Merge Bug#47991 fix from mysql-5.1-innodb

  ------------------------------------------------------------
  revno: 3517
  revision-id: vasil.dimov@oracle.com-20100622163043-dc0lxy0byg74viet
  parent: marko.makela@oracle.com-20100621095148-8g73k8k68dpj080u
  committer: Vasil Dimov <vasil.dimov@oracle.com>
  branch nick: mysql-5.1-innodb
  timestamp: Tue 2010-06-22 19:30:43 +0300
  message:
    Fix Bug#47991 InnoDB Dictionary Cache memory usage increases indefinitely
    when renaming tables
    
    Allocate the table name using ut_malloc() instead of table->heap because
    the latter cannot be freed.
    
    Adjust dict_sys->size calculations all over the code.
    
    Change dict_table_t::name from const char* to char* because we need to
    ut_malloc()/ut_free() it.
    
    Reviewed by:	Inaam, Marko, Heikki (rb://384)
    Approved by:	Heikki (rb://384)
  ------------------------------------------------------------

1 files changed, 26 insertions, 8 deletions

diff --git a/storage/innobase/dict/dict0dict.c b/storage/innobase/dict/dict0dict.c
index a298d785449..734c104183d 100644
--- a/storage/innobase/dict/dict0dict.c
+++ b/storage/innobase/dict/dict0dict.c
@@ -864,7 +864,8 @@ dict_table_add_to_cache(
 	/* Add table to LRU list of tables */
 	UT_LIST_ADD_FIRST(table_LRU, dict_sys->table_LRU, table);
 
-	dict_sys->size += mem_heap_get_size(table->heap);
+	dict_sys->size += mem_heap_get_size(table->heap)
+		+ strlen(table->name) + 1;
 }
 
 /**********************************************************************//**
@@ -918,14 +919,21 @@ dict_table_rename_in_cache(
 	dict_foreign_t*	foreign;
 	dict_index_t*	index;
 	ulint		fold;
-	ulint		old_size;
-	const char*	old_name;
+	char		old_name[MAX_TABLE_NAME_LEN + 1];
 
 	ut_ad(table);
 	ut_ad(mutex_own(&(dict_sys->mutex)));
 
-	old_size = mem_heap_get_size(table->heap);
-	old_name = table->name;
+	/* store the old/current name to an automatic variable */
+	if (strlen(table->name) + 1 <= sizeof(old_name)) {
+		memcpy(old_name, table->name, strlen(table->name) + 1);
+	} else {
+		ut_print_timestamp(stderr);
+		fprintf(stderr, "InnoDB: too long table name: '%s', "
+			"max length is %d\n", table->name,
+			MAX_TABLE_NAME_LEN);
+		ut_error;
+	}
 
 	fold = ut_fold_string(new_name);
 
@@ -971,12 +979,22 @@ dict_table_rename_in_cache(
 	/* Remove table from the hash tables of tables */
 	HASH_DELETE(dict_table_t, name_hash, dict_sys->table_hash,
 		    ut_fold_string(old_name), table);
-	table->name = mem_heap_strdup(table->heap, new_name);
+
+	if (strlen(new_name) > strlen(table->name)) {
+		/* We allocate MAX_TABLE_NAME_LEN+1 bytes here to avoid
+		memory fragmentation, we assume a repeated calls of
+		ut_realloc() with the same size do not cause fragmentation */
+		ut_a(strlen(new_name) <= MAX_TABLE_NAME_LEN);
+		table->name = ut_realloc(table->name, MAX_TABLE_NAME_LEN + 1);
+	}
+	memcpy(table->name, new_name, strlen(new_name) + 1);
 
 	/* Add table to hash table of tables */
 	HASH_INSERT(dict_table_t, name_hash, dict_sys->table_hash, fold,
 		    table);
-	dict_sys->size += (mem_heap_get_size(table->heap) - old_size);
+
+	dict_sys->size += strlen(new_name) - strlen(old_name);
+	ut_a(dict_sys->size > 0);
 
 	/* Update the table_name field in indexes */
 	index = dict_table_get_first_index(table);
@@ -1201,7 +1219,7 @@ dict_table_remove_from_cache(
 	/* Remove table from LRU list of tables */
 	UT_LIST_REMOVE(table_LRU, dict_sys->table_LRU, table);
 
-	size = mem_heap_get_size(table->heap);
+	size = mem_heap_get_size(table->heap) + strlen(table->name) + 1;
 
 	ut_ad(dict_sys->size >= size);