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 <stdint.h>
  28
  29 // some variables/functions needed
  30 void stdio_init();                                       ///< @see stdio.h
  31 void env_init();                                         ///< @see env.c
  32 llist_t atexit_list;                                     ///< @see stdlib.c
  33 void _close_all_filehandles();                           ///< @see files.c
  34 void _signal_init();                                     ///< @see signal.c
  35 void _fs_init(char *_stdin,char *_stdout,char *_stderr); ///< @see apps/lib/stdlibc/files.c
  36
  37 void _stdlib_init_pre() {
  38   rand_seed = rand_seed%RAND_MAX;
  39   errno = 0;
  40   atexit_list = llist_create();
  41   _signal_init();
  42 }
  43 #include <stdio.h>
  44 void _stdlib_init_post(char *_stdin,char *_stdout,char *_stderr) {
  45   env_init();
  46   _fs_init(_stdin,_stdout,_stderr);
  47   stdio_init();
  48 }
  49
  50 /**
  51  * Exits process
  52  *  @param result Program result value
  53  *  @see also used by crt0.asm
  54  */
  55 void exit(int result) {
  56   void (*func)(void);
  57   while ((func = llist_pop(atexit_list))!=NULL) func();
  58   _Exit(result);
  59 }
  60
  61 /**
  62  * Closes all filehandles and exits
  63  *  @param result Program result
  64  */
  65 void _Exit(int result) {
  66   _close_all_filehandles();
  67   syscall_call(SYSCALL_PROC_EXIT,1,result);
  68 }
  69
  70 /**
  71  * Registers a function to run at process termination
  72  *  @param func Function
  73  *  @return 0=successful; -1=failed
  74  */
  75 int atexit(void (*func)(void)) {
  76   return llist_push(atexit_list,func)!=NULL?0:-1;
  77 }
  78
  79 /**
  80  * Converts a string to a number
  81  *  @param str String representing a number
  82  *  @return Represented number from string
  83  */
  84 int atoi(const char *str) {
  85   size_t len,i;
  86   int num = 0;
  87   int sign = 0;
  88
  89   len = strlen(str);
  90   for (i=0;i<len;i++) {
  91     if (str[i]=='+') sign = 0;
  92     else if (str[i]=='-') sign = 1;
  93     else num = num*10+str[i]-'0';
  94   }
  95   if (sign) num *= -1;
  96   return num;
  97 }
  98
  99 /**
 100  * Returns absolute number
 101  *  @param num Number to get absolute number of
 102  *  @return Absolute number
 103  */
 104 int abs(int num) {
 105   if (num<0) num = -num;
 106   return num;
 107 }
 108
 109 /**
 110  * Devides a number
 111  *  @param numer Numer
 112  *  @param denom Denom
 113  *  @return Devision result
 114  */
 115 div_t div(int numer, int denom) {
 116   div_t res;
 117   res.quot = numer/denom;
 118   res.rem = numer%denom;
 119   return res;
 120 }
 121
 122 /**
 123  * Binary search a sorted table
 124  *  @param vdkey Key
 125  *  @param vdbase Base
 126  *  @param nel Num elements
 127  *  @param width Size of an element
 128  *  @param compar Function called when match found
 129  */
 130 void *bsearch(const void *vdkey,const void *vdbase,size_t nel,size_t width,int (*compar)(const void *, const void *)) {
 131   char *key = (char*)vdkey;
 132   char *cpkey = memcpy(malloc(width),key,width);
 133   char *base = (char*)vdbase;
 134   void *last = NULL;
 135   size_t found = 0;
 136   size_t i;
 137
 138   for (i=0;i<nel;i++) {
 139     if (*(base+nel*width)==*key) found++;
 140     if (found==width) {
 141       char *cpbase = memcpy(malloc(width),base,width);
 142       if (compar!=NULL) compar(key,base);
 143       *key = *cpkey;
 144       *base = *cpbase;
 145       free(cpbase);
 146       found = 0;
 147       last = (void*)(vdbase+nel*width);
 148     }
 149   }
 150
 151   free(cpkey);
 152   return last;
 153 }
 154
 155 /**
 156  * Gets a new page from kernel
 157  *  @param size How many bytes (should be devidable by PAGESIZE)
 158  *  @return Pointer to new page
 159  */
 160 void *sbrk(intptr_t size) {
 161   return (void*)syscall_call(SYSCALL_MEM_MALLOC,1,size);
 162 }
 163
 164 /// @todo FIXME
 165 int rand() {
 166   return 0xD00FC0DE;
 167   const int N = 624;
 168   const int M = 397;
 169   const unsigned A[2] = { 0, 0x9908b0df };
 170   const unsigned HI = 0x80000000;
 171   const unsigned LO = 0x7fffffff;
 172
 173   static unsigned *y;
 174   static int init = 0;
 175   static int index;
 176   if (!init) {
 177     index = N;
 178     init = 1;
 179   }
 180
 181   if (index >= N) {
 182     if (index > N) {
 183        // initialisiere y mit Pseudozufallszahlen:
 184        y = calloc(N,sizeof(unsigned int));
 185        unsigned r = 9, s = 3402;
 186        int i;
 187        for (i=0 ; i<N ; ++i) {
 188           r = 509845221 * r + 3;
 189           s *= s + 1;
 190           y[i] = s + (r >> 10);
 191        }
 192     }
 193     unsigned h;
 194     int k;
 195     for (k=0 ; k<N-M ; ++k) {
 196        h = (y[k] & HI) | (y[k+1] & LO);
 197        y[k] = y[k+M] ^ (h >> 1) ^ A[h & 1];
 198     }
 199     for (k=N-M ; k<N-1 ; ++k) {
 200        h = (y[k] & HI) | (y[k+1] & LO);
 201        y[k] = y[k+(M-N)] ^ (h >> 1) ^ A[h & 1];
 202     }
 203     h = (y[N-1] & HI) | (y[0] & LO);
 204     y[N-1] = y[M-1] ^ (h >> 1) ^ A[h & 1];
 205     index = 0;
 206   }
 207
 208   unsigned e = y[index++];
 209   // tempering:
 210   e ^= (e >> 11);
 211   e ^= (e << 7) & 0x9d2c5680;
 212   e ^= (e << 15) & 0xefc60000;
 213   e ^= (e >> 18);
 214   return e%RAND_MAX;
 215 }