bk commit into 4.1 tree (ingo:1.2448) BUG#14397

[ingo]

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4.1 repository of mydev. When mydev does a push these changes will
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ChangeSet
  1.2448 05/11/03 18:26:52 ingo@stripped +7 -0
  Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
  Version for 4.1.
  It fixes two problems:
  1. The cause of the bug was that we did not check the table version for
     the HANDLER ... READ commands. We did not notice when a table was
     replaced by a new one. This can happen during ALTER TABLE, REPAIR
     TABLE, and OPTIMIZE TABLE (there might be more cases). I call the fix
     for this problem "the primary bug fix".
  2. mysql_ha_flush() was not always called with a locked LOCK_open.
     Though the function comment clearly said it must.
     I changed the code so that the locking is done when required. I call
     the fix for this problem "the secondary fix".

  sql/sql_table.cc
    1.303 05/11/03 18:26:48 ingo@stripped +3 -3
    Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
    Changed function calls for the secondary fix.

  sql/sql_handler.cc
    1.63 05/11/03 18:26:48 ingo@stripped +45 -4
    Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
    The first two diffs make the primary bug fix.
    The rest is for the secondary fix.

  sql/sql_class.cc
    1.203 05/11/03 18:26:48 ingo@stripped +1 -1
    Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
    Changed a function call for the secondary fix.

  sql/sql_base.cc
    1.260 05/11/03 18:26:48 ingo@stripped +4 -3
    Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
    Changed function calls for the secondary fix.

  sql/mysql_priv.h
    1.368 05/11/03 18:26:48 ingo@stripped +2 -1
    Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
    Changed a definition for the secondary fix.

  mysql-test/t/handler.test
    1.23 05/11/03 18:26:48 ingo@stripped +28 -0
    Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
    The test case.

  mysql-test/r/handler.result
    1.23 05/11/03 18:26:48 ingo@stripped +18 -0
    Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
    The test result.

# 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:	ingo
# Host:	chilla.local
# Root:	/home/mydev/mysql-4.1-4100

--- 1.367/sql/mysql_priv.h	2005-09-14 14:31:32 +02:00
+++ 1.368/sql/mysql_priv.h	2005-11-03 18:26:48 +01:00
@@ -701,7 +701,8 @@
 int mysql_ha_close(THD *thd, TABLE_LIST *tables);
 int mysql_ha_read(THD *, TABLE_LIST *,enum enum_ha_read_modes,char *,
                List<Item> *,enum ha_rkey_function,Item *,ha_rows,ha_rows);
-int mysql_ha_flush(THD *thd, TABLE_LIST *tables, uint mode_flags);
+int mysql_ha_flush(THD *thd, TABLE_LIST *tables, uint mode_flags,
+                   bool is_locked);
 /* mysql_ha_flush mode_flags bits */
 #define MYSQL_HA_CLOSE_FINAL        0x00
 #define MYSQL_HA_REOPEN_ON_USAGE    0x01

--- 1.259/sql/sql_base.cc	2005-09-13 20:46:53 +02:00
+++ 1.260/sql/sql_base.cc	2005-11-03 18:26:48 +01:00
@@ -306,7 +306,8 @@
     thd->proc_info="Flushing tables";
 
     close_old_data_files(thd,thd->open_tables,1,1);
-    mysql_ha_flush(thd, tables, MYSQL_HA_REOPEN_ON_USAGE | MYSQL_HA_FLUSH_ALL);
+    mysql_ha_flush(thd, tables, MYSQL_HA_REOPEN_ON_USAGE | MYSQL_HA_FLUSH_ALL,
+                   TRUE);
     bool found=1;
     /* Wait until all threads has closed all the tables we had locked */
     DBUG_PRINT("info",
@@ -860,7 +861,7 @@
   }
 
   /* close handler tables which are marked for flush */
-  mysql_ha_flush(thd, (TABLE_LIST*) NULL, MYSQL_HA_REOPEN_ON_USAGE);
+  mysql_ha_flush(thd, (TABLE_LIST*) NULL, MYSQL_HA_REOPEN_ON_USAGE, TRUE);
 
   for (table=(TABLE*) hash_search(&open_cache,(byte*) key,key_length) ;
        table && table->in_use ;
@@ -1265,7 +1266,7 @@
   {
     thd->some_tables_deleted=0;
     close_old_data_files(thd,thd->open_tables,0,dropping_tables != 0);
-    mysql_ha_flush(thd, (TABLE_LIST*) NULL, MYSQL_HA_REOPEN_ON_USAGE);
+    mysql_ha_flush(thd, (TABLE_LIST*) NULL, MYSQL_HA_REOPEN_ON_USAGE, TRUE);
     if (!table_is_used(thd->open_tables,1))
       break;
     (void) pthread_cond_wait(&COND_refresh,&LOCK_open);

--- 1.202/sql/sql_class.cc	2005-10-14 15:34:49 +02:00
+++ 1.203/sql/sql_class.cc	2005-11-03 18:26:48 +01:00
@@ -353,7 +353,7 @@
     close_thread_tables(this);
   }
   mysql_ha_flush(this, (TABLE_LIST*) 0,
-                 MYSQL_HA_CLOSE_FINAL | MYSQL_HA_FLUSH_ALL);
+                 MYSQL_HA_CLOSE_FINAL | MYSQL_HA_FLUSH_ALL, FALSE);
   hash_free(&handler_tables_hash);
   delete_dynamic(&user_var_events);
   hash_free(&user_vars);

--- 1.302/sql/sql_table.cc	2005-09-12 14:08:36 +02:00
+++ 1.303/sql/sql_table.cc	2005-11-03 18:26:48 +01:00
@@ -220,7 +220,7 @@
   for (table=tables ; table ; table=table->next)
   {
     char *db=table->db;
-    mysql_ha_flush(thd, table, MYSQL_HA_CLOSE_FINAL);
+    mysql_ha_flush(thd, table, MYSQL_HA_CLOSE_FINAL, TRUE);
     if (!close_temporary_table(thd, db, table->real_name))
     {
       tmp_table_deleted=1;
@@ -1920,7 +1920,7 @@
   if (protocol->send_fields(&field_list, 1))
     DBUG_RETURN(-1);
 
-  mysql_ha_flush(thd, tables, MYSQL_HA_CLOSE_FINAL);
+  mysql_ha_flush(thd, tables, MYSQL_HA_CLOSE_FINAL, FALSE);
   for (table = tables; table; table = table->next)
   {
     char table_name[NAME_LEN*2+2];
@@ -2773,7 +2773,7 @@
     new_db= db;
   used_fields=create_info->used_fields;
 
-  mysql_ha_flush(thd, table_list, MYSQL_HA_CLOSE_FINAL);
+  mysql_ha_flush(thd, table_list, MYSQL_HA_CLOSE_FINAL, FALSE);
   /* DISCARD/IMPORT TABLESPACE is always alone in an ALTER TABLE */
   if (alter_info->tablespace_op != NO_TABLESPACE_OP)
     DBUG_RETURN(mysql_discard_or_import_tablespace(thd,table_list,

--- 1.22/mysql-test/r/handler.result	2004-10-07 09:50:09 +02:00
+++ 1.23/mysql-test/r/handler.result	2005-11-03 18:26:48 +01:00
@@ -445,3 +445,21 @@
 drop table t3;
 drop table t4;
 drop table t5;
+create table t1 (c1 int);
+insert into t1 values (1);
+handler t1 open;
+handler t1 read first;
+c1
+1
+send the below to another connection, do not wait for the result
+ optimize table t1;
+proceed with the normal connection
+handler t1 read next;
+c1
+1
+handler t1 close;
+read the result from the other connection
+Table	Op	Msg_type	Msg_text
+test.t1	optimize	status	OK
+proceed with the normal connection
+drop table t1;

--- 1.22/mysql-test/t/handler.test	2005-09-01 17:19:15 +02:00
+++ 1.23/mysql-test/t/handler.test	2005-11-03 18:26:48 +01:00
@@ -347,4 +347,32 @@
 drop table t4;
 drop table t5;
 
+#
+# Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
+#
+create table t1 (c1 int);
+insert into t1 values (1);
+# client 1
+handler t1 open;
+handler t1 read first;
+# client 2
+connect (con2,localhost,root,,);
+connection con2;
+--exec echo send the below to another connection, do not wait for the result
+send optimize table t1;
+--sleep 1
+# client 1
+--exec echo proceed with the normal connection
+connection default;
+handler t1 read next;
+handler t1 close;
+# client 2
+--exec echo read the result from the other connection
+connection con2;
+reap;
+# client 1
+--exec echo proceed with the normal connection
+connection default;
+drop table t1;
+
 # End of 4.1 tests

--- 1.62/sql/sql_handler.cc	2005-06-07 22:43:18 +02:00
+++ 1.63/sql/sql_handler.cc	2005-11-03 18:26:48 +01:00
@@ -354,6 +354,7 @@
     ha_rows select_limit,ha_rows offset_limit)
 {
   TABLE_LIST    *hash_tables;
+  TABLE         **table_ptr;
   TABLE         *table;
   MYSQL_LOCK    *lock;
   List<Item>	list;
@@ -383,6 +384,27 @@
     DBUG_PRINT("info-in-hash",("'%s'.'%s' as '%s' tab %p",
                                hash_tables->db, hash_tables->real_name,
                                hash_tables->alias, table));
+    /* Table might have been flushed. */
+    if (table && (table->version != refresh_version))
+    {
+      /*
+        We must follow the thd->handler_tables chain, as we need the
+        address of the 'next' pointer referencing this table
+        for close_thread_table().
+      */
+      for (table_ptr= &(thd->handler_tables);
+           *table_ptr && (*table_ptr != table);
+           table_ptr= &(*table_ptr)->next)
+      {}
+      VOID(pthread_mutex_lock(&LOCK_open));
+      if (close_thread_table(thd, table_ptr))
+      {
+        /* Tell threads waiting for refresh that something has happened */
+        VOID(pthread_cond_broadcast(&COND_refresh));
+      }
+      VOID(pthread_mutex_unlock(&LOCK_open));
+      table= hash_tables->table= NULL;
+    }
     if (!table)
     {
       /*
@@ -616,6 +638,7 @@
                                 MYSQL_HA_REOPEN_ON_USAGE mark for reopen.
                                 MYSQL_HA_FLUSH_ALL flush all tables, not only
                                 those marked for flush.
+    is_locked                   If LOCK_open is locked.
 
   DESCRIPTION
     The list of HANDLER tables may be NULL, in which case all HANDLER
@@ -623,7 +646,6 @@
     If 'tables' is NULL and MYSQL_HA_FLUSH_ALL is not set,
     all HANDLER tables marked for flush are closed.
     Broadcasts a COND_refresh condition, for every table closed.
-    The caller must lock LOCK_open.
 
   NOTE
     Since mysql_ha_flush() is called when the base table has to be closed,
@@ -633,10 +655,12 @@
     0  ok
 */
 
-int mysql_ha_flush(THD *thd, TABLE_LIST *tables, uint mode_flags)
+int mysql_ha_flush(THD *thd, TABLE_LIST *tables, uint mode_flags,
+                   bool is_locked)
 {
   TABLE_LIST    *tmp_tables;
   TABLE         **table_ptr;
+  bool          did_lock= FALSE;
   DBUG_ENTER("mysql_ha_flush");
   DBUG_PRINT("enter", ("tables: %p  mode_flags: 0x%02x", tables, mode_flags));
 
@@ -662,6 +686,12 @@
                              (*table_ptr)->table_cache_key,
                              (*table_ptr)->real_name,
                              (*table_ptr)->table_name));
+          /* The first time it is required, lock for close_thread_table(). */
+          if (! did_lock && ! is_locked)
+          {
+            VOID(pthread_mutex_lock(&LOCK_open));
+            did_lock= TRUE;
+          }
           mysql_ha_flush_table(thd, table_ptr, mode_flags);
           continue;
         }
@@ -680,6 +710,12 @@
       if ((mode_flags & MYSQL_HA_FLUSH_ALL) ||
           ((*table_ptr)->version != refresh_version))
       {
+        /* The first time it is required, lock for close_thread_table(). */
+        if (! did_lock && ! is_locked)
+        {
+          VOID(pthread_mutex_lock(&LOCK_open));
+          did_lock= TRUE;
+        }
         mysql_ha_flush_table(thd, table_ptr, mode_flags);
         continue;
       }
@@ -687,6 +723,10 @@
     }
   }
 
+  /* Release the lock if it was taken by this function. */
+  if (did_lock)
+    VOID(pthread_mutex_unlock(&LOCK_open));
+
   DBUG_RETURN(0);
 }
 
@@ -718,8 +758,8 @@
                       table->table_name, mode_flags));
 
   if ((hash_tables= (TABLE_LIST*) hash_search(&thd->handler_tables_hash,
-                                        (byte*) (*table_ptr)->table_name,
-                                        strlen((*table_ptr)->table_name) + 1)))
+                                              (byte*) table->table_name,
+                                              strlen(table->table_name) + 1)))
   {
     if (! (mode_flags & MYSQL_HA_REOPEN_ON_USAGE))
     {
@@ -734,6 +774,7 @@
   }    
 
   (*table_ptr)->file->ha_index_or_rnd_end();
+  safe_mutex_assert_owner(&LOCK_open);
   if (close_thread_table(thd, table_ptr))
   {
     /* Tell threads waiting for refresh that something has happened */