Annotation of kernel/ipc/port.h, revision 1.1.1.1

1.1       root        1: /*
                      2:  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
                      3:  *
                      4:  * @APPLE_LICENSE_HEADER_START@
                      5:  * 
                      6:  * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
                      7:  * Reserved.  This file contains Original Code and/or Modifications of
                      8:  * Original Code as defined in and that are subject to the Apple Public
                      9:  * Source License Version 1.1 (the "License").  You may not use this file
                     10:  * except in compliance with the License.  Please obtain a copy of the
                     11:  * License at http://www.apple.com/publicsource and read it before using
                     12:  * this file.
                     13:  * 
                     14:  * The Original Code and all software distributed under the License are
                     15:  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
                     16:  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
                     17:  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
                     18:  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
                     19:  * License for the specific language governing rights and limitations
                     20:  * under the License.
                     21:  * 
                     22:  * @APPLE_LICENSE_HEADER_END@
                     23:  */
                     24: 
                     25: /*
                     26:  * Copyright (c) 1995, 1994, 1993, 1992, 1991, 1990  
                     27:  * Open Software Foundation, Inc. 
                     28:  *  
                     29:  * Permission to use, copy, modify, and distribute this software and 
                     30:  * its documentation for any purpose and without fee is hereby granted, 
                     31:  * provided that the above copyright notice appears in all copies and 
                     32:  * that both the copyright notice and this permission notice appear in 
                     33:  * supporting documentation, and that the name of ("OSF") or Open Software 
                     34:  * Foundation not be used in advertising or publicity pertaining to 
                     35:  * distribution of the software without specific, written prior permission. 
                     36:  *  
                     37:  * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE 
                     38:  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
                     39:  * FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL OSF BE LIABLE FOR ANY 
                     40:  * SPECIAL, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 
                     41:  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 
                     42:  * ACTION OF CONTRACT, NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING 
                     43:  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE 
                     44:  */
                     45: /*
                     46:  * OSF Research Institute MK6.1 (unencumbered) 1/31/1995
                     47:  */
                     48: /* 
                     49:  * Mach Operating System
                     50:  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
                     51:  * All Rights Reserved.
                     52:  * 
                     53:  * Permission to use, copy, modify and distribute this software and its
                     54:  * documentation is hereby granted, provided that both the copyright
                     55:  * notice and this permission notice appear in all copies of the
                     56:  * software, derivative works or modified versions, and any portions
                     57:  * thereof, and that both notices appear in supporting documentation.
                     58:  * 
                     59:  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
                     60:  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
                     61:  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
                     62:  * 
                     63:  * Carnegie Mellon requests users of this software to return to
                     64:  * 
                     65:  *  Software Distribution Coordinator  or  [email protected]
                     66:  *  School of Computer Science
                     67:  *  Carnegie Mellon University
                     68:  *  Pittsburgh PA 15213-3890
                     69:  * 
                     70:  * any improvements or extensions that they make and grant Carnegie Mellon
                     71:  * the rights to redistribute these changes.
                     72:  */
                     73: /*
                     74:  *     File:   ipc/ipc_port.h
                     75:  *     Author: Rich Draves
                     76:  *     Date:   1989
                     77:  *
                     78:  *     Implementation specific complement to mach/port.h.
                     79:  */
                     80: 
                     81: #ifndef        _IPC_PORT_H_
                     82: #define _IPC_PORT_H_
                     83: 
                     84: #include <mach/port.h>
                     85: 
                     86: /*
                     87:  *     mach_port_t must be an unsigned type.  Port values
                     88:  *     have two parts, a generation number and an index.
                     89:  *     These macros encapsulate all knowledge of how
                     90:  *     a mach_port_t is layed out.  However, ipc/ipc_entry.c
                     91:  *     implicitly assumes when it uses the splay tree functions
                     92:  *     that the generation number is in the low bits, so that
                     93:  *     names are ordered first by index and then by generation.
                     94:  *
                     95:  *     If the size of generation numbers changes,
                     96:  *     be sure to update IE_BITS_GEN_MASK and friends
                     97:  *     in ipc/ipc_entry.h.
                     98:  */
                     99: 
                    100: #define        MACH_PORT_INDEX(name)           ((name) >> 8)
                    101: #define        MACH_PORT_GEN(name)             (((name) & 0xff) << 24)
                    102: #define        MACH_PORT_MAKE(index, gen)      (((index) << 8) | ((gen) >> 24))
                    103: 
                    104: #define        MACH_PORT_NGEN(name)            MACH_PORT_MAKE(0, MACH_PORT_GEN(name))
                    105: #define        MACH_PORT_MAKEB(index, bits)    \
                    106:                MACH_PORT_MAKE(index, IE_BITS_GEN(bits))
                    107: 
                    108: /*
                    109:  *     Typedefs for code cleanliness.  These must all have
                    110:  *     the same (unsigned) type as mach_port_t.
                    111:  */
                    112: 
                    113: typedef mach_port_t mach_port_index_t;         /* index values */
                    114: typedef mach_port_t mach_port_gen_t;           /* generation numbers */
                    115: 
                    116: 
                    117: #define        MACH_PORT_UREFS_MAX     ((mach_port_urefs_t) ((1 << 16) - 1))
                    118: 
                    119: #define        MACH_PORT_UREFS_OVERFLOW(urefs, delta)                          \
                    120:                (((delta) > 0) &&                                       \
                    121:                 ((((urefs) + (delta)) <= (urefs)) ||                   \
                    122:                  (((urefs) + (delta)) > MACH_PORT_UREFS_MAX)))
                    123: 
                    124: #define        MACH_PORT_UREFS_UNDERFLOW(urefs, delta)                         \
                    125:                (((delta) < 0) && (-(delta) > (urefs)))
                    126: 
                    127: #endif /* _IPC_PORT_H_ */

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