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/*****************************************************************************
Copyright (c) 1994, 2016, 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 as published by the Free Software
Foundation; version 2 of the License.
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 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 Street, Suite 500, Boston, MA 02110-1335 USA
*****************************************************************************/
/********************************************************************//**
@file include/mem0mem.ic
The memory management
Created 6/8/1994 Heikki Tuuri
*************************************************************************/
#include "ut0new.h"
#ifdef UNIV_DEBUG
# define mem_heap_create_block(heap, n, type, file_name, line) \
mem_heap_create_block_func(heap, n, file_name, line, type)
# define mem_heap_create_at(N, file_name, line) \
mem_heap_create_func(N, file_name, line, MEM_HEAP_DYNAMIC)
#else /* UNIV_DEBUG */
# define mem_heap_create_block(heap, n, type, file_name, line) \
mem_heap_create_block_func(heap, n, type)
# define mem_heap_create_at(N, file_name, line) \
mem_heap_create_func(N, MEM_HEAP_DYNAMIC)
#endif /* UNIV_DEBUG */
/***************************************************************//**
Creates a memory heap block where data can be allocated.
@return own: memory heap block, NULL if did not succeed (only possible
for MEM_HEAP_BTR_SEARCH type heaps) */
mem_block_t*
mem_heap_create_block_func(
/*=======================*/
mem_heap_t* heap, /*!< in: memory heap or NULL if first block
should be created */
ulint n, /*!< in: number of bytes needed for user data */
#ifdef UNIV_DEBUG
const char* file_name,/*!< in: file name where created */
ulint line, /*!< in: line where created */
#endif /* UNIV_DEBUG */
ulint type); /*!< in: type of heap: MEM_HEAP_DYNAMIC or
MEM_HEAP_BUFFER */
/******************************************************************//**
Frees a block from a memory heap. */
void
mem_heap_block_free(
/*================*/
mem_heap_t* heap, /*!< in: heap */
mem_block_t* block); /*!< in: block to free */
#ifndef UNIV_HOTBACKUP
/******************************************************************//**
Frees the free_block field from a memory heap. */
void
mem_heap_free_block_free(
/*=====================*/
mem_heap_t* heap); /*!< in: heap */
#endif /* !UNIV_HOTBACKUP */
/***************************************************************//**
Adds a new block to a memory heap.
@param[in] heap memory heap
@param[in] n number of bytes needed
@return created block, NULL if did not succeed (only possible for
MEM_HEAP_BTR_SEARCH type heaps) */
mem_block_t*
mem_heap_add_block(
mem_heap_t* heap,
ulint n);
UNIV_INLINE
void
mem_block_set_len(mem_block_t* block, ulint len)
{
ut_ad(len > 0);
block->len = len;
}
UNIV_INLINE
ulint
mem_block_get_len(mem_block_t* block)
{
return(block->len);
}
UNIV_INLINE
void
mem_block_set_type(mem_block_t* block, ulint type)
{
ut_ad((type == MEM_HEAP_DYNAMIC) || (type == MEM_HEAP_BUFFER)
|| (type == MEM_HEAP_BUFFER + MEM_HEAP_BTR_SEARCH));
block->type = type;
}
UNIV_INLINE
ulint
mem_block_get_type(mem_block_t* block)
{
return(block->type);
}
UNIV_INLINE
void
mem_block_set_free(mem_block_t* block, ulint free)
{
ut_ad(free > 0);
ut_ad(free <= mem_block_get_len(block));
block->free = free;
}
UNIV_INLINE
ulint
mem_block_get_free(mem_block_t* block)
{
return(block->free);
}
UNIV_INLINE
void
mem_block_set_start(mem_block_t* block, ulint start)
{
ut_ad(start > 0);
block->start = start;
}
UNIV_INLINE
ulint
mem_block_get_start(mem_block_t* block)
{
return(block->start);
}
/** Checks that an object is a memory heap block
@param[in] block Memory block to check. */
UNIV_INLINE
void
mem_block_validate(
const mem_block_t* block)
{
ut_a(block->magic_n == MEM_BLOCK_MAGIC_N);
}
/** 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)
{
ut_ad(heap);
ut_ad(!(heap->type & MEM_HEAP_BTR_SEARCH));
return(memset(mem_heap_alloc(heap, n), 0, 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)
{
mem_block_t* block;
void* buf;
ulint free;
ut_d(mem_block_validate(heap));
block = UT_LIST_GET_LAST(heap->base);
ut_ad(!(block->type & MEM_HEAP_BUFFER) || (n <= MEM_MAX_ALLOC_IN_BUF));
/* Check if there is enough space in block. If not, create a new
block to the heap */
if (mem_block_get_len(block)
< mem_block_get_free(block) + MEM_SPACE_NEEDED(n)) {
block = mem_heap_add_block(heap, n);
if (block == NULL) {
return(NULL);
}
}
free = mem_block_get_free(block);
buf = (byte*) block + free;
mem_block_set_free(block, free + MEM_SPACE_NEEDED(n));
UNIV_MEM_ALLOC(buf, n);
return(buf);
}
/** 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)
{
mem_block_t* block;
byte* buf;
ut_d(mem_block_validate(heap));
block = UT_LIST_GET_LAST(heap->base);
buf = (byte*) block + mem_block_get_free(block);
return(buf);
}
/** 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)
{
mem_block_t* block;
mem_block_t* prev_block;
ut_d(mem_heap_validate(heap));
block = UT_LIST_GET_LAST(heap->base);
while (block != NULL) {
if (((byte*) block + mem_block_get_free(block) >= old_top)
&& ((byte*) block <= old_top)) {
/* Found the right block */
break;
}
/* Store prev_block value before freeing the current block
(the current block will be erased in freeing) */
prev_block = UT_LIST_GET_PREV(list, block);
mem_heap_block_free(heap, block);
block = prev_block;
}
ut_ad(block);
/* Set the free field of block */
mem_block_set_free(block, old_top - (byte*) block);
ut_ad(mem_block_get_start(block) <= mem_block_get_free(block));
UNIV_MEM_ASSERT_W(old_top, (byte*) block + block->len - old_top);
UNIV_MEM_ALLOC(old_top, (byte*) block + block->len - old_top);
/* If free == start, we may free the block if it is not the first
one */
if ((heap != block) && (mem_block_get_free(block)
== mem_block_get_start(block))) {
mem_heap_block_free(heap, block);
}
}
/** 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)
{
mem_heap_free_heap_top(heap, (byte*) heap + mem_block_get_start(heap));
#ifndef UNIV_HOTBACKUP
if (heap->free_block) {
mem_heap_free_block_free(heap);
}
#endif /* !UNIV_HOTBACKUP */
}
/** 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)
{
mem_block_t* block;
byte* buf;
ut_d(mem_block_validate(heap));
block = UT_LIST_GET_LAST(heap->base);
buf = (byte*) block + mem_block_get_free(block) - MEM_SPACE_NEEDED(n);
return((void*) buf);
}
/** 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)
{
const byte* first_free_byte;
const byte* presumed_start_of_buf;
ut_d(mem_block_validate(heap));
first_free_byte = mem_heap_get_heap_top(heap);
presumed_start_of_buf = first_free_byte - MEM_SPACE_NEEDED(buf_sz);
return(presumed_start_of_buf == buf);
}
/*****************************************************************//**
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().
@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, /*!< in/out: memory heap */
const void* top, /*!< in: chunk to discard if possible */
ulint top_sz, /*!< in: size of top in bytes */
ulint new_sz) /*!< in: desired size of the new chunk */
{
if (mem_heap_is_top(heap, top, top_sz)) {
mem_heap_free_top(heap, top_sz);
}
return(mem_heap_alloc(heap, 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
equivallent to mem_heap_dup().
@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, /*!< in/out: memory heap */
const void* top, /*!< in: chunk to discard if possible */
ulint top_sz, /*!< in: size of top in bytes */
const void* data, /*!< in: new data to duplicate */
ulint data_sz)/*!< in: size of data in bytes */
{
void* p = mem_heap_replace(heap, top, top_sz, data_sz);
memcpy(p, data, data_sz);
return(p);
}
/*****************************************************************//**
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
equivallent to mem_heap_strdup().
@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, /*!< in/out: memory heap */
const void* top, /*!< in: chunk to discard if possible */
ulint top_sz, /*!< in: size of top in bytes */
const char* str) /*!< in: new data to duplicate */
{
return(reinterpret_cast<char*>(mem_heap_dup_replace(
heap, top, top_sz, str, strlen(str) + 1)));
}
/*****************************************************************//**
Frees the topmost element in a memory heap. The size of the element must be
given. */
UNIV_INLINE
void
mem_heap_free_top(
/*==============*/
mem_heap_t* heap, /*!< in: memory heap */
ulint n) /*!< in: size of the topmost element */
{
mem_block_t* block;
ut_d(mem_block_validate(heap));
block = UT_LIST_GET_LAST(heap->base);
/* Subtract the free field of block */
mem_block_set_free(block, mem_block_get_free(block)
- MEM_SPACE_NEEDED(n));
UNIV_MEM_ASSERT_W((byte*) block + mem_block_get_free(block), n);
/* If free == start, we may free the block if it is not the first
one */
if ((heap != block) && (mem_block_get_free(block)
== mem_block_get_start(block))) {
mem_heap_block_free(heap, block);
} else {
/* Avoid a bogus UNIV_MEM_ASSERT_W() warning in a
subsequent invocation of mem_heap_free_top().
Originally, this was UNIV_MEM_FREE(), to catch writes
to freed memory. */
UNIV_MEM_ALLOC((byte*) block + mem_block_get_free(block), n);
}
}
/** 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)
{
mem_block_t* block;
if (!size) {
size = MEM_BLOCK_START_SIZE;
}
block = mem_heap_create_block(NULL, size, type, file_name, line);
if (block == NULL) {
return(NULL);
}
/* The first block should not be in buffer pool,
because it might be relocated to resize buffer pool. */
ut_ad(block->buf_block == NULL);
UT_LIST_INIT(block->base, &mem_block_t::list);
/* Add the created block itself as the first block in the list */
UT_LIST_ADD_FIRST(block->base, block);
return(block);
}
/** 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)
{
mem_block_t* block;
mem_block_t* prev_block;
ut_d(mem_block_validate(heap));
block = UT_LIST_GET_LAST(heap->base);
#ifndef UNIV_HOTBACKUP
if (heap->free_block) {
mem_heap_free_block_free(heap);
}
#endif /* !UNIV_HOTBACKUP */
while (block != NULL) {
/* Store the contents of info before freeing current block
(it is erased in freeing) */
prev_block = UT_LIST_GET_PREV(list, block);
mem_heap_block_free(heap, block);
block = prev_block;
}
}
/*****************************************************************//**
Returns the space in bytes occupied by a memory heap. */
UNIV_INLINE
ulint
mem_heap_get_size(
/*==============*/
mem_heap_t* heap) /*!< in: heap */
{
ulint size = 0;
ut_d(mem_block_validate(heap));
size = heap->total_size;
#ifndef UNIV_HOTBACKUP
if (heap->free_block) {
size += UNIV_PAGE_SIZE;
}
#endif /* !UNIV_HOTBACKUP */
return(size);
}
/**********************************************************************//**
Duplicates a NUL-terminated string.
@return own: a copy of the string, must be deallocated with ut_free */
UNIV_INLINE
char*
mem_strdup(
/*=======*/
const char* str) /*!< in: string to be copied */
{
ulint len = strlen(str) + 1;
return(static_cast<char*>(memcpy(ut_malloc_nokey(len), str, len)));
}
/**********************************************************************//**
Makes a NUL-terminated copy of a nonterminated string.
@return own: a copy of the string, must be deallocated with ut_free */
UNIV_INLINE
char*
mem_strdupl(
/*========*/
const char* str, /*!< in: string to be copied */
ulint len) /*!< in: length of str, in bytes */
{
char* s = static_cast<char*>(ut_malloc_nokey(len + 1));
s[len] = 0;
return(static_cast<char*>(memcpy(s, str, len)));
}
/**********************************************************************//**
Makes a NUL-terminated copy of a nonterminated string,
allocated from a memory heap.
@return own: a copy of the string */
UNIV_INLINE
char*
mem_heap_strdupl(
/*=============*/
mem_heap_t* heap, /*!< in: memory heap where string is allocated */
const char* str, /*!< in: string to be copied */
ulint len) /*!< in: length of str, in bytes */
{
char* s = (char*) mem_heap_alloc(heap, len + 1);
s[len] = 0;
return((char*) memcpy(s, str, len));
}
|