branches/zip: buf_page_t: Introduce the field in_flush_list #ifdef UNIV_DEBUG.

buf_flush_batch(): Remove the local variable "found".

buf/buf0buf.c

@@ -612,6 +612,7 @@ buf_block_init(
 	block->index = NULL;
 
 #ifdef UNIV_DEBUG
+	block->page.in_flush_list = FALSE;
 	block->page.in_free_list = FALSE;
 	block->page.in_LRU_list = FALSE;
 	block->n_pointers = 0;
@@ -851,6 +852,7 @@ buf_chunk_free(
 		ut_a(!block->page.zip.data);
 
 		ut_ad(!block->page.in_LRU_list);
+		ut_ad(!block->page.in_flush_list);
 		/* Remove the block from the free list. */
 		ut_ad(block->page.in_free_list);
 		UT_LIST_REMOVE(list, buf_pool->free, (&block->page));
@@ -1211,6 +1213,7 @@ buf_pool_page_hash_rebuild(void)
 	for (b = UT_LIST_GET_FIRST(buf_pool->zip_clean); b;
 	     b = UT_LIST_GET_NEXT(list, b)) {
 		ut_a(buf_page_get_state(b) == BUF_BLOCK_ZIP_PAGE);
+		ut_ad(!b->in_flush_list);
 
 		HASH_INSERT(buf_page_t, hash, page_hash,
 			    buf_page_address_fold(b->space, b->offset), b);
@@ -1218,6 +1221,8 @@ buf_pool_page_hash_rebuild(void)
 
 	for (b = UT_LIST_GET_FIRST(buf_pool->flush_list); b;
 	     b = UT_LIST_GET_NEXT(list, b)) {
+		ut_ad(b->in_flush_list);
+
 		switch (buf_page_get_state(b)) {
 		case BUF_BLOCK_ZIP_DIRTY:
 			HASH_INSERT(buf_page_t, hash, page_hash,
@@ -2138,6 +2143,10 @@ buf_page_init_for_read(
 				buf_page_t*	b;
 
 				b = UT_LIST_GET_PREV(list, bpage);
+				ut_ad(bpage->in_flush_list);
+				ut_ad(!block->page.in_flush_list);
+				ut_d(bpage->in_flush_list = FALSE);
+				ut_d(block->page.in_flush_list = TRUE);
 				UT_LIST_REMOVE(list, buf_pool->flush_list,
 					       bpage);
 
@@ -2707,6 +2716,8 @@ buf_validate(void)
 
 	for (b = UT_LIST_GET_FIRST(buf_pool->flush_list); b;
 	     b = UT_LIST_GET_NEXT(list, b)) {
+		ut_ad(b->in_flush_list);
+
 		switch (buf_page_get_state(b)) {
 		case BUF_BLOCK_ZIP_DIRTY:
 			ut_a(b->oldest_modification);
@@ -2950,6 +2961,8 @@ buf_get_latched_pages_number(void)
 
 	for (b = UT_LIST_GET_FIRST(buf_pool->flush_list); b;
 	     b = UT_LIST_GET_NEXT(list, b)) {
+		ut_ad(b->in_flush_list);
+
 		switch (buf_page_get_state(b)) {
 		case BUF_BLOCK_ZIP_DIRTY:
 			if (b->buf_fix_count != 0

buf/buf0flu.c

@@ -68,6 +68,8 @@ buf_flush_insert_into_flush_list(
 		/* fall through */
 	case BUF_BLOCK_ZIP_DIRTY:
 	case BUF_BLOCK_FILE_PAGE:
+		ut_ad(!bpage->in_flush_list);
+		ut_a(bpage->in_flush_list = TRUE);
 		UT_LIST_ADD_FIRST(list, buf_pool->flush_list, bpage);
 		break;
 	case BUF_BLOCK_ZIP_FREE:
@@ -124,10 +126,14 @@ buf_flush_insert_sorted_into_flush_list(
 	b = UT_LIST_GET_FIRST(buf_pool->flush_list);
 
 	while (b && b->oldest_modification > bpage->oldest_modification) {
+		ut_ad(b->in_flush_list);
 		prev_b = b;
 		b = UT_LIST_GET_NEXT(list, b);
 	}
 
+	ut_ad(!bpage->in_flush_list);
+	ut_d(bpage->in_flush_list = TRUE);
+
 	if (prev_b == NULL) {
 		UT_LIST_ADD_FIRST(list, buf_pool->flush_list, bpage);
 	} else {
@@ -223,6 +229,9 @@ buf_flush_remove(
 	ut_a(mutex_own(&buf_pool->mutex));
 #endif /* UNIV_SYNC_DEBUG */
 
+	ut_ad(bpage->in_flush_list);
+	ut_d(bpage->in_flush_list = FALSE);
+
 	switch (buf_page_get_state(bpage)) {
 	case BUF_BLOCK_ZIP_PAGE:
 		/* clean compressed pages should not be on the flush list */
@@ -972,7 +981,6 @@ buf_flush_batch(
 	ulint		old_page_count;
 	ulint		space;
 	ulint		offset;
-	ibool		found;
 
 	ut_ad((flush_type == BUF_FLUSH_LRU)
 	      || (flush_type == BUF_FLUSH_LIST));
@@ -995,6 +1003,7 @@ buf_flush_batch(
 	buf_pool->init_flush[flush_type] = TRUE;
 
 	for (;;) {
+flush_next:
 		/* If we have flushed enough, leave the loop */
 		if (page_count >= min_n) {
 
@@ -1016,17 +1025,16 @@ buf_flush_batch(
 
 				break;
 			}
+			ut_ad(bpage->in_flush_list);
 		}
 
-		found = FALSE;
-
 		/* Note that after finding a single flushable page, we try to
 		flush also all its neighbors, and after that start from the
 		END of the LRU list or flush list again: the list may change
 		during the flushing and we cannot safely preserve within this
 		function a pointer to a block in the list! */
 
-		while ((bpage != NULL) && !found) {
+		do {
 			mutex_t* block_mutex = buf_page_get_mutex(bpage);
 
 			ut_a(buf_page_in_file(bpage));
@@ -1035,7 +1043,6 @@ buf_flush_batch(
 
 			if (buf_flush_ready_for_flush(bpage, flush_type)) {
 
-				found = TRUE;
 				space = buf_page_get_space(bpage);
 				offset = buf_page_get_page_no(bpage);
 
@@ -1053,6 +1060,7 @@ buf_flush_batch(
 				page_count - old_page_count); */
 
 				mutex_enter(&(buf_pool->mutex));
+				goto flush_next;
 
 			} else if (flush_type == BUF_FLUSH_LRU) {
 
@@ -1065,14 +1073,13 @@ buf_flush_batch(
 				mutex_exit(block_mutex);
 
 				bpage = UT_LIST_GET_PREV(list, bpage);
+				ut_ad(!bpage || bpage->in_flush_list);
 			}
-		}
+		} while (bpage != NULL);
 
 		/* If we could not find anything to flush, leave the loop */
 
-		if (!found) {
+		break;
-			break;
-		}
 	}
 
 	buf_pool->init_flush[flush_type] = FALSE;
@@ -1216,6 +1223,7 @@ buf_flush_validate_low(void)
 
 	while (bpage != NULL) {
 		const ib_uint64_t om = bpage->oldest_modification;
+		ut_ad(bpage->in_flush_list);
 		ut_a(buf_page_in_file(bpage));
 		ut_a(om > 0);
 

buf/buf0lru.c

@@ -371,6 +371,7 @@ buf_LRU_get_free_only(void)
 	if (block) {
 		ut_ad(block->page.in_free_list);
 		ut_d(block->page.in_free_list = FALSE);
+		ut_ad(!block->page.in_flush_list);
 		ut_ad(!block->page.in_LRU_list);
 		ut_a(!buf_page_in_file(&block->page));
 		UT_LIST_REMOVE(list, buf_pool->free, (&block->page));
@@ -1022,6 +1023,8 @@ buf_LRU_block_free_non_file_page(
 
 	ut_ad(block->n_pointers == 0);
 	ut_ad(!block->page.in_free_list);
+	ut_ad(!block->page.in_flush_list);
+	ut_ad(!block->page.in_LRU_list);
 
 	buf_block_set_state(block, BUF_BLOCK_NOT_USED);
 
@@ -1131,6 +1134,7 @@ buf_LRU_block_remove_hashed_page(
 	switch (buf_page_get_state(bpage)) {
 	case BUF_BLOCK_ZIP_PAGE:
 		ut_ad(!bpage->in_free_list);
+		ut_ad(!bpage->in_flush_list);
 		ut_ad(!bpage->in_LRU_list);
 		ut_a(bpage->zip.data);
 		ut_a(buf_page_get_zip_size(bpage));

include/buf0buf.h

@@ -959,6 +959,11 @@ struct buf_page_struct{
 					BUF_BLOCK_ZIP_PAGE:	zip_clean
 					BUF_BLOCK_ZIP_FREE:	zip_free[] */
 #ifdef UNIV_DEBUG
+	ibool		in_flush_list;	/* TRUE if in buf_pool->flush_list;
+					when buf_pool->mutex is free, the
+					following should hold: in_flush_list
+					== (state == BUF_BLOCK_FILE_PAGE
+					    || state == BUF_BLOCK_ZIP_DIRTY) */
 	ibool		in_free_list;	/* TRUE if in buf_pool->free; when
 					buf_pool->mutex is free, the following
 					should hold: in_free_list

include/buf0buf.ic

@@ -83,6 +83,7 @@ buf_pool_get_oldest_modification(void)
 	if (bpage == NULL) {
 		lsn = 0;
 	} else {
+		ut_ad(bpage->in_flush_list);
 		lsn = bpage->oldest_modification;
 	}