vlc_atomic.h

/*****************************************************************************
 * vlc_atomic.h:
 *****************************************************************************
 * Copyright (C) 2010 Rémi Denis-Courmont
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

#ifdef __cplusplus
# error Not implemented in C++.
#endif

#ifndef VLC_ATOMIC_H
# define VLC_ATOMIC_H

/**
 * \file
 * Atomic operations do not require locking, but they are not very powerful.
 */

# include <stdatomic.h>

typedef atomic_uint_least32_t vlc_atomic_float;

static inline void vlc_atomic_init_float(vlc_atomic_float *var, float f)
{
    union { float f; uint32_t i; } u;
    u.f = f;
    atomic_init(var, u.i);
}

/** Helper to retrieve a single precision from an atom. */
static inline float vlc_atomic_load_float(vlc_atomic_float *atom)
{
    union { float f; uint32_t i; } u;
    u.i = atomic_load(atom);
    return u.f;
}

/** Helper to store a single precision into an atom. */
static inline void vlc_atomic_store_float(vlc_atomic_float *atom, float f)
{
    union { float f; uint32_t i; } u;
    u.f = f;
    atomic_store(atom, u.i);
}

#endif