as the field will be read without mutex protection in buf_page_io_complete().

(state == BUF_BLOCK_ZIP_PAGE).  Make use of buf_page_in_file()
and buf_page_get_mutex().

buf_block_get_newest_modification(): Rename to
buf_page_get_newest_modification().

Add m_nonempty for facilitating the test in page_zip_alloc().  This
reduces the combined size of the bit-fields to 32 bits.  Thus,
sizeof(page_zip_des_t) == 2 machine words on 32-bit and wider systems.

LRU_position and possibly freed_page_clock.  All these fields are
protected by buf_pool->mutex rather than buf_page_get_mutex().

buf_page_set_accessed(): Add a mutex_own() assertion.

on a NULL pointer.  This error was introduced in r1082.

of the buffer pool from buf_block_t to buf_page_t.  Replace some buf_block_t*
parameters with buf_page_t*.  Add accessor functions.

decompression from page_zip_des_t to buf_page_t, because the fields
needed in compression are modified without holding the block mutex.
All writes to bit-fields sharing a machine word must be protected
by the same mutex or rw-lock.

buf_block_buf_fix_inc_func() to eliminate an #ifdef in every invocation.

to ut_uint64_align_down() and ut_uint64_align_up(), to reflect the rename
of ib_ulonglong to ib_uint64_t in r1085.

64 bits.  "long long" might be longer than 64 bits on some systems.

buf_block_t.  Move the fields "hash" and "file_page_was_freed" from
buf_block_t to buf_page_t.

buf_page_in_file(): New function, for checking block state in assertions.

was broken in r1066.

of the fields "freed_page_clock" and "old".

buf_page_t and page_zip_des_t.

storage size from 16 to 3 bits.

page_zip_get_size(), page_zip_set_size(): New functions.

Replace direct references to page_zip_des_t:size with calls to
buf_block_get_zip_size(), page_zip_get_size(), and page_zip_set_size().

for log sequence numbers, to replace dulint.

buf_block_get_state().

buf_block_init(), buf_page_init_for_backup_restore(): Assign
block->page.zip.state after invoking page_zip_des_init(&block->page).

introduced in r1057 are of the int type.

which should have been replaced in r1057.

threshold.

and uncompressed buffer pool pages.

buf_block_t: Replace page_zip, space, and offset with buf_page_t page.
Replace some integers with bit-fields.

enum buf_block_state: Rename to buf_page_state.  Add BUF_BLOCK_ZIP_PAGE.

page_zip_des_t: Add the field "state".  Make the integer fields bit-fields.

page_zip_copy(): Document which fields are copied.

buf_block_state_valid(): New macro for replacing the magic_n check

BUF_BLOCK_READY_FOR_USE to BUF_BLOCK_NOT_USED.

buf_block_get_space(), buf_block_get_page_no():
Remove ut_ad(block->buf_fix_count > 0), because since r1052
these functions are also used in low-level code.

buf_block_set_state(): New function.  Also checks the state transitions.

buf_block_set_file_page(): New function.

and block->space with buf_block_get_state(block), buf_block_get_page_no(block),
and buf_block_get_space(block).

enum buf_block_state: Replaces the #define'd buf_block_t.state values.

buf_block_get_state(): New function.

buf_block_get_frame(): Add __attribute__((const)).

buf0buf.ic: Remove the extern declaration of buf_dbg_counter.
It was declared static in buf0buf.c in r1025.

ha0ha.c: #include "btr0sea.h" #ifdef UNIV_SYNC_DEBUG.  Assertions on
btr_search_latch were added in r1041.

buf_pool_page_hash_rebuild(): New function.

hash index, because it might occupy the chunk we would like to free.

TODO: In btr_search_check_free_space_in_heap(), release the block if
btr_search_latch is not immediately available.

buf_pool_shrink(): Split from buf_pool_resize().

btr_search_disabled: New variable, similar to srv_use_adaptive_hash_indexes
that was removed earlier.

btr_search_disable(): New function: disable and purge the adaptive hash index.

btr_search_enable(): New function: enable the adaptive hash index.

ha_clear(): New function: Empty a hash table and free the memory heaps.

function to ha_node_set_data_func().  In this way, the #ifdef in the
callers can be removed.

SHOW MUTEX STATUS in non-debug builds.  (Bug #24386)

assume that non-file pages are free.  After trying to free or flush
file pages, do not proceed to buf_chunk_free(), because the calls will
temporarily release buf_pool->mutex.  Do not flush if there are non-free
blocks, because it would not achieve anything.

enclose buf_validate() and friends in it.

enclose all related debug code in #ifdef UNIV_DEBUG_FILE_ACCESSES.
This should have no effect on the behaviour, as the symbol is
not defined by default.  It only reduces the size of buf_block_t
and removes some assignments and debug functions.

statement that was accidentally checked in in r1022.

record on every compressed BLOB page header, so that compressed BLOBs
can be relocated or the chain of BLOB pages can be validated.

buf_LRU_block_free_non_file_page(): Deallocate block->page_zip.data
to avoid ut_a(!block->page_zip.data) in buf_chunk_free().

buf_chunk_free(): Add the assertion ut_a(!block->in_LRU_list).

buf_pool_resize(): When shrinking the buffer pool and there are
non-free blocks in the candidate chunk, free the clean blocks
and move the dirty blocks to the end of the LRU list and request a flush.
Proceed if the chunk becomes free, and retry otherwise.