/**********************************************************************//**
Allocate a block from a bigger object.
@return allocated block */
static
void*
buf_buddy_alloc_from(
/*=================*/
buf_pool_t* buf_pool, /*!< in: buffer pool instance */
void* buf, /*!< in: a block that is free to use */
ulint i, /*!< in: index of
buf_pool->zip_free[] */
ulint j) /*!< in: size of buf as an index
of buf_pool->zip_free[] */
{
ulint offs = BUF_BUDDY_LOW << j;
ut_ad(j <= BUF_BUDDY_SIZES);
ut_ad(i >= buf_buddy_get_slot(PAGE_ZIP_MIN_SIZE));
ut_ad(j >= i);
ut_ad(!ut_align_offset(buf, offs));
/* Add the unused parts of the block to the free lists. */
while (j > i) {
buf_page_t* bpage;
offs >>= 1;
j--;
bpage = (buf_page_t*) ((byte*) buf + offs);
ut_d(memset(bpage, j, BUF_BUDDY_LOW << j));
bpage->state = BUF_BLOCK_ZIP_FREE;
ut_d(BUF_BUDDY_LIST_VALIDATE(buf_pool, i));
buf_buddy_add_to_free(buf_pool, bpage, j);
}
return(buf);
}
/**********************************************************************//**
Get the offset of the buddy of a compressed page frame.
@return the buddy relative of page */
UNIV_INLINE
byte*
buf_buddy_get(
/*==========*/
byte* page, /*!< in: compressed page */
ulint size) /*!< in: page size in bytes */
{
ut_ad(ut_is_2pow(size));
ut_ad(size >= BUF_BUDDY_LOW);
ut_ad(size < BUF_BUDDY_HIGH);
ut_ad(!ut_align_offset(page, size));
if (((ulint) page) & size) {
return(page - size);
} else {
return(page + size);
}
}
/**********************************************************************//**
Deallocate a buffer frame of UNIV_PAGE_SIZE. */
static
void
buf_buddy_block_free(
/*=================*/
buf_pool_t* buf_pool, /*!< in: buffer pool instance */
void* buf) /*!< in: buffer frame to deallocate */
{
const ulint fold = BUF_POOL_ZIP_FOLD_PTR(buf);
buf_page_t* bpage;
buf_block_t* block;
ut_ad(buf_pool_mutex_own(buf_pool));
ut_ad(!mutex_own(&buf_pool->zip_mutex));
ut_a(!ut_align_offset(buf, UNIV_PAGE_SIZE));
HASH_SEARCH(hash, buf_pool->zip_hash, fold, buf_page_t*, bpage,
ut_ad(buf_page_get_state(bpage) == BUF_BLOCK_MEMORY
&& bpage->in_zip_hash && !bpage->in_page_hash),
((buf_block_t*) bpage)->frame == buf);
ut_a(bpage);
ut_a(buf_page_get_state(bpage) == BUF_BLOCK_MEMORY);
ut_ad(!bpage->in_page_hash);
ut_ad(bpage->in_zip_hash);
ut_d(bpage->in_zip_hash = FALSE);
HASH_DELETE(buf_page_t, hash, buf_pool->zip_hash, fold, bpage);
ut_d(memset(buf, 0, UNIV_PAGE_SIZE));
UNIV_MEM_INVALID(buf, UNIV_PAGE_SIZE);
block = (buf_block_t*) bpage;
mutex_enter(&block->mutex);
buf_LRU_block_free_non_file_page(block);
mutex_exit(&block->mutex);
ut_ad(buf_pool->buddy_n_frames > 0);
ut_d(buf_pool->buddy_n_frames--);
}
/**********************************************************************//**
Allocate a buffer block to the buddy allocator. */
static
void
buf_buddy_block_register(
/*=====================*/
buf_block_t* block) /*!< in: buffer frame to allocate */
{
buf_pool_t* buf_pool = buf_pool_from_block(block);
const ulint fold = BUF_POOL_ZIP_FOLD(block);
ut_ad(buf_pool_mutex_own(buf_pool));
ut_ad(!mutex_own(&buf_pool->zip_mutex));
ut_ad(buf_block_get_state(block) == BUF_BLOCK_READY_FOR_USE);
buf_block_set_state(block, BUF_BLOCK_MEMORY);
ut_a(block->frame);
ut_a(!ut_align_offset(block->frame, UNIV_PAGE_SIZE));
ut_ad(!block->page.in_page_hash);
ut_ad(!block->page.in_zip_hash);
ut_d(block->page.in_zip_hash = TRUE);
HASH_INSERT(buf_page_t, hash, buf_pool->zip_hash, fold, &block->page);
ut_d(buf_pool->buddy_n_frames++);
}
/**********************************************************************//**
Try to relocate a block.
@return TRUE if relocated */
static
ibool
buf_buddy_relocate(
/*===============*/
buf_pool_t* buf_pool, /*!< in: buffer pool instance */
void* src, /*!< in: block to relocate */
void* dst, /*!< in: free block to relocate to */
ulint i) /*!< in: index of
buf_pool->zip_free[] */
{
buf_page_t* bpage;
const ulint size = BUF_BUDDY_LOW << i;
ullint usec = ut_time_us(NULL);
mutex_t* mutex;
ulint space;
ulint page_no;
ut_ad(buf_pool_mutex_own(buf_pool));
ut_ad(!mutex_own(&buf_pool->zip_mutex));
ut_ad(!ut_align_offset(src, size));
ut_ad(!ut_align_offset(dst, size));
ut_ad(i >= buf_buddy_get_slot(PAGE_ZIP_MIN_SIZE));
UNIV_MEM_ASSERT_W(dst, size);
/* We assume that all memory from buf_buddy_alloc()
is used for compressed page frames. */
/* We look inside the allocated objects returned by
buf_buddy_alloc() and assume that each block is a compressed
page that contains a valid space_id and page_no in the page
header. Should the fields be invalid, we will be unable to
relocate the block. */
/* The src block may be split into smaller blocks,
some of which may be free. Thus, the
mach_read_from_4() calls below may attempt to read
from free memory. The memory is "owned" by the buddy
allocator (and it has been allocated from the buffer
pool), so there is nothing wrong about this. The
mach_read_from_4() calls here will only trigger bogus
Valgrind memcheck warnings in UNIV_DEBUG_VALGRIND builds. */
space = mach_read_from_4((const byte *) src
+ FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID);
page_no = mach_read_from_4((const byte *) src
+ FIL_PAGE_OFFSET);
/* Suppress Valgrind warnings about conditional jump
on uninitialized value. */
UNIV_MEM_VALID(&space, sizeof space);
UNIV_MEM_VALID(&page_no, sizeof page_no);
bpage = buf_page_hash_get(buf_pool, space, page_no);
if (!bpage || bpage->zip.data != src) {
/* The block has probably been freshly
allocated by buf_LRU_get_free_block() but not
added to buf_pool->page_hash yet. Obviously,
it cannot be relocated. */
return(FALSE);
}
if (page_zip_get_size(&bpage->zip) != size) {
/* The block is of different size. We would
have to relocate all blocks covered by src.
For the sake of simplicity, give up. */
ut_ad(page_zip_get_size(&bpage->zip) < size);
return(FALSE);
}
/* The block must have been allocated, but it may
contain uninitialized data. */
UNIV_MEM_ASSERT_W(src, size);
mutex = buf_page_get_mutex(bpage);
mutex_enter(mutex);
if (buf_page_can_relocate(bpage)) {
/* Relocate the compressed page. */
ut_a(bpage->zip.data == src);
memcpy(dst, src, size);
bpage->zip.data = dst;
mutex_exit(mutex);
UNIV_MEM_INVALID(src, size);
{
buf_buddy_stat_t* buddy_stat
= &buf_pool->buddy_stat[i];
buddy_stat->relocated++;
buddy_stat->relocated_usec
+= ut_time_us(NULL) - usec;
}
return(TRUE);
}
mutex_exit(mutex);
return(FALSE);
}
void
btr_pcur_store_position(
/*====================*/
btr_pcur_t* cursor, /* in: persistent cursor */
mtr_t* mtr) /* in: mtr */
{
page_cur_t* page_cursor;
rec_t* rec;
dict_tree_t* tree;
page_t* page;
ulint offs;
ut_a(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
tree = btr_cur_get_tree(btr_pcur_get_btr_cur(cursor));
page_cursor = btr_pcur_get_page_cur(cursor);
rec = page_cur_get_rec(page_cursor);
page = ut_align_down(rec, UNIV_PAGE_SIZE);
offs = ut_align_offset(rec, UNIV_PAGE_SIZE);
ut_ad(mtr_memo_contains(mtr, buf_block_align(page),
MTR_MEMO_PAGE_S_FIX)
|| mtr_memo_contains(mtr, buf_block_align(page),
MTR_MEMO_PAGE_X_FIX));
ut_a(cursor->latch_mode != BTR_NO_LATCHES);
if (UNIV_UNLIKELY(page_get_n_recs(page) == 0)) {
/* It must be an empty index tree; NOTE that in this case
we do not store the modify_clock, but always do a search
if we restore the cursor position */
ut_a(btr_page_get_next(page, mtr) == FIL_NULL);
ut_a(btr_page_get_prev(page, mtr) == FIL_NULL);
cursor->old_stored = BTR_PCUR_OLD_STORED;
if (page_rec_is_supremum_low(offs)) {
cursor->rel_pos = BTR_PCUR_AFTER_LAST_IN_TREE;
} else {
cursor->rel_pos = BTR_PCUR_BEFORE_FIRST_IN_TREE;
}
return;
}
if (page_rec_is_supremum_low(offs)) {
rec = page_rec_get_prev(rec);
cursor->rel_pos = BTR_PCUR_AFTER;
} else if (page_rec_is_infimum_low(offs)) {
rec = page_rec_get_next(rec);
cursor->rel_pos = BTR_PCUR_BEFORE;
} else {
cursor->rel_pos = BTR_PCUR_ON;
}
cursor->old_stored = BTR_PCUR_OLD_STORED;
cursor->old_rec = dict_tree_copy_rec_order_prefix(tree, rec,
&cursor->old_n_fields,
&cursor->old_rec_buf,
&cursor->buf_size);
cursor->block_when_stored = buf_block_align(page);
cursor->modify_clock = buf_block_get_modify_clock(
cursor->block_when_stored);
}
