empserver/include/loan.h
Markus Armbruster 20b31defe7 Generation numbers to catch write back of stale copies
Oops when a stale copy is written back, i.e. the processor was yielded
since the copy was made.  Such bugs are difficult to spot.  Sequence
numbers catch them when they do actual harm (they also catch different
bugs).  Generation numbers catch them even when they don't.

New ef_generation to count generations.  Call new ef_make_stale() to
step it whenever the processor may be yielded.

New struct emptypedstr member generation.  Make sure all members of
unit empobj_storage share it.  It is only used in copies; its value on
disk and in the cache is meaningless.  Set it to ef_generation by
calling new ef_mark_fresh() when making copies in ef_read() and
ef_blank().  Do the same in obj_changed() to make check_sect_ok() &
friends freshen their argument when it is unchanged.  Copies with
generation other than ef_generation are stale.

Oops in ef_write() when a stale copy is written back.
2009-03-10 15:27:52 +01:00

73 lines
2.3 KiB
C

/*
* Empire - A multi-player, client/server Internet based war game.
* Copyright (C) 1986-2009, Dave Pare, Jeff Bailey, Thomas Ruschak,
* Ken Stevens, Steve McClure
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* ---
*
* See files README, COPYING and CREDITS in the root of the source
* tree for related information and legal notices. It is expected
* that future projects/authors will amend these files as needed.
*
* ---
*
* loan.h: Definitions for loans
*
* Known contributors to this file:
*
*/
#ifndef LOAN_H
#define LOAN_H
#include <time.h>
#include "types.h"
#define MAXLOAN 100000
#define SECS_PER_DAY (60*60*24)
struct lonstr {
/* initial part must match struct empobj */
short ef_type;
short l_uid;
unsigned l_seqno;
unsigned l_generation;
time_t l_timestamp;
/* end of part matching struct empobj */
natid l_loner; /* loan shark */
natid l_lonee; /* sucker */
signed char l_status; /* loan status */
short l_sell; /* pointer to trade file (unused) */
int l_irate; /* interest rate */
int l_ldur; /* intended duration */
long l_amtpaid; /* amount paid so far */
long l_amtdue; /* amount still owed */
time_t l_lastpay; /* date of most recent payment */
time_t l_duedate; /* date after which interest doubles, etc */
};
#define LS_FREE AGREE_FREE
#define LS_PROPOSED AGREE_PROPOSED
#define LS_SIGNED AGREE_SIGNED
extern double loan_owed(struct lonstr *loan, time_t paytime);
#define getloan(n, p) ef_read(EF_LOAN, (n), (p))
#define putloan(n, p) ef_write(EF_LOAN, (n), (p))
#define getloanp(n) ((struct lonstr *)ef_ptr(EF_LOAN, (n)))
#endif