auto import from //depot/cupcake/@135843
diff --git a/include/utils/SharedBuffer.h b/include/utils/SharedBuffer.h
new file mode 100644
index 0000000..24508b0
--- /dev/null
+++ b/include/utils/SharedBuffer.h
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2005 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.
+ */
+
+#ifndef ANDROID_SHARED_BUFFER_H
+#define ANDROID_SHARED_BUFFER_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+// ---------------------------------------------------------------------------
+
+namespace android {
+
+class SharedBuffer
+{
+public:
+
+ /* flags to use with release() */
+ enum {
+ eKeepStorage = 0x00000001
+ };
+
+ /*! allocate a buffer of size 'size' and acquire() it.
+ * call release() to free it.
+ */
+ static SharedBuffer* alloc(size_t size);
+
+ /*! free the memory associated with the SharedBuffer.
+ * Fails if there are any users associated with this SharedBuffer.
+ * In other words, the buffer must have been release by all its
+ * users.
+ */
+ static ssize_t dealloc(const SharedBuffer* released);
+
+ //! get the SharedBuffer from the data pointer
+ static inline const SharedBuffer* sharedBuffer(const void* data);
+
+ //! access the data for read
+ inline const void* data() const;
+
+ //! access the data for read/write
+ inline void* data();
+
+ //! get size of the buffer
+ inline size_t size() const;
+
+ //! get back a SharedBuffer object from its data
+ static inline SharedBuffer* bufferFromData(void* data);
+
+ //! get back a SharedBuffer object from its data
+ static inline const SharedBuffer* bufferFromData(const void* data);
+
+ //! get the size of a SharedBuffer object from its data
+ static inline size_t sizeFromData(const void* data);
+
+ //! edit the buffer (get a writtable, or non-const, version of it)
+ SharedBuffer* edit() const;
+
+ //! edit the buffer, resizing if needed
+ SharedBuffer* editResize(size_t size) const;
+
+ //! like edit() but fails if a copy is required
+ SharedBuffer* attemptEdit() const;
+
+ //! resize and edit the buffer, loose it's content.
+ SharedBuffer* reset(size_t size) const;
+
+ //! acquire/release a reference on this buffer
+ void acquire() const;
+
+ /*! release a reference on this buffer, with the option of not
+ * freeing the memory associated with it if it was the last reference
+ * returns the previous reference count
+ */
+ int32_t release(uint32_t flags = 0) const;
+
+ //! returns wether or not we're the only owner
+ inline bool onlyOwner() const;
+
+
+private:
+ inline SharedBuffer() { }
+ inline ~SharedBuffer() { }
+ inline SharedBuffer(const SharedBuffer&);
+
+ // 16 bytes. must be sized to preserve correct alingment.
+ mutable int32_t mRefs;
+ size_t mSize;
+ uint32_t mReserved[2];
+};
+
+// ---------------------------------------------------------------------------
+
+const SharedBuffer* SharedBuffer::sharedBuffer(const void* data) {
+ return data ? reinterpret_cast<const SharedBuffer *>(data)-1 : 0;
+}
+
+const void* SharedBuffer::data() const {
+ return this + 1;
+}
+
+void* SharedBuffer::data() {
+ return this + 1;
+}
+
+size_t SharedBuffer::size() const {
+ return mSize;
+}
+
+SharedBuffer* SharedBuffer::bufferFromData(void* data)
+{
+ return ((SharedBuffer*)data)-1;
+}
+
+const SharedBuffer* SharedBuffer::bufferFromData(const void* data)
+{
+ return ((const SharedBuffer*)data)-1;
+}
+
+size_t SharedBuffer::sizeFromData(const void* data)
+{
+ return (((const SharedBuffer*)data)-1)->mSize;
+}
+
+bool SharedBuffer::onlyOwner() const {
+ return (mRefs == 1);
+}
+
+}; // namespace android
+
+// ---------------------------------------------------------------------------
+
+#endif // ANDROID_VECTOR_H