include/linux/refcount.h

   1 #ifndef _LINUX_REFCOUNT_H
   2 #define _LINUX_REFCOUNT_H
   3
   4 #include <linux/atomic.h>
   5 #include <linux/mutex.h>
   6 #include <linux/spinlock.h>
   7 #include <linux/kernel.h>
   8
   9 typedef struct refcount_struct {
  10         atomic_t refs;
  11 } refcount_t;
  12
  13 #define REFCOUNT_INIT(n)        { .refs = ATOMIC_INIT(n), }
  14
  15 static inline void refcount_set(refcount_t *r, unsigned int n)
  16 {
  17         atomic_set(&r->refs, n);
  18 }
  19
  20 static inline unsigned int refcount_read(const refcount_t *r)
  21 {
  22         return atomic_read(&r->refs);
  23 }
  24
  25 extern __must_check bool refcount_add_not_zero(unsigned int i, refcount_t *r);
  26 extern void refcount_add(unsigned int i, refcount_t *r);
  27
  28 extern __must_check bool refcount_inc_not_zero(refcount_t *r);
  29 extern void refcount_inc(refcount_t *r);
  30
  31 extern __must_check bool refcount_sub_and_test(unsigned int i, refcount_t *r);
  32 extern void refcount_sub(unsigned int i, refcount_t *r);
  33
  34 extern __must_check bool refcount_dec_and_test(refcount_t *r);
  35 extern void refcount_dec(refcount_t *r);
  36
  37 extern __must_check bool refcount_dec_if_one(refcount_t *r);
  38 extern __must_check bool refcount_dec_not_one(refcount_t *r);
  39 extern __must_check bool refcount_dec_and_mutex_lock(refcount_t *r, struct mutex *lock);
  40 extern __must_check bool refcount_dec_and_lock(refcount_t *r, spinlock_t *lock);
  41
  42 #endif /* _LINUX_REFCOUNT_H */