WL#2269 Enable query cache for NDB part 2

-This is mostly fixes for correct behaviour when using query cache + transactions + the thread that
fetches commit count from NDB at regular intervals. The major fix is to add a
list in thd_ndb, that keeps a list of NDB_SHARE's that were modified by
transaction and then "clearing" them in ndbcluster_commit.


mysql-test/r/ndb_cache2.result:
  Updated test cases for the ndb_util thread, more simultaneous tables and more tesst
mysql-test/t/ndb_cache2.test:
  Updated test cases for the ndb_util thread, more simultaneous tables and more advanced tesst
sql/ha_ndbcluster.cc:
  Add table changed during transaction to list of changed tables in Thd_ndb, this list is then used in ndbcluster_commit to invalidate the cached commit_count in share
  Fix so that ndb_util_thread uses milliseconds "sleeps"
  Changed so that ndb_commit_count uses the commit_count from share if available
sql/ha_ndbcluster.h:
  Add commit_count_lock to NBD_SHARE, use for detecting simultaneous attempts to update commit_count
  Add list of tables changed by transaction to Thd_ndb
  Change check_ndb_connection to take thd as argument, use current_thd as default
  Added m_rows_changed variable to keep track of if this handler has modified any records within the transaction
sql/set_var.cc:
  Change format of code
  Sort sys__ variables in aplha order

1 files changed, 4 insertions, 1 deletions

diff --git a/sql/ha_ndbcluster.h b/sql/ha_ndbcluster.h
index 10ee568df69..a88a05b3543 100644
--- a/sql/ha_ndbcluster.h
+++ b/sql/ha_ndbcluster.h
@@ -60,6 +60,7 @@ typedef struct st_ndbcluster_share {
   pthread_mutex_t mutex;
   char *table_name;
   uint table_name_length,use_count;
+  uint commit_count_lock;
   ulonglong commit_count;
 } NDB_SHARE;
 
@@ -77,6 +78,7 @@ class Thd_ndb {
   NdbTransaction *all;
   NdbTransaction *stmt;
   int error;
+  List<NDB_SHARE> changed_tables;
 };
 
 class ha_ndbcluster: public handler
@@ -226,7 +228,7 @@ private:
   char *update_table_comment(const char * comment);
 
  private:
-  int check_ndb_connection();
+  int check_ndb_connection(THD* thd= current_thd);
 
   NdbTransaction *m_active_trans;
   NdbScanOperation *m_active_cursor;
@@ -250,6 +252,7 @@ private:
   ha_rows m_rows_to_insert;
   ha_rows m_rows_inserted;
   ha_rows m_bulk_insert_rows;
+  ha_rows m_rows_changed;
   bool m_bulk_insert_not_flushed;
   ha_rows m_ops_pending;
   bool m_skip_auto_increment;