branches/zip: Make use of the previously unused state BUF_BLOCK_MEMORY.

buf_LRU_get_free_block(): Document that the block is in the state
BUF_BLOCK_READY_FOR_USE.

buf_block_alloc(): Change the state of the block to BUF_BLOCK_MEMORY
and document it.

Replace those invocations of buf_block_alloc() with
buf_LRU_get_free_block() where the allocated block is used for buffer
pool input and output.  However, temporary copies of B-tree pages
during reorganization are not used for file I/O, and such blocks are
still allocated with buf_block_alloc().

buf/buf0buddy.c

@@ -95,7 +95,7 @@ buf_buddy_block_register(
 #ifdef UNIV_SYNC_DEBUG
 	ut_a(mutex_own(&buf_pool->mutex));
 #endif /* UNIV_SYNC_DEBUG */
-	ut_a(buf_block_get_state(block) == BUF_BLOCK_MEMORY);
+	buf_block_set_state(block, BUF_BLOCK_MEMORY);
 
 	ut_a(block->frame);
 	ut_a(block->frame == ut_align_down(block->frame, UNIV_PAGE_SIZE));

buf/buf0buf.c

@@ -1923,7 +1923,7 @@ buf_page_init_for_read(
 		ut_ad(mode == BUF_READ_ANY_PAGE);
 	}
 
-	block = buf_block_alloc(zip_size);
+	block = buf_LRU_get_free_block(zip_size);
 
 	ut_a(block);
 

buf/buf0lru.c

@@ -423,7 +423,8 @@ LRU list to the free list. */
 buf_block_t*
 buf_LRU_get_free_block(
 /*===================*/
-				/* out: the free control block */
+				/* out: the free control block,
+				in state BUF_BLOCK_READY_FOR_USE */
 	ulint	zip_size)	/* in: compressed page size in bytes,
 				or 0 if uncompressed tablespace */
 {

include/buf0buf.h

@@ -114,7 +114,8 @@ UNIV_INLINE
 buf_block_t*
 buf_block_alloc(
 /*============*/
-				/* out, own: the allocated block */
+				/* out, own: the allocated block,
+				in state BUF_BLOCK_MEMORY */
 	ulint	zip_size);	/* in: compressed page size in bytes,
 				or 0 if uncompressed tablespace */
 /************************************************************************

include/buf0buf.ic

@@ -656,7 +656,8 @@ UNIV_INLINE
 buf_block_t*
 buf_block_alloc(
 /*============*/
-				/* out, own: the allocated block */
+				/* out, own: the allocated block,
+				in state BUF_BLOCK_MEMORY */
 	ulint	zip_size)	/* in: compressed page size in bytes,
 				or 0 if uncompressed tablespace */
 {
@@ -664,6 +665,8 @@ buf_block_alloc(
 
 	block = buf_LRU_get_free_block(zip_size);
 
+	buf_block_set_state(block, BUF_BLOCK_MEMORY);
+
 	return(block);
 }
 

include/buf0lru.h

@@ -104,7 +104,8 @@ LRU list to the free list. */
 buf_block_t*
 buf_LRU_get_free_block(
 /*===================*/
-				/* out: the free control block */
+				/* out: the free control block,
+				in state BUF_BLOCK_READY_FOR_USE */
 	ulint	zip_size);	/* in: compressed page size in bytes,
 				or 0 if uncompressed tablespace */
 

log/log0recv.c

@@ -1564,7 +1564,7 @@ recv_apply_log_recs_for_backup(void)
 	recv_sys->apply_log_recs = TRUE;
 	recv_sys->apply_batch_on = TRUE;
 
-	block = buf_block_alloc(UNIV_PAGE_SIZE);
+	block = buf_LRU_get_free_block(UNIV_PAGE_SIZE);
 
 	fputs("InnoDB: Starting an apply batch of log records"
 	      " to the database...\n"