ttt/ttt-server.c

   1 /**************\r
   2 * Name:         gluefile.c\r
   3 * Author:       Jan Vales (e0726236@student.tuwien.ac.at)\r
   4 * Date:         3.12.2009\r
   5 * Purpose:      Game-Server. Does basic game stuff: init, cheat-checking and AI.\r
   6 * Usage:        ttt-server [-c]\r
   7 * Output:       debuginfo only\r
   8 **************/\r
   9 \r
  10 #include "globals.h"\r
  11 \r
  12 static int nSharedMemID = -1; /* ID for shared memory */\r
  13 static int semIDa = -1; /* semaphore 1 ID */\r
  14 static int semIDb = -1; /* semaphore 2 ID */\r
  15 static sharedmem_t *pSharedMem = (sharedmem_t *) -1;  /* pointer on sharedmem_t */\r
  16  \r
  17 char *szCommand = "";\r
  18 static char ccf[3][3];\r
  19 void bailOut(); /* Forward declaration */\r
  20 \r
  21 /* cleanup on shutdown */\r
  22 void cleanup() {\r
  23     if(pSharedMem!=(sharedmem_t *) -1) { /* shared mem attached? */\r
  24         if(shmdt((void *) pSharedMem)==-1) { \r
  25             pSharedMem = (sharedmem_t *) -1; /* shared mem not attached */\r
  26             bailOut("Can not detach semaphore");\r
  27         }\r
  28         pSharedMem = (sharedmem_t *) -1; /* shared mem not attached */\r
  29     }\r
  30     if(nSharedMemID!=-1) { /* shared mem already created ? */\r
  31         if(shmctl(nSharedMemID,IPC_RMID,(struct shmid_ds *) 0) == -1) {\r
  32             nSharedMemID = -1; /* shared mem not created */\r
  33             bailOut("Could not remove shared memory");\r
  34         }\r
  35         nSharedMemID = -1; /* shared mem not created */\r
  36     }\r
  37         \r
  38         if(semIDa!=-1){\r
  39         if((semrm(semIDa))==-1){ \r
  40             semIDa=-1; \r
  41             bailOut("Can not remove semaphore");\r
  42         }\r
  43         semIDa=-1;\r
  44     }\r
  45     if(semIDb!=-1){\r
  46         if(semrm(semIDb)==-1){\r
  47             semIDb=-1; \r
  48             bailOut("Can not remove semaphore");\r
  49         }\r
  50     }\r
  51 }\r
  52 \r
  53 \r
  54 /* prints error messages if an error has occoured */\r
  55 void bailOut(char *szMessage) {\r
  56     if(errno!=0) {\r
  57         (void) fprintf(stderr,"%s: %s - %s\n", szCommand,szMessage,strerror(errno));\r
  58     }else{\r
  59         (void) fprintf(stderr,"%s: %s\n", szCommand,szMessage);\r
  60     }\r
  61     cleanup();\r
  62     exit(EXIT_FAILURE);\r
  63 }\r
  64 \r
  65 /* handles signals */\r
  66 void handler(int nSignal) {\r
  67     cleanup();\r
  68     exit(EXIT_SUCCESS);\r
  69 }\r
  70 \r
  71 \r
  72 /* Game stuff starts here */\r
  73 \r
  74 void restartGame(){\r
  75         int i,j;\r
  76         for(i=0;i<3;i++) {\r
  77                 for(j=0;j<3;j++) {\r
  78                         ccf[i][j]=0;\r
  79                 }\r
  80         }\r
  81 \r
  82         for(i=0;i<3;i++) {\r
  83                 for(j=0;j<3;j++) {\r
  84                         pSharedMem->field[i][j]=0;\r
  85                 }\r
  86         }\r
  87 }\r
  88 \r
  89 int main(int argc, char **argv) {\r
  90         int i,j,cnt;\r
  91         int ccheck = 1;\r
  92         char c;\r
  93         szCommand = argv[0];\r
  94 \r
  95         while( (c = getopt(argc, argv, "c")) != EOF )  {\r
  96                 switch (c) {\r
  97                         case 'c':\r
  98                                 ccheck = 0;\r
  99                                 (void) fprintf(stdout,"Cheating erlaubt!\n");\r
 100                                 break;\r
 101                         case '?': (void) fprintf(stderr,"USAGE: %s [-c]\n", szCommand); exit(EXIT_FAILURE); break;\r
 102                         default: assert(0);\r
 103                 }\r
 104         }\r
 105 \r
 106         /* INIT SEM + SHM*/     \r
 107         if ((nSharedMemID = shmget(SHM_KEY,sizeof(sharedmem_t),PERM | IPC_CREAT | IPC_EXCL))==-1) {\r
 108                 bailOut("Cannot create shared memory");\r
 109         }\r
 110         if ((pSharedMem = (sharedmem_t *) shmat(nSharedMemID,(const void *) 0,0))==(sharedmem_t *) -1) {\r
 111                 bailOut("Cannot attach shared memory");\r
 112         }\r
 113         if ((semIDa=seminit(SEM_KEY_A, PERM, 1))==-1) {\r
 114                 bailOut("Cannot allocate semaphoreA");\r
 115         }\r
 116         if ((semIDb=seminit(SEM_KEY_B, PERM, 0))==-1) {\r
 117                 bailOut("Cannot allocate semaphoreB");\r
 118         }\r
 119 \r
 120         /* register handler */\r
 121         (void) signal(SIGINT, handler);\r
 122         (void) signal(SIGTERM, handler);\r
 123         (void) signal(SIGQUIT, handler);\r
 124 \r
 125         /* start game + reset cchk field */\r
 126         restartGame();\r
 127         (void) fprintf(stdout,"Server bereit!\n");\r
 128 \r
 129         /* the game routine */\r
 130         while (1) {\r
 131                 if(P(semIDb)==-1)bailOut("Could not P semaphore");\r
 132 \r
 133                 /* Cheack for cheating */\r
 134                 cnt = 0;\r
 135                 for(i=0;i<3;i++) {\r
 136                         for(j=0;j<3;j++) {\r
 137                                 if(pSharedMem->field[i][j] != ccf[i][j]){\r
 138                                         cnt++;\r
 139                                         ccf[i][j] = pSharedMem->field[i][j];\r
 140                                 }\r
 141                         }\r
 142                 }\r
 143                 if(pSharedMem->status == -1){\r
 144                         pSharedMem->status = 0;\r
 145                         cnt = 0;\r
 146                 }\r
 147                 if((cnt > 1) & (ccheck == 1) & (pSharedMem->status != -1)){\r
 148                         pSharedMem->status = -1;\r
 149                 }\r
 150 \r
 151                 if(pSharedMem->status == -1)(void)fprintf(stderr,"clientcheat detectet!\n");\r
 152 \r
 153 \r
 154                 /* check if Player is the winner */\r
 155                 for(i=0;i<3;i++) { /* check horizentale - */\r
 156                         if((pSharedMem->field[i][0] == 'X') & (pSharedMem->field[i][1] == 'X') & (pSharedMem->field[i][2] == 'X'))pSharedMem->status=2;\r
 157                         if((pSharedMem->field[0][i] == 'X') & (pSharedMem->field[1][i] == 'X') & (pSharedMem->field[2][i] == 'X'))pSharedMem->status=2;\r
 158                 }\r
 159                 if((pSharedMem->field[0][0] == 'X') & (pSharedMem->field[1][1] == 'X') & (pSharedMem->field[2][2] == 'X'))pSharedMem->status=2;\r
 160                 if((pSharedMem->field[0][2] == 'X') & (pSharedMem->field[1][1] == 'X') & (pSharedMem->field[2][0] == 'X'))pSharedMem->status=2;\r
 161 \r
 162 \r
 163                 /* only place my token, if client wanted to! */\r
 164                 if(pSharedMem->status == 1){\r
 165                         cnt = (rand() % 9)+1;\r
 166                         (void)fprintf(stderr,"rand: %d, %d, %d\n", cnt, (cnt/3), (cnt%3));\r
 167                         for(i = 0; i <= 10; i++) {\r
 168                                 if((i < 10) & (pSharedMem->field[(((cnt + i)%8)/3)][((cnt + i)%3)] == 0)){\r
 169                                         pSharedMem->field[(((cnt + i)%8)/3)][((cnt + i)%3)] = 'O';\r
 170                                         ccf[(((cnt + i)%8)/3)][((cnt + i)%3)] = 'O';\r
 171                                         break;\r
 172                                 }else{\r
 173                                 }\r
 174                         }\r
 175                         pSharedMem->status = 0;\r
 176                         if(i == 10){\r
 177                                 (void)fprintf(stderr," draw!");\r
 178                                 pSharedMem->status = 4;\r
 179                         }\r
 180 \r
 181                         /* print field on finish */\r
 182                         for(i=0; i < 3; i++) {\r
 183                                 (void) fprintf(stdout,"%c, %c, %c\n", pSharedMem->field[i][0], pSharedMem->field[i][1],pSharedMem->field[i][2]);\r
 184                         }\r
 185                 }\r
 186 \r
 187 \r
 188                 /* check if AI is the winner */\r
 189                 for(i=0;i<3;i++) { /* check horizentale - */\r
 190                         if((pSharedMem->field[i][0] == 'O') & (pSharedMem->field[i][1] == 'O') & (pSharedMem->field[i][2] == 'O'))pSharedMem->status=3;\r
 191                         if((pSharedMem->field[0][i] == 'O') & (pSharedMem->field[1][i] == 'O') & (pSharedMem->field[2][i] == 'O'))pSharedMem->status=3;\r
 192                 }\r
 193                 if((pSharedMem->field[0][0] == 'O') & (pSharedMem->field[1][1] == 'O') & (pSharedMem->field[2][2] == 'O'))pSharedMem->status=3;\r
 194                 if((pSharedMem->field[0][2] == 'O') & (pSharedMem->field[1][1] == 'O') & (pSharedMem->field[2][0] == 'O'))pSharedMem->status=3;\r
 195 \r
 196                 printf("status: %d\n", pSharedMem->status);\r
 197                 if(V(semIDa))bailOut("Could not V semaphore");\r
 198         }\r
 199 \r
 200     /* return 1337 for the guy who reached this impossible state! */\r
 201     return 1337; \r
 202 }\r