Exporting C++ headers from system/core

Moved headers from include/libutils and include/libsysutils to
libutils/include and libsysutils/include respectively, so they can be
exported via these libs. They needed to be moved since Soong does
not allow export from external folder.

Added symlink from old locations. They are needed since Soong
includes system/core/include by default. Once all modules are
cleaned up to explicitly add the required libs, the symlinks will be
removed.

Moved headers of libutils to libutils_headers. They should be used
by modules for header-only inlines. Added libutils_headers as
dependency of libutils.

Split of C++ headers into those that have no dependency and those that
have dependency on libutils.so will be handled in a later CL.

Test: Add above libs to shared lib of local module
Change-Id: I122db72056b26b1f39bad1d9a0c2a1c5efda3550

1 files changed, 731 insertions, 0 deletions

diff --git a/libutils/include/utils/RefBase.h b/libutils/include/utils/RefBase.h
new file mode 100644
index 000000000..36016cde6
--- /dev/null
+++ b/libutils/include/utils/RefBase.h
@@ -0,0 +1,731 @@
+/*
+ * 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.
+ */
+
+
+// SOME COMMENTS ABOUT USAGE:
+
+// This provides primarily wp<> weak pointer types and RefBase, which work
+// together with sp<> from <StrongPointer.h>.
+
+// sp<> (and wp<>) are a type of smart pointer that use a well defined protocol
+// to operate. As long as the object they are templated with implements that
+// protocol, these smart pointers work. In several places the platform
+// instantiates sp<> with non-RefBase objects; the two are not tied to each
+// other.
+
+// RefBase is such an implementation and it supports strong pointers, weak
+// pointers and some magic features for the binder.
+
+// So, when using RefBase objects, you have the ability to use strong and weak
+// pointers through sp<> and wp<>.
+
+// Normally, when the last strong pointer goes away, the object is destroyed,
+// i.e. it's destructor is called. HOWEVER, parts of its associated memory is not
+// freed until the last weak pointer is released.
+
+// Weak pointers are essentially "safe" pointers. They are always safe to
+// access through promote(). They may return nullptr if the object was
+// destroyed because it ran out of strong pointers. This makes them good candidates
+// for keys in a cache for instance.
+
+// Weak pointers remain valid for comparison purposes even after the underlying
+// object has been destroyed. Even if object A is destroyed and its memory reused
+// for B, A remaining weak pointer to A will not compare equal to one to B.
+// This again makes them attractive for use as keys.
+
+// How is this supposed / intended to be used?
+
+// Our recommendation is to use strong references (sp<>) when there is an
+// ownership relation. e.g. when an object "owns" another one, use a strong
+// ref. And of course use strong refs as arguments of functions (it's extremely
+// rare that a function will take a wp<>).
+
+// Typically a newly allocated object will immediately be used to initialize
+// a strong pointer, which may then be used to construct or assign to other
+// strong and weak pointers.
+
+// Use weak references when there are no ownership relation. e.g. the keys in a
+// cache (you cannot use plain pointers because there is no safe way to acquire
+// a strong reference from a vanilla pointer).
+
+// This implies that two objects should never (or very rarely) have sp<> on
+// each other, because they can't both own each other.
+
+
+// Caveats with reference counting
+
+// Obviously, circular strong references are a big problem; this creates leaks
+// and it's hard to debug -- except it's in fact really easy because RefBase has
+// tons of debugging code for that. It can basically tell you exactly where the
+// leak is.
+
+// Another problem has to do with destructors with side effects. You must
+// assume that the destructor of reference counted objects can be called AT ANY
+// TIME. For instance code as simple as this:
+
+// void setStuff(const sp<Stuff>& stuff) {
+//   std::lock_guard<std::mutex> lock(mMutex);
+//   mStuff = stuff;
+// }
+
+// is very dangerous. This code WILL deadlock one day or another.
+
+// What isn't obvious is that ~Stuff() can be called as a result of the
+// assignment. And it gets called with the lock held. First of all, the lock is
+// protecting mStuff, not ~Stuff(). Secondly, if ~Stuff() uses its own internal
+// mutex, now you have mutex ordering issues.  Even worse, if ~Stuff() is
+// virtual, now you're calling into "user" code (potentially), by that, I mean,
+// code you didn't even write.
+
+// A correct way to write this code is something like:
+
+// void setStuff(const sp<Stuff>& stuff) {
+//   std::unique_lock<std::mutex> lock(mMutex);
+//   sp<Stuff> hold = mStuff;
+//   mStuff = stuff;
+//   lock.unlock();
+// }
+
+// More importantly, reference counted objects should do as little work as
+// possible in their destructor, or at least be mindful that their destructor
+// could be called from very weird and unintended places.
+
+// Other more specific restrictions for wp<> and sp<>:
+
+// Do not construct a strong pointer to "this" in an object's constructor.
+// The onFirstRef() callback would be made on an incompletely constructed
+// object.
+// Construction of a weak pointer to "this" in an object's constructor is also
+// discouraged. But the implementation was recently changed so that, in the
+// absence of extendObjectLifetime() calls, weak pointers no longer impact
+// object lifetime, and hence this no longer risks premature deallocation,
+// and hence usually works correctly.
+
+// Such strong or weak pointers can be safely created in the RefBase onFirstRef()
+// callback.
+
+// Use of wp::unsafe_get() for any purpose other than debugging is almost
+// always wrong.  Unless you somehow know that there is a longer-lived sp<> to
+// the same object, it may well return a pointer to a deallocated object that
+// has since been reallocated for a different purpose. (And if you know there
+// is a longer-lived sp<>, why not use an sp<> directly?) A wp<> should only be
+// dereferenced by using promote().
+
+// Any object inheriting from RefBase should always be destroyed as the result
+// of a reference count decrement, not via any other means.  Such objects
+// should never be stack allocated, or appear directly as data members in other
+// objects. Objects inheriting from RefBase should have their strong reference
+// count incremented as soon as possible after construction. Usually this
+// will be done via construction of an sp<> to the object, but may instead
+// involve other means of calling RefBase::incStrong().
+// Explicitly deleting or otherwise destroying a RefBase object with outstanding
+// wp<> or sp<> pointers to it will result in an abort or heap corruption.
+
+// It is particularly important not to mix sp<> and direct storage management
+// since the sp from raw pointer constructor is implicit. Thus if a RefBase-
+// -derived object of type T is managed without ever incrementing its strong
+// count, and accidentally passed to f(sp<T>), a strong pointer to the object
+// will be temporarily constructed and destroyed, prematurely deallocating the
+// object, and resulting in heap corruption. None of this would be easily
+// visible in the source.
+
+// Extra Features:
+
+// RefBase::extendObjectLifetime() can be used to prevent destruction of the
+// object while there are still weak references. This is really special purpose
+// functionality to support Binder.
+
+// Wp::promote(), implemented via the attemptIncStrong() member function, is
+// used to try to convert a weak pointer back to a strong pointer.  It's the
+// normal way to try to access the fields of an object referenced only through
+// a wp<>.  Binder code also sometimes uses attemptIncStrong() directly.
+
+// RefBase provides a number of additional callbacks for certain reference count
+// events, as well as some debugging facilities.
+
+// Debugging support can be enabled by turning on DEBUG_REFS in RefBase.cpp.
+// Otherwise little checking is provided.
+
+// Thread safety:
+
+// Like std::shared_ptr, sp<> and wp<> allow concurrent accesses to DIFFERENT
+// sp<> and wp<> instances that happen to refer to the same underlying object.
+// They do NOT support concurrent access (where at least one access is a write)
+// to THE SAME sp<> or wp<>.  In effect, their thread-safety properties are
+// exactly like those of T*, NOT atomic<T*>.
+
+#ifndef ANDROID_REF_BASE_H
+#define ANDROID_REF_BASE_H
+
+#include <atomic>
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <utils/StrongPointer.h>
+#include <utils/TypeHelpers.h>
+
+// ---------------------------------------------------------------------------
+namespace android {
+
+class TextOutput;
+TextOutput& printWeakPointer(TextOutput& to, const void* val);
+
+// ---------------------------------------------------------------------------
+
+#define COMPARE_WEAK(_op_)                                      \
+inline bool operator _op_ (const sp<T>& o) const {              \
+    return m_ptr _op_ o.m_ptr;                                  \
+}                                                               \
+inline bool operator _op_ (const T* o) const {                  \
+    return m_ptr _op_ o;                                        \
+}                                                               \
+template<typename U>                                            \
+inline bool operator _op_ (const sp<U>& o) const {              \
+    return m_ptr _op_ o.m_ptr;                                  \
+}                                                               \
+template<typename U>                                            \
+inline bool operator _op_ (const U* o) const {                  \
+    return m_ptr _op_ o;                                        \
+}
+
+// ---------------------------------------------------------------------------
+
+// RefererenceRenamer is pure abstract, there is no virtual method
+// implementation to put in a translation unit in order to silence the
+// weak vtables warning.
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wweak-vtables"
+#endif
+
+class ReferenceRenamer {
+protected:
+    // destructor is purposedly not virtual so we avoid code overhead from
+    // subclasses; we have to make it protected to guarantee that it
+    // cannot be called from this base class (and to make strict compilers
+    // happy).
+    ~ReferenceRenamer() { }
+public:
+    virtual void operator()(size_t i) const = 0;
+};
+
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+
+// ---------------------------------------------------------------------------
+
+class RefBase
+{
+public:
+            void            incStrong(const void* id) const;
+            void            decStrong(const void* id) const;
+    
+            void            forceIncStrong(const void* id) const;
+
+            //! DEBUGGING ONLY: Get current strong ref count.
+            int32_t         getStrongCount() const;
+
+    class weakref_type
+    {
+    public:
+        RefBase*            refBase() const;
+        
+        void                incWeak(const void* id);
+        void                decWeak(const void* id);
+        
+        // acquires a strong reference if there is already one.
+        bool                attemptIncStrong(const void* id);
+        
+        // acquires a weak reference if there is already one.
+        // This is not always safe. see ProcessState.cpp and BpBinder.cpp
+        // for proper use.
+        bool                attemptIncWeak(const void* id);
+
+        //! DEBUGGING ONLY: Get current weak ref count.
+        int32_t             getWeakCount() const;
+
+        //! DEBUGGING ONLY: Print references held on object.
+        void                printRefs() const;
+
+        //! DEBUGGING ONLY: Enable tracking for this object.
+        // enable -- enable/disable tracking
+        // retain -- when tracking is enable, if true, then we save a stack trace
+        //           for each reference and dereference; when retain == false, we
+        //           match up references and dereferences and keep only the 
+        //           outstanding ones.
+        
+        void                trackMe(bool enable, bool retain);
+    };
+    
+            weakref_type*   createWeak(const void* id) const;
+            
+            weakref_type*   getWeakRefs() const;
+
+            //! DEBUGGING ONLY: Print references held on object.
+    inline  void            printRefs() const { getWeakRefs()->printRefs(); }
+
+            //! DEBUGGING ONLY: Enable tracking of object.
+    inline  void            trackMe(bool enable, bool retain)
+    { 
+        getWeakRefs()->trackMe(enable, retain); 
+    }
+
+    typedef RefBase basetype;
+
+protected:
+                            RefBase();
+    virtual                 ~RefBase();
+    
+    //! Flags for extendObjectLifetime()
+    enum {
+        OBJECT_LIFETIME_STRONG  = 0x0000,
+        OBJECT_LIFETIME_WEAK    = 0x0001,
+        OBJECT_LIFETIME_MASK    = 0x0001
+    };
+    
+            void            extendObjectLifetime(int32_t mode);
+            
+    //! Flags for onIncStrongAttempted()
+    enum {
+        FIRST_INC_STRONG = 0x0001
+    };
+    
+    // Invoked after creation of initial strong pointer/reference.
+    virtual void            onFirstRef();
+    // Invoked when either the last strong reference goes away, or we need to undo
+    // the effect of an unnecessary onIncStrongAttempted.
+    virtual void            onLastStrongRef(const void* id);
+    // Only called in OBJECT_LIFETIME_WEAK case.  Returns true if OK to promote to
+    // strong reference. May have side effects if it returns true.
+    // The first flags argument is always FIRST_INC_STRONG.
+    // TODO: Remove initial flag argument.
+    virtual bool            onIncStrongAttempted(uint32_t flags, const void* id);
+    // Invoked in the OBJECT_LIFETIME_WEAK case when the last reference of either
+    // kind goes away.  Unused.
+    // TODO: Remove.
+    virtual void            onLastWeakRef(const void* id);
+
+private:
+    friend class weakref_type;
+    class weakref_impl;
+    
+                            RefBase(const RefBase& o);
+            RefBase&        operator=(const RefBase& o);
+
+private:
+    friend class ReferenceMover;
+
+    static void renameRefs(size_t n, const ReferenceRenamer& renamer);
+
+    static void renameRefId(weakref_type* ref,
+            const void* old_id, const void* new_id);
+
+    static void renameRefId(RefBase* ref,
+            const void* old_id, const void* new_id);
+
+        weakref_impl* const mRefs;
+};
+
+// ---------------------------------------------------------------------------
+
+template <class T>
+class LightRefBase
+{
+public:
+    inline LightRefBase() : mCount(0) { }
+    inline void incStrong(__attribute__((unused)) const void* id) const {
+        mCount.fetch_add(1, std::memory_order_relaxed);
+    }
+    inline void decStrong(__attribute__((unused)) const void* id) const {
+        if (mCount.fetch_sub(1, std::memory_order_release) == 1) {
+            std::atomic_thread_fence(std::memory_order_acquire);
+            delete static_cast<const T*>(this);
+        }
+    }
+    //! DEBUGGING ONLY: Get current strong ref count.
+    inline int32_t getStrongCount() const {
+        return mCount.load(std::memory_order_relaxed);
+    }
+
+    typedef LightRefBase<T> basetype;
+
+protected:
+    inline ~LightRefBase() { }
+
+private:
+    friend class ReferenceMover;
+    inline static void renameRefs(size_t /*n*/,
+            const ReferenceRenamer& /*renamer*/) { }
+    inline static void renameRefId(T* /*ref*/,
+            const void* /*old_id*/ , const void* /*new_id*/) { }
+
+private:
+    mutable std::atomic<int32_t> mCount;
+};
+
+// This is a wrapper around LightRefBase that simply enforces a virtual
+// destructor to eliminate the template requirement of LightRefBase
+class VirtualLightRefBase : public LightRefBase<VirtualLightRefBase> {
+public:
+    virtual ~VirtualLightRefBase();
+};
+
+// ---------------------------------------------------------------------------
+
+template <typename T>
+class wp
+{
+public:
+    typedef typename RefBase::weakref_type weakref_type;
+    
+    inline wp() : m_ptr(0) { }
+
+    wp(T* other);  // NOLINT(implicit)
+    wp(const wp<T>& other);
+    explicit wp(const sp<T>& other);
+    template<typename U> wp(U* other);  // NOLINT(implicit)
+    template<typename U> wp(const sp<U>& other);  // NOLINT(implicit)
+    template<typename U> wp(const wp<U>& other);  // NOLINT(implicit)
+
+    ~wp();
+    
+    // Assignment
+
+    wp& operator = (T* other);
+    wp& operator = (const wp<T>& other);
+    wp& operator = (const sp<T>& other);
+    
+    template<typename U> wp& operator = (U* other);
+    template<typename U> wp& operator = (const wp<U>& other);
+    template<typename U> wp& operator = (const sp<U>& other);
+    
+    void set_object_and_refs(T* other, weakref_type* refs);
+
+    // promotion to sp
+    
+    sp<T> promote() const;
+
+    // Reset
+    
+    void clear();
+
+    // Accessors
+    
+    inline  weakref_type* get_refs() const { return m_refs; }
+    
+    inline  T* unsafe_get() const { return m_ptr; }
+
+    // Operators
+
+    COMPARE_WEAK(==)
+    COMPARE_WEAK(!=)
+    COMPARE_WEAK(>)
+    COMPARE_WEAK(<)
+    COMPARE_WEAK(<=)
+    COMPARE_WEAK(>=)
+
+    inline bool operator == (const wp<T>& o) const {
+        return (m_ptr == o.m_ptr) && (m_refs == o.m_refs);
+    }
+    template<typename U>
+    inline bool operator == (const wp<U>& o) const {
+        return m_ptr == o.m_ptr;
+    }
+
+    inline bool operator > (const wp<T>& o) const {
+        return (m_ptr == o.m_ptr) ? (m_refs > o.m_refs) : (m_ptr > o.m_ptr);
+    }
+    template<typename U>
+    inline bool operator > (const wp<U>& o) const {
+        return (m_ptr == o.m_ptr) ? (m_refs > o.m_refs) : (m_ptr > o.m_ptr);
+    }
+
+    inline bool operator < (const wp<T>& o) const {
+        return (m_ptr == o.m_ptr) ? (m_refs < o.m_refs) : (m_ptr < o.m_ptr);
+    }
+    template<typename U>
+    inline bool operator < (const wp<U>& o) const {
+        return (m_ptr == o.m_ptr) ? (m_refs < o.m_refs) : (m_ptr < o.m_ptr);
+    }
+                         inline bool operator != (const wp<T>& o) const { return m_refs != o.m_refs; }
+    template<typename U> inline bool operator != (const wp<U>& o) const { return !operator == (o); }
+                         inline bool operator <= (const wp<T>& o) const { return !operator > (o); }
+    template<typename U> inline bool operator <= (const wp<U>& o) const { return !operator > (o); }
+                         inline bool operator >= (const wp<T>& o) const { return !operator < (o); }
+    template<typename U> inline bool operator >= (const wp<U>& o) const { return !operator < (o); }
+
+private:
+    template<typename Y> friend class sp;
+    template<typename Y> friend class wp;
+
+    T*              m_ptr;
+    weakref_type*   m_refs;
+};
+
+template <typename T>
+TextOutput& operator<<(TextOutput& to, const wp<T>& val);
+
+#undef COMPARE_WEAK
+
+// ---------------------------------------------------------------------------
+// No user serviceable parts below here.
+
+template<typename T>
+wp<T>::wp(T* other)
+    : m_ptr(other)
+{
+    if (other) m_refs = other->createWeak(this);
+}
+
+template<typename T>
+wp<T>::wp(const wp<T>& other)
+    : m_ptr(other.m_ptr), m_refs(other.m_refs)
+{
+    if (m_ptr) m_refs->incWeak(this);
+}
+
+template<typename T>
+wp<T>::wp(const sp<T>& other)
+    : m_ptr(other.m_ptr)
+{
+    if (m_ptr) {
+        m_refs = m_ptr->createWeak(this);
+    }
+}
+
+template<typename T> template<typename U>
+wp<T>::wp(U* other)
+    : m_ptr(other)
+{
+    if (other) m_refs = other->createWeak(this);
+}
+
+template<typename T> template<typename U>
+wp<T>::wp(const wp<U>& other)
+    : m_ptr(other.m_ptr)
+{
+    if (m_ptr) {
+        m_refs = other.m_refs;
+        m_refs->incWeak(this);
+    }
+}
+
+template<typename T> template<typename U>
+wp<T>::wp(const sp<U>& other)
+    : m_ptr(other.m_ptr)
+{
+    if (m_ptr) {
+        m_refs = m_ptr->createWeak(this);
+    }
+}
+
+template<typename T>
+wp<T>::~wp()
+{
+    if (m_ptr) m_refs->decWeak(this);
+}
+
+template<typename T>
+wp<T>& wp<T>::operator = (T* other)
+{
+    weakref_type* newRefs =
+        other ? other->createWeak(this) : 0;
+    if (m_ptr) m_refs->decWeak(this);
+    m_ptr = other;
+    m_refs = newRefs;
+    return *this;
+}
+
+template<typename T>
+wp<T>& wp<T>::operator = (const wp<T>& other)
+{
+    weakref_type* otherRefs(other.m_refs);
+    T* otherPtr(other.m_ptr);
+    if (otherPtr) otherRefs->incWeak(this);
+    if (m_ptr) m_refs->decWeak(this);
+    m_ptr = otherPtr;
+    m_refs = otherRefs;
+    return *this;
+}
+
+template<typename T>
+wp<T>& wp<T>::operator = (const sp<T>& other)
+{
+    weakref_type* newRefs =
+        other != NULL ? other->createWeak(this) : 0;
+    T* otherPtr(other.m_ptr);
+    if (m_ptr) m_refs->decWeak(this);
+    m_ptr = otherPtr;
+    m_refs = newRefs;
+    return *this;
+}
+
+template<typename T> template<typename U>
+wp<T>& wp<T>::operator = (U* other)
+{
+    weakref_type* newRefs =
+        other ? other->createWeak(this) : 0;
+    if (m_ptr) m_refs->decWeak(this);
+    m_ptr = other;
+    m_refs = newRefs;
+    return *this;
+}
+
+template<typename T> template<typename U>
+wp<T>& wp<T>::operator = (const wp<U>& other)
+{
+    weakref_type* otherRefs(other.m_refs);
+    U* otherPtr(other.m_ptr);
+    if (otherPtr) otherRefs->incWeak(this);
+    if (m_ptr) m_refs->decWeak(this);
+    m_ptr = otherPtr;
+    m_refs = otherRefs;
+    return *this;
+}
+
+template<typename T> template<typename U>
+wp<T>& wp<T>::operator = (const sp<U>& other)
+{
+    weakref_type* newRefs =
+        other != NULL ? other->createWeak(this) : 0;
+    U* otherPtr(other.m_ptr);
+    if (m_ptr) m_refs->decWeak(this);
+    m_ptr = otherPtr;
+    m_refs = newRefs;
+    return *this;
+}
+
+template<typename T>
+void wp<T>::set_object_and_refs(T* other, weakref_type* refs)
+{
+    if (other) refs->incWeak(this);
+    if (m_ptr) m_refs->decWeak(this);
+    m_ptr = other;
+    m_refs = refs;
+}
+
+template<typename T>
+sp<T> wp<T>::promote() const
+{
+    sp<T> result;
+    if (m_ptr && m_refs->attemptIncStrong(&result)) {
+        result.set_pointer(m_ptr);
+    }
+    return result;
+}
+
+template<typename T>
+void wp<T>::clear()
+{
+    if (m_ptr) {
+        m_refs->decWeak(this);
+        m_ptr = 0;
+    }
+}
+
+template <typename T>
+inline TextOutput& operator<<(TextOutput& to, const wp<T>& val)
+{
+    return printWeakPointer(to, val.unsafe_get());
+}
+
+// ---------------------------------------------------------------------------
+
+// this class just serves as a namespace so TYPE::moveReferences can stay
+// private.
+class ReferenceMover {
+public:
+    // it would be nice if we could make sure no extra code is generated
+    // for sp<TYPE> or wp<TYPE> when TYPE is a descendant of RefBase:
+    // Using a sp<RefBase> override doesn't work; it's a bit like we wanted
+    // a template<typename TYPE inherits RefBase> template...
+
+    template<typename TYPE> static inline
+    void move_references(sp<TYPE>* dest, sp<TYPE> const* src, size_t n) {
+
+        class Renamer : public ReferenceRenamer {
+            sp<TYPE>* d_;
+            sp<TYPE> const* s_;
+            virtual void operator()(size_t i) const {
+                // The id are known to be the sp<>'s this pointer
+                TYPE::renameRefId(d_[i].get(), &s_[i], &d_[i]);
+            }
+        public:
+            Renamer(sp<TYPE>* d, sp<TYPE> const* s) : d_(d), s_(s) { }
+            virtual ~Renamer() { }
+        };
+
+        memmove(dest, src, n*sizeof(sp<TYPE>));
+        TYPE::renameRefs(n, Renamer(dest, src));
+    }
+
+
+    template<typename TYPE> static inline
+    void move_references(wp<TYPE>* dest, wp<TYPE> const* src, size_t n) {
+
+        class Renamer : public ReferenceRenamer {
+            wp<TYPE>* d_;
+            wp<TYPE> const* s_;
+            virtual void operator()(size_t i) const {
+                // The id are known to be the wp<>'s this pointer
+                TYPE::renameRefId(d_[i].get_refs(), &s_[i], &d_[i]);
+            }
+        public:
+            Renamer(wp<TYPE>* rd, wp<TYPE> const* rs) : d_(rd), s_(rs) { }
+            virtual ~Renamer() { }
+        };
+
+        memmove(dest, src, n*sizeof(wp<TYPE>));
+        TYPE::renameRefs(n, Renamer(dest, src));
+    }
+};
+
+// specialization for moving sp<> and wp<> types.
+// these are used by the [Sorted|Keyed]Vector<> implementations
+// sp<> and wp<> need to be handled specially, because they do not
+// have trivial copy operation in the general case (see RefBase.cpp
+// when DEBUG ops are enabled), but can be implemented very
+// efficiently in most cases.
+
+template<typename TYPE> inline
+void move_forward_type(sp<TYPE>* d, sp<TYPE> const* s, size_t n) {
+    ReferenceMover::move_references(d, s, n);
+}
+
+template<typename TYPE> inline
+void move_backward_type(sp<TYPE>* d, sp<TYPE> const* s, size_t n) {
+    ReferenceMover::move_references(d, s, n);
+}
+
+template<typename TYPE> inline
+void move_forward_type(wp<TYPE>* d, wp<TYPE> const* s, size_t n) {
+    ReferenceMover::move_references(d, s, n);
+}
+
+template<typename TYPE> inline
+void move_backward_type(wp<TYPE>* d, wp<TYPE> const* s, size_t n) {
+    ReferenceMover::move_references(d, s, n);
+}
+
+}; // namespace android
+
+// ---------------------------------------------------------------------------
+
+#endif // ANDROID_REF_BASE_H