bk commit into 5.0 tree (knielsen:1.2428) BUG#27560

[knielsen]

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ChangeSet@stripped, 2007-04-02 15:50:57+02:00, knielsen@ymer.(none) +1 -0
  BUG#27560: Memory usage of mysqld grows while doing nothing
  
  The query-cache watch thread was continually allocating new thread entries on the
  THD MEM_ROOT, not freed until server exit.
  
  Fixed by using a simple array, auto-expanded as necessary.

  sql/ha_ndbcluster.cc@stripped, 2007-04-02 15:50:42+02:00, knielsen@ymer.(none) +28 -9
    Use a fixed array (auto-expanded as necessary) for temporary copy of open shares,
    don't keep pushing list entries on the THD mem root.

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	knielsen
# Host:	ymer.(none)
# Root:	/usr/local/mysql/mysql-5.0-bug27560

--- 1.303/sql/ha_ndbcluster.cc	2007-04-02 15:51:31 +02:00
+++ 1.304/sql/ha_ndbcluster.cc	2007-04-02 15:51:31 +02:00
@@ -6695,7 +6695,15 @@ pthread_handler_t ndb_util_thread_func(v
     DBUG_RETURN(NULL);
   }
 
-  List<NDB_SHARE> util_open_tables;
+  uint share_list_size= 50;
+  NDB_SHARE **share_list= new NDB_SHARE * [share_list_size];
+  if (!share_list)
+  {
+    thd->cleanup();
+    delete thd;
+    delete ndb;
+    DBUG_RETURN(NULL);
+  }
   set_timespec(abstime, 0);
   for (;;)
   {
@@ -6725,7 +6733,20 @@ pthread_handler_t ndb_util_thread_func(v
     /* Lock mutex and fill list with pointers to all open tables */
     NDB_SHARE *share;
     pthread_mutex_lock(&ndbcluster_mutex);
-    for (uint i= 0; i < ndbcluster_open_tables.records; i++)
+    uint record_count= ndbcluster_open_tables.records;
+    if (share_list_size < record_count)
+    {
+      uint new_share_list_size= share_list_size*3/2;
+      if (share_list_size < record_count)
+        share_list_size= record_count;
+      NDB_SHARE ** new_share_list= new NDB_SHARE * [new_share_list_size];
+      if (!new_share_list_size)
+        continue;                               // At least do not crash
+      delete [] share_list;
+      share_list_size= new_share_list_size;
+      share_list= new_share_list;
+    }
+    for (uint i= 0; i < record_count; i++)
     {
       share= (NDB_SHARE *)hash_element(&ndbcluster_open_tables, i);
       share->use_count++; /* Make sure the table can't be closed */
@@ -6734,14 +6755,14 @@ pthread_handler_t ndb_util_thread_func(v
                   i, share->table_name, share->use_count));
 
       /* Store pointer to table */
-      util_open_tables.push_back(share);
+      share_list[i]= share;
     }
     pthread_mutex_unlock(&ndbcluster_mutex);
 
-    /* Iterate through the  open files list */
-    List_iterator_fast<NDB_SHARE> it(util_open_tables);
-    while ((share= it++))
+    /* Iterate through the open files list */
+    for (uint i= 0; i < record_count; i++)
     {
+      share= share_list[i];
       /* Split tab- and dbname */
       char buf[FN_REFLEN];
       char *tabname, *db;
@@ -6791,9 +6812,6 @@ pthread_handler_t ndb_util_thread_func(v
       free_share(share);
     }
 
-    /* Clear the list of open tables */
-    util_open_tables.empty();
-
     /* Calculate new time to wake up */
     int secs= 0;
     int msecs= ndb_cache_check_time;
@@ -6816,6 +6834,7 @@ pthread_handler_t ndb_util_thread_func(v
     }
   }
 
+  delete [] share_list;
   thd->cleanup();
   delete thd;
   delete ndb;