Commit f56e8734 authored by unknown's avatar unknown
Browse files

BUG#2845 client fails to reconnect if using TCP/IP 

 - Use 'poll' if available
 - Check that sd <= FD_SETSIZE if using 'select'
 - Handle case when 'net_data_is_ready' returns -1, ie. sd > FD_SETSIZE and 'select' is used 


sql/net_serv.cc:
  Use 'poll' in favor of 'select' if avaliable
  This is to avoid the limitation with 'select' only being able to handle fd's with numbers <= 1024 as default.
  If 'poll' is not available use 'select' but check that we are not having a number higher than FD_SETSIZE
  Handle the case when 'net_data_is_ready' can't check if there is data to read, since the sd number is too high
parent b97082c5

sql/net_serv.cc

+25 −4
Original line number Diff line number Diff line
@@ -208,23 +208,40 @@ my_bool net_realloc(NET *net, ulong length) 
  RETURN VALUES

    0	No data to read

    1	Data or EOF to read

    -1  Don't know if data is ready or not

*/



static my_bool net_data_is_ready(my_socket sd)

static int net_data_is_ready(my_socket sd)

{

#ifdef HAVE_POLL

  struct pollfd ufds;

  int res;



  ufds.fd= sd;

  ufds.events= POLLIN | POLLPRI;

  if (!(res= poll(&ufds, 1, 0)))

    return 0;

  if (res < 0 || !(ufds.revents & (POLLIN | POLLPRI)))

    return 0;

  return 1;

#else

  fd_set sfds;

  struct timeval tv;

  int res;



  if (sd >= FD_SETSIZE)

    return -1;



  FD_ZERO(&sfds);

  FD_SET(sd, &sfds);



  tv.tv_sec= tv.tv_usec= 0;



  if ((res= select(sd+1, &sfds, NULL, NULL, &tv)) < 0)

    return FALSE;

    return 0;

  else

    return test(res ? FD_ISSET(sd, &sfds) : 0);

#endif

}
@@ -251,10 +268,10 @@ static my_bool net_data_is_ready(my_socket sd) 


void net_clear(NET *net)

{

  int count;

  int count, ready;

  DBUG_ENTER("net_clear");

#if !defined(EMBEDDED_LIBRARY)

  while(net_data_is_ready(net->vio->sd))

  while((ready= net_data_is_ready(net->vio->sd)) != 0)

  {

    /* The socket is ready */

    if ((count= vio_read(net->vio, (char*) (net->buff),
@@ -269,6 +286,10 @@ void net_clear(NET *net) 
    }

    else

    {

      /* No data to read and 'net_data_is_ready' returned "don't know" */

      if (ready == -1)

        break;



      DBUG_PRINT("info",("socket ready but only EOF to read - disconnected"));

      net->error= 2;

      break;