/* Copyright (C) 2010, 2011 Tony Garnock-Jones. All rights reserved. */

#ifndef cmsg_ref_h
#define cmsg_ref_h

typedef struct refcount_t_ {
  unsigned int count;
} refcount_t;

#define ZERO_REFCOUNT() ((refcount_t) { .count = 0 })

#define INCREF(x) ({				\
      typeof(x) __x = (x);			\
      if (__x != NULL) {			\
	__x->refcount.count++;			\
      }						\
      __x;					\
    })

#define UNGRAB(x) ({				\
      typeof(x) __x = (x);			\
      if (__x != NULL) {			\
	assert(__x->refcount.count);		\
	__x->refcount.count--;			\
      }						\
      __x;					\
    })

#define DECREF(x, dtor) ({			\
    typeof(x) __x = (x);			\
    if (__x != NULL) {				\
      assert(__x->refcount.count);		\
      (__x->refcount.count)--;			\
      if (__x->refcount.count == 0) {		\
	(dtor)(__x);				\
      }						\
    }						\
    (typeof(__x)) 0;				\
  })

#endif