apps/lib/stdlibc/stdlib.c

   1 /*
   2     meinOS - A unix-like x86 microkernel operating system
   3     Copyright (C) 2008  Janosch Gräf <janosch.graef@gmx.net>
   4
   5     This program is free software: you can redistribute it and/or modify
   6     it under the terms of the GNU Lesser General Public License as published by
   7     the Free Software Foundation, either version 3 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU Lesser General Public License for more details.
  14
  15     You should have received a copy of the GNU Lesser General Public License
  16     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 #include <sys/types.h>
  20 #include <string.h>
  21 #include <errno.h>
  22 #include <stdlib.h>
  23 #include <limits.h>
  24 #include <ctype.h>
  25 #include <llist.h>
  26 #include <syscall.h>
  27 #include <time.h>
  28 #include <stdint.h>
  29
  30 // some variables/functions needed
  31 void stdio_init();                                       ///< @see stdio.h
  32 void env_init();                                         ///< @see env.c
  33 llist_t atexit_list;                                     ///< @see stdlib.c
  34 void _close_all_filehandles();                           ///< @see files.c
  35 void _signal_init();                                     ///< @see signal.c
  36 void _fs_init(char *_stdin,char *_stdout,char *_stderr); ///< @see apps/lib/stdlibc/files.c
  37
  38 void _stdlib_init_pre() {
  39   rand_seed = rand_seed%RAND_MAX;
  40   errno = 0;
  41   atexit_list = llist_create();
  42   _signal_init();
  43 }
  44 #include <stdio.h>
  45 void _stdlib_init_post(char *_stdin,char *_stdout,char *_stderr) {
  46   env_init();
  47   _fs_init(_stdin,_stdout,_stderr);
  48   stdio_init();
  49 }
  50
  51 /**
  52  * Exits process
  53  *  @param result Program result value
  54  *  @see also used by crt0.asm
  55  */
  56 void exit(int result) {
  57   void (*func)(void);
  58   while ((func = llist_pop(atexit_list))!=NULL) func();
  59   _Exit(result);
  60 }
  61
  62 /**
  63  * Closes all filehandles and exits
  64  *  @param result Program result
  65  */
  66 void _Exit(int result) {
  67   _close_all_filehandles();
  68   syscall_call(SYSCALL_PROC_EXIT,1,result);
  69 }
  70
  71 /**
  72  * Registers a function to run at process termination
  73  *  @param func Function
  74  *  @return 0=successful; -1=failed
  75  */
  76 int atexit(void (*func)(void)) {
  77   return llist_push(atexit_list,func)!=NULL?0:-1;
  78 }
  79
  80 /**
  81  * Converts a string to a number
  82  *  @param str String representing a number
  83  *  @return Represented number from string
  84  */
  85 int atoi(const char *str) {
  86   size_t len,i;
  87   int num = 0;
  88   int sign = 0;
  89
  90   len = strlen(str);
  91   for (i=0;i<len;i++) {
  92     if (str[i]=='+') sign = 0;
  93     else if (str[i]=='-') sign = 1;
  94     else num = num*10+str[i]-'0';
  95   }
  96   if (sign) num *= -1;
  97   return num;
  98 }
  99
 100 /**
 101  * Returns absolute number
 102  *  @param num Number to get absolute number of
 103  *  @return Absolute number
 104  */
 105 int abs(int num) {
 106   if (num<0) num = -num;
 107   return num;
 108 }
 109
 110 /**
 111  * Devides a number
 112  *  @param numer Numer
 113  *  @param denom Denom
 114  *  @return Devision result
 115  */
 116 div_t div(int numer, int denom) {
 117   div_t res;
 118   res.quot = numer/denom;
 119   res.rem = numer%denom;
 120   return res;
 121 }
 122
 123 /**
 124  * Binary search a sorted table
 125  *  @param vdkey Key
 126  *  @param vdbase Base
 127  *  @param nel Num elements
 128  *  @param width Size of an element
 129  *  @param compar Function called when match found
 130  */
 131 void *bsearch(const void *vdkey,const void *vdbase,size_t nel,size_t width,int (*compar)(const void *, const void *)) {
 132   char *key = (char*)vdkey;
 133   char *cpkey = memcpy(malloc(width),key,width);
 134   char *base = (char*)vdbase;
 135   void *last = NULL;
 136   size_t found = 0;
 137   size_t i;
 138
 139   for (i=0;i<nel;i++) {
 140     if (*(base+nel*width)==*key) found++;
 141     if (found==width) {
 142       char *cpbase = memcpy(malloc(width),base,width);
 143       if (compar!=NULL) compar(key,base);
 144       *key = *cpkey;
 145       *base = *cpbase;
 146       free(cpbase);
 147       found = 0;
 148       last = (void*)(vdbase+nel*width);
 149     }
 150   }
 151
 152   free(cpkey);
 153   return last;
 154 }
 155
 156 /**
 157  * Gets a new page from kernel
 158  *  @param size How many bytes (should be devidable by PAGESIZE)
 159  *  @return Pointer to new page
 160  */
 161 void *sbrk(intptr_t size) {
 162   return (void*)syscall_call(SYSCALL_MEM_MALLOC,1,size);
 163 }
 164
 165 /// @todo FIXME
 166 int rand() {
 167   return 0xD00FC0DE;
 168   const int N = 624;
 169   const int M = 397;
 170   const unsigned A[2] = { 0, 0x9908b0df };
 171   const unsigned HI = 0x80000000;
 172   const unsigned LO = 0x7fffffff;
 173
 174   static unsigned *y;
 175   static int init = 0;
 176   static int index;
 177   if (!init) {
 178     index = N;
 179     init = 1;
 180   }
 181
 182   if (index >= N) {
 183     if (index > N) {
 184        // initialisiere y mit Pseudozufallszahlen:
 185        y = calloc(N,sizeof(unsigned int));
 186        unsigned r = 9, s = 3402;
 187        int i;
 188        for (i=0 ; i<N ; ++i) {
 189           r = 509845221 * r + 3;
 190           s *= s + 1;
 191           y[i] = s + (r >> 10);
 192        }
 193     }
 194     unsigned h;
 195     int k;
 196     for (k=0 ; k<N-M ; ++k) {
 197        h = (y[k] & HI) | (y[k+1] & LO);
 198        y[k] = y[k+M] ^ (h >> 1) ^ A[h & 1];
 199     }
 200     for (k=N-M ; k<N-1 ; ++k) {
 201        h = (y[k] & HI) | (y[k+1] & LO);
 202        y[k] = y[k+(M-N)] ^ (h >> 1) ^ A[h & 1];
 203     }
 204     h = (y[N-1] & HI) | (y[0] & LO);
 205     y[N-1] = y[M-1] ^ (h >> 1) ^ A[h & 1];
 206     index = 0;
 207   }
 208
 209   unsigned e = y[index++];
 210   // tempering:
 211   e ^= (e >> 11);
 212   e ^= (e << 7) & 0x9d2c5680;
 213   e ^= (e << 15) & 0xefc60000;
 214   e ^= (e >> 18);
 215   return e%RAND_MAX;
 216 }