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/*
* Copyright 2008-2012 NVIDIA Corporation
*
* 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.
*/
/*! \file thrust/memory.h
* \brief Abstractions for Thrust's memory model.
*/
#include <thrust/detail/config.h>
#include <thrust/detail/type_traits/pointer_traits.h>
#include <thrust/detail/pointer.h>
#include <thrust/detail/reference.h>
#include <thrust/detail/raw_pointer_cast.h>
#include <thrust/detail/raw_reference_cast.h>
#include <thrust/detail/malloc_and_free.h>
#include <thrust/detail/temporary_buffer.h>
namespace thrust
{
/*! \addtogroup memory_management Memory Management
* \addtogroup memory_management_classes Memory Management Classes
* \ingroup memory_management
* \{
*/
/*! \p pointer stores a pointer to an object allocated in memory. Like \p device_ptr, this
* type ensures type safety when dispatching standard algorithms on ranges resident in memory.
*
* \p pointer generalizes \p device_ptr by relaxing the backend system associated with the \p pointer.
* Instead of the backend system specified by \p THRUST_DEFAULT_DEVICE_BACKEND, \p pointer's
* system is given by its second template parameter, \p Tag. For the purpose of Thrust dispatch,
* <tt>device_ptr<Element></tt> and <tt>pointer<Element,device_system_tag></tt> are considered equivalent.
*
* The raw pointer encapsulated by a \p pointer may be obtained through its <tt>get</tt> member function
* or the \p raw_pointer_cast free function.
*
* \tparam Element specifies the type of the pointed-to object.
*
* \tparam Tag specifies the system with which this \p pointer is associated. This may be any Thrust
* backend system, or a user-defined tag.
*
* \tparam Reference allows the client to specify the reference type returned upon derereference.
* By default, this type is <tt>reference<Element,pointer></tt>.
*
* \tparam Derived allows the client to specify the name of the derived type when \p pointer is used as
* a base class. This is useful to ensure that arithmetic on values of the derived type return
* values of the derived type as a result. By default, this type is <tt>pointer<Element,Tag,Reference></tt>.
*
* \note \p pointer is not a smart pointer; it is the client's responsibility to deallocate memory
* pointer to by \p pointer.
*
* \see device_ptr
* \see reference
* \see raw_pointer_cast
*/
// define pointer for the purpose of Doxygenating it
// it is actually defined elsewhere
#if 0
template<typename Element, typename Tag, typename Reference = thrust::use_default, typename Derived = thrust::use_default>
class pointer
{
public:
/*! The type of the raw pointer
*/
typedef typename super_t::base_type raw_pointer;
/*! \p pointer's default constructor initializes its encapsulated pointer to \c 0
*/
__host__ __device__
pointer();
/*! This constructor allows construction of a <tt>pointer<const T, ...></tt> from a <tt>T*</tt>.
*
* \param ptr A raw pointer to copy from, presumed to point to a location in \p Tag's memory.
* \tparam OtherElement \p OtherElement shall be convertible to \p Element.
*/
template<typename OtherElement>
__host__ __device__
explicit pointer(OtherElement *ptr);
/*! This contructor allows initialization from another pointer-like object.
*
* \param other The \p OtherPointer to copy.
*
* \tparam OtherPointer The tag associated with \p OtherPointer shall be convertible to \p Tag,
* and its element type shall be convertible to \p Element.
*/
template<typename OtherPointer>
__host__ __device__
pointer(const OtherPointer &other,
typename thrust::detail::enable_if_pointer_is_convertible<
OtherPointer,
pointer<Element,Tag,Reference,Derived>
>::type * = 0);
/*! Assignment operator allows assigning from another pointer-like object with related type.
*
* \param other The other pointer-like object to assign from.
* \return <tt>*this</tt>
*
* \tparam OtherPointer The tag associated with \p OtherPointer shall be convertible to \p Tag,
* and its element type shall be convertible to \p Element.
*/
template<typename OtherPointer>
__host__ __device__
typename thrust::detail::enable_if_pointer_is_convertible<
OtherPointer,
pointer,
derived_type &
>::type
operator=(const OtherPointer &other);
/*! \p get returns this \p pointer's encapsulated raw pointer.
* \return This \p pointer's raw pointer.
*/
__host__ __device__
Element *get() const;
};
#endif
/*! \p reference is a wrapped reference to an object stored in memory. \p reference generalizes
* \p device_reference by relaxing the type of pointer associated with the object. \p reference
* is the type of the result of dereferencing a tagged pointer-like object such as \p pointer, and
* intermediates operations on objects existing in a remote memory.
*
* \tparam Element specifies the type of the referent object.
* \tparam Pointer specifies the type of the result of taking the address of \p reference.
* \tparam Derived allows the client to specify the name of the derived type when \p reference is used as
* a base class. This is useful to ensure that assignment to objects of the derived type return
* values of the derived type as a result. By default, this type is <tt>reference<Element,Pointer></tt>.
*/
// define pointer for the purpose of Doxygenating it
// it is actually defined elsewhere
#if 0
template<typename Element, typename Pointer, typename Derived = thrust::use_default>
class reference
{
public:
/*! The type of this \p reference's wrapped pointers.
*/
typedef Pointer pointer;
/*! The \p value_type of this \p reference.
*/
typedef typename thrust::detail::remove_const<Element>::type value_type;
/*! This copy constructor initializes this \p reference
* to refer to an object pointed to by the given \p pointer. After
* this \p reference is constructed, it shall refer to the
* object pointed to by \p ptr.
*
* \param ptr A \p pointer to copy from.
*/
__host__ __device__
explicit reference(const pointer &ptr);
/*! This copy constructor accepts a const reference to another
* \p reference of related type. After this \p reference is constructed,
* it shall refer to the same object as \p other.
*
* \param other A \p reference to copy from.
* \tparam OtherElement the element type of the other \p reference.
* \tparam OtherPointer the pointer type of the other \p reference.
* \tparam OtherDerived the derived type of the other \p reference.
*
* \note This constructor is templated primarily to allow initialization of
* <tt>reference<const T,...></tt> from <tt>reference<T,...></tt>.
*/
template<typename OtherElement, typename OtherPointer, typename OtherDerived>
__host__ __device__
reference(const reference<OtherElement,OtherPointer,OtherDerived> &other,
typename thrust::detail::enable_if_convertible<
typename reference<OtherElement,OtherPointer,OtherDerived>::pointer,
pointer
>::type * = 0);
/*! Copy assignment operator copy assigns from another \p reference.
*
* \param other The other \p reference to assign from.
* \return <tt>static_cast<derived_type&>(*this)</tt>
*/
__host__ __device__
derived_type &operator=(const reference &other);
/*! Assignment operator copy assigns from another \p reference of related type.
*
* \param other The other \p reference to assign from.
* \return <tt>static_cast<derived_type&>(*this)</tt>
*
* \tparam OtherElement the element type of the other \p reference.
* \tparam OtherPointer the pointer type of the other \p reference.
* \tparam OtherDerived the derived type of the other \p reference.
*/
template<typename OtherElement, typename OtherPointer, typename OtherDerived>
__host__ __device__
derived_type &operator=(const reference<OtherElement,OtherPointer,OtherDerived> &other);
/*! Assignment operator assigns from a \p value_type.
*
* \param x The \p value_type to assign from.
* \return <tt>static_cast<derived_type&>(*this)</tt>.
*/
__host__ __device__
derived_type &operator=(const value_type &x);
/*! Address-of operator returns a \p pointer pointing to the object
* referenced by this \p reference. It does not return the address of this
* \p reference.
*
* \return A \p pointer pointing to the referenct object.
*/
__host__ __device__
pointer operator&() const;
/*! Conversion operator converts this \p reference to \p value_type by
* returning a copy of the referent object.
*
* \return A copy of the referent object.
*/
__host__ __device__
operator value_type () const;
/*! Swaps the value of the referent object with another.
*
* \param other The other \p reference with which to swap.
* \note The argument is of type \p derived_type rather than \p reference.
*/
__host__ __device__
void swap(derived_type &other);
/*! Prefix increment operator increments the referent object.
*
* \return <tt>static_Cast<derived_type&>(*this)</tt>.
*
* \note Documentation for other arithmetic operators omitted for brevity.
*/
derived_type &operator++();
};
#endif
/*! \}
*/
/*!
* \addtogroup memory_management_functions Memory Management Functions
* \ingroup memory_management
* \{
*/
/*! \p raw_pointer_cast creates a "raw" pointer from a pointer-like type,
* simply returning the wrapped pointer, should it exist.
*
* \param ptr The pointer of interest.
* \return <tt>ptr.get()</tt>, if the expression is well formed; <tt>ptr</tt>, otherwise.
* \see raw_reference_cast
*/
template<typename Pointer>
__host__ __device__
inline typename thrust::detail::pointer_traits<Pointer>::raw_pointer
raw_pointer_cast(const Pointer &ptr);
/*! \p raw_reference_cast creates a "raw" reference from a wrapped reference type,
* simply returning the underlying reference, should it exist.
*
* If the argument is not a reference wrapper, the result is a reference to the argument.
*
* \param ref The reference of interest.
* \return <tt>*thrust::raw_pointer_cast(&ref)</tt>.
* \note There are two versions of \p raw_reference_cast. One for <tt>const</tt> references,
* and one for non-<tt>const</tt>.
* \see raw_pointer_cast
*/
template<typename T>
__host__ __device__
inline typename detail::raw_reference<T>::type
raw_reference_cast(T &ref);
/*! \p raw_reference_cast creates a "raw" reference from a wrapped reference type,
* simply returning the underlying reference, should it exist.
*
* If the argument is not a reference wrapper, the result is a reference to the argument.
*
* \param ref The reference of interest.
* \return <tt>*thrust::raw_pointer_cast(&ref)</tt>.
* \note There are two versions of \p raw_reference_cast. One for <tt>const</tt> references,
* and one for non-<tt>const</tt>.
* \see raw_pointer_cast
*/
template<typename T>
__host__ __device__
inline typename detail::raw_reference<const T>::type
raw_reference_cast(const T &ref);
/*! \}
*/
} // end thrust