1 /*- 2 * Copyright (c) 1991 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)tp_seq.h 7.5 (Berkeley) 05/06/91 8 */ 9 10 /*********************************************************** 11 Copyright IBM Corporation 1987 12 13 All Rights Reserved 14 15 Permission to use, copy, modify, and distribute this software and its 16 documentation for any purpose and without fee is hereby granted, 17 provided that the above copyright notice appear in all copies and that 18 both that copyright notice and this permission notice appear in 19 supporting documentation, and that the name of IBM not be 20 used in advertising or publicity pertaining to distribution of the 21 software without specific, written prior permission. 22 23 IBM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING 24 ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL 25 IBM BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR 26 ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, 27 WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 28 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 29 SOFTWARE. 30 31 ******************************************************************/ 32 33 /* 34 * ARGO Project, Computer Sciences Dept., University of Wisconsin - Madison 35 */ 36 /* 37 * ARGO TP 38 * 39 * $Header: tp_seq.h,v 5.1 88/10/12 12:20:59 root Exp $ 40 * $Source: /usr/argo/sys/netiso/RCS/tp_seq.h,v $ 41 * 42 * These macros perform sequence number arithmetic modulo (2**7 or 2**31). 43 * The relevant fields in the tpcb are: 44 * tp_seqmask : the mask of bits that define the sequence space. 45 * tp_seqbit : 1 + tp_seqmask 46 * tp_seqhalf : tp_seqbit / 2 or half the sequence space (rounded up) 47 * Not exactly fast, but at least it's maintainable. 48 */ 49 50 #ifndef __TP_SEQ__ 51 #define __TP_SEQ__ 52 53 #define SEQ(tpcb,x) \ 54 ((x) & (tpcb)->tp_seqmask) 55 56 #define SEQ_GT(tpcb, seq, operand ) \ 57 ( ((int)((seq)-(operand)) > 0)\ 58 ? ((int)((seq)-(operand)) < (int)(tpcb)->tp_seqhalf)\ 59 : !(-((int)(seq)-(operand)) < (int)(tpcb)->tp_seqhalf)) 60 61 #define SEQ_GEQ(tpcb, seq, operand ) \ 62 ( ((int)((seq)-(operand)) >= 0)\ 63 ? ((int)((seq)-(operand)) < (int)(tpcb)->tp_seqhalf)\ 64 : !((-((int)(seq)-(operand))) < (int)(tpcb)->tp_seqhalf)) 65 66 #define SEQ_LEQ(tpcb, seq, operand ) \ 67 ( ((int)((seq)-(operand)) <= 0)\ 68 ? ((-(int)((seq)-(operand))) < (int)(tpcb)->tp_seqhalf)\ 69 : !(((int)(seq)-(operand)) < (int)(tpcb)->tp_seqhalf)) 70 71 #define SEQ_LT(tpcb, seq, operand ) \ 72 ( ((int)((seq)-(operand)) < 0)\ 73 ? ((-(int)((seq)-(operand))) < (int)(tpcb)->tp_seqhalf)\ 74 : !(((int)(seq)-(operand)) < (int)(tpcb)->tp_seqhalf)) 75 76 #define SEQ_MIN(tpcb, a, b) ( SEQ_GT(tpcb, a, b) ? b : a) 77 78 #define SEQ_MAX(tpcb, a, b) ( SEQ_GT(tpcb, a, b) ? a : b) 79 80 #define SEQ_INC(tpcb, Seq) ((++Seq), ((Seq) &= (tpcb)->tp_seqmask)) 81 82 #define SEQ_DEC(tpcb, Seq)\ 83 ((Seq) = (((Seq)+(unsigned)((int)(tpcb)->tp_seqbit - 1))&(tpcb)->tp_seqmask)) 84 85 /* (amt) had better be less than the seq bit ! */ 86 87 #define SEQ_SUB(tpcb, Seq, amt)\ 88 (((Seq) + (unsigned)((int)(tpcb)->tp_seqbit - amt)) & (tpcb)->tp_seqmask) 89 #define SEQ_ADD(tpcb, Seq, amt) (((Seq) + (unsigned)amt) & (tpcb)->tp_seqmask) 90 91 92 #define IN_RWINDOW(tpcb, seq, lwe, uwe)\ 93 ( SEQ_GEQ(tpcb, seq, lwe) && SEQ_LT(tpcb, seq, uwe) ) 94 95 #define IN_SWINDOW(tpcb, seq, lwe, uwe)\ 96 ( SEQ_GT(tpcb, seq, lwe) && SEQ_LEQ(tpcb, seq, uwe) ) 97 98 #endif __TP_SEQ__ 99