bk commit into 5.0 tree (svoj:1.2303) BUG#23526

[Sergey Vojtovich]

Below is the list of changes that have just been committed into a local
5.0 repository of svoj. When svoj does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
For information on how to access the public repository
see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet@stripped, 2006-12-05 18:44:14+04:00, svoj@stripped +5 -0
  BUG#23526 - show table status reports incorrect values for MyISAM tables
  
  This problem could happen when show table status get outdated copy
  of TABLE object from table cache.
  
  MyISAM updates state info when external_lock() method is called. Though
  I_S does not lock a table to avoid deadlocks. If I_S opens a table which
  is in a table cache it will likely get outdated state info copy.
  
  In this case shared state copy is more recent than local copy. This problem
  is fixed by correctly restoring myisam state info pointer back to original
  value, that is to shared state.
  
  Affects MyISAM only. No good deterministic test case for this fix.

  include/thr_lock.h@stripped, 2006-12-05 18:44:12+04:00, svoj@stripped +1 -0
    Added restore_status, that will be called prior to release a
    read lock.

  myisam/mi_locking.c@stripped, 2006-12-05 18:44:12+04:00, svoj@stripped +9 -0
    Added mi_restore_status, that will be called prior to release a
    read lock. This function is intended to set myisam state pointer
    back to original value, that is to shared state.

  myisam/mi_open.c@stripped, 2006-12-05 18:44:12+04:00, svoj@stripped +1 -0
    Added restore_status, that will be called prior to release a
    read lock.

  myisam/myisamdef.h@stripped, 2006-12-05 18:44:12+04:00, svoj@stripped +1 -0
    Added mi_restore_status, that will be called prior to release a
    read lock.

  mysys/thr_lock.c@stripped, 2006-12-05 18:44:12+04:00, svoj@stripped +10 -2
    Call restore_status if we have lock with priority lower than
    TL_WRITE_CONCURRENT_INSERT.

# 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:	svoj
# Host:	april.(none)
# Root:	/home/svoj/devel/mysql/BUG23526/mysql-5.0-engines2

--- 1.17/include/thr_lock.h	2006-12-05 18:44:19 +04:00
+++ 1.18/include/thr_lock.h	2006-12-05 18:44:19 +04:00
@@ -122,6 +122,7 @@ typedef struct st_thr_lock {
   void (*get_status)(void*, int);	/* When one gets a lock */
   void (*copy_status)(void*,void*);
   void (*update_status)(void*);		/* Before release of write */
+  void (*restore_status)(void*);         /* Before release of read */
   my_bool (*check_status)(void *);
 } THR_LOCK;
 

--- 1.42/myisam/mi_locking.c	2006-12-05 18:44:19 +04:00
+++ 1.43/myisam/mi_locking.c	2006-12-05 18:44:19 +04:00
@@ -326,6 +326,15 @@ void mi_update_status(void* param)
   }
 }
 
+
+void mi_restore_status(void *param)
+{
+  MI_INFO *info= (MI_INFO*) param;
+  info->state= &info->s->state.state;
+  info->append_insert_at_end= 0;
+}
+
+
 void mi_copy_status(void* to,void *from)
 {
   ((MI_INFO*) to)->state= &((MI_INFO*) from)->save_state;

--- 1.98/myisam/mi_open.c	2006-12-05 18:44:19 +04:00
+++ 1.99/myisam/mi_open.c	2006-12-05 18:44:19 +04:00
@@ -505,6 +505,7 @@ MI_INFO *mi_open(const char *name, int m
 	share->lock.get_status=mi_get_status;
 	share->lock.copy_status=mi_copy_status;
 	share->lock.update_status=mi_update_status;
+        share->lock.restore_status= mi_restore_status;
 	share->lock.check_status=mi_check_status;
       }
     }

--- 1.86/myisam/myisamdef.h	2006-12-05 18:44:19 +04:00
+++ 1.87/myisam/myisamdef.h	2006-12-05 18:44:19 +04:00
@@ -732,6 +732,7 @@ int mi_unique_comp(MI_UNIQUEDEF *def, co
 		   my_bool null_are_equal);
 void mi_get_status(void* param, int concurrent_insert);
 void mi_update_status(void* param);
+void mi_restore_status(void* param);
 void mi_copy_status(void* to,void *from);
 my_bool mi_check_status(void* param);
 void mi_disable_non_unique_index(MI_INFO *info, ha_rows rows);

--- 1.51/mysys/thr_lock.c	2006-12-05 18:44:19 +04:00
+++ 1.52/mysys/thr_lock.c	2006-12-05 18:44:19 +04:00
@@ -758,8 +758,16 @@ void thr_unlock(THR_LOCK_DATA *data)
   }
   else
     lock->write.last=data->prev;
-  if (lock_type >= TL_WRITE_CONCURRENT_INSERT && lock->update_status)
-    (*lock->update_status)(data->status_param);
+  if (lock_type >= TL_WRITE_CONCURRENT_INSERT)
+  {
+    if (lock->update_status)
+      (*lock->update_status)(data->status_param);
+  }
+  else
+  {
+    if (lock->restore_status)
+      (*lock->restore_status)(data->status_param);
+  }
   if (lock_type == TL_READ_NO_INSERT)
     lock->read_no_write_count--;
   data->type=TL_UNLOCK;				/* Mark unlocked */