view src/shmem.c @ 18:1424868939a8

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author darius
date Wed, 24 Dec 1997 12:38:35 +0000
parents 8c6d5731234d
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/*--------------------------------------------------------------------------
NETREK II -- Paradise

Permission to use, copy, modify, and distribute this software and its
documentation, or any derivative works thereof, for any NON-COMMERCIAL
purpose and without fee is hereby granted, provided that this copyright
notice appear in all copies.  No representations are made about the
suitability of this software for any purpose.  This software is provided
"as is" without express or implied warranty.

    Xtrek Copyright 1986                            Chris Guthrie
    Netrek (Xtrek II) Copyright 1989                Kevin P. Smith
                                                    Scott Silvey
    Paradise II (Netrek II) Copyright 1993          Larry Denys
                                                    Kurt Olsen
                                                    Brandon Gillespie
--------------------------------------------------------------------------*/

#include "config.h"
#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <errno.h>
#include <signal.h>

#include "shmem.h"
#include "path.h"
#include "data.h"

/*---------------------------SHARED MEMORY STRUCTURE----------------------*/

#include "shmemP.h"

/*-------------------------------------------------------------------------*/

struct player *players;
struct torp *torps;
struct missile *missiles;
struct thingy *thingies;
struct plasmatorp *plasmatorps;
struct status *status;
struct status2 *status2;
struct planet *planets;
struct t_unit *terrain_grid;
struct phaser *phasers;
int *stars;
struct mctl *mctl;
struct message *messages;
struct team *teams;

struct ship *shipvals;
struct configuration *configvals;
int *shipsallowed;		/* points inside configvals */
int *weaponsallowed;		/* ditto */
int *sun_effect;
int *ast_effect;
int *neb_effect;
int *wh_effect;
int *num_nebula;
int *nebula_density;
int *nebula_subclouds;
int *num_asteroid;
float *asteroid_thickness;
int *asteroid_density;
int *asteroid_radius;
float *asteroid_thick_variance;
int *asteroid_dens_variance;
int *asteroid_rad_variance;
int *improved_tracking;
int *tstart;
int *newgalaxy;
int *nontteamlock;
char *cluephrase_storage;

static int PKEY = 128;

/*------------------------------STARTDAEMON---------------------------------*/
/*
 * This function starts the daemon.  It get the path to where the daemon
 * resides, then tries to start it up.
 */


#ifndef SYSV			/* HP/UX hates this */
extern int fprintf();
#endif
extern pid_t fork();
extern int execl();
extern void perror();
extern int shmget();
#ifndef IRIX
extern int shmctl();
#endif
extern unsigned int sleep();
extern uid_t geteuid();

void
startdaemon(leagueflag, restart)
  int leagueflag, restart;
{
  int i;			/* temp var */
  char *hell;			/* to hold path to daemon */

  if (restart)
  {
    fprintf(stderr, "RE-");
    kill(status->nukegame, SIGKILL);	/* daemon is killed without giving it
					 * a chance to blast the shmem */
    sleep(2);
  }
  fprintf(stderr, "Starting daemon...\n");	/* record that deaemon is */
  i = fork();			/* starting */
  if (i == 0)
  {				/* if successful */
    char *nargv[10];
    int argc = 0;
    hell = build_path(DAEMON);
    nargv[argc++] = "daemon";
    if (leagueflag)
      nargv[argc++] = "-l";
    if (restart)
      nargv[argc++] = "-a";
    nargv[argc] = 0;
    execv(hell, nargv);

    perror(hell);		/* did it work */
    fprintf(stderr, "Couldn't start daemon!!!\n");
    _exit(1);			/* let's get out of here */
  }
}



static int shmid = -1;		/* ID number of shared mem */


/*--------------------------------OPENMEM----------------------------------*/
/*
 * if code is 0, openmem will exit(1) upon finding the memory gone. if code
 * is 1, openmem will fork a netrek daemon and retry. if code is 2, openmem
 * will blast any already existing shared memory.
 */

void
openmem(code, leagueflag)
  int code;
  int leagueflag;		/* only used if code==1 */
{
  extern int errno;		/* to get error number */
  key_t shmemKey = PKEY;	/* shared memory's key */
  struct memory *sharedMemory;	/* to point to shared memory */
  char *k;

  k = getenv("TREKSHMKEY");	/* grab shared mem id environment variable */
  if (k)
  {				/* if it's set... */
    int i;
    if (sscanf(k, "%d", &i) > 0 && i > 0)	/* ...grab its value... */
      shmemKey = i;		/* ...and use it */
  }

  errno = 0;			/* clear error number */
  shmid = shmget(shmemKey, 0, 0);	/* get id of shared mem */
  if (code == 2)
  {
    if (shmid >= 0)
    {
      /* If we're in daemon mode and we opened the memory */
      /* "There can be only one". */
      fprintf(stderr, "Killing existing segment\n");
      shmctl(shmid, IPC_RMID, (struct shmid_ds *) 0);
      /* create a new one */
    }
    shmid = shmget(shmemKey, sizeof(struct memory), IPC_CREAT | 0666);
  }
  if (shmid < 0)
  {				/* if shared mem does not exist */
    switch (code)
    {
     case 0:
      if (errno != ENOENT)
      {				/* catastrophic, sell all your stock */
	perror("shmget");	/* and leave the country type of */
	exit(1);		/* error--suicide */
      }
      fprintf(stderr, "Daemon not running (err:%d)\n", errno);
      exit(1);
     case 1:
      if (errno != ENOENT)
      {				/* catastrophic, sell all your stock */
	perror("shmget");	/* and leave the country type of */
	exit(1);		/* error--suicide */
      }
      startdaemon(leagueflag, 0);	/* try to start the daemon */
      sleep(2);			/* wait for a sec for deamon to start */
      shmid = shmget(shmemKey, 0, 0);	/* try again to get shared mem */
      if (shmid < 0)
      {				/* failure again then get out of here */
	fprintf(stderr, "Daemon not running (err:%d)\n", errno);
	exit(1);
      }
      break;
     case 2:
      perror("daemon: can't open shared memory");
      exit(1);
    }
  }
  if (code == 2)
  {
    struct shmid_ds smbuf;

    shmctl(shmid, IPC_STAT, &smbuf);	/* Hose Ed's robots */
    smbuf.shm_perm.uid = geteuid();
    smbuf.shm_perm.mode = 0666;
    shmctl(shmid, IPC_SET, &smbuf);
  }
  sharedMemory = (struct memory *) shmat(shmid, (char *) 0, 0);
  if (sharedMemory == (struct memory *) - 1)
  {
    perror("shared memory");
    exit(1);
  }
  if (code == 2)
  {
    /* set the magic number */
    sharedMemory->shmem_size = sizeof(struct memory);
  }
  else
  {
    if (sharedMemory->shmem_size != sizeof(struct memory))
    {
      fprintf(stderr, "shared memory segment magic number mismatch!\
 (%d != %ld)\n  aborting to prevent corruption of game data\n",
	      sharedMemory->shmem_size, (long) sizeof(struct memory));
      exit(1);
    }
  }
  players = sharedMemory->players;	/* set pointer to fields */
  torps = sharedMemory->torps;	/* in shared memory structure */
  missiles = sharedMemory->missiles;	/* for easy access */
  thingies = sharedMemory->thingies;
  plasmatorps = sharedMemory->plasmatorps;
  status = &sharedMemory->status;
  status2 = &sharedMemory->status2;
  planets = sharedMemory->planets;
  terrain_grid = sharedMemory->terrain_grid;
  phasers = sharedMemory->phasers;
  stars = sharedMemory->stars;
  mctl = &sharedMemory->mctl;
  messages = sharedMemory->messages;
  teams = sharedMemory->teams;
  shipvals = sharedMemory->shipvals;
  configvals = &sharedMemory->configvals;
  galaxyValid = &sharedMemory->galaxyValid;
  /* configvals->gwidth = 200000; *//* pick up from galaxy generator later */
  /* configvals->numplanets = 60; *//* this too */

  shipsallowed = configvals->shipsallowed;
  weaponsallowed = configvals->weaponsallowed;
  sun_effect = configvals->sun_effect;
  ast_effect = configvals->ast_effect;
  neb_effect = configvals->neb_effect;
  wh_effect = configvals->wh_effect;
  num_nebula = &(configvals->num_nebula);
  nebula_density = &(configvals->nebula_density);
  nebula_subclouds = &(configvals->nebula_subclouds);
  num_asteroid = &(configvals->num_asteroid);
  asteroid_thickness = &(configvals->asteroid_thickness);
  asteroid_density = &(configvals->asteroid_density);
  asteroid_radius = &(configvals->asteroid_radius);
  asteroid_thick_variance = &(configvals->asteroid_thick_variance);
  asteroid_dens_variance = &(configvals->asteroid_dens_variance);
  asteroid_rad_variance = &(configvals->asteroid_rad_variance);
  improved_tracking = configvals->improved_tracking;

  cluephrase_storage = sharedMemory->cluephrase_storage;

  stars[1] = -1;
}

void
blast_shmem()
{
  shmctl(shmid, IPC_RMID, (struct shmid_ds *) 0);
}