oro_atomic.h

#ifndef __ARCH_NOASM_ORO_ATOMIC__
#define __ARCH_NOASM_ORO_ATOMIC__

/*
 * @file Atomic operations that C can't guarantee us.  Useful for
 * resource counting etc. We emulate it using mutexes.
 */

#include "../../rtt-config.h"
#include "../fosi.h"

#ifndef __GNUC__
#define __inline__
#endif

/*
 * Make sure gcc doesn't try to be clever and move things around
 * on us. We need to use _exactly_ the address the user gave us,
 * not some alias that contains the same information.
 */
typedef struct { rt_mutex_t m; volatile int counter; } oro_atomic_t;

#define ORO_ATOMIC_INIT(i)  { (i) }
#define ORO_ATOMIC_SETUP(v,i)   rtos_mutex_init(&((v)->m)); (v)->counter = (i);
#define ORO_ATOMIC_CLEANUP(v)   rtos_mutex_destroy(&((v)->m));

#define oro_atomic_read(v)      ((v)->counter)

#define oro_atomic_set(v,i)     (((v)->counter) = (i))

static __inline__ void oro_atomic_add(int i, oro_atomic_t *v)
{
  rtos_mutex_lock(&((v)->m)); (v)->counter += i; rtos_mutex_unlock(&((v)->m));
}

static __inline__ void oro_atomic_sub(int i, oro_atomic_t *v)
{
  rtos_mutex_lock(&((v)->m)); (v)->counter -= i; rtos_mutex_unlock(&((v)->m));
}

static __inline__ int oro_atomic_sub_and_test(int i, oro_atomic_t *v)
{
  int ret = 0;
  rtos_mutex_lock(&((v)->m)); (v)->counter -= i;  ret = ((v)->counter == 0); rtos_mutex_unlock(&((v)->m));
  return ret;
}

static __inline__ void oro_atomic_inc(oro_atomic_t *v)
{
  rtos_mutex_lock(&((v)->m)); ++((v)->counter) ; rtos_mutex_unlock(&((v)->m));
}

static __inline__ void oro_atomic_dec(oro_atomic_t *v)
{
  rtos_mutex_lock(&((v)->m)); --((v)->counter) ; rtos_mutex_unlock(&((v)->m));
}

static __inline__ int oro_atomic_dec_and_test(oro_atomic_t *v)
{
  int ret = 0;
  rtos_mutex_lock(&((v)->m)); --((v)->counter);  ret = ((v)->counter == 0); rtos_mutex_unlock(&((v)->m));
  return ret;
}

static __inline__ int oro_atomic_inc_and_test(oro_atomic_t *v)
{
  int ret = 0;
  rtos_mutex_lock(&((v)->m)); ++((v)->counter);  ret = ((v)->counter == 0); rtos_mutex_unlock(&((v)->m));
  return ret;
}

static __inline__ int oro_atomic_add_negative(int i, oro_atomic_t *v)
{
  int ret = 0;
  rtos_mutex_lock(&((v)->m)); (v)->counter += i;  ret = ((v)->counter < 0); rtos_mutex_unlock(&((v)->m));
  return ret;
}

#endif