include/bit_array.h

   1 /***************************************************************************
   2  * Copyright 1995, Technion, Israel Institute of Technology
   3  * Electrical Eng, Software Lab.
   4  * Author:    Michael Veksler.
   5  ***************************************************************************
   6  * File:      bit_array.h
   7  * Purpose :  manipulate array of bits,
   8  * Important: operations may be considered atomic.
   9  *
  10  ***************************************************************************
  11  */
  12 #ifndef __WINE_BIT_ARRAY_H
  13 #define __WINE_BIT_ARRAY_H
  14
  15
  16 #define BITS_PER_BYTE (8)
  17 #define BITS_PER_INT (sizeof(int)*BITS_PER_BYTE) /* must be power of 2 */
  18
  19 #define BYTE_LOG2 (3)
  20 #if defined(INT_LOG2)
  21 /* nothing to do, IN_LOG2 is ok */
  22 #elif defined(__i386__)
  23 #  define INT_LOG2 (5)
  24 #else
  25 #  error "Can't find log2 of BITS_PER_INT, please code it manualy"
  26 #endif
  27
  28
  29 typedef struct bit_array {
  30         int bits;                  /* number of bits in the array */
  31         unsigned int *array;       /* Actual array data (Never NULL) */
  32 } bit_array ;
  33
  34 bit_array *AssembleArray(bit_array *new_array, unsigned int *buff, int bits);
  35 int ResetArray(bit_array *bits);
  36
  37 /* Return index of first free bit, or -1 on failure */
  38 int VacantBit(bit_array *bits);
  39
  40
  41 /* Return the value of bit 'i' */
  42 int SampleBit(bit_array *bits, int i);
  43
  44 /* Assign 'val' to a bit no. 'i'.      Return: old bit's value */
  45 int AssignBit(bit_array *bits, int i, int val);
  46
  47 /*
  48 ** Allocate a free bit (==0) and make it used (==1).
  49 ** Return: allocated bit index, or -1 on failure.
  50 */
  51 int AllocateBit(bit_array *bits);
  52
  53 #endif /* __WINE_BIT_ARRAY_H */