fifo: isolate atomic and futex operations
Now all atomic and futex operations occur in fifo_index.cpp.
This implements these TODOs:
- Abstract out atomic operations to audio_utils_fifo_index
- Replace friend by setter and getter, and abstract the futex
This is one of a series of CLs to isolate the dependencies.
Test: builds OK on Android, host Linux, and host macOS
Change-Id: Ic4ec46d472c583dce8525f11ed8cb1db89928d30
diff --git a/audio_utils/fifo_index.cpp b/audio_utils/fifo_index.cpp
new file mode 100644
index 0000000..b35319c
--- /dev/null
+++ b/audio_utils/fifo_index.cpp
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <audio_utils/fifo_index.h>
+#include <audio_utils/futex.h>
+
+// These are not implemented within <audio_utils/fifo_index.h>
+// so that we don't expose futex.
+
+uint32_t audio_utils_fifo_index::loadAcquire()
+{
+ return atomic_load_explicit(&mIndex, std::memory_order_acquire);
+}
+
+void audio_utils_fifo_index::storeRelease(uint32_t value)
+{
+ atomic_store_explicit(&mIndex, value, std::memory_order_release);
+}
+
+int audio_utils_fifo_index::wait(int op, uint32_t expected, const struct timespec *timeout)
+{
+ return sys_futex(&mIndex, op, expected, timeout, NULL, 0);
+}
+
+int audio_utils_fifo_index::wake(int op, int waiters)
+{
+ return sys_futex(&mIndex, op, waiters, NULL, NULL, 0);
+}