From 2dd4bdd715f586d4d30cf90cc6fc2bbfbce60fe0 Mon Sep 17 00:00:00 2001
From: Glenn Kasten <gkasten@google.com>
Date: Wed, 29 Aug 2012 11:10:32 -0700
Subject: Move libnbaio out of AudioFlinger

libnbaio is now a separate shared library from AudioFlinger, rather
than a static library used only by AudioFlinger.

AudioBufferProvider interface is now also independent of AudioFlinger,
moved to include/media/

Change-Id: I9bb62ffbc38d42a38b0af76e66da5e9ab1e0e21b
---
 media/libnbaio/Pipe.cpp | 70 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 media/libnbaio/Pipe.cpp

(limited to 'media/libnbaio/Pipe.cpp')

diff --git a/media/libnbaio/Pipe.cpp b/media/libnbaio/Pipe.cpp
new file mode 100644
index 0000000..1c21f9c
--- /dev/null
+++ b/media/libnbaio/Pipe.cpp
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2012 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.
+ */
+
+#define LOG_TAG "Pipe"
+//#define LOG_NDEBUG 0
+
+#include <cutils/atomic.h>
+#include <cutils/compiler.h>
+#include <utils/Log.h>
+#include <media/nbaio/Pipe.h>
+#include <media/nbaio/roundup.h>
+
+namespace android {
+
+Pipe::Pipe(size_t maxFrames, NBAIO_Format format) :
+        NBAIO_Sink(format),
+        mMaxFrames(roundup(maxFrames)),
+        mBuffer(malloc(mMaxFrames * Format_frameSize(format))),
+        mRear(0),
+        mReaders(0)
+{
+}
+
+Pipe::~Pipe()
+{
+    ALOG_ASSERT(android_atomic_acquire_load(&mReaders) == 0);
+    free(mBuffer);
+}
+
+ssize_t Pipe::write(const void *buffer, size_t count)
+{
+    // count == 0 is unlikely and not worth checking for
+    if (CC_UNLIKELY(!mNegotiated)) {
+        return NEGOTIATE;
+    }
+    // write() is not multi-thread safe w.r.t. itself, so no mutex or atomic op needed to read mRear
+    size_t rear = mRear & (mMaxFrames - 1);
+    size_t written = mMaxFrames - rear;
+    if (CC_LIKELY(written > count)) {
+        written = count;
+    }
+    memcpy((char *) mBuffer + (rear << mBitShift), buffer, written << mBitShift);
+    if (CC_UNLIKELY(rear + written == mMaxFrames)) {
+        if (CC_UNLIKELY((count -= written) > rear)) {
+            count = rear;
+        }
+        if (CC_LIKELY(count > 0)) {
+            memcpy(mBuffer, (char *) buffer + (written << mBitShift), count << mBitShift);
+            written += count;
+        }
+    }
+    android_atomic_release_store(written + mRear, &mRear);
+    mFramesWritten += written;
+    return written;
+}
+
+}   // namespace android
-- 
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