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polardbxengine/storage/innobase/include/mem0mem.h

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/*****************************************************************************
Copyright (c) 1994, 2018, Oracle and/or its affiliates. All Rights Reserved.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License, version 2.0, as published by the
Free Software Foundation.
This program is also distributed with certain software (including but not
limited to OpenSSL) that is licensed under separate terms, as designated in a
particular file or component or in included license documentation. The authors
of MySQL hereby grant you an additional permission to link the program and
your derivative works with the separately licensed software that they have
included with MySQL.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0,
for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*****************************************************************************/
/** @file include/mem0mem.h
The memory management
Created 6/9/1994 Heikki Tuuri
*******************************************************/
#ifndef mem0mem_h
#define mem0mem_h
#include "mach0data.h"
#include "univ.i"
#include "ut0byte.h"
#include "ut0mem.h"
#include "ut0rnd.h"
#include <limits.h>
#include <memory>
/* -------------------- MEMORY HEAPS ----------------------------- */
/** A block of a memory heap consists of the info structure
followed by an area of memory */
typedef struct mem_block_info_t mem_block_t;
/** A memory heap is a nonempty linear list of memory blocks */
typedef mem_block_t mem_heap_t;
/** Types of allocation for memory heaps: DYNAMIC means allocation from the
dynamic memory pool of the C compiler, BUFFER means allocation from the
buffer pool; the latter method is used for very big heaps */
#define MEM_HEAP_DYNAMIC 0 /* the most common type */
#define MEM_HEAP_BUFFER 1
#define MEM_HEAP_BTR_SEARCH \
2 /* this flag can optionally be \
ORed to MEM_HEAP_BUFFER, in which \
case heap->free_block is used in \
some cases for memory allocations, \
and if it's NULL, the memory \
allocation functions can return \
NULL. */
/** Different type of heaps in terms of which data structure is using them */
#define MEM_HEAP_FOR_BTR_SEARCH (MEM_HEAP_BTR_SEARCH | MEM_HEAP_BUFFER)
#define MEM_HEAP_FOR_PAGE_HASH (MEM_HEAP_DYNAMIC)
#define MEM_HEAP_FOR_RECV_SYS (MEM_HEAP_BUFFER)
#define MEM_HEAP_FOR_LOCK_HEAP (MEM_HEAP_BUFFER)
/** The following start size is used for the first block in the memory heap if
the size is not specified, i.e., 0 is given as the parameter in the call of
create. The standard size is the maximum (payload) size of the blocks used for
allocations of small buffers. */
#define MEM_BLOCK_START_SIZE 64
#define MEM_BLOCK_STANDARD_SIZE \
(UNIV_PAGE_SIZE >= 16384 ? 8000 : MEM_MAX_ALLOC_IN_BUF)
/** If a memory heap is allowed to grow into the buffer pool, the following
is the maximum size for a single allocated buffer
(from UNIV_PAGE_SIZE we subtract MEM_BLOCK_HEADER_SIZE and 2*MEM_NO_MANS_LAND
since it's something we always need to put. Since in MEM_SPACE_NEEDED we round
n to the next multiple of UNIV_MEM_ALINGMENT, we need to cut from the rest the
part that cannot be divided by UNIV_MEM_ALINGMENT): */
#define MEM_MAX_ALLOC_IN_BUF \
((UNIV_PAGE_SIZE - MEM_BLOCK_HEADER_SIZE - 2 * MEM_NO_MANS_LAND) & \
~(UNIV_MEM_ALIGNMENT - 1))
/* Before and after any allocated object we will put MEM_NO_MANS_LAND bytes of
some data (different before and after) which is supposed not to be modified by
anyone. This way it would be much easier to determine whether anyone was
writing on not his memory, especially that Valgrind can assure there was no
reads or writes to this memory. */
#ifdef UNIV_DEBUG
const int MEM_NO_MANS_LAND = 16;
#else
const int MEM_NO_MANS_LAND = 0;
#endif
/* Byte that we would put before allocated object MEM_NO_MANS_LAND times.*/
const byte MEM_NO_MANS_LAND_BEFORE_BYTE = 0xCE;
/* Byte that we would put after allocated object MEM_NO_MANS_LAND times.*/
const byte MEM_NO_MANS_LAND_AFTER_BYTE = 0xDF;
/** Space needed when allocating for a user a field of length N.
The space is allocated only in multiples of UNIV_MEM_ALIGNMENT. In debug mode
contains two areas of no mans lands before and after the buffer requested. */
#define MEM_SPACE_NEEDED(N) \
ut_calc_align(N + 2 * MEM_NO_MANS_LAND, UNIV_MEM_ALIGNMENT)
#ifdef UNIV_DEBUG
/** Macro for memory heap creation.
@param[in] size Desired start block size. */
#define mem_heap_create(size) \
mem_heap_create_func((size), __FILE__, __LINE__, MEM_HEAP_DYNAMIC)
/** Macro for memory heap creation.
@param[in] size Desired start block size.
@param[in] type Heap type */
#define mem_heap_create_typed(size, type) \
mem_heap_create_func((size), __FILE__, __LINE__, (type))
#else /* UNIV_DEBUG */
/** Macro for memory heap creation.
@param[in] size Desired start block size. */
#define mem_heap_create(size) mem_heap_create_func((size), MEM_HEAP_DYNAMIC)
/** Macro for memory heap creation.
@param[in] size Desired start block size.
@param[in] type Heap type */
#define mem_heap_create_typed(size, type) mem_heap_create_func((size), (type))
#endif /* UNIV_DEBUG */
/** Creates a memory heap.
NOTE: Use the corresponding macros instead of this function.
A single user buffer of 'size' will fit in the block.
0 creates a default size block.
@param[in] size Desired start block size.
@param[in] file_name File name where created
@param[in] line Line where created
@param[in] type Heap type
@return own: memory heap, NULL if did not succeed (only possible for
MEM_HEAP_BTR_SEARCH type heaps) */
UNIV_INLINE
mem_heap_t *mem_heap_create_func(ulint size,
#ifdef UNIV_DEBUG
const char *file_name, ulint line,
#endif /* UNIV_DEBUG */
ulint type);
/** Frees the space occupied by a memory heap.
NOTE: Use the corresponding macro instead of this function.
@param[in] heap Heap to be freed */
UNIV_INLINE
void mem_heap_free(mem_heap_t *heap);
/** Allocates and zero-fills n bytes of memory from a memory heap.
@param[in] heap memory heap
@param[in] n number of bytes; if the heap is allowed to grow into
the buffer pool, this must be <= MEM_MAX_ALLOC_IN_BUF
@return allocated, zero-filled storage */
UNIV_INLINE
void *mem_heap_zalloc(mem_heap_t *heap, ulint n);
/** Allocates n bytes of memory from a memory heap.
@param[in] heap memory heap
@param[in] n number of bytes; if the heap is allowed to grow into
the buffer pool, this must be <= MEM_MAX_ALLOC_IN_BUF
@return allocated storage, NULL if did not succeed (only possible for
MEM_HEAP_BTR_SEARCH type heaps) */
UNIV_INLINE
void *mem_heap_alloc(mem_heap_t *heap, ulint n);
/** Returns a pointer to the heap top.
@param[in] heap memory heap
@return pointer to the heap top */
UNIV_INLINE
byte *mem_heap_get_heap_top(mem_heap_t *heap);
/** Frees the space in a memory heap exceeding the pointer given.
The pointer must have been acquired from mem_heap_get_heap_top.
The first memory block of the heap is not freed.
@param[in] heap heap from which to free
@param[in] old_top pointer to old top of heap */
UNIV_INLINE
void mem_heap_free_heap_top(mem_heap_t *heap, byte *old_top);
/** Empties a memory heap.
The first memory block of the heap is not freed.
@param[in] heap heap to empty */
UNIV_INLINE
void mem_heap_empty(mem_heap_t *heap);
/** Returns a pointer to the topmost element in a memory heap.
The size of the element must be given.
@param[in] heap memory heap
@param[in] n size of the topmost element
@return pointer to the topmost element */
UNIV_INLINE
void *mem_heap_get_top(mem_heap_t *heap, ulint n);
/** Checks if a given chunk of memory is the topmost element stored in the
heap. If this is the case, then calling mem_heap_free_top() would free
that element from the heap.
@param[in] heap memory heap
@param[in] buf presumed topmost element
@param[in] buf_sz size of buf in bytes
@return true if topmost */
UNIV_INLINE
bool mem_heap_is_top(mem_heap_t *heap, const void *buf, ulint buf_sz)
MY_ATTRIBUTE((warn_unused_result));
/** Allocate a new chunk of memory from a memory heap, possibly discarding the
topmost element. If the memory chunk specified with (top, top_sz) is the
topmost element, then it will be discarded, otherwise it will be left untouched
and this function will be equivallent to mem_heap_alloc().
@param[in,out] heap memory heap
@param[in] top chunk to discard if possible
@param[in] top_sz size of top in bytes
@param[in] new_sz desired size of the new chunk
@return allocated storage, NULL if did not succeed (only possible for
MEM_HEAP_BTR_SEARCH type heaps) */
UNIV_INLINE
void *mem_heap_replace(mem_heap_t *heap, const void *top, ulint top_sz,
ulint new_sz);
/** Allocate a new chunk of memory from a memory heap, possibly discarding the
topmost element and then copy the specified data to it. If the memory chunk
specified with (top, top_sz) is the topmost element, then it will be discarded,
otherwise it will be left untouched and this function will be equivalent to
mem_heap_dup().
@param[in,out] heap memory heap
@param[in] top chunk to discard if possible
@param[in] top_sz size of top in bytes
@param[in] data new data to duplicate
@param[in] data_sz size of data in bytes
@return allocated storage, NULL if did not succeed (only possible for
MEM_HEAP_BTR_SEARCH type heaps) */
UNIV_INLINE
void *mem_heap_dup_replace(mem_heap_t *heap, const void *top, ulint top_sz,
const void *data, ulint data_sz);
/** Allocate a new chunk of memory from a memory heap, possibly discarding the
topmost element and then copy the specified string to it. If the memory chunk
specified with (top, top_sz) is the topmost element, then it will be discarded,
otherwise it will be left untouched and this function will be equivalent to
mem_heap_strdup().
@param[in,out] heap memory heap
@param[in] top chunk to discard if possible
@param[in] top_sz size of top in bytes
@param[in] str new data to duplicate
@return allocated string, NULL if did not succeed (only possible for
MEM_HEAP_BTR_SEARCH type heaps) */
UNIV_INLINE
char *mem_heap_strdup_replace(mem_heap_t *heap, const void *top, ulint top_sz,
const char *str);
/** Frees the topmost element in a memory heap.
@param[in] heap memory heap
@param[in] n size of the topmost element
The size of the element must be given. */
UNIV_INLINE
void mem_heap_free_top(mem_heap_t *heap, ulint n);
/** Returns the space in bytes occupied by a memory heap. */
UNIV_INLINE
ulint mem_heap_get_size(mem_heap_t *heap); /*!< in: heap */
/** Duplicates a NUL-terminated string.
@param[in] str string to be copied
@return own: a copy of the string, must be deallocated with ut_free */
UNIV_INLINE
char *mem_strdup(const char *str);
/** Makes a NUL-terminated copy of a nonterminated string.
@param[in] str string to be copied
@param[in] len length of str, in bytes
@return own: a copy of the string, must be deallocated with ut_free */
UNIV_INLINE
char *mem_strdupl(const char *str, ulint len);
/** Duplicates a NUL-terminated string, allocated from a memory heap.
@param[in] heap memory heap where string is allocated
@param[in] str string to be copied
@return own: a copy of the string */
char *mem_heap_strdup(mem_heap_t *heap, const char *str);
/** Makes a NUL-terminated copy of a nonterminated string, allocated from a
memory heap.
@param[in] heap memory heap where string is allocated
@param[in] str string to be copied
@param[in] len length of str, in bytes
@return own: a copy of the string */
UNIV_INLINE
char *mem_heap_strdupl(mem_heap_t *heap, const char *str, ulint len);
/** Concatenate two strings and return the result, using a memory heap.
@return own: the result */
char *mem_heap_strcat(
mem_heap_t *heap, /*!< in: memory heap where string is allocated */
const char *s1, /*!< in: string 1 */
const char *s2); /*!< in: string 2 */
/** Duplicate a block of data, allocated from a memory heap.
@return own: a copy of the data */
void *mem_heap_dup(
mem_heap_t *heap, /*!< in: memory heap where copy is allocated */
const void *data, /*!< in: data to be copied */
ulint len); /*!< in: length of data, in bytes */
/** A simple sprintf replacement that dynamically allocates the space for the
formatted string from the given heap. This supports a very limited set of
the printf syntax: types 's' and 'u' and length modifier 'l' (which is
required for the 'u' type).
@return heap-allocated formatted string */
char *mem_heap_printf(mem_heap_t *heap, /*!< in: memory heap */
const char *format, /*!< in: format string */
...) MY_ATTRIBUTE((format(printf, 2, 3)));
/** Checks that an object is a memory heap (or a block of it)
@param[in] heap Memory heap to check */
UNIV_INLINE
void mem_block_validate(const mem_heap_t *heap);
#ifdef UNIV_DEBUG
/** Validates the contents of a memory heap.
Asserts that the memory heap is consistent
@param[in] heap Memory heap to validate */
void mem_heap_validate(const mem_heap_t *heap);
#endif /* UNIV_DEBUG */
/*#######################################################################*/
/** The info structure stored at the beginning of a heap block */
struct mem_block_info_t {
uint64_t magic_n; /* magic number for debugging */
#ifdef UNIV_DEBUG
char file_name[16]; /* file name where the mem heap was created */
ulint line; /*!< line number where the mem heap was created */
#endif /* UNIV_DEBUG */
UT_LIST_BASE_NODE_T(mem_block_t)
base; /* In the first block in the
the list this is the base node of the list of blocks;
in subsequent blocks this is undefined */
UT_LIST_NODE_T(mem_block_t)
list; /* This contains pointers to next
and prev in the list. The first block allocated
to the heap is also the first block in this list,
though it also contains the base node of the list. */
ulint len; /*!< physical length of this block in bytes */
ulint total_size; /*!< physical length in bytes of all blocks
in the heap. This is defined only in the base
node and is set to ULINT_UNDEFINED in others. */
ulint type; /*!< type of heap: MEM_HEAP_DYNAMIC, or
MEM_HEAP_BUF possibly ORed to MEM_HEAP_BTR_SEARCH */
ulint free; /*!< offset in bytes of the first free position for
user data in the block */
ulint start; /*!< the value of the struct field 'free' at the
creation of the block */
void *free_block;
/* if the MEM_HEAP_BTR_SEARCH bit is set in type,
and this is the heap root, this can contain an
allocated buffer frame, which can be appended as a
free block to the heap, if we need more space;
otherwise, this is NULL */
void *buf_block;
/* if this block has been allocated from the buffer
pool, this contains the buf_block_t handle;
otherwise, this is NULL */
};
#define MEM_BLOCK_MAGIC_N 0x445566778899AABB
#define MEM_FREED_BLOCK_MAGIC_N 0xBBAA998877665544
/* Header size for a memory heap block */
#define MEM_BLOCK_HEADER_SIZE \
ut_calc_align(sizeof(mem_block_info_t), UNIV_MEM_ALIGNMENT)
#include "mem0mem.ic"
/** A C++ wrapper class to the mem_heap_t routines, so that it can be used
as an STL allocator */
template <typename T>
class mem_heap_allocator {
public:
typedef T value_type;
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef T *pointer;
typedef const T *const_pointer;
typedef T &reference;
typedef const T &const_reference;
mem_heap_allocator(mem_heap_t *heap) : m_heap(heap) {}
mem_heap_allocator(const mem_heap_allocator &other) : m_heap(other.m_heap) {
// Do nothing
}
template <typename U>
mem_heap_allocator(const mem_heap_allocator<U> &other)
: m_heap(other.m_heap) {
// Do nothing
}
~mem_heap_allocator() { m_heap = 0; }
size_type max_size() const { return (ULONG_MAX / sizeof(T)); }
/** This function returns a pointer to the first element of a newly
allocated array large enough to contain n objects of type T; only the
memory is allocated, and the objects are not constructed. Moreover,
an optional pointer argument (that points to an object already
allocated by mem_heap_allocator) can be used as a hint to the
implementation about where the new memory should be allocated in
order to improve locality. */
pointer allocate(size_type n, const_pointer hint = 0) {
return (reinterpret_cast<pointer>(mem_heap_alloc(m_heap, n * sizeof(T))));
}
void deallocate(pointer p, size_type n) {}
pointer address(reference r) const { return (&r); }
const_pointer address(const_reference r) const { return (&r); }
void construct(pointer p, const_reference t) {
new (reinterpret_cast<void *>(p)) T(t);
}
void destroy(pointer p) { (reinterpret_cast<T *>(p))->~T(); }
/** Allocators are required to supply the below template class member
which enables the possibility of obtaining a related allocator,
parametrized in terms of a different type. For example, given an
allocator type IntAllocator for objects of type int, a related
allocator type for objects of type long could be obtained using
IntAllocator::rebind<long>::other */
template <typename U>
struct rebind {
typedef mem_heap_allocator<U> other;
};
/** Get the underlying memory heap object.
@return the underlying memory heap object. */
mem_heap_t *get_mem_heap() const { return (m_heap); }
private:
mem_heap_t *m_heap;
template <typename U>
friend class mem_heap_allocator;
};
template <class T>
bool operator==(const mem_heap_allocator<T> &left,
const mem_heap_allocator<T> &right) {
return (left.get_mem_heap() == right.get_mem_heap());
}
template <class T>
bool operator!=(const mem_heap_allocator<T> &left,
const mem_heap_allocator<T> &right) {
return (left.get_mem_heap() != right.get_mem_heap());
}
#endif
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