net.c

php-4.4.7学习linux时下载的源代码

		      "%s: my_net_write: fcntl returned error %d, aborting thread\n",
		      my_progname,vio_errno(net->vio));
#endif /* EXTRA_DEBUG */
	      net->error=2;                     /* Close socket */
	      goto end;
	    }
	  }
	  retry_count=0;
	  continue;
	}
      }
      else
#endif /* (!defined(__WIN__) && !defined(__EMX__)) */
	if (thr_alarm_in_use(&alarmed) && !thr_got_alarm(&alarmed) &&
	    interrupted)
      {
	if (retry_count++ < RETRY_COUNT)
	    continue;
#ifdef EXTRA_DEBUG
	  fprintf(stderr, "%s: write looped, aborting thread\n",
		  my_progname);
#endif /* EXTRA_DEBUG */
      }
#if defined(THREAD_SAFE_CLIENT) && !defined(MYSQL_SERVER)
      if (vio_errno(net->vio) == SOCKET_EINTR)
      {
	DBUG_PRINT("warning",("Interrupted write. Retrying..."));
	continue;
      }
#endif /* defined(THREAD_SAFE_CLIENT) && !defined(MYSQL_SERVER) */
      net->error=2;				/* Close socket */
#ifdef MYSQL_SERVER
      net->last_errno= (interrupted ? ER_NET_WRITE_INTERRUPTED :
			ER_NET_ERROR_ON_WRITE);
#endif /* MYSQL_SERVER */
      break;
    }
    pos+=length;
    statistic_add(bytes_sent,length,&LOCK_bytes_sent);
  }
#ifndef __WIN__
 end:
#endif
#ifdef HAVE_COMPRESS
  if (net->compress)
    my_free((char*) packet,MYF(0));
#endif
  if (thr_alarm_in_use(&alarmed))
  {
    thr_end_alarm(&alarmed);
    vio_blocking(net->vio, net_blocking);
  }
  net->reading_or_writing=0;
  DBUG_RETURN(((int) (pos != end)));
}


/*****************************************************************************
** Read something from server/clinet
*****************************************************************************/

#ifdef MYSQL_SERVER

/*
  Help function to clear the commuication buffer when we get a too
  big packet
*/

static void my_net_skip_rest(NET *net, ulong remain, thr_alarm_t *alarmed)
{
  ALARM alarm_buff;
  uint retry_count=0;
  if (!thr_alarm_in_use(&alarmed))
  {
    if (!thr_alarm(alarmed,net->timeout,&alarm_buff) ||
	(!vio_is_blocking(net->vio) && vio_blocking(net->vio,TRUE) < 0))
      return;					/* Can't setup, abort */
  }
  while (remain > 0)
  {
    ulong length;
    if ((int) (length=vio_read(net->vio,(char*) net->buff,remain)) <= 0L)
    {
      my_bool interrupted = vio_should_retry(net->vio);
      if (!thr_got_alarm(alarmed) && interrupted)
      {					/* Probably in MIT threads */
	if (retry_count++ < RETRY_COUNT)
	  continue;
      }
      return;
    }
    remain -=(ulong) length;
    statistic_add(bytes_received,(ulong) length,&LOCK_bytes_received);
  }
}
#endif /* MYSQL_SERVER */


static uint
my_real_read(NET *net, ulong *complen)
{
  uchar *pos;
  long length;
  uint i,retry_count=0;
  ulong len=packet_error;
  thr_alarm_t alarmed;
#if (!defined(__WIN__) && !defined(__EMX__) && !defined(OS2)) || defined(MYSQL_SERVER)
  ALARM alarm_buff;
#endif
  my_bool net_blocking=vio_is_blocking(net->vio);
  ulong remain= (net->compress ? NET_HEADER_SIZE+COMP_HEADER_SIZE :
		 NET_HEADER_SIZE);
  *complen = 0;

  net->reading_or_writing=1;
  thr_alarm_init(&alarmed);
#ifdef MYSQL_SERVER
  if (net_blocking)
    thr_alarm(&alarmed,net->timeout,&alarm_buff);
#endif /* MYSQL_SERVER */

    pos = net->buff + net->where_b;		/* net->packet -4 */
    for (i=0 ; i < 2 ; i++)
    {
      while (remain > 0)
      {
	/* First read is done with non blocking mode */
        if ((int) (length=vio_read(net->vio,(char*) pos,remain)) <= 0L)
        {
          my_bool interrupted = vio_should_retry(net->vio);

	  DBUG_PRINT("info",("vio_read returned %d,  errno: %d",
			     length, vio_errno(net->vio)));
#if (!defined(__WIN__) && !defined(__EMX__) && !defined(OS2)) || defined(MYSQL_SERVER)
	  /*
	    We got an error that there was no data on the socket. We now set up
	    an alarm to not 'read forever', change the socket to non blocking
	    mode and try again
	  */
	  if ((interrupted || length == 0) && !thr_alarm_in_use(&alarmed))
	  {
	    if (!thr_alarm(&alarmed,net->timeout,&alarm_buff)) /* Don't wait too long */
	    {
              if (!vio_is_blocking(net->vio))
              {
                while (vio_blocking(net->vio,TRUE) < 0)
                {
                  if (vio_should_retry(net->vio) &&
		      retry_count++ < RETRY_COUNT)
                    continue;
                  DBUG_PRINT("error",
			     ("fcntl returned error %d, aborting thread",
			      vio_errno(net->vio)));
#ifdef EXTRA_DEBUG
                  fprintf(stderr,
                          "%s: read: fcntl returned error %d, aborting thread\n",
                          my_progname,vio_errno(net->vio));
#endif /* EXTRA_DEBUG */
                  len= packet_error;
                  net->error=2;                 /* Close socket */
#ifdef MYSQL_SERVER
		  net->last_errno=ER_NET_FCNTL_ERROR;
#endif
		  goto end;
                }
              }
	      retry_count=0;
	      continue;
	    }
	  }
#endif /* (!defined(__WIN__) && !defined(__EMX__)) || defined(MYSQL_SERVER) */
	  if (thr_alarm_in_use(&alarmed) && !thr_got_alarm(&alarmed) &&
	      interrupted)
	  {					/* Probably in MIT threads */
	    if (retry_count++ < RETRY_COUNT)
	      continue;
#ifdef EXTRA_DEBUG
	    fprintf(stderr, "%s: read looped with error %d, aborting thread\n",
		    my_progname,vio_errno(net->vio));
#endif /* EXTRA_DEBUG */
	  }
#if defined(THREAD_SAFE_CLIENT) && !defined(MYSQL_SERVER)
	  if (vio_should_retry(net->vio))
	  {
	    DBUG_PRINT("warning",("Interrupted read. Retrying..."));
	    continue;
	  }
#endif
	  DBUG_PRINT("error",("Couldn't read packet: remain: %d  errno: %d  length: %d  alarmed: %d", remain,vio_errno(net->vio),length,alarmed));
	  len= packet_error;
	  net->error=2;				/* Close socket */
#ifdef MYSQL_SERVER
	  net->last_errno= (interrupted ? ER_NET_READ_INTERRUPTED :
			    ER_NET_READ_ERROR);
#endif
	  goto end;
	}
	remain -= (ulong) length;
	pos+= (ulong) length;
	statistic_add(bytes_received,(ulong) length,&LOCK_bytes_received);
      }
      if (i == 0)
      {					/* First parts is packet length */
	ulong helping;
	if (net->buff[net->where_b + 3] != (uchar) net->pkt_nr)
	{
	  if (net->buff[net->where_b] != (uchar) 255)
	  {
	    DBUG_PRINT("error",
		       ("Packets out of order (Found: %d, expected %d)",
			(int) net->buff[net->where_b + 3],
			(uint) (uchar) net->pkt_nr));
#ifdef EXTRA_DEBUG
	    fprintf(stderr,"Packets out of order (Found: %d, expected %d)\n",
		    (int) net->buff[net->where_b + 3],
		    (uint) (uchar) net->pkt_nr);
#endif
	  }
	  len= packet_error;
#ifdef MYSQL_SERVER
	  net->last_errno=ER_NET_PACKETS_OUT_OF_ORDER;
#endif
	  goto end;
	}
	net->pkt_nr++;
#ifdef HAVE_COMPRESS
	if (net->compress)
	{
	  /* complen is > 0 if package is really compressed */
	  *complen=uint3korr(&(net->buff[net->where_b + NET_HEADER_SIZE]));
	}
#endif

	len=uint3korr(net->buff+net->where_b);
	helping = max(len,*complen) + net->where_b;
	/* The necessary size of net->buff */
	if (helping >= net->max_packet)
	{
	  /* We must allocate one extra byte for the end null */
	  if (net_realloc(net,helping+1))
	  {
#ifdef MYSQL_SERVER
	    if (i == 1)
	      my_net_skip_rest(net, len, &alarmed);
#endif
	    len= packet_error;		/* Return error */
	    goto end;
	  }
	}
	pos=net->buff + net->where_b;
	remain = len;
      }
    }

end:
  if (thr_alarm_in_use(&alarmed))
  {
    thr_end_alarm(&alarmed);
    vio_blocking(net->vio, net_blocking);
  }
  net->reading_or_writing=0;
  return(len);
}

uint
my_net_read(NET *net)
{
  ulong len,complen;

#ifdef HAVE_COMPRESS
  if (!net->compress)
  {
#endif
    len = my_real_read (net,&complen);
    net->read_pos = net->buff + net->where_b;
    if (len != packet_error)
      net->read_pos[len]=0;		/* Safeguard for mysql_use_result */
    return len;
#ifdef HAVE_COMPRESS
  }
  if (net->remain_in_buf)
    net->buff[net->buf_length - net->remain_in_buf]=net->save_char;
  for (;;)
  {
    if (net->remain_in_buf)
    {
      uchar *pos = net->buff + net->buf_length - net->remain_in_buf;
      if (net->remain_in_buf >= 4)
      {
	net->length = uint3korr(pos);
	if (net->length <= net->remain_in_buf - 4)
	{
	  /* We have a full packet */
	  len=net->length;
	  net->remain_in_buf -= net->length + 4;
	  net->read_pos=pos + 4;
	  break;			/* We have a full packet */
	}
      }
      /* Move data down to read next data packet after current one */
      if (net->buf_length != net->remain_in_buf)
      {
	memmove(net->buff,pos,net->remain_in_buf);
	net->buf_length=net->remain_in_buf;
      }
      net->where_b=net->buf_length;
    }
    else
    {
      net->where_b=0;
      net->buf_length=0;
    }

    if ((len = my_real_read(net,&complen)) == packet_error)
      break;
    if (my_uncompress((byte*) net->buff + net->where_b, &len, &complen))
    {
      len= packet_error;
      net->error=2;			/* caller will close socket */
#ifdef MYSQL_SERVER
      net->last_errno=ER_NET_UNCOMPRESS_ERROR;
#endif
      break;
    }
    net->buf_length+=len;
    net->remain_in_buf+=len;
  }
  if (len != packet_error)
  {
    net->save_char= net->read_pos[len];	/* Must be saved */
    net->read_pos[len]=0;		/* Safeguard for mysql_use_result */
  }
  return len;
#endif
}