1 files changed, 121 insertions, 86 deletions

diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index 3f0c1ee8a80..d25057789ac 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -345,26 +345,9 @@ TABLE_SHARE *get_table_share(THD *thd, TABLE_LIST *table_list, char *key,
 
   if (!(share= alloc_table_share(table_list, key, key_length)))
   {
-#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
-    pthread_mutex_unlock(&LOCK_open);
-#endif
     DBUG_RETURN(0);
   }
 
-#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
-  // We need a write lock to be able to add a new entry
-  pthread_mutex_unlock(&LOCK_open);
-  pthread_mutex_lock(&LOCK_open);
-  /* Check that another thread didn't insert the same table in between */
-  if ((old_share= hash_search(&table_def_cache, (uchar*) key, key_length)))
-  {
-    (void) pthread_mutex_lock(&share->mutex);
-    free_table_share(share);
-    share= old_share;
-    goto found;
-  }
-#endif
-
   /*
     Lock mutex to be able to read table definition from file without
     conflicts
@@ -388,29 +371,11 @@ TABLE_SHARE *get_table_share(THD *thd, TABLE_LIST *table_list, char *key,
 
   if (my_hash_insert(&table_def_cache, (uchar*) share))
   {
-#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
-    pthread_mutex_unlock(&LOCK_open);    
-    (void) pthread_mutex_unlock(&share->mutex);
-#endif
     free_table_share(share);
     DBUG_RETURN(0);				// return error
   }
-#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
-  pthread_mutex_unlock(&LOCK_open);
-#endif
   if (open_table_def(thd, share, db_flags))
   {
-#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
-    /*
-      No such table or wrong table definition file
-      Lock first the table cache and then the mutex.
-      This will ensure that no other thread is using the share
-      structure.
-    */
-    (void) pthread_mutex_unlock(&share->mutex);
-    (void) pthread_mutex_lock(&LOCK_open);
-    (void) pthread_mutex_lock(&share->mutex);
-#endif
     *error= share->error;
     (void) hash_delete(&table_def_cache, (uchar*) share);
     DBUG_RETURN(0);
@@ -429,9 +394,6 @@ found:
 
   /* We must do a lock to ensure that the structure is initialized */
   (void) pthread_mutex_lock(&share->mutex);
-#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
-  pthread_mutex_unlock(&LOCK_open);
-#endif
   if (share->error)
   {
     /* Table definition contained an error */
@@ -618,52 +580,6 @@ void release_table_share(TABLE_SHARE *share, enum release_type type)
   }
   pthread_mutex_unlock(&share->mutex);
   DBUG_VOID_RETURN;
-
-
-#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
-  if (to_be_deleted)
-  {
-    /*
-      We must try again with new locks as we must get LOCK_open
-      before share->mutex
-    */
-    pthread_mutex_unlock(&share->mutex);
-    pthread_mutex_lock(&LOCK_open);
-    pthread_mutex_lock(&share->mutex);
-    if (!share->ref_count)
-    {						// No one is using this now
-      TABLE_SHARE *name_lock;
-      if (share->replace_with_name_lock && (name_lock=get_name_lock(share)))
-      {
-	/*
-	  This code is execured when someone does FLUSH TABLES while on has
-	  locked tables.
-	 */
-	(void) hash_search(&def_cache,(uchar*) key,key_length);
-	hash_replace(&def_cache, def_cache.current_record,(uchar*) name_lock);
-      }
-      else
-      {
-	/* Remove table definition */
-	hash_delete(&def_cache,(uchar*) share);
-      }
-      pthread_mutex_unlock(&LOCK_open);
-      free_table_share(share);
-    }
-    else
-    {
-      pthread_mutex_unlock(&LOCK_open);
-      if (type == RELEASE_WAIT_FOR_DROP)
-	wait_for_table(share, "Waiting for close");
-      else
-	pthread_mutex_unlock(&share->mutex);
-    }
-  }
-  else if (type == RELEASE_WAIT_FOR_DROP)
-    wait_for_table(share, "Waiting for close");
-  else
-    pthread_mutex_unlock(&share->mutex);
-#endif
 }
 
 
@@ -3801,6 +3717,73 @@ void assign_new_table_id(TABLE_SHARE *share)
   DBUG_VOID_RETURN;
 }
 
+
+/**
+  Compare metadata versions of an element obtained from the table
+  definition cache and its corresponding node in the parse tree.
+
+  @details If the new and the old values mismatch, invoke
+  Metadata_version_observer.
+  At prepared statement prepare, all TABLE_LIST version values are
+  NULL and we always have a mismatch. But there is no observer set
+  in THD, and therefore no error is reported. Instead, we update
+  the value in the parse tree, effectively recording the original
+  version.
+  At prepared statement execute, an observer may be installed.  If
+  there is a version mismatch, we push an error and return TRUE.
+
+  For conventional execution (no prepared statements), the
+  observer is never installed.
+
+  @sa Execute_observer
+  @sa check_prepared_statement() to see cases when an observer is installed
+  @sa TABLE_LIST::is_table_ref_id_equal()
+  @sa TABLE_SHARE::get_table_ref_id()
+
+  @param[in]      thd         used to report errors
+  @param[in,out]  tables      TABLE_LIST instance created by the parser
+                              Metadata version information in this object
+                              is updated upon success.
+  @param[in]      table_share an element from the table definition cache
+
+  @retval  TRUE  an error, which has been reported
+  @retval  FALSE success, version in TABLE_LIST has been updated
+*/
+
+bool
+check_and_update_table_version(THD *thd,
+                               TABLE_LIST *tables, TABLE_SHARE *table_share)
+{
+  if (! tables->is_table_ref_id_equal(table_share))
+  {
+    if (thd->m_reprepare_observer &&
+        thd->m_reprepare_observer->report_error(thd))
+    {
+      /*
+        Version of the table share is different from the
+        previous execution of the prepared statement, and it is
+        unacceptable for this SQLCOM. Error has been reported.
+      */
+      DBUG_ASSERT(thd->is_error());
+      return TRUE;
+    }
+    /* Always maintain the latest version and type */
+    tables->set_table_ref_id(table_share);
+  }
+
+#ifndef DBUG_OFF
+  /* Spuriously reprepare each statement. */
+  if (_db_strict_keyword_("reprepare_each_statement") &&
+      thd->m_reprepare_observer && thd->stmt_arena->is_reprepared == FALSE)
+  {
+    thd->m_reprepare_observer->report_error(thd);
+    return TRUE;
+  }
+#endif
+
+  return FALSE;
+}
+
 /*
   Load a table definition from file and open unireg table
 
@@ -3846,6 +3829,12 @@ retry:
 
   if (share->is_view)
   {
+    /*
+      This table is a view. Validate its metadata version: in particular,
+      that it was a view when the statement was prepared.
+    */
+    if (check_and_update_table_version(thd, table_list, share))
+      goto err;
     if (table_list->i_s_requested_object &  OPEN_TABLE_ONLY)
       goto err;
 
@@ -3863,6 +3852,26 @@ retry:
     release_table_share(share, RELEASE_NORMAL);
     DBUG_RETURN((flags & OPEN_VIEW_NO_PARSE)? -1 : 0);
   }
+  else if (table_list->view)
+  {
+    /*
+      We're trying to open a table for what was a view.
+      This can only happen during (re-)execution.
+      At prepared statement prepare the view has been opened and
+      merged into the statement parse tree. After that, someone
+      performed a DDL and replaced the view with a base table.
+      Don't try to open the table inside a prepared statement,
+      invalidate it instead.
+
+      Note, the assert below is known to fail inside stored
+      procedures (Bug#27011).
+    */
+    DBUG_ASSERT(thd->m_reprepare_observer);
+    check_and_update_table_version(thd, table_list, share);
+    /* Always an error. */
+    DBUG_ASSERT(thd->is_error());
+    goto err;
+  }
 
   if (table_list->i_s_requested_object &  OPEN_VIEW_ONLY)
     goto err;
@@ -4367,6 +4376,11 @@ bool fix_merge_after_open(TABLE_LIST *old_child_list, TABLE_LIST **old_last,
     prelocking it won't do such precaching and will simply reuse table list
     which is already built.
 
+    If any table has a trigger and start->trg_event_map is non-zero
+    the final lock will end up in thd->locked_tables, otherwise, the
+    lock will be placed in thd->lock. See also comments in
+    st_lex::set_trg_event_type_for_tables().
+
   RETURN
     0  - OK
     -1 - error
@@ -4459,8 +4473,18 @@ int open_tables(THD *thd, TABLE_LIST **start, uint *counter, uint flags)
     */
     if (tables->schema_table)
     {
-      if (!mysql_schema_table(thd, thd->lex, tables))
+      /*
+        If this information_schema table is merged into a mergeable
+        view, ignore it for now -- it will be filled when its respective
+        TABLE_LIST is processed. This code works only during re-execution.
+      */
+      if (tables->view)
+        goto process_view_routines;
+      if (!mysql_schema_table(thd, thd->lex, tables) &&
+          !check_and_update_table_version(thd, tables, tables->table->s))
+      {
         continue;
+      }
       DBUG_RETURN(-1);
     }
     (*counter)++;
@@ -4579,7 +4603,7 @@ int open_tables(THD *thd, TABLE_LIST **start, uint *counter, uint flags)
         process its triggers since they never will be activated.
       */
       if (!thd->prelocked_mode && !thd->lex->requires_prelocking() &&
-          tables->table->triggers &&
+          tables->trg_event_map && tables->table->triggers &&
           tables->lock_type >= TL_WRITE_ALLOW_WRITE)
       {
         if (!query_tables_last_own)
@@ -4608,6 +4632,13 @@ int open_tables(THD *thd, TABLE_LIST **start, uint *counter, uint flags)
     }
     tables->table->grant= tables->grant;
 
+    /* Check and update metadata version of a base table. */
+    if (check_and_update_table_version(thd, tables, tables->table->s))
+    {
+      result= -1;
+      goto err;
+    }
+
     /* Attach MERGE children if not locked already. */
     DBUG_PRINT("tcache", ("is parent: %d  is child: %d",
                           test(tables->table->child_l),
@@ -4666,7 +4697,11 @@ process_view_routines:
       error happens on a MERGE child, clear the parents TABLE reference.
     */
     if (tables->parent_l)
+    {
+      if (tables->parent_l->next_global == tables->parent_l->table->child_l)
+        tables->parent_l->next_global= *tables->parent_l->table->child_last_l;
       tables->parent_l->table= NULL;
+    }
     tables->table= NULL;
   }
   DBUG_PRINT("tcache", ("returning: %d", result));