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workinf_Blender_Wasm/blender-5.2.0/intern/guardedalloc/MEM_guardedalloc.h
2026-08-12 04:47:48 -04:00

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/* SPDX-FileCopyrightText: 2001-2002 NaN Holding BV. All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0-or-later */
/** \file
* \ingroup intern_mem
*
* \brief Read \ref MEMPage
*
* \page MEMPage Blender memory allocation and freeing
*
* \section aboutmem About the MEM allocator module
*
* \subsection Guarded memory allocation
*
* MEM provides guarded memory management when using the --debug-memory option. All allocated
* memory is then enclosed by pads, to detect out-of-bound writes. All allocations are named
* to detect the source of memory leaks and print memory usage at runtime with the
* "Memory Statistics" operator.
*
* \subsection How to use the MEM API
*
* MEM provides C++ template versions of the `new`/`delete` operators (#MEM_new and #MEM_delete),
* which are the preferred way to create and delete data in new code.
*
* It also provides #MEM_new_uninitialized and #MEM_new_zeroed functions that behave like malloc
* and calloc respectively. These provide improved type safety, ensure that the allocated types
* are trivial, and reduce the casting verbosity by directly returning a pointer of the expected
* type. This memory should be freed with either #MEM_delete or #MEM_delete_void.
*
* There are a few reasons to use these functions:
* - Performance: When allocating large arrays like image buffers or mesh attributes that will
* be initialized soon after, doing an uninitialized memory allocation is faster.
* - Low level code: Core data structures and other low level code that directly allocate untyped
* memory buffers and provide their own type safety.
* - Legacy: Code that has not yet been updated to follow current conventions.
*
* \subsection memdependencies Dependencies
* - `stdlib`
* - `stdio`
*
* \subsection memdocs API Documentation
* See \ref MEM_guardedalloc.h
*/
#ifndef __MEM_GUARDEDALLOC_H__
#define __MEM_GUARDEDALLOC_H__
/* Needed for uintptr_t and attributes, exception, don't use BLI anywhere else in `MEM_*` */
#include "../../source/blender/blenlib/BLI_compiler_attrs.h"
#include "../../source/blender/blenlib/BLI_sys_types.h"
#include <cstring>
#ifdef __cplusplus
extern "C" {
#endif
/* -------------------------------------------------------------------- */
/**
* \name Untyped Allocation API.
*
* Defines the 'C-style' part of the API, where memory management is fully untyped (i.e. done with
* void pointers and explicit size values).
*
* This API should usually not be used anymore in C++ code, unless some form of raw memory
* management is necessary (e.g. for allocation of various ID types based on their
* #IDTypeInfo::struct_size data).
*
* \{ */
/**
* Returns the length of the allocated memory segment pointed at
* by vmemh. If the pointer was not previously allocated by this
* module, the result is undefined.
*/
extern size_t (*MEM_allocN_len)(const void *vmemh) ATTR_WARN_UNUSED_RESULT;
/**
* Release memory previously allocated by the C-style functions of this module.
*
* It is illegal to call this function with data allocated by #MEM_new.
*/
void MEM_delete_void(void *vmemh);
#if 0 /* UNUSED */
/**
* Return zero if memory is not in allocated list
*/
extern short (*MEM_testN)(void *vmemh);
#endif
/**
* Duplicates a block of memory, and returns a pointer to the
* newly allocated block.
* NULL-safe; will return NULL when receiving a NULL pointer.
*
* Use this version only for void pointers. */
void *MEM_dupalloc_void(const void *vmemh) /* ATTR_MALLOC */ ATTR_WARN_UNUSED_RESULT;
/**
* Reallocates a block of memory, and returns pointer to the newly
* allocated block, the old one is freed. this is not as optimized
* as a system realloc but just makes a new allocation and copies
* over from existing memory. */
extern void *(*MEM_realloc_uninitialized_id)(
void *vmemh, size_t len, const char *str) /* ATTR_MALLOC */ ATTR_WARN_UNUSED_RESULT
ATTR_ALLOC_SIZE(2);
/**
* A variant of realloc which zeros new bytes
*/
extern void *(*MEM_realloc_zeroed_id)(void *vmemh,
size_t len,
const char *str) /* ATTR_MALLOC */ ATTR_WARN_UNUSED_RESULT
ATTR_ALLOC_SIZE(2);
#define MEM_realloc_uninitialized(vmemh, len) MEM_realloc_uninitialized_id(vmemh, len, __func__)
#define MEM_realloc_zeroed(vmemh, len) MEM_realloc_zeroed_id(vmemh, len, __func__)
/**
* Allocate a block of memory of size len, with tag name str. The
* memory is cleared. The name must be static, because only a
* pointer to it is stored!
*/
void *MEM_new_zeroed(size_t len, const char *str) ATTR_WARN_UNUSED_RESULT ATTR_ALLOC_SIZE(1)
ATTR_NONNULL(2);
/**
* Allocate a block of memory of size (len * size), with tag name
* str, aborting in case of integer overflows to prevent vulnerabilities.
* The memory is cleared. The name must be static, because only a
* pointer to it is stored! */
void *MEM_new_array_zeroed(size_t len,
size_t size,
const char *str) /* ATTR_MALLOC */ ATTR_WARN_UNUSED_RESULT
ATTR_ALLOC_SIZE(1, 2) ATTR_NONNULL(3);
/**
* Allocate a block of memory of size len, with tag name str. The
* name must be a static, because only a pointer to it is stored!
*/
void *MEM_new_uninitialized(size_t len, const char *str) /* ATTR_MALLOC */ ATTR_WARN_UNUSED_RESULT
ATTR_ALLOC_SIZE(1) ATTR_NONNULL(2);
/**
* Allocate a block of memory of size (len * size), with tag name str,
* aborting in case of integer overflow to prevent vulnerabilities. The
* name must be a static, because only a pointer to it is stored!
*/
void *MEM_new_array_uninitialized(size_t len,
size_t size,
const char *str) /* ATTR_MALLOC */ ATTR_WARN_UNUSED_RESULT
ATTR_ALLOC_SIZE(1, 2) ATTR_NONNULL(3);
/**
* Allocate an aligned block of memory of size len, with tag name str. The
* name must be a static, because only a pointer to it is stored!
*/
void *MEM_new_uninitialized_aligned(size_t len,
size_t alignment,
const char *str) /* ATTR_MALLOC */ ATTR_WARN_UNUSED_RESULT
ATTR_ALLOC_SIZE(1) ATTR_NONNULL(3);
/**
* Allocate an aligned block of memory that remains uninitialized.
*/
extern void *(*MEM_new_array_uninitialized_aligned)(
size_t len,
size_t size,
size_t alignment,
const char *str) /* ATTR_MALLOC */ ATTR_WARN_UNUSED_RESULT ATTR_ALLOC_SIZE(1, 2)
ATTR_NONNULL(4);
/**
* Allocate an aligned block of memory that is initialized with zeros.
*/
extern void *(*MEM_new_array_zeroed_aligned)(
size_t len,
size_t size,
size_t alignment,
const char *str) /* ATTR_MALLOC */ ATTR_WARN_UNUSED_RESULT ATTR_ALLOC_SIZE(1, 2)
ATTR_NONNULL(4);
/** \} */
/* -------------------------------------------------------------------- */
/**
* \name Various Helpers.
*
* These functions allow to control the behavior of the guarded allocator, and to retrieve (debug)
* information about allocated memory.
* \{ */
/**
* Print a list of the names and sizes of all allocated memory
* blocks. as a python dict for easy investigation.
*/
extern void (*MEM_printmemlist_pydict)();
/**
* Print a list of the names and sizes of all allocated memory blocks.
*/
extern void (*MEM_printmemlist)();
/** calls the function on all allocated memory blocks. */
extern void (*MEM_callbackmemlist)(void (*func)(void *));
/** Print statistics about memory usage */
extern void (*MEM_printmemlist_stats)();
/** Set the callback function for error output. */
extern void (*MEM_set_error_callback)(void (*func)(const char *));
/**
* Are the start/end block markers still correct ?
*
* \retval true for correct memory, false for corrupted memory.
*/
extern bool (*MEM_consistency_check)();
/** Attempt to enforce OSX (or other OS's) to have malloc and stack nonzero */
extern void (*MEM_set_memory_debug)();
/** Memory usage stats. */
extern size_t (*MEM_get_memory_in_use)();
/** Get amount of memory blocks in use. */
extern unsigned int (*MEM_get_memory_blocks_in_use)();
/** Reset the peak memory statistic to zero. */
extern void (*MEM_reset_peak_memory)();
/** Get the peak memory usage in bytes, including `mmap` allocations. */
extern size_t (*MEM_get_peak_memory)() ATTR_WARN_UNUSED_RESULT;
/** Overhead for lockfree allocator (use to avoid slop-space). */
#define MEM_SIZE_OVERHEAD sizeof(size_t)
#define MEM_SIZE_OPTIMAL(size) ((size) - MEM_SIZE_OVERHEAD)
#ifndef NDEBUG
extern const char *(*MEM_name_ptr)(void *vmemh);
/**
* Change the debugging name/string assigned to the memory allocated at \a vmemh. Only affects the
* guarded allocator. The name must be a static string, because only a pointer to it is stored!
*
* Handy when debugging leaking memory allocated by some often called, generic function with a
* unspecific name. A caller with more info can set a more specific name, and see which call to the
* generic function allocates the leaking memory.
*/
extern void (*MEM_name_ptr_set)(void *vmemh, const char *str) ATTR_NONNULL();
#endif
/**
* This should be called as early as possible in the program. When it has been called, information
* about memory leaks will be printed on exit.
*/
void MEM_init_memleak_detection(void);
/**
* When this has been called and memory leaks have been detected, the process will have an exit
* code that indicates failure. This can be used for when checking for memory leaks with automated
* tests.
*/
void MEM_enable_fail_on_memleak(void);
/**
* Switch allocator to fast mode, with less tracking.
*
* Use in the production code where performance is the priority, and exact details about allocation
* is not. This allocator keeps track of number of allocation and amount of allocated bytes, but it
* does not track of names of allocated blocks.
*
* \note The switch between allocator types can only happen before any allocation did happen.
*/
void MEM_use_lockfree_allocator(void);
/**
* Switch allocator to slow fully guarded mode.
*
* Use for debug purposes. This allocator contains lock section around every allocator call, which
* makes it slow. What is gained with this is the ability to have list of allocated blocks (in an
* addition to the tracking of number of allocations and amount of allocated bytes).
*
* \note The switch between allocator types can only happen before any allocation did happen.
*/
void MEM_use_guarded_allocator(void);
/** \} */
#ifdef __cplusplus
}
#endif /* __cplusplus */
#ifdef __cplusplus
# include <any>
# include <memory>
# include <new>
# include <type_traits>
# include <utility>
# include "intern/mallocn_intern_function_pointers.hh"
/**
* Conservative value of memory alignment returned by non-aligned OS-level memory allocation
* functions. For alignments smaller than this value, using non-aligned versions of allocator API
* functions is okay, allowing use of `calloc`, for example.
*/
# define MEM_MIN_CPP_ALIGNMENT \
(__STDCPP_DEFAULT_NEW_ALIGNMENT__ < alignof(void *) ? __STDCPP_DEFAULT_NEW_ALIGNMENT__ : \
alignof(void *))
/* -------------------------------------------------------------------- */
/**
* \name Type-aware allocation & construction API.
*
* Defines some `new`/`delete`-like helpers, which allocate/free memory using `MEM_guardedalloc`,
* and construct/destruct the objects.
*
* When possible, it is preferred to use these, even on trivial types, as it makes potential
* future changes to these types less disruptive, and is overall closer to standard C++ data
* creation and destruction.
*
* However, if the type is trivial, `MEM_[cm]allocN<T>` and related functions can be used to
* allocate an object that will be managed by external historic code still using C-style
* allocation/duplication/freeing.
*
* \{ */
namespace mem_guarded::internal {
/* Note that we intentionally don't care about a non-trivial default constructor here. */
template<typename T>
constexpr bool is_trivial_after_construction = std::is_trivially_copyable_v<T> &&
std::is_trivially_destructible_v<T>;
} // namespace mem_guarded::internal
/**
* Allocate new memory for an object of type #T, and construct it.
* #MEM_delete must be used to delete the object. Calling #MEM_delete_void on it is illegal.
*
* Do not assume that this ever zero-initializes memory (even when it does), explicitly initialize.
*
* Although calling this without arguments will cause zero-initialization for many types, simple
* changes to the type can break this. Basic explanation:
* With no arguments, this will initialize using `T()` (value initialization) not `T` (default
* initialization). Details are involved, but for "C-style" structs ("Plain old Data" structs or
* structs with a compiler generated constructor) memory will be zero-initialized. A change like
* simply adding a custom default constructor would change initialization behavior.
* See: https://stackoverflow.com/a/4982720, https://stackoverflow.com/a/620402
*/
template<typename T, typename... Args>
inline T *MEM_new(const char *allocation_name, Args &&...args)
{
void *buffer = mem_guarded::internal::mem_mallocN_aligned_ex(
sizeof(T),
alignof(T),
allocation_name,
std::is_trivially_destructible_v<T> ? mem_guarded::internal::DestructorType::Trivial :
mem_guarded::internal::DestructorType::NonTrivial);
return new (buffer) T(std::forward<Args>(args)...);
}
/**
* Allocate new memory for an array of objects with type #T, and construct them.
*
* See #MEM_new for initialization logic. Unlike #MEM_new this is only supported for trivially
* destructible types. This makes it safe to use #MEM_delete on arrays without the need for an
* equivalent of the delete [] operator.
*
* In new code it is preferred to use data structures like Vector instead, whenever possible.
*/
template<typename T> inline T *MEM_new_array(const size_t length, const char *allocation_name)
{
# ifdef _MSC_VER
static_assert(
std::is_trivially_destructible_v<T>,
"For non-trivially copyable and destructible types, use higher level types like Vector.");
# else
static_assert(
mem_guarded::internal::is_trivial_after_construction<T>,
"For non-trivially copyable and destructible types, use higher level types like Vector.");
# endif
T *buffer = static_cast<T *>(
MEM_new_array_uninitialized_aligned(length, sizeof(T), alignof(T), allocation_name));
for (size_t i = 0; i < length; i++) {
new (buffer + i) T();
}
return buffer;
}
/**
* Destruct and deallocate an object previously allocated and constructed with #MEM_new, or some
* type-overloaded `new` operators using MEM_guardedalloc as backend.
*
* As with the `delete` C++ operator, passing in `nullptr` is allowed and does nothing.
*
* It is illegal to call this function with data allocated by the C-style allocation functions of
* this module.
*/
template<typename T> inline void MEM_delete(const T *ptr)
{
static_assert(
!std::is_void_v<T>,
"MEM_delete on a void pointer is not possible, `static_cast` it to the correct type");
if (ptr == nullptr) {
return;
}
const void *complete_ptr = [ptr]() {
if constexpr (std::is_polymorphic_v<T>) {
/* Polymorphic objects lifetime can be managed with pointers to their most derived type or
* with pointers to any of their ancestor types in their hierarchy tree that define a virtual
* destructor, however ancestor pointers may differ in a offset from the same derived object.
* For freeing the correct memory allocated with #MEM_new, we need to ensure that the given
* pointer is equal to the pointer to the most derived object, which can be obtained with
* `dynamic_cast<void *>(ptr)`. */
return dynamic_cast<const void *>(ptr);
}
else {
return static_cast<const void *>(ptr);
}
}();
/* Explicitly don't call destructor when not needed, also because it doesn't work
* for pointers like float (*x)[2]. */
if constexpr (!std::is_trivially_destructible_v<T>) {
ptr->~T();
}
/* C++ allows destruction of `const` objects, so the pointer is allowed to be `const`. */
mem_guarded::internal::mem_freeN_ex(const_cast<void *>(complete_ptr),
mem_guarded::internal::DestructorType::NonTrivial);
}
/**
* Helper shortcut to #MEM_delete, that also ensures that the target pointer is set to nullptr
* after deleting it.
*/
# define MEM_SAFE_DELETE(v) \
do { \
if (v) { \
MEM_delete(v); \
(v) = nullptr; \
} \
} while (0)
/**
* Helper shortcut to #MEM_delete_void, that also ensures that the target pointer is set to nullptr
* after deleting it.
*/
# define MEM_SAFE_DELETE_VOID(v) \
do { \
if (v) { \
MEM_delete_void(v); \
(v) = nullptr; \
} \
} while (0)
/** Wrapper for MEM_SAFE_DELETE<() as deallocator for std::unique_ptr. */
template<typename T> struct MEM_smart_ptr_deleter {
void operator()(T *pointer) const noexcept
{
MEM_SAFE_DELETE(pointer);
}
};
/** Define overloaded new/delete operators for C++ types. */
# define MEM_CXX_CLASS_ALLOC_FUNCS(_id) \
public: \
void *operator new(size_t num_bytes) \
{ \
return mem_guarded::internal::mem_mallocN_aligned_ex( \
num_bytes, \
__STDCPP_DEFAULT_NEW_ALIGNMENT__, \
_id, \
mem_guarded::internal::DestructorType::NonTrivial); \
} \
void *operator new(size_t num_bytes, std::align_val_t alignment) \
{ \
return mem_guarded::internal::mem_mallocN_aligned_ex( \
num_bytes, size_t(alignment), _id, mem_guarded::internal::DestructorType::NonTrivial); \
} \
void operator delete(void *mem) \
{ \
if (mem) { \
mem_guarded::internal::mem_freeN_ex(mem, \
mem_guarded::internal::DestructorType::NonTrivial); \
} \
} \
void *operator new[](size_t num_bytes) \
{ \
return mem_guarded::internal::mem_mallocN_aligned_ex( \
num_bytes, \
__STDCPP_DEFAULT_NEW_ALIGNMENT__, \
_id "[]", \
mem_guarded::internal::DestructorType::NonTrivial); \
} \
void *operator new[](size_t num_bytes, std::align_val_t alignment) \
{ \
return mem_guarded::internal::mem_mallocN_aligned_ex( \
num_bytes, \
size_t(alignment), \
_id "[]", \
mem_guarded::internal::DestructorType::NonTrivial); \
} \
void operator delete[](void *mem) \
{ \
if (mem) { \
mem_guarded::internal::mem_freeN_ex(mem, \
mem_guarded::internal::DestructorType::NonTrivial); \
} \
} \
void *operator new(size_t /*count*/, void *ptr) \
{ \
return ptr; \
} \
/** \
* This is the matching delete operator to the placement-new operator above. \
* Both parameters \
* will have the same value. Without this, we get the warning C4291 on windows. \
*/ \
void operator delete(void * /*ptr_to_free*/, void * /*ptr*/) {}
/** \} */
/* -------------------------------------------------------------------- */
/**
* \name Type-aware allocation API.
*
* Templated, type-safe versions of C-style allocation & freeing API.
*
* These functions only allocate or free memory, without any calls to constructors or destructors.
*
* \note MSVC considers C-style types using the #DNA_DEFINE_CXX_METHODS as non-trivial (more
* specifically, non-trivially copyable, likely because the default copy constructors are
* deleted by this macro). GCC and clang (both on linux, OSX, and clang-cl on Windows on Arm) do
* not. So for now, `MEM_[cm]allocN<T>` and related templates use slightly more relaxed checks on
* MSVC. These should still catch most of the real-life invalid cases.
*
* \{ */
/**
* Allocate zero-initialized memory for an object of type #T. The constructor of #T is not called,
* therefore this must only be used with trivial types (like all C types).
*
* When allocating an enforced specific amount of bytes, the C version of this function should be
* used instead. While this should be avoided in C++ code, it is still required in some cases, e.g.
* for ID allocation based on #IDTypeInfo::struct_size.
*
* #MEM_delete must be used to free a pointer returned by this call. In legacy code,
* #MEM_delete_void may also be used if the type is trivially destructible.
*/
template<typename T> inline T *MEM_new_zeroed(const char *allocation_name)
{
# ifdef _MSC_VER
static_assert(std::is_trivially_constructible_v<T>,
"For non-trivial types, MEM_new must be used.");
# else
static_assert(std::is_trivial_v<T>, "For non-trivial types, MEM_new must be used.");
# endif
return static_cast<T *>(MEM_new_array_zeroed_aligned(1, sizeof(T), alignof(T), allocation_name));
}
/**
* Type-safe version of #MEM_new_array_zeroed/#MEM_new_array_zeroed_aligned.
*
* It has the same restrictions and limitations as the type-safe version of #MEM_new_zeroed<T>.
*/
template<typename T>
inline T *MEM_new_array_zeroed(const size_t length, const char *allocation_name)
{
# ifdef _MSC_VER
static_assert(std::is_trivially_constructible_v<T>,
"For non-trivial types, MEM_new must be used.");
# else
static_assert(std::is_trivial_v<T>, "For non-trivial types, MEM_new must be used.");
# endif
return static_cast<T *>(
MEM_new_array_zeroed_aligned(length, sizeof(T), alignof(T), allocation_name));
}
/**
* Allocate uninitialized memory for an object of type #T. The constructor of #T is not called,
* therefore this must only be used with trivial types (like all C types).
*
* When allocating an enforced specific amount of bytes, the C version of this function should be
* used instead. While this should be avoided in C++ code, it is still required in some cases, e.g.
* for ID allocation based on #IDTypeInfo::struct_size.
*
* #MEM_delete_void must be used to free a pointer returned by this call. Calling #MEM_delete on it
* is illegal.
*/
template<typename T> inline T *MEM_new_uninitialized(const char *allocation_name)
{
# ifdef _MSC_VER
static_assert(std::is_trivially_constructible_v<T>,
"For non-trivial types, MEM_new must be used.");
# else
static_assert(std::is_trivial_v<T>, "For non-trivial types, MEM_new must be used.");
# endif
return static_cast<T *>(
MEM_new_array_uninitialized_aligned(1, sizeof(T), alignof(T), allocation_name));
}
/**
* Type-safe version of #MEM_new_array_uninitialized/#MEM_new_uninitialized_aligned.
*
* It has the same restrictions and limitations as the type-safe version of
* #MEM_new_uninitialized<T>.
*/
template<typename T>
inline T *MEM_new_array_uninitialized(const size_t length, const char *allocation_name)
{
# ifdef _MSC_VER
static_assert(std::is_trivially_constructible_v<T>,
"For non-trivial types, MEM_new must be used.");
# else
static_assert(std::is_trivial_v<T>, "For non-trivial types, MEM_new must be used.");
# endif
return static_cast<T *>(
MEM_new_array_uninitialized_aligned(length, sizeof(T), alignof(T), allocation_name));
}
/**
* Duplicates a block of memory, and returns a pointer to the newly allocated block.
* NULL-safe; will return NULL when receiving a NULL pointer.
*
* Only supported for trivially copyable types, use #MEM_new for other types.
* */
template<typename T> inline T *MEM_dupalloc(const T *other)
{
# ifdef _MSC_VER
/* TODO: Add back is_trivially_copyable_v condition, temporarily disabled
* because of build error on MSVC. */
static_assert(/*std::is_trivially_copyable_v<T> &&*/ std::is_trivially_destructible_v<T>,
"MEM_dupalloc can only duplicate types that are trivially copyable and "
"destructible, use MEM_new instead.");
# else
static_assert(std::is_trivially_copyable_v<T> &&
mem_guarded::internal::is_trivial_after_construction<T>,
"MEM_dupalloc can only duplicate types that are trivially copyable and "
"destructible, use MEM_new instead.");
# endif
static_assert(!std::is_void_v<T>);
return static_cast<T *>(MEM_dupalloc_void(other));
}
template<typename T> inline void MEM_delete_void(T *ptr)
{
static_assert(std::is_void_v<T>,
"MEM_delete_void only supported for void pointer, use MEM_delete instead");
mem_guarded::internal::mem_freeN_ex(const_cast<void *>(static_cast<const void *>(ptr)),
mem_guarded::internal::DestructorType::Trivial);
}
/** \} */
/**
* Construct a T that will only be destructed after leak detection is run.
*
* This call is thread-safe. Calling code should typically keep a reference to that data as a
* `static thread_local` variable, or use some lock, to prevent concurrent accesses.
*
* The returned value should not own any memory allocated with `MEM_*` functions, since these would
* then be detected as leaked.
*/
template<typename T, typename... Args> T &MEM_construct_leak_detection_data(Args &&...args)
{
std::shared_ptr<T> data = std::make_shared<T>(std::forward<Args>(args)...);
std::any any_data = std::make_any<std::shared_ptr<T>>(data);
mem_guarded::internal::add_memleak_data(any_data);
return *data;
}
#endif /* __cplusplus */
#endif /* __MEM_GUARDEDALLOC_H__ */