Memory ordering constraints other than the default (sequentially
consistent) can behave in very unintuitive and unexpected ways, and so
should be avoided unless there is a strong (typically performance)
reason for using them. This holds especially for memory_order_relaxed,
which imposes no ordering constraints.
---
libavformat/fifo.c | 8 ++++----
libavutil/cpu.c | 8 ++++----
libavutil/mem.c | 10 +++++-----
3 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/libavformat/fifo.c b/libavformat/fifo.c
index 50656f78b7..2ac14207b8 100644
--- a/libavformat/fifo.c
+++ b/libavformat/fifo.c
@@ -185,7 +185,7 @@ static int fifo_thread_write_packet(FifoThreadContext *ctx,
AVPacket *pkt)
int ret, s_idx;
if (fifo->timeshift && pkt->dts != AV_NOPTS_VALUE)
- atomic_fetch_sub_explicit(&fifo->queue_duration, next_duration(avf,
pkt, &ctx->last_received_dts), memory_order_relaxed);
+ atomic_fetch_sub(&fifo->queue_duration, next_duration(avf, pkt,
&ctx->last_received_dts));
if (ctx->drop_until_keyframe) {
if (pkt->flags & AV_PKT_FLAG_KEY) {
@@ -454,7 +454,7 @@ static void *fifo_consumer_thread(void *data)
av_log(avf, AV_LOG_INFO, "FIFO queue flushed\n");
if (fifo->timeshift)
- while (atomic_load_explicit(&fifo->queue_duration,
memory_order_relaxed) < fifo->timeshift)
+ while (atomic_load(&fifo->queue_duration) < fifo->timeshift)
av_usleep(10000);
ret = av_thread_message_queue_recv(queue, &msg, 0);
@@ -594,7 +594,7 @@ static int fifo_write_packet(AVFormatContext *avf, AVPacket
*pkt)
}
if (fifo->timeshift && pkt && pkt->dts != AV_NOPTS_VALUE)
- atomic_fetch_add_explicit(&fifo->queue_duration, next_duration(avf,
pkt, &fifo->last_sent_dts), memory_order_relaxed);
+ atomic_fetch_add(&fifo->queue_duration, next_duration(avf, pkt,
&fifo->last_sent_dts));
return ret;
fail:
@@ -621,7 +621,7 @@ static int fifo_write_trailer(AVFormatContext *avf)
} else {
now += delay;
}
- atomic_fetch_add_explicit(&fifo->queue_duration, delay,
memory_order_relaxed);
+ atomic_fetch_add(&fifo->queue_duration, delay);
elapsed += delay;
if (elapsed > fifo->timeshift)
break;
diff --git a/libavutil/cpu.c b/libavutil/cpu.c
index 8960415d00..8a6af81ae4 100644
--- a/libavutil/cpu.c
+++ b/libavutil/cpu.c
@@ -89,15 +89,15 @@ void av_force_cpu_flags(int arg){
arg |= AV_CPU_FLAG_MMX;
}
- atomic_store_explicit(&cpu_flags, arg, memory_order_relaxed);
+ atomic_store(&cpu_flags, arg);
}
int av_get_cpu_flags(void)
{
- int flags = atomic_load_explicit(&cpu_flags, memory_order_relaxed);
+ int flags = atomic_load(&cpu_flags);
if (flags == -1) {
flags = get_cpu_flags();
- atomic_store_explicit(&cpu_flags, flags, memory_order_relaxed);
+ atomic_store(&cpu_flags, flags);
}
return flags;
}
@@ -221,7 +221,7 @@ int av_cpu_count(void)
nb_cpus = sysinfo.dwNumberOfProcessors;
#endif
- if (!atomic_exchange_explicit(&printed, 1, memory_order_relaxed))
+ if (!atomic_exchange(&printed, 1))
av_log(NULL, AV_LOG_DEBUG, "detected %d logical cores\n", nb_cpus);
return nb_cpus;
diff --git a/libavutil/mem.c b/libavutil/mem.c
index a52d33d4a6..c216c0314f 100644
--- a/libavutil/mem.c
+++ b/libavutil/mem.c
@@ -72,14 +72,14 @@ void free(void *ptr);
static atomic_size_t max_alloc_size = ATOMIC_VAR_INIT(INT_MAX);
void av_max_alloc(size_t max){
- atomic_store_explicit(&max_alloc_size, max, memory_order_relaxed);
+ atomic_store(&max_alloc_size, max);
}
void *av_malloc(size_t size)
{
void *ptr = NULL;
- if (size > atomic_load_explicit(&max_alloc_size, memory_order_relaxed))
+ if (size > atomic_load(&max_alloc_size))
return NULL;
#if HAVE_POSIX_MEMALIGN
@@ -135,7 +135,7 @@ void *av_malloc(size_t size)
void *av_realloc(void *ptr, size_t size)
{
void *ret;
- if (size > atomic_load_explicit(&max_alloc_size, memory_order_relaxed))
+ if (size > atomic_load(&max_alloc_size))
return NULL;
#if HAVE_ALIGNED_MALLOC
@@ -489,7 +489,7 @@ void *av_fast_realloc(void *ptr, unsigned int *size, size_t
min_size)
if (min_size <= *size)
return ptr;
- max_size = atomic_load_explicit(&max_alloc_size, memory_order_relaxed);
+ max_size = atomic_load(&max_alloc_size);
if (min_size > max_size) {
*size = 0;
@@ -521,7 +521,7 @@ static inline void fast_malloc(void *ptr, unsigned int
*size, size_t min_size, i
return;
}
- max_size = atomic_load_explicit(&max_alloc_size, memory_order_relaxed);
+ max_size = atomic_load(&max_alloc_size);
if (min_size > max_size) {
av_freep(ptr);
--
2.30.2
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