi->num_msgs)
      return NULL; /* no messages left to return */

    easy=multi->easy.next;
    while(easy != &multi->easy) {
      if(easy->msg_num) {
        easy->msg_num--;
        break;
      }
      easy = easy->next;
    }
    if(!easy)
      return NULL; /* this means internal count confusion really */

    multi->num_msgs--;
    *msgs_in_queue = multi->num_msgs;

    return &easy->msg->extmsg;
  }
  else
    return NULL;
}

/*
 * singlesocket() checks what sockets we deal with and their "action state"
 * and if we have a different state in any of those sockets from last time we
 * call the callback accordingly.
 */
static void singlesocket(struct Curl_multi *multi,
                         struct Curl_one_easy *easy)
{
  curl_socket_t socks[MAX_SOCKSPEREASYHANDLE];
  int i;
  struct Curl_sh_entry *entry;
  curl_socket_t s;
  int num;
  unsigned int curraction;

  memset(&socks, 0, sizeof(socks));
  for(i=0; i< MAX_SOCKSPEREASYHANDLE; i++)
    socks[i] = CURL_SOCKET_BAD;

  /* Fill in the 'current' struct with the state as it is now: what sockets to
     supervise and for what actions */
  curraction = multi_getsock(easy, socks, MAX_SOCKSPEREASYHANDLE);

  /* We have 0 .. N sockets already and we get to know about the 0 .. M
     sockets we should have from now on. Detect the differences, remove no
     longer supervised ones and add new ones */

  /* walk over the sockets we got right now */
  for(i=0; (i< MAX_SOCKSPEREASYHANDLE) &&
        (curraction & (GETSOCK_READSOCK(i) | GETSOCK_WRITESOCK(i)));
      i++) {
    int action = CURL_POLL_NONE;

    s = socks[i];

    /* get it from the hash */
    entry = Curl_hash_pick(multi->sockhash, (char *)&s, sizeof(s));

    if(curraction & GETSOCK_READSOCK(i))
      action |= CURL_POLL_IN;
    if(curraction & GETSOCK_WRITESOCK(i))
      action |= CURL_POLL_OUT;

    if(entry) {
      /* yeps, already present so check if it has the same action set */
      if(entry->action == action)
        /* same, continue */
        continue;
    }
    else {
      /* this is a socket we didn't have before, add it! */
      entry = sh_addentry(multi->sockhash, s, easy->easy_handle);
      if(!entry)
        /* fatal */
        return;
    }

    multi->socket_cb(easy->easy_handle,
                     s,
                     action,
                     multi->socket_userp,
                     entry ? entry->socketp : NULL);

    entry->action = action; /* store the current action state */
  }

  num = i; /* number of sockets */

  /* when we've walked over all the sockets we should have right now, we must
     make sure to detect sockets that are removed */
  for(i=0; i< easy->numsocks; i++) {
    int j;
    s = easy->sockets[i];
    for(j=0; j<num; j++) {
      if(s == socks[j]) {
        /* this is still supervised */
        s = CURL_SOCKET_BAD;
        break;
      }
    }
    if(s != CURL_SOCKET_BAD) {
      /* this socket has been removed. Remove it */

      entry = Curl_hash_pick(multi->sockhash, (char *)&s, sizeof(s));
      if(entry) {
        /* just a precaution, this socket really SHOULD be in the hash already
           but in case it isn't, we don't have to tell the app to remove it
           either since it never got to know about it */
        multi->socket_cb(easy->easy_handle,
                         s,
                         CURL_POLL_REMOVE,
                         multi->socket_userp,
                         entry ? entry->socketp : NULL);

        sh_delentry(multi->sockhash, s);
      }
    }
  }

  memcpy(easy->sockets, socks, num*sizeof(curl_socket_t));
  easy->numsocks = num;
}

static CURLMcode multi_socket(struct Curl_multi *multi,
                              bool checkall,
                              curl_socket_t s,
                              int ev_bitmask,
                              int *running_handles)
{
  CURLMcode result = CURLM_OK;
  struct SessionHandle *data = NULL;
  struct Curl_tree *t;

  if(checkall) {
    struct Curl_one_easy *easyp;
    /* *perform() deals with running_handles on its own */
    result = curl_multi_perform(multi, running_handles);

    /* walk through each easy handle and do the socket state change magic
       and callbacks */
    easyp=multi->easy.next;
    while(easyp != &multi->easy) {
      singlesocket(multi, easyp);
      easyp = easyp->next;
    }

    /* or should we fall-through and do the timer-based stuff? */
    return result;
  }
  else if(s != CURL_SOCKET_TIMEOUT) {

    struct Curl_sh_entry *entry =
      Curl_hash_pick(multi->sockhash, (char *)&s, sizeof(s));

    if(!entry)
      /* unmatched socket, major problemo! */
      return CURLM_BAD_SOCKET; /* better return code? */

    data = entry->easy;

    if(data->magic != CURLEASY_MAGIC_NUMBER)
      /* bad bad bad bad bad bad bad */
      return CURLM_INTERNAL_ERROR;

    if(data->set.one_easy->easy_conn)  /* set socket event bitmask */
      data->set.one_easy->easy_conn->cselect_bits = ev_bitmask;

    result = multi_runsingle(multi, data->set.one_easy);

    if(data->set.one_easy->easy_conn)
      data->set.one_easy->easy_conn->cselect_bits = 0;

    if(CURLM_OK >= result)
      /* get the socket(s) and check if the state has been changed since
         last */
      singlesocket(multi, data->set.one_easy);

    /* Now we fall-through and do the timer-based stuff, since we don't want
       to force the user to have to deal with timeouts as long as at least one
       connection in fact has traffic. */

    data = NULL; /* set data to NULL again to avoid calling multi_runsingle()
                    in case there's no need to */
  }

  /*
   * The loop following here will go on as long as there are expire-times left
   * to process in the splay and 'data' will be re-assigned for every expired
   * handle we deal with.
   */
  do {
    int key;
    struct timeval now;

    /* the first loop lap 'data' can be NULL */
    if(data) {
      result = multi_runsingle(multi, data->set.one_easy);

      if(CURLM_OK >= result)
        /* get the socket(s) and check if the state has been changed since
           last */
        singlesocket(multi, data->set.one_easy);
    }

    /* Check if there's one (more) expired timer to deal with! This function
       extracts a matching node if there is one */

    now = Curl_tvnow();
    key = now.tv_sec; /* drop the usec part */

    multi->timetree = Curl_splaygetbest(key, multi->timetree, &t);
    if(t) {
      /* assign 'data' to be the easy handle we just removed from the splay
         tree */
      data = t->payload;
      /* clear the expire time within the handle we removed from the
         splay tree */
      data->state.expiretime.tv_sec = 0;
      data->state.expiretime.tv_usec = 0;
    }

  } while(t);

  *running_handles = multi->num_alive;
  return result;
}

CURLMcode curl_multi_setopt(CURLM *multi_handle,
                            CURLMoption option, ...)
{
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
  CURLMcode res = CURLM_OK;
  va_list param;

  if(!GOOD_MULTI_HANDLE(multi))
    return CURLM_BAD_HANDLE;

  va_start(param, option);

  switch(option) {
  case CURLMOPT_SOCKETFUNCTION:
    multi->socket_cb = va_arg(param, curl_socket_callback);
    break;
  case CURLMOPT_SOCKETDATA:
    multi->socket_userp = va_arg(param, void *);
    break;
  case CURLMOPT_PIPELINING:
    multi->pipelining_enabled = (bool)(0 != va_arg(param, long));
    break;
  case CURLMOPT_TIMERFUNCTION:
    multi->timer_cb = va_arg(param, curl_multi_timer_callback);
    break;
  case CURLMOPT_TIMERDATA:
    multi->timer_userp = va_arg(param, void *);
    break;
  case CURLMOPT_MAXCONNECTS:
    multi->maxconnects = va_arg(param, long);
    break;
  default:
    res = CURLM_UNKNOWN_OPTION;
    break;
  }
  va_end(param);
  return res;
}

/* we define curl_multi_socket() in the public multi.h header */
#undef curl_multi_socket

CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s,
                            int *running_handles)
{
  CURLMcode result = multi_socket((struct Curl_multi *)multi_handle, FALSE, s,
                                  0, running_handles);
  if(CURLM_OK >= result)
    update_timer((struct Curl_multi *)multi_handle);
  return result;
}

CURLMcode curl_multi_socket_action(CURLM *multi_handle, curl_socket_t s,
                                     int ev_bitmask, int *running_handles)
{
  CURLMcode result = multi_socket((struct Curl_multi *)multi_handle, FALSE, s,
                                  ev_bitmask, running_handles);
  if(CURLM_OK >= result)
    update_timer((struct Curl_multi *)multi_handle);
  return result;
}

CURLMcode curl_multi_socket_all(CURLM *multi_handle, int *running_handles)

{
  CURLMcode result = multi_socket((struct Curl_multi *)multi_handle,
                                  TRUE, CURL_SOCKET_BAD, 0, running_handles);
  if(CURLM_OK >= result)
    update_timer((struct Curl_multi *)multi_handle);
  return result;
}

static CURLMcode multi_timeout(struct Curl_multi *multi,
                               long *timeout_ms)
{
  if(multi->timetree) {
    /* we have a tree of expire times */
    struct timeval now = Curl_tvnow();

    /* splay the lowest to the bottom */
    multi->timetree = Curl_splay(0, multi->timetree);

    /* At least currently, the splay key is a time_t for the expire time */
    *timeout_ms = (multi->timetree->key - now.tv_sec) * 1000 -
      now.tv_usec/1000;
    if(*timeout_ms < 0)
      /* 0 means immediately */
      *timeout_ms = 0;
  }
  else
    *timeout_ms = -1;

  return CURLM_OK;
}

CURLMcode curl_multi_timeout(CURLM *multi_handle,
                             long *timeout_ms)
{
  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;

  /* First, make some basic checks that the CURLM handle is a good handle */
  if(!GOOD_MULTI_HANDLE(multi))
    return CURLM_BAD_HANDLE;

  return multi_timeout(multi, timeout_ms);
}

/*
 * Tell the application it should update its timers, if it subscribes to the
 * update timer callback.
 */
static int update_timer(struct Curl_multi *multi)
{
  long timeout_ms;
  if(!multi->timer_cb)
    return 0;
  if( multi_timeout(multi, &timeout_ms) != CURLM_OK )
    return -1;
  if( timeout_ms < 0 )
    return 0;

  /* When multi_timeout() is done, multi->timetree points to the node with the
   * timeout we got the (relative) time-out time for. We can thus easily check
   * if this is the same (fixed) time as we got in a previous call and then
   * avoid calling the callback again. */
  if(multi->timetree->key == multi->timer_lastcall)
    return 0;

  multi->timer_lastcall = multi->timetree->key;

  return multi->timer_cb((CURLM*)multi, timeout_ms, multi->timer_userp);
}

static CURLcode addHandleToSendOrPendPipeline(struct SessionHandle *handle,
                                              struct connectdata *conn)
{
  size_t pipeLen = conn->send_pipe->size + conn->recv_pipe->size;
  struct curl_llist *pipeline;

  if(!Curl_isPipeliningEnabled(handle) ||
     pipeLen == 0)
    pipeline = conn->send_pipe;
  else {
    if(conn->server_supports_pipelining &&
       pipeLen < MAX_PIPELINE_LENGTH)
      pipeline = conn->send_pipe;
    else
      pipeline = conn->pend_pipe;
  }

  return Curl_addHandleToPipeline(handle, pipeline);
}

static int checkPendPipeline(struct connectdata *conn)
{
  int result = 0;

  if (conn->server_supports_pipelining) {
    size_t pipeLen = conn->send_pipe->size + conn->recv_pipe->size;
    struct curl_llist_element *curr = conn->pend_pipe->head;

    while(pipeLen < MAX_PIPELINE_LENGTH && curr) {
      Curl_llist_move(conn->pend_pipe, curr,
                      conn->send_pipe, conn->send_pipe->tail);
      Curl_pgrsTime(curr->ptr, TIMER_CONNECT);
      ++result; /* count how many handles we moved */
      curr = conn->pend_pipe->head;
      ++pipeLen;
    }
    if (result > 0)
      conn->now = Curl_tvnow();
  }

  return result;
}

static int moveHandleFromSendToRecvPipeline(struct SessionHandle *handle,
                                            struct connectdata *conn)
{
  struct curl_llist_element *curr;

  curr = conn->send_pipe->head;
  while(curr) {
    if(curr->ptr == handle) {
      Curl_llist_move(conn->send_pipe, curr,
                      conn->recv_pipe, conn->recv_pipe->tail);
      return 1; /* we moved a handle */
    }
    curr = curr->next;
  }

  return 0;