branches/zip: buf_buddy_alloc(): Assign *lru = TRUE whenever the buffer pool

mutex is temporarily released.

buf_LRU_free_block(), buf_buddy_alloc_clean(): Add an output parameter that
will be assigned TRUE when the buffer pool mutex is released.

This bug was spotted by and fix provided by Sunny.

btr/btr0cur.c

@@ -3625,12 +3625,12 @@ btr_blob_free(
 	    && buf_block_get_space(block) == space
 	    && buf_block_get_page_no(block) == page_no) {
 
-		if (!buf_LRU_free_block(&block->page, all)
+		if (!buf_LRU_free_block(&block->page, all, NULL)
 		    && all && block->page.zip.data) {
 			/* Attempt to deallocate the uncompressed page
 			if the whole block cannot be deallocted. */
 
-			buf_LRU_free_block(&block->page, FALSE);
+			buf_LRU_free_block(&block->page, FALSE, NULL);
 		}
 	}
 

buf/buf0buddy.c

@@ -268,7 +268,10 @@ void*
 buf_buddy_alloc_clean(
 /*==================*/
 			/* out: allocated block, or NULL */
-	ulint	i)	/* in: index of buf_pool->zip_free[] */
+	ulint	i,	/* in: index of buf_pool->zip_free[] */
+	ibool*	lru)	/* in: pointer to a variable that will be assigned
+			TRUE if storage was allocated from the LRU list
+			and buf_pool->mutex was temporarily released */
 {
 	buf_page_t*	bpage;
 
@@ -297,7 +300,7 @@ buf_buddy_alloc_clean(
 
 		for (; j--; bpage = UT_LIST_GET_NEXT(list, bpage)) {
 			if (bpage->zip.ssize != dummy_zip.ssize
-			    || !buf_LRU_free_block(bpage, FALSE)) {
+			    || !buf_LRU_free_block(bpage, FALSE, lru)) {
 
 				continue;
 			}
@@ -344,7 +347,7 @@ free_LRU:
 		mutex_enter(block_mutex);
 
 		/* Keep the compressed pages of uncompressed blocks. */
-		if (!buf_LRU_free_block(bpage, FALSE)) {
+		if (!buf_LRU_free_block(bpage, FALSE, lru)) {
 
 			mutex_exit(block_mutex);
 			continue;
@@ -433,7 +436,7 @@ buf_buddy_alloc_low(
 
 	/* Try replacing a clean page in the buffer pool. */
 
-	block = buf_buddy_alloc_clean(i);
+	block = buf_buddy_alloc_clean(i, lru);
 
 	if (block) {
 

buf/buf0buf.c

@@ -1079,7 +1079,8 @@ shrink_again:
 
 				buf_LRU_make_block_old(&block->page);
 				dirty++;
-			} else if (!buf_LRU_free_block(&block->page, TRUE)) {
+			} else if (!buf_LRU_free_block(&block->page,
+						       TRUE, NULL)) {
 				nonfree++;
 			}
 
@@ -1513,7 +1514,7 @@ lookup:
 		break;
 	case BUF_BLOCK_FILE_PAGE:
 		/* Discard the uncompressed page frame if possible. */
-		if (buf_LRU_free_block(bpage, FALSE)) {
+		if (buf_LRU_free_block(bpage, FALSE, NULL)) {
 
 			mutex_exit(block_mutex);
 			goto lookup;

buf/buf0lru.c

@@ -279,7 +279,7 @@ buf_LRU_search_and_free_block(
 				= buf_page_get_mutex(bpage);
 
 			mutex_enter(block_mutex);
-			freed = buf_LRU_free_block(bpage, TRUE);
+			freed = buf_LRU_free_block(bpage, TRUE, NULL);
 			mutex_exit(block_mutex);
 
 			if (freed) {
@@ -302,7 +302,7 @@ buf_LRU_search_and_free_block(
 				= buf_page_get_mutex(bpage);
 
 			mutex_enter(block_mutex);
-			freed = buf_LRU_free_block(bpage, TRUE);
+			freed = buf_LRU_free_block(bpage, TRUE, NULL);
 			mutex_exit(block_mutex);
 
 			if (freed) {
@@ -330,7 +330,7 @@ buf_LRU_search_and_free_block(
 
 				buf_block_t*	block = (buf_block_t*) bpage;
 				mutex_enter(&block->mutex);
-				freed = buf_LRU_free_block(bpage, TRUE);
+				freed = buf_LRU_free_block(bpage, TRUE, NULL);
 				mutex_exit(&block->mutex);
 
 				if (freed) {
@@ -938,8 +938,12 @@ buf_LRU_free_block(
 				it will not temporarily release
 				buf_pool->mutex. */
 	buf_page_t*	bpage,	/* in: block to be freed */
-	ibool		zip)	/* in: TRUE if should remove also the
+	ibool		zip,	/* in: TRUE if should remove also the
 				compressed page of an uncompressed page */
+	ibool*		buf_pool_mutex_released)
+				/* in: pointer to a variable that will
+				be assigned TRUE if buf_pool->mutex
+				was temporarily released, or NULL */
 {
 	buf_page_t*	b = NULL;
 	mutex_t*	block_mutex = buf_page_get_mutex(bpage);
@@ -1054,6 +1058,10 @@ alloc:
 			b->io_fix = BUF_IO_READ;
 		}
 
+		if (buf_pool_mutex_released) {
+			*buf_pool_mutex_released = TRUE;
+		}
+
 		mutex_exit(&buf_pool->mutex);
 		mutex_exit(block_mutex);
 

include/buf0lru.h

@@ -85,8 +85,12 @@ buf_LRU_free_block(
 				it will not temporarily release
 				buf_pool->mutex. */
 	buf_page_t*	block,	/* in: block to be freed */
-	ibool		zip);	/* in: TRUE if should remove also the
+	ibool		zip,	/* in: TRUE if should remove also the
 				compressed page of an uncompressed page */
+	ibool*		buf_pool_mutex_released);
+				/* in: pointer to a variable that will
+				be assigned TRUE if buf_pool->mutex
+				was temporarily released, or NULL */
 /**********************************************************************
 Look for a replaceable block from the end of the LRU list and put it to
 the free list if found. */