Many files:

  Small improvements
row0mysql.c:
  Small improvements + fix the ALTER TABLE problem by introducing a lazy drop table it can use
ha_innobase.cc:
  Some fine-tuning of optimization


sql/ha_innobase.cc:
  Some fine-tuning of optimization
innobase/include/log0recv.h:
  Small improvements
innobase/include/mem0mem.h:
  Small improvements
innobase/include/mem0pool.h:
  Small improvements
innobase/include/row0mysql.h:
  Small improvements
innobase/include/srv0srv.h:
  Small improvements
innobase/include/trx0trx.h:
  Small improvements
innobase/buf/buf0lru.c:
  Small improvements
innobase/fil/fil0fil.c:
  Small improvements
innobase/log/log0recv.c:
  Small improvements
innobase/mem/mem0mem.c:
  Small improvements
innobase/mem/mem0pool.c:
  Small improvements
innobase/row/row0mysql.c:
  Small improvements + fix the ALTER TABLE problem by introducing a lazy drop table it can use
innobase/srv/srv0srv.c:
  Small improvements
innobase/srv/srv0start.c:
  Small improvements
innobase/trx/trx0purge.c:
  Small improvements
innobase/trx/trx0trx.c:
  Small improvements

1 files changed, 17 insertions, 0 deletions

diff --git a/innobase/include/trx0trx.h b/innobase/include/trx0trx.h
index d67628b8bad..26c9ace08b6 100644
--- a/innobase/include/trx0trx.h
+++ b/innobase/include/trx0trx.h
@@ -50,6 +50,13 @@ trx_allocate_for_mysql(void);
 /*========================*/
 				/* out, own: transaction object */
 /************************************************************************
+Creates a transaction object for background operations by the master thread. */
+
+trx_t*
+trx_allocate_for_background(void);
+/*=============================*/
+				/* out, own: transaction object */
+/************************************************************************
 Frees a transaction object. */
 
 void
@@ -63,6 +70,13 @@ void
 trx_free_for_mysql(
 /*===============*/
 	trx_t*	trx);	/* in, own: trx object */
+/************************************************************************
+Frees a transaction object of a background operation of the master thread. */
+
+void
+trx_free_for_background(
+/*====================*/
+	trx_t*	trx);	/* in, own: trx object */
 /********************************************************************
 Creates trx objects for transactions and initializes the trx list of
 trx_sys at database start. Rollback segment and undo log lists must
@@ -266,11 +280,14 @@ struct trx_sig_struct{
 					transaction is waiting a reply */
 };
 
+#define TRX_MAGIC_N	91118598
+
 /* The transaction handle; every session has a trx object which is freed only
 when the session is freed; in addition there may be session-less transactions
 rolling back after a database recovery */
 
 struct trx_struct{
+	ulint		magic_n;
 	/* All the next fields are protected by the kernel mutex, except the
 	undo logs which are protected by undo_mutex */
 	char*		op_info;	/* English text describing the