lavu: add support for atomic operations.

These could be used for reference counting, or for keeping track of
decoding progress in references in multithreaded decoders.

Support is provided by gcc/msvc/suncc intrinsics, with a fallback using
pthread mutexes.

Signed-off-by: Anton Khirnov <anton@khirnov.net>

1 files changed, 51 insertions, 0 deletions

diff --git a/libavutil/atomic_suncc.h b/libavutil/atomic_suncc.h
new file mode 100644
index 0000000000..85373f5564
--- /dev/null
+++ b/libavutil/atomic_suncc.h
@@ -0,0 +1,51 @@
+/*
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <atomic.h>
+#include <mbarrier.h>
+
+#include "atomic.h"
+
+#define avpriv_atomic_int_get atomic_int_get_suncc
+static inline int atomic_int_get_suncc(volatile int *ptr)
+{
+    __machine_rw_barrier();
+    return *ptr;
+}
+
+#define avpriv_atomic_int_set atomic_int_set_suncc
+static inline void atomic_int_set_suncc(volatile int *ptr, int val)
+{
+    *ptr = val;
+    __machine_rw_barrier();
+}
+
+#define avpriv_atomic_int_add_and_fetch atomic_int_add_and_fetch_suncc
+static inline int atomic_int_add_and_fetch_suncc(volatile int *ptr, int inc)
+{
+    return atomic_add_int_nv(ptr, inc);
+}
+
+#define avpriv_atomic_ptr_cas atomic_ptr_cas_suncc
+static inline void *atomic_ptr_cas_suncc(void * volatile *ptr,
+                                         void *oldval, void *newval)
+{
+    return atomic_cas_ptr(ptr, oldval, newval);
+}
+