usr/src/lib/libbc/libc/stdio/common/stdiom.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*      Copyright (c) 1984 AT&T */
  23 /*        All Rights Reserved   */
  24
  25 #pragma ident   "%Z%%M% %I%     %E% SMI"
  26
  27 /* The following macros improve performance of the stdio by reducing the
  28         number of calls to _bufsync and _wrtchk.  _BUFSYNC has the same
  29         effect as _bufsync, and _WRTCHK has the same effect as _wrtchk,
  30         but often these functions have no effect, and in those cases the
  31         macros avoid the expense of calling the functions.  */
  32
  33 #define _BUFSYNC(iop)   if ((iop->_base + iop->_bufsiz) - iop->_ptr <   \
  34                                 ( iop->_cnt < 0 ? 0 : iop->_cnt ) )  \
  35                                         _bufsync(iop)
  36 #define _WRTCHK(iop)    ((((iop->_flag & (_IOWRT | _IOEOF)) != _IOWRT) \
  37                                 || (iop->_base == NULL)  \
  38                                 || (iop->_ptr == iop->_base && iop->_cnt == 0 \
  39                                         && !(iop->_flag & (_IONBF | _IOLBF)))) \
  40                         ? _wrtchk(iop) : 0 )