===== sql/sql_base.cc 1.422 vs edited =====
--- 1.422/sql/sql_base.cc	2007-12-21 15:15:39 +08:00
+++ edited/sql/sql_base.cc	2007-12-05 15:53:35 +08:00
@@ -843,6 +843,17 @@
     }
     check_unused();				// consisty check
   }
+
+  if(table->hash_head == table){
+    TABLE *t;
+    for(t=table->hash_next;t!=table;t=t->hash_next){
+      t->hash_head = table->hash_next;
+    }
+  }
+
+  table->hash_next->hash_prev=table->hash_prev;
+  table->hash_prev->hash_next=table->hash_next;
+
   my_free((uchar*) table,MYF(0));
   DBUG_VOID_RETURN;
 }
@@ -1284,6 +1295,26 @@
     /* Free memory and reset for next loop */
     table->file->ha_reset();
     table->in_use=0;
+
+    if(table != table->hash_head){
+
+      /* removed from the list (hash_next,hash_prev)*/
+      table->hash_prev->hash_next=table->hash_next;
+      table->hash_next->hash_prev=table->hash_prev;
+      
+
+      /* insert into the list prev the hash_head */
+      TABLE *head;
+      head= table->hash_head;
+
+      head->hash_prev->hash_next=table;
+
+      table->hash_prev=head->hash_prev;
+      table->hash_next=head;
+
+      head->hash_prev=table;
+    }
+
     if (unused_tables)
     {
       table->next=unused_tables;		/* Link in last */
@@ -2032,6 +2063,10 @@
     table->next= orig_table.next;
   }
 
+  table->hash_head=orig_table.hash_head;
+  table->hash_next=orig_table.hash_next;
+  table->hash_prev=orig_table.hash_prev;
+
   table->tablenr=thd->current_tablenr++;
   table->used_fields=0;
   table->const_table=0;
@@ -2082,12 +2117,28 @@
   table->in_use= thd;
   table->locked_by_name=1;
 
+  TABLE *find_table=(TABLE *)hash_search(&open_cache,(const uchar *)key,key_length);
+
   if (my_hash_insert(&open_cache, (uchar*)table))
   {
     my_free((uchar*) table, MYF(0));
     DBUG_RETURN(NULL);
   }
 
+  if(find_table){
+    TABLE * head;
+    head= find_table->hash_head;
+    head->hash_next->hash_prev=table;
+
+    table->hash_next=head->hash_next;
+    table->hash_prev=head;
+    table->hash_head=head;
+
+    head->hash_next=table;
+  }else{
+    table->hash_head = table->hash_next = table->hash_prev = table;
+  }
+
   DBUG_RETURN(table);
 }
 
@@ -2484,6 +2535,15 @@
     an implicit "pending locks queue" - see
     wait_for_locked_table_names for details.
   */
+  table = (TABLE *)hash_search(&open_cache,(uchar *)key,key_length);
+
+  if(table){
+    table = table->hash_head;
+  }
+
+
+  if(table && table->needs_reopen_or_name_lock()){
+
   for (table= (TABLE*) hash_first(&open_cache, (uchar*) key, key_length,
                                   &state);
        table && table->in_use ;
@@ -2572,6 +2632,18 @@
       DBUG_RETURN(0);
     }
   }
+  }else if(table && table->in_use){
+    if(table->hash_prev){
+      if(table->hash_prev->in_use)
+	table=NULL;
+      else
+	table=table->hash_prev;
+    }else{
+      table=NULL;
+    }
+  }
+
+
   if (table)
   {
     /* Unlink the table from "unused_tables" list. */
@@ -2584,6 +2656,22 @@
     table->prev->next=table->next;		/* Remove from unused list */
     table->next->prev=table->prev;
     table->in_use= thd;
+    if(table != table->hash_head){
+      table->hash_prev->hash_next=table->hash_next;
+      table->hash_next->hash_prev=table->hash_prev;
+
+      TABLE *head;
+      
+      head= table->hash_head;
+
+      head->hash_next->hash_prev=table;
+
+      table->hash_next=head->hash_next;
+      table->hash_prev=head;
+      table->hash_head=head;
+
+      head->hash_next=table;
+    }
   }
   else
   {
@@ -2656,7 +2744,21 @@
       DBUG_RETURN(0); // VIEW
     }
     DBUG_PRINT("info", ("inserting table 0x%lx into the cache", (long) table));
+    TABLE * find_table=(TABLE *)hash_search(&open_cache,(const uchar *)key,key_length);
     VOID(my_hash_insert(&open_cache,(uchar*) table));
+    if(find_table){
+      TABLE * head;
+      head= find_table->hash_head;
+      head->hash_next->hash_prev=table;
+
+      table->hash_next=head->hash_next;
+      table->hash_prev=head;
+      table->hash_head=head;
+
+      head->hash_next=table;
+    }else{
+      table->hash_head = table->hash_next = table->hash_prev=table;
+    }
   }
 
   check_unused();				// Debugging call
@@ -2787,6 +2889,10 @@
   /* Replace table in open list */
   tmp.next=		table->next;
   tmp.prev=		table->prev;
+
+  tmp.hash_head = table->hash_head;
+  tmp.hash_next = table->hash_next;
+  tmp.hash_prev = table->hash_prev;
 
   delete table->triggers;
   if (table->file)
===== sql/table.h 1.181 vs edited =====
--- 1.181/sql/table.h	2007-12-21 15:15:40 +08:00
+++ edited/sql/table.h	2007-12-05 15:31:09 +08:00
@@ -455,6 +455,8 @@
 #endif
   struct st_table *next, *prev;
 
+  struct st_table *hash_head, *hash_next, *hash_prev;  /* Link to instances */
+
   THD	*in_use;                        /* Which thread uses this */
   Field **field;			/* Pointer to fields */