mirror of
https://github.com/mpv-player/mpv
synced 2024-12-12 18:06:18 +00:00
70c990cda5
The waf build system generates this already. No point in redoing it in the header file. The legacy build system (which we really should drop) didn't; fix it.
103 lines
3.6 KiB
C
103 lines
3.6 KiB
C
/*
|
|
* This file is part of mpv.
|
|
* Copyright (c) 2013 Stefano Pigozzi <stefano.pigozzi@gmail.com>
|
|
*
|
|
* mpv is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* mpv 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 General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with mpv. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#ifndef MP_ATOMICS_H
|
|
#define MP_ATOMICS_H
|
|
|
|
#include <inttypes.h>
|
|
#include "config.h"
|
|
|
|
#if HAVE_STDATOMIC
|
|
#include <stdatomic.h>
|
|
#else
|
|
|
|
// Emulate the parts of C11 stdatomic.h needed by mpv.
|
|
// Still relies on gcc/clang atomic builtins.
|
|
// The t field is a hack to make the non-atomic fallback macro mess work.
|
|
|
|
typedef struct { volatile unsigned long v, t; } atomic_ulong;
|
|
typedef struct { volatile int v, t; } atomic_int;
|
|
typedef struct { volatile unsigned int v, t; } atomic_uint;
|
|
typedef struct { volatile _Bool v, t; } atomic_bool;
|
|
typedef struct { volatile long long v, t; } atomic_llong;
|
|
typedef struct { volatile uint_least32_t v, t; } atomic_uint_least32_t;
|
|
typedef struct { volatile unsigned long long v, t; } atomic_ullong;
|
|
|
|
#define ATOMIC_VAR_INIT(x) \
|
|
{.v = (x)}
|
|
|
|
#define memory_order_relaxed 1
|
|
#define memory_order_seq_cst 2
|
|
|
|
#define atomic_load_explicit(p, e) atomic_load(p)
|
|
|
|
#if HAVE_ATOMIC_BUILTINS
|
|
|
|
#define atomic_load(p) \
|
|
__atomic_load_n(&(p)->v, __ATOMIC_SEQ_CST)
|
|
#define atomic_store(p, val) \
|
|
__atomic_store_n(&(p)->v, val, __ATOMIC_SEQ_CST)
|
|
#define atomic_fetch_add(a, b) \
|
|
__atomic_fetch_add(&(a)->v, b, __ATOMIC_SEQ_CST)
|
|
#define atomic_fetch_and(a, b) \
|
|
__atomic_fetch_and(&(a)->v, b, __ATOMIC_SEQ_CST)
|
|
#define atomic_fetch_or(a, b) \
|
|
__atomic_fetch_or(&(a)->v, b, __ATOMIC_SEQ_CST)
|
|
#define atomic_compare_exchange_strong(a, b, c) \
|
|
__atomic_compare_exchange_n(&(a)->v, b, c, 0, __ATOMIC_SEQ_CST, \
|
|
__ATOMIC_SEQ_CST)
|
|
|
|
#elif HAVE_SYNC_BUILTINS
|
|
|
|
#define atomic_load(p) \
|
|
__sync_fetch_and_add(&(p)->v, 0)
|
|
#define atomic_store(p, val) \
|
|
(__sync_synchronize(), (p)->v = (val), __sync_synchronize())
|
|
#define atomic_fetch_add(a, b) \
|
|
__sync_fetch_and_add(&(a)->v, b)
|
|
#define atomic_fetch_and(a, b) \
|
|
__sync_fetch_and_and(&(a)->v, b)
|
|
#define atomic_fetch_or(a, b) \
|
|
__sync_fetch_and_or(&(a)->v, b)
|
|
// Assumes __sync_val_compare_and_swap is "strong" (using the C11 meaning).
|
|
#define atomic_compare_exchange_strong(p, old, new) \
|
|
({ __typeof__((p)->v) val_ = __sync_val_compare_and_swap(&(p)->v, *(old), new); \
|
|
bool ok_ = val_ == *(old); \
|
|
if (!ok_) *(old) = val_; \
|
|
ok_; })
|
|
|
|
#else
|
|
|
|
// This is extremely wrong. The build system actually disables code that has
|
|
// a serious dependency on working atomics, so this is barely ok.
|
|
#define atomic_load(p) ((p)->v)
|
|
#define atomic_store(p, val) ((p)->v = (val))
|
|
#define atomic_fetch_op_(a, b, op) \
|
|
((a)->t = (a)->v, (a)->v = (a)->v op (b), (a)->t)
|
|
#define atomic_fetch_add(a, b) atomic_fetch_op_(a, b, +)
|
|
#define atomic_fetch_and(a, b) atomic_fetch_op_(a, b, &)
|
|
#define atomic_fetch_or(a, b) atomic_fetch_op_(a, b, |)
|
|
#define atomic_compare_exchange_strong(p, old, new) \
|
|
((p)->v == *(old) ? ((p)->v = (new), 1) : (*(old) = (p)->v, 0))
|
|
|
|
#endif /* no atomics */
|
|
|
|
#endif /* else HAVE_STDATOMIC */
|
|
|
|
#endif
|