1 /*****************************************************************************
3 *****************************************************************************
4 * Copyright (C) 2010 RĂ©mi Denis-Courmont
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
19 *****************************************************************************/
25 #include <vlc_common.h>
26 #include <vlc_atomic.h>
28 #if defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
31 uintptr_t vlc_atomic_get (const vlc_atomic_t *atom)
33 __sync_synchronize ();
37 uintptr_t vlc_atomic_set (vlc_atomic_t *atom, uintptr_t v)
40 __sync_synchronize ();
44 uintptr_t vlc_atomic_add (vlc_atomic_t *atom, uintptr_t v)
46 return __sync_add_and_fetch (&atom->u, v);
49 uintptr_t vlc_atomic_swap (vlc_atomic_t *atom, uintptr_t v)
51 /* grmbl, gcc does not provide an intrinsic for this! */
55 u = vlc_atomic_get (atom);
56 while (vlc_atomic_compare_swap (atom, u, v) != u);
61 uintptr_t vlc_atomic_compare_swap (vlc_atomic_t *atom,
62 uintptr_t oldval, uintptr_t newval)
64 return __sync_val_compare_and_swap (&atom->u, oldval, newval);
68 /* Worst-case fallback implementation with a mutex */
70 static vlc_mutex_t lock = VLC_STATIC_MUTEX;
72 uintptr_t vlc_atomic_get (const vlc_atomic_t *atom)
76 vlc_mutex_lock (&lock);
78 vlc_mutex_unlock (&lock);
82 uintptr_t vlc_atomic_set (vlc_atomic_t *atom, uintptr_t v)
84 vlc_mutex_lock (&lock);
86 vlc_mutex_unlock (&lock);
90 uintptr_t vlc_atomic_add (vlc_atomic_t *atom, uintptr_t v)
92 vlc_mutex_lock (&lock);
95 vlc_mutex_unlock (&lock);
99 uintptr_t vlc_atomic_swap (vlc_atomic_t *atom, uintptr_t v)
103 vlc_mutex_lock (&lock);
106 vlc_mutex_unlock (&lock);
111 uintptr_t vlc_atomic_compare_swap (vlc_atomic_t *atom,
112 uintptr_t oldval, uintptr_t newval)
116 vlc_mutex_lock (&lock);
120 vlc_mutex_unlock (&lock);