Linux 内核数据结构bitmap

 #include <stdio.h>
 #include <stdlib.h>

 #define MAX_PRIO 10000
 #define BITS_PER_LONG 32
 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))

 #define BIT(nr)            (1UL << (nr))
 #define BIT_MASK(nr)        (1UL << ((nr) % BITS_PER_LONG))
 #define BIT_WORD(nr)        ((nr) / BITS_PER_LONG)
 #define BITS_PER_BYTE        8

 #define BITS_TO_LONGS(nr)    DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))

 #define DECLARE_BITMAP(name,bits) \
     unsigned long name[BITS_TO_LONGS(bits)]

 static inline void __set_bit(int nr, volatile unsigned long *addr)
 {
     unsigned long mask = BIT_MASK(nr);
     unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);

     *p  |= mask;
 }

 static inline void __clear_bit(int nr, volatile unsigned long *addr)
 {
     unsigned long mask = BIT_MASK(nr);
     unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);

     *p &= ~mask;
 }

 static inline void __change_bit(int nr, volatile unsigned long *addr)
 {
     unsigned long mask = BIT_MASK(nr);
     unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);

     *p ^= mask;
 }

 static inline int __test_and_set_bit(int nr, volatile unsigned long *addr)
 {
     unsigned long mask = BIT_MASK(nr);
     unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
     unsigned long old = *p;

     *p = old | mask;
     return (old & mask) != ;
 }

 static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr)
 {
     unsigned long mask = BIT_MASK(nr);
     unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
     unsigned long old = *p;

     *p = old & ~mask;
     return (old & mask) != ;
 }

 static inline int __test_and_change_bit(int nr, volatile unsigned long *addr)
 {
     unsigned long mask = BIT_MASK(nr);
     unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
     unsigned long old = *p;

     *p = old ^ mask;
     return (old & mask) != ;
 }

 static inline int test_bit(int nr, const volatile unsigned long *addr)
 {
     return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-)));
 }

 #ifndef container_of
 /**
  * container_of - cast a member of a structure out to the containing structure
  * @ptr:    the pointer to the member.
  * @type:    the type of the container struct this is embedded in.
  * @member:    the name of the member within the struct.
  *
  */
 #define container_of(ptr, type, member) ({            \
     const typeof(((type *))->member) * __mptr = (ptr);    \
     (type *)((char *)__mptr - offsetof(type, member)); })
 #endif

 #define list_entry(ptr, type, member) container_of(ptr, type, member)

 int _tmain(int argc, _TCHAR* argv[])
 {
     DECLARE_BITMAP(bitmap1, MAX_PRIO);
     DECLARE_BITMAP(bitmap2, MAX_PRIO);
     int i;

     /* 00000000 - 99999999 使用一个bitmap */
     int num1 = ;
     int num2 = ;

     char buff[] = {};

     for (i = ; i < MAX_PRIO; i++) {

         __clear_bit(i, bitmap1);
         __clear_bit(i, bitmap2);
     }

     __set_bit(num1, bitmap1);
     __set_bit(num2, bitmap2);

     printf("bitmap size = %d\n", sizeof(bitmap1)/sizeof(long));
     printf("bitmap = %d\n", test_bit(num1, bitmap1));
     printf("bitmap = %d\n", test_bit(num2, bitmap2));
     printf("atoi : %d\n", atoi(""));
     printf("%.4d%.4d\n", num1, num2);
      return ;
 }