buf0buf.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

		return(FALSE);
	}

	ut_a(block->state == BUF_BLOCK_FILE_PAGE);

#ifdef UNIV_SYNC_DEBUG
	buf_block_buf_fix_inc_debug(block, file, line);
#else
	buf_block_buf_fix_inc(block);
#endif
	if (mode == BUF_MAKE_YOUNG) {
		buf_block_make_young(block);
	}

	mutex_exit(&(buf_pool->mutex));

	ut_ad(!ibuf_inside() || (mode == BUF_KEEP_OLD));

	if (rw_latch == RW_S_LATCH) {
		success = rw_lock_s_lock_func_nowait(&(block->lock),
								file, line);
		fix_type = MTR_MEMO_PAGE_S_FIX;
	} else {
		success = rw_lock_x_lock_func_nowait(&(block->lock),
								file, line);
		fix_type = MTR_MEMO_PAGE_X_FIX;
	}
	
	if (!success) {
		mutex_enter(&(buf_pool->mutex));
		
		block->buf_fix_count--;
#ifdef UNIV_SYNC_DEBUG
		rw_lock_s_unlock(&(block->debug_latch));
#endif		
		mutex_exit(&(buf_pool->mutex));

		return(FALSE);
	}

	mtr_memo_push(mtr, block, fix_type);

#ifdef UNIV_DEBUG
	buf_dbg_counter++;

	if (buf_dbg_counter % 5771 == 0) {
		ut_ad(buf_validate());
	}
#endif
	ut_ad(block->buf_fix_count > 0);
	ut_ad(block->state == BUF_BLOCK_FILE_PAGE);
#ifdef UNIV_DEBUG_FILE_ACCESSES
	ut_a(block->file_page_was_freed == FALSE);
#endif

#ifdef UNIV_IBUF_DEBUG
	ut_a((mode == BUF_KEEP_OLD)
		|| (ibuf_count_get(block->space, block->offset) == 0));
#endif
	buf_pool->n_page_gets++;

	return(TRUE);
}

/************************************************************************
Inits a page to the buffer buf_pool, for use in ibbackup --restore. */

void
buf_page_init_for_backup_restore(
/*=============================*/
	ulint		space,	/* in: space id */
	ulint		offset,	/* in: offset of the page within space
				in units of a page */
	buf_block_t*	block)	/* in: block to init */
{
	/* Set the state of the block */
	block->magic_n		= BUF_BLOCK_MAGIC_N;

	block->state 		= BUF_BLOCK_FILE_PAGE;
	block->space 		= space;
	block->offset 		= offset;

	block->lock_hash_val	= 0;
	block->lock_mutex	= NULL;
	
	block->freed_page_clock = 0;

	block->newest_modification = ut_dulint_zero;
	block->oldest_modification = ut_dulint_zero;
	
	block->accessed		= FALSE;
	block->buf_fix_count 	= 0;
	block->io_fix		= 0;

	block->n_hash_helps	= 0;
	block->is_hashed	= FALSE;
	block->n_fields         = 1;
	block->n_bytes          = 0;
	block->side             = BTR_SEARCH_LEFT_SIDE;

	block->file_page_was_freed = FALSE;
}

/************************************************************************
Inits a page to the buffer buf_pool. */
static
void
buf_page_init(
/*==========*/
	ulint		space,	/* in: space id */
	ulint		offset,	/* in: offset of the page within space
				in units of a page */
	buf_block_t*	block)	/* in: block to init */
{
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&(buf_pool->mutex)));
#endif /* UNIV_SYNC_DEBUG */
	ut_a(block->state != BUF_BLOCK_FILE_PAGE);

	/* Set the state of the block */
	block->magic_n		= BUF_BLOCK_MAGIC_N;

	block->state 		= BUF_BLOCK_FILE_PAGE;
	block->space 		= space;
	block->offset 		= offset;

	block->check_index_page_at_flush = FALSE;
	block->index		= NULL;
	
	block->lock_hash_val	= lock_rec_hash(space, offset);
	block->lock_mutex	= NULL;
	
	/* Insert into the hash table of file pages */

        if (buf_page_hash_get(space, offset)) {
                fprintf(stderr,
"InnoDB: Error: page %lu %lu already found from the hash table\n",
			(ulong) space,
			(ulong) offset);
#ifdef UNIV_DEBUG
                buf_print();
                buf_LRU_print();
                buf_validate();
                buf_LRU_validate();
#endif /* UNIV_DEBUG */
                ut_a(0);
        }

	HASH_INSERT(buf_block_t, hash, buf_pool->page_hash,
				buf_page_address_fold(space, offset), block);

	block->freed_page_clock = 0;

	block->newest_modification = ut_dulint_zero;
	block->oldest_modification = ut_dulint_zero;
	
	block->accessed		= FALSE;
	block->buf_fix_count 	= 0;
	block->io_fix		= 0;

	block->n_hash_helps	= 0;
	block->is_hashed	= FALSE;
	block->n_fields         = 1;
	block->n_bytes          = 0;
	block->side             = BTR_SEARCH_LEFT_SIDE;

	block->file_page_was_freed = FALSE;
}

/************************************************************************
Function which inits a page for read to the buffer buf_pool. If the page is
(1) already in buf_pool, or
(2) if we specify to read only ibuf pages and the page is not an ibuf page, or
(3) if the space is deleted or being deleted,
then this function does nothing.
Sets the io_fix flag to BUF_IO_READ and sets a non-recursive exclusive lock
on the buffer frame. The io-handler must take care that the flag is cleared
and the lock released later. This is one of the functions which perform the
state transition NOT_USED => FILE_PAGE to a block (the other is
buf_page_create). */ 

buf_block_t*
buf_page_init_for_read(
/*===================*/
				/* out: pointer to the block or NULL */
	ulint*		err,	/* out: DB_SUCCESS or DB_TABLESPACE_DELETED */
	ulint		mode,	/* in: BUF_READ_IBUF_PAGES_ONLY, ... */
	ulint		space,	/* in: space id */
	ib_longlong	tablespace_version,/* in: prevents reading from a wrong
				version of the tablespace in case we have done
				DISCARD + IMPORT */
	ulint		offset)	/* in: page number */
{
	buf_block_t*	block;
	mtr_t		mtr;

	ut_ad(buf_pool);

	*err = DB_SUCCESS;

	if (mode == BUF_READ_IBUF_PAGES_ONLY) {
		/* It is a read-ahead within an ibuf routine */

		ut_ad(!ibuf_bitmap_page(offset));
		ut_ad(ibuf_inside());
	
		mtr_start(&mtr);
	
		if (!ibuf_page_low(space, offset, &mtr)) {

			mtr_commit(&mtr);

			return(NULL);
		}
	} else {
		ut_ad(mode == BUF_READ_ANY_PAGE);
	}
	
	block = buf_block_alloc();

	ut_a(block);

	mutex_enter(&(buf_pool->mutex));

	if (fil_tablespace_deleted_or_being_deleted_in_mem(space,
							tablespace_version)) {
		*err = DB_TABLESPACE_DELETED;
	}

	if (*err == DB_TABLESPACE_DELETED
	    || NULL != buf_page_hash_get(space, offset)) {

		/* The page belongs to a space which has been deleted or is
		being deleted, or the page is already in buf_pool, return */

		mutex_exit(&(buf_pool->mutex));
		buf_block_free(block);

		if (mode == BUF_READ_IBUF_PAGES_ONLY) {

			mtr_commit(&mtr);
		}

		return(NULL);
	}

	ut_ad(block);
	
	buf_page_init(space, offset, block);

	/* The block must be put to the LRU list, to the old blocks */

	buf_LRU_add_block(block, TRUE); 	/* TRUE == to old blocks */
	
	block->io_fix = BUF_IO_READ;
	buf_pool->n_pend_reads++;
	
	/* We set a pass-type x-lock on the frame because then the same
	thread which called for the read operation (and is running now at
	this point of code) can wait for the read to complete by waiting
	for the x-lock on the frame; if the x-lock were recursive, the
	same thread would illegally get the x-lock before the page read
	is completed. The x-lock is cleared by the io-handler thread. */
	
	rw_lock_x_lock_gen(&(block->lock), BUF_IO_READ);
	
 	mutex_exit(&(buf_pool->mutex));

	if (mode == BUF_READ_IBUF_PAGES_ONLY) {

		mtr_commit(&mtr);
	}

	return(block);
}	

/************************************************************************
Initializes a page to the buffer buf_pool. The page is usually not read
from a file even if it cannot be found in the buffer buf_pool. This is one
of the functions which perform to a block a state transition NOT_USED =>
FILE_PAGE (the other is buf_page_init_for_read above). */

buf_frame_t*
buf_page_create(
/*============*/
			/* out: pointer to the frame, page bufferfixed */
	ulint	space,	/* in: space id */
	ulint	offset,	/* in: offset of the page within space in units of
			a page */
	mtr_t*	mtr)	/* in: mini-transaction handle */
{
	buf_frame_t*	frame;
	buf_block_t*	block;
	buf_block_t*	free_block	= NULL;
	
	ut_ad(mtr);

	free_block = buf_LRU_get_free_block();
	
	mutex_enter(&(buf_pool->mutex));

	block = buf_page_hash_get(space, offset);

	if (block != NULL) {
#ifdef UNIV_IBUF_DEBUG
		ut_a(ibuf_count_get(block->space, block->offset) == 0);
#endif
		block->file_page_was_freed = FALSE;

		/* Page can be found in buf_pool */
		mutex_exit(&(buf_pool->mutex));

		buf_block_free(free_block);

		frame = buf_page_get_with_no_latch(space, offset, mtr);

		return(frame);
	}

	/* If we get here, the page was not in buf_pool: init it there */

#ifdef UNIV_DEBUG
	if (buf_debug_prints) {
		fprintf(stderr, "Creating space %lu page %lu to buffer\n",
			(ulong) space, (ulong) offset);
	}
#endif /* UNIV_DEBUG */

	block = free_block;
	
	buf_page_init(space, offset, block);

	/* The block must be put to the LRU list */
	buf_LRU_add_block(block, FALSE);
		
#ifdef UNIV_SYNC_DEBUG
	buf_block_buf_fix_inc_debug(block, __FILE__, __LINE__);
#else
	buf_block_buf_fix_inc(block);
#endif
	mtr_memo_push(mtr, block, MTR_MEMO_BUF_FIX);

	block->accessed = TRUE;
	
	buf_pool->n_pages_created++;

	mutex_exit(&(buf_pool->mutex));

	/* Delete possible entries for the page from the insert buffer:
	such can exist if the page belonged to an index which was dropped */

	ibuf_merge_or_delete_for_page(NULL, space, offset, TRUE);

	/* Flush pages from the end of the LRU list if necessary */
	buf_flush_free_margin();

	frame = block->frame;

	/* Reset to zero the file flush lsn field in the page; if the first
	page of an ibdata file is 'created' in this function into the buffer
	pool then we lose the original contents of the file flush lsn stamp.
	Then InnoDB could in a crash recovery print a big, false, corruption
	warning if the stamp contains an lsn bigger than the ib_logfile lsn. */

	memset(frame + FIL_PAGE_FILE_FLUSH_LSN, 0, 8);

#ifdef UNIV_DEBUG
	buf_dbg_counter++;

	if (buf_dbg_counter % 357 == 0) {
		ut_ad(buf_validate());
	}
#endif
#ifdef UNIV_IBUF_DEBUG
	ut_a(ibuf_count_get(block->space, block->offset) == 0);
#endif
	return(frame);
}

/************************************************************************
Completes an asynchronous read or write request of a file page to or from
the buffer pool. */

void
buf_page_io_complete(
/*=================*/
	buf_block_t*	block)	/* in: pointer to the block in question */
{
	ulint		io_type;
	ulint		read_page_no;
	
	ut_ad(block);

	ut_a(block->state == BUF_BLOCK_FILE_PAGE);

	io_type = block->io_fix;

	if (io_type == BUF_IO_READ) {
		/* If this page is not uninitialized and not in the
		doublewrite buffer, then the page number should be the
		same as in block */

		read_page_no = mach_read_from_4((block->frame)
						+ FIL_PAGE_OFFSET);
		if (read_page_no != 0
			&& !trx_doublewrite_page_inside(read_page_no)
	    		&& read_page_no != block->offset) {

			fprintf(stderr,
"InnoDB: Error: page n:o stored in the page read in is %lu, should be %lu!\n",
				(ulong) read_page_no, (ulong) block->offset);
		}
		/* From version 3.23.38 up we store the page checksum
		   to the 4 first bytes of the page end lsn field */

		if (buf_page_is_corrupted(block->frame)) {
		  	fprintf(stderr,
		"InnoDB: Database page corruption on disk or a failed\n"
		"InnoDB: file read of page %lu.\n", (ulong) block->offset);
			  
			fputs(
		"InnoDB: You may have to recover from a backup.\n", stderr);

			buf_page_print(block->frame);

		  	fprintf(stderr,
		"InnoDB: Database page corruption on disk or a failed\n"
		"InnoDB: file read of page %lu.\n", (ulong) block->offset);
			fputs(
		"InnoDB: You may have to recover from a backup.\n", stderr);
			fputs(
		"InnoDB: It is also possible that your operating\n"
		"InnoDB: system has corrupted its own file cache\n"
		"InnoDB: and rebooting your computer removes the\n"
		"InnoDB: error.\n"
		"InnoDB: If the corrupt page is an index page\n"
		"InnoDB: you can also try to fix the corruption\n"
		"InnoDB: by dumping, dropping, and reimporting\n"
		"InnoDB: the corrupt table. You can use CHECK\n"
		"InnoDB: TABLE to scan your table for corruption.\n"
		"InnoDB: See also "
		"http://dev.mysql.com/doc/mysql/en/Forcing_recovery.html\n"
		"InnoDB: about forcing recovery.\n", stderr);
			  
			if (srv_force_recovery < SRV_FORCE_IGNORE_CORRUPT) {
				fputs(
	"InnoDB: Ending processing because of a corrupt database page.\n",
					stderr);
		  		exit(1);
		  	}
		}

		if (recv_recovery_is_on()) {
			recv_recover_page(FALSE, TRUE, block->frame,
						block->space, block->offset);
		}

		if (!recv_no_ibuf_operations) {
			ibuf_merge_or_delete_for_page(block->frame,
					block->space, block->offset, TRUE);
		}
	}
	
#ifdef UNIV_IBUF_DEBUG
	ut_a(ibuf_count_get(block->space, block->offset) == 0);
#endif
	mutex_enter(&(buf_pool->mutex));
	
	/* Because this thread which does the unlocking is not the same that
	did the locking, we use a pass value != 0 in unlock, which simply
	removes the newest lock debug record, without checking the thread
	id. */

	block->io_fix = 0;
	
	if (io_type == BUF_IO_READ) {