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-rw-r--r--mysys/my_alloc.c671
1 files changed, 671 insertions, 0 deletions
diff --git a/mysys/my_alloc.c b/mysys/my_alloc.c
new file mode 100644
index 00000000..eff5a031
--- /dev/null
+++ b/mysys/my_alloc.c
@@ -0,0 +1,671 @@
+/*
+ Copyright (c) 2000, 2010, Oracle and/or its affiliates
+ Copyright (c) 2010, 2020, MariaDB
+
+ 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 St, Fifth Floor, Boston, MA 02110-1335 USA */
+
+/* Routines to handle mallocing of results which will be freed the same time */
+
+#include <my_global.h>
+#include <my_sys.h>
+#include <m_string.h>
+#include <my_bit.h>
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+
+#undef EXTRA_DEBUG
+#define EXTRA_DEBUG
+
+#ifndef DBUG_OFF
+/* Put a protected barrier after every element when using multi_alloc_root() */
+#define ALLOC_BARRIER
+#endif
+
+/* data packed in MEM_ROOT -> min_malloc */
+
+/* Don't allocate too small blocks */
+#define ROOT_MIN_BLOCK_SIZE 256
+
+/* bits in MEM_ROOT->flags */
+#define ROOT_FLAG_THREAD_SPECIFIC 1
+#define ROOT_FLAG_MPROTECT 2
+
+#define MALLOC_FLAG(R) MYF((R)->flags & ROOT_FLAG_THREAD_SPECIFIC ? THREAD_SPECIFIC : 0)
+
+#define TRASH_MEM(X) TRASH_FREE(((char*)(X) + ((X)->size-(X)->left)), (X)->left)
+
+
+/*
+ Alloc memory through either my_malloc or mmap()
+*/
+
+static void *root_alloc(MEM_ROOT *root, size_t size, size_t *alloced_size,
+ myf my_flags)
+{
+ *alloced_size= size;
+#if defined(HAVE_MMAP) && defined(HAVE_MPROTECT) && defined(MAP_ANONYMOUS)
+ if (root->flags & ROOT_FLAG_MPROTECT)
+ {
+ void *res;
+ *alloced_size= MY_ALIGN(size, my_system_page_size);
+ res= my_mmap(0, *alloced_size, PROT_READ | PROT_WRITE,
+ MAP_NORESERVE | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ if (res == MAP_FAILED)
+ res= 0;
+ return res;
+ }
+#endif /* HAVE_MMAP */
+
+ return my_malloc(root->psi_key, size,
+ my_flags | MYF(root->flags & ROOT_FLAG_THREAD_SPECIFIC ?
+ MY_THREAD_SPECIFIC : 0));
+}
+
+static void root_free(MEM_ROOT *root, void *ptr, size_t size)
+{
+#if defined(HAVE_MMAP) && defined(HAVE_MPROTECT) && defined(MAP_ANONYMOUS)
+ if (root->flags & ROOT_FLAG_MPROTECT)
+ my_munmap(ptr, size);
+ else
+#endif
+ my_free(ptr);
+}
+
+
+/*
+ Calculate block sizes to use
+
+ Sizes will be updated to next power of 2, minus operating system
+ memory management size.
+
+ The idea is to reduce memory fragmentation as most system memory
+ allocators are using power of 2 block size internally.
+*/
+
+static void calculate_block_sizes(MEM_ROOT *mem_root, size_t block_size,
+ size_t *pre_alloc_size)
+{
+ size_t pre_alloc= *pre_alloc_size;
+
+ if (mem_root->flags & ROOT_FLAG_MPROTECT)
+ {
+ mem_root->block_size= MY_ALIGN(block_size, my_system_page_size);
+ if (pre_alloc)
+ pre_alloc= MY_ALIGN(pre_alloc, my_system_page_size);
+ }
+ else
+ {
+ DBUG_ASSERT(block_size <= UINT_MAX32);
+ mem_root->block_size= (my_round_up_to_next_power((uint32) block_size -
+ MALLOC_OVERHEAD)-
+ MALLOC_OVERHEAD);
+ if (pre_alloc)
+ pre_alloc= (my_round_up_to_next_power((uint32) pre_alloc -
+ MALLOC_OVERHEAD)-
+ MALLOC_OVERHEAD);
+ }
+ *pre_alloc_size= pre_alloc;
+}
+
+
+/*
+ Initialize memory root
+
+ SYNOPSIS
+ init_alloc_root()
+ key - key to register instrumented memory
+ mem_root - memory root to initialize
+ block_size - size of chunks (blocks) used for memory allocation.
+ Will be updated to next power of 2, minus
+ internal and system memory management size. This is
+ will reduce memory fragmentation as most system memory
+ allocators are using power of 2 block size internally.
+ (It is external size of chunk i.e. it should include
+ memory required for internal structures, thus it
+ should be no less than ROOT_MIN_BLOCK_SIZE).
+ pre_alloc_size - if non-0, then size of block that should be
+ pre-allocated during memory root initialization.
+ my_flags MY_THREAD_SPECIFIC flag for my_malloc
+ MY_RROOT_USE_MPROTECT for read only protected memory
+
+ DESCRIPTION
+ This function prepares memory root for further use, sets initial size of
+ chunk for memory allocation and pre-allocates first block if specified.
+ Although error can happen during execution of this function if
+ pre_alloc_size is non-0 it won't be reported. Instead it will be
+ reported as error in first alloc_root() on this memory root.
+*/
+
+void init_alloc_root(PSI_memory_key key, MEM_ROOT *mem_root, size_t block_size,
+ size_t pre_alloc_size __attribute__((unused)),
+ myf my_flags)
+{
+ DBUG_ENTER("init_alloc_root");
+ DBUG_PRINT("enter",("root: %p prealloc: %zu", mem_root, pre_alloc_size));
+
+ mem_root->free= mem_root->used= mem_root->pre_alloc= 0;
+ mem_root->min_malloc= 32 + REDZONE_SIZE;
+ mem_root->block_size= MY_MAX(block_size, ROOT_MIN_BLOCK_SIZE);
+ mem_root->flags= 0;
+ DBUG_ASSERT(!test_all_bits(mem_root->flags,
+ (MY_THREAD_SPECIFIC | MY_ROOT_USE_MPROTECT)));
+ if (my_flags & MY_THREAD_SPECIFIC)
+ mem_root->flags|= ROOT_FLAG_THREAD_SPECIFIC;
+ if (my_flags & MY_ROOT_USE_MPROTECT)
+ mem_root->flags|= ROOT_FLAG_MPROTECT;
+
+ calculate_block_sizes(mem_root, block_size, &pre_alloc_size);
+
+ mem_root->error_handler= 0;
+ mem_root->block_num= 4; /* We shift this with >>2 */
+ mem_root->first_block_usage= 0;
+ mem_root->psi_key= key;
+#ifdef PROTECT_STATEMENT_MEMROOT
+ mem_root->read_only= 0;
+#endif
+
+#if !(defined(HAVE_valgrind) && defined(EXTRA_DEBUG))
+ if (pre_alloc_size)
+ {
+ size_t alloced_size;
+ if ((mem_root->free= mem_root->pre_alloc=
+ (USED_MEM*) root_alloc(mem_root, pre_alloc_size, &alloced_size,
+ MYF(0))))
+ {
+ mem_root->free->size= alloced_size;
+ mem_root->free->left= alloced_size - ALIGN_SIZE(sizeof(USED_MEM));
+ mem_root->free->next= 0;
+ TRASH_MEM(mem_root->free);
+ }
+ }
+#endif
+ DBUG_VOID_RETURN;
+}
+
+/*
+ SYNOPSIS
+ reset_root_defaults()
+ mem_root memory root to change defaults of
+ block_size new value of block size. Must be greater or equal
+ than ALLOC_ROOT_MIN_BLOCK_SIZE (this value is about
+ 68 bytes and depends on platform and compilation flags)
+ pre_alloc_size new size of preallocated block. If not zero,
+ must be equal to or greater than block size,
+ otherwise means 'no prealloc'.
+ DESCRIPTION
+ Function aligns and assigns new value to block size; then it tries to
+ reuse one of existing blocks as prealloc block, or malloc new one of
+ requested size. If no blocks can be reused, all unused blocks are freed
+ before allocation.
+*/
+
+void reset_root_defaults(MEM_ROOT *mem_root, size_t block_size,
+ size_t pre_alloc_size __attribute__((unused)))
+{
+ DBUG_ENTER("reset_root_defaults");
+ DBUG_ASSERT(alloc_root_inited(mem_root));
+
+ calculate_block_sizes(mem_root, block_size, &pre_alloc_size);
+
+#if !(defined(HAVE_valgrind) && defined(EXTRA_DEBUG))
+ if (pre_alloc_size)
+ {
+ size_t size= mem_root->block_size, alloced_size;
+ if (!mem_root->pre_alloc ||
+ mem_root->pre_alloc->size != mem_root->block_size)
+ {
+ USED_MEM *mem, **prev= &mem_root->free;
+ /*
+ Free unused blocks, so that consequent calls
+ to reset_root_defaults won't eat away memory.
+ */
+ while (*prev)
+ {
+ mem= *prev;
+ if (mem->size == size)
+ {
+ /* We found a suitable block, no need to do anything else */
+ mem_root->pre_alloc= mem;
+ DBUG_VOID_RETURN;
+ }
+ if (mem->left + ALIGN_SIZE(sizeof(USED_MEM)) == mem->size)
+ {
+ /* remove block from the list and free it */
+ *prev= mem->next;
+ root_free(mem_root, mem, mem->size);
+ }
+ else
+ prev= &mem->next;
+ }
+ /* Allocate new prealloc block and add it to the end of free list */
+ if ((mem= (USED_MEM *) root_alloc(mem_root, size, &alloced_size,
+ MYF(MY_WME))))
+ {
+ mem->size= alloced_size;
+ mem->left= alloced_size - ALIGN_SIZE(sizeof(USED_MEM));
+ mem->next= *prev;
+ *prev= mem_root->pre_alloc= mem;
+ TRASH_MEM(mem);
+ }
+ else
+ mem_root->pre_alloc= 0;
+ }
+ }
+ else
+#endif
+ mem_root->pre_alloc= 0;
+
+ DBUG_VOID_RETURN;
+}
+
+
+void *alloc_root(MEM_ROOT *mem_root, size_t length)
+{
+ size_t get_size, block_size;
+ uchar* point;
+ reg1 USED_MEM *next= 0;
+ reg2 USED_MEM **prev;
+ size_t original_length __attribute__((unused)) = length;
+ DBUG_ENTER("alloc_root");
+ DBUG_PRINT("enter",("root: %p", mem_root));
+ DBUG_ASSERT(alloc_root_inited(mem_root));
+
+#ifdef PROTECT_STATEMENT_MEMROOT
+ DBUG_ASSERT(mem_root->read_only == 0);
+#endif
+
+ DBUG_EXECUTE_IF("simulate_out_of_memory",
+ {
+ if (mem_root->error_handler)
+ (*mem_root->error_handler)();
+ DBUG_SET("-d,simulate_out_of_memory");
+ DBUG_RETURN((void*) 0); /* purecov: inspected */
+ });
+
+#if defined(HAVE_valgrind) && defined(EXTRA_DEBUG)
+ if (!(mem_root->flags & ROOT_FLAG_MPROTECT))
+ {
+ length+= ALIGN_SIZE(sizeof(USED_MEM));
+ if (!(next = (USED_MEM*) my_malloc(mem_root->psi_key, length,
+ MYF(MY_WME | ME_FATAL |
+ (mem_root->flags &
+ ROOT_FLAG_THREAD_SPECIFIC ?
+ MY_THREAD_SPECIFIC : 0)))))
+ {
+ if (mem_root->error_handler)
+ (*mem_root->error_handler)();
+ DBUG_RETURN((uchar*) 0); /* purecov: inspected */
+ }
+ next->next= mem_root->used;
+ next->left= 0;
+ next->size= length;
+ mem_root->used= next;
+ DBUG_PRINT("exit",("ptr: %p", (((char*)next)+ALIGN_SIZE(sizeof(USED_MEM)))));
+ DBUG_RETURN((((uchar*) next)+ALIGN_SIZE(sizeof(USED_MEM))));
+ }
+#endif /* defined(HAVE_valgrind) && defined(EXTRA_DEBUG) */
+
+ length= ALIGN_SIZE(length) + REDZONE_SIZE;
+ if ((*(prev= &mem_root->free)) != NULL)
+ {
+ if ((*prev)->left < length &&
+ mem_root->first_block_usage++ >= ALLOC_MAX_BLOCK_USAGE_BEFORE_DROP &&
+ (*prev)->left < ALLOC_MAX_BLOCK_TO_DROP)
+ {
+ next= *prev;
+ *prev= next->next; /* Remove block from list */
+ next->next= mem_root->used;
+ mem_root->used= next;
+ mem_root->first_block_usage= 0;
+ }
+ for (next= *prev ; next && next->left < length ; next= next->next)
+ prev= &next->next;
+ }
+ if (! next)
+ { /* Time to alloc new block */
+ size_t alloced_length;
+
+ /* Increase block size over time if there is a lot of mallocs */
+ block_size= (MY_ALIGN(mem_root->block_size, ROOT_MIN_BLOCK_SIZE) *
+ (mem_root->block_num >> 2)- MALLOC_OVERHEAD);
+ get_size= length + ALIGN_SIZE(sizeof(USED_MEM));
+ get_size= MY_MAX(get_size, block_size);
+
+ if (!(next= (USED_MEM*) root_alloc(mem_root, get_size, &alloced_length,
+ MYF(MY_WME | ME_FATAL))))
+ {
+ if (mem_root->error_handler)
+ (*mem_root->error_handler)();
+ DBUG_RETURN((void*) 0); /* purecov: inspected */
+ }
+ mem_root->block_num++;
+ next->next= *prev;
+ next->size= alloced_length;
+ next->left= alloced_length - ALIGN_SIZE(sizeof(USED_MEM));
+ *prev=next;
+ TRASH_MEM(next);
+ }
+
+ point= (uchar*) ((char*) next+ (next->size-next->left));
+ /*TODO: next part may be unneded due to mem_root->first_block_usage counter*/
+ if ((next->left-= length) < mem_root->min_malloc)
+ { /* Full block */
+ *prev= next->next; /* Remove block from list */
+ next->next= mem_root->used;
+ mem_root->used= next;
+ mem_root->first_block_usage= 0;
+ }
+ point+= REDZONE_SIZE;
+ TRASH_ALLOC(point, original_length);
+ DBUG_PRINT("exit",("ptr: %p", point));
+ DBUG_RETURN((void*) point);
+}
+
+
+/*
+ Allocate many pointers at the same time.
+
+ DESCRIPTION
+ ptr1, ptr2, etc all point into big allocated memory area.
+
+ SYNOPSIS
+ multi_alloc_root()
+ root Memory root
+ ptr1, length1 Multiple arguments terminated by a NULL pointer
+ ptr2, length2 ...
+ ...
+ NULL
+
+ RETURN VALUE
+ A pointer to the beginning of the allocated memory block
+ in case of success or NULL if out of memory.
+*/
+
+void *multi_alloc_root(MEM_ROOT *root, ...)
+{
+ va_list args;
+ char **ptr, *start, *res;
+ size_t tot_length, length;
+ DBUG_ENTER("multi_alloc_root");
+ /*
+ We don't need to do DBUG_PRINT here as it will be done when alloc_root
+ is called
+ */
+
+ va_start(args, root);
+ tot_length= 0;
+ while ((ptr= va_arg(args, char **)))
+ {
+ length= va_arg(args, uint);
+ tot_length+= ALIGN_SIZE(length);
+#ifdef ALLOC_BARRIER
+ tot_length+= ALIGN_SIZE(1);
+#endif
+ }
+ va_end(args);
+
+ if (!(start= (char*) alloc_root(root, tot_length)))
+ DBUG_RETURN(0); /* purecov: inspected */
+
+ va_start(args, root);
+ res= start;
+ while ((ptr= va_arg(args, char **)))
+ {
+ *ptr= res;
+ length= va_arg(args, uint);
+ res+= ALIGN_SIZE(length);
+#ifdef ALLOC_BARRIER
+ TRASH_FREE(res, ALIGN_SIZE(1));
+ res+= ALIGN_SIZE(1);
+#endif
+ }
+ va_end(args);
+ DBUG_RETURN((void*) start);
+}
+
+
+#if !(defined(HAVE_valgrind) && defined(EXTRA_DEBUG))
+/** Mark all data in blocks free for reusage */
+
+static inline void mark_blocks_free(MEM_ROOT* root)
+{
+ reg1 USED_MEM *next;
+ reg2 USED_MEM **last;
+
+ /* iterate through (partially) free blocks, mark them free */
+ last= &root->free;
+ for (next= root->free; next; next= *(last= &next->next))
+ {
+ next->left= next->size - ALIGN_SIZE(sizeof(USED_MEM));
+ TRASH_MEM(next);
+ }
+
+ /* Combine the free and the used list */
+ *last= next=root->used;
+
+ /* now go through the used blocks and mark them free */
+ for (; next; next= next->next)
+ {
+ next->left= next->size - ALIGN_SIZE(sizeof(USED_MEM));
+ TRASH_MEM(next);
+ }
+
+ /* Now everything is set; Indicate that nothing is used anymore */
+ root->used= 0;
+ root->first_block_usage= 0;
+ root->block_num= 4;
+}
+#endif
+
+
+/*
+ Deallocate everything used by alloc_root or just move
+ used blocks to free list if called with MY_USED_TO_FREE
+
+ SYNOPSIS
+ free_root()
+ root Memory root
+ MyFlags Flags for what should be freed:
+
+ MY_MARK_BLOCKS_FREED Don't free blocks, just mark them free
+ MY_KEEP_PREALLOC If this is not set, then free also the
+ preallocated block
+
+ NOTES
+ One can call this function either with root block initialised with
+ init_alloc_root() or with a bzero()-ed block.
+ It's also safe to call this multiple times with the same mem_root.
+*/
+
+void free_root(MEM_ROOT *root, myf MyFlags)
+{
+ reg1 USED_MEM *next,*old;
+ DBUG_ENTER("free_root");
+ DBUG_PRINT("enter",("root: %p flags: %lu", root, MyFlags));
+
+#if !(defined(HAVE_valgrind) && defined(EXTRA_DEBUG))
+ /*
+ There is no point in using mark_blocks_free when using valgrind as
+ it will not reclaim any memory
+ */
+ if (MyFlags & MY_MARK_BLOCKS_FREE)
+ {
+ mark_blocks_free(root);
+ DBUG_VOID_RETURN;
+ }
+#endif
+ if (!(MyFlags & MY_KEEP_PREALLOC))
+ root->pre_alloc=0;
+
+ for (next=root->used; next ;)
+ {
+ old=next; next= next->next ;
+ if (old != root->pre_alloc)
+ root_free(root, old, old->size);
+ }
+ for (next=root->free ; next ;)
+ {
+ old=next; next= next->next;
+ if (old != root->pre_alloc)
+ root_free(root, old, old->size);
+ }
+ root->used=root->free=0;
+ if (root->pre_alloc)
+ {
+ root->free=root->pre_alloc;
+ root->free->left=root->pre_alloc->size-ALIGN_SIZE(sizeof(USED_MEM));
+ TRASH_MEM(root->pre_alloc);
+ root->free->next=0;
+ }
+ root->block_num= 4;
+ root->first_block_usage= 0;
+ DBUG_VOID_RETURN;
+}
+
+
+/*
+ Find block that contains an object and set the pre_alloc to it
+*/
+
+void set_prealloc_root(MEM_ROOT *root, char *ptr)
+{
+ USED_MEM *next;
+ for (next=root->used; next ; next=next->next)
+ {
+ if ((char*) next <= ptr && (char*) next + next->size > ptr)
+ {
+ root->pre_alloc=next;
+ return;
+ }
+ }
+ for (next=root->free ; next ; next=next->next)
+ {
+ if ((char*) next <= ptr && (char*) next + next->size > ptr)
+ {
+ root->pre_alloc=next;
+ return;
+ }
+ }
+}
+
+
+/*
+ Remember last MEM_ROOT block.
+
+ This allows one to free all new allocated blocks.
+*/
+
+USED_MEM *get_last_memroot_block(MEM_ROOT* root)
+{
+ return root->used ? root->used : root->pre_alloc;
+}
+
+/*
+ Free all newly allocated blocks
+*/
+
+void free_all_new_blocks(MEM_ROOT *root, USED_MEM *last_block)
+{
+ USED_MEM *old, *next;
+ if (!root->used)
+ return; /* Nothing allocated */
+ return;
+ /*
+ Free everying allocated up to, but not including, last_block.
+ However do not go past pre_alloc as we do not want to free
+ that one. This should not be a problem as in almost all normal
+ usage pre_alloc is last in the list.
+ */
+
+ for (next= root->used ;
+ next && next != last_block && next != root->pre_alloc ; )
+ {
+ old= next; next= next->next;
+ root_free(root, old, old->size);
+ }
+ root->used= next;
+ root->block_num= 4;
+ root->first_block_usage= 0;
+}
+
+/**
+ Change protection for all blocks in the mem root
+*/
+
+#if defined(HAVE_MMAP) && defined(HAVE_MPROTECT) && defined(MAP_ANONYMOUS)
+void protect_root(MEM_ROOT *root, int prot)
+{
+ reg1 USED_MEM *next,*old;
+ DBUG_ENTER("protect_root");
+ DBUG_PRINT("enter",("root: %p prot: %d", root, prot));
+
+ DBUG_ASSERT(root->flags & ROOT_FLAG_MPROTECT);
+
+ for (next= root->used; next ;)
+ {
+ old= next; next= next->next ;
+ mprotect(old, old->size, prot);
+ }
+ for (next= root->free; next ;)
+ {
+ old= next; next= next->next ;
+ mprotect(old, old->size, prot);
+ }
+ DBUG_VOID_RETURN;
+}
+#else
+void protect_root(MEM_ROOT *root, int prot)
+{
+}
+#endif /* defined(HAVE_MMAP) && ... */
+
+
+char *strdup_root(MEM_ROOT *root, const char *str)
+{
+ return strmake_root(root, str, strlen(str));
+}
+
+
+char *strmake_root(MEM_ROOT *root, const char *str, size_t len)
+{
+ char *pos;
+ if ((pos=alloc_root(root,len+1)))
+ {
+ if (len)
+ memcpy(pos,str,len);
+ pos[len]=0;
+ }
+ return pos;
+}
+
+
+void *memdup_root(MEM_ROOT *root, const void *str, size_t len)
+{
+ char *pos;
+ if ((pos=alloc_root(root,len)) && len)
+ memcpy(pos,str,len);
+ return pos;
+}
+
+LEX_CSTRING safe_lexcstrdup_root(MEM_ROOT *root, const LEX_CSTRING str)
+{
+ LEX_CSTRING res;
+ if (str.length)
+ res.str= strmake_root(root, str.str, str.length);
+ else
+ res.str= (const char *)"";
+ res.length= str.length;
+ return res;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-20 10:48:44 +0000