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

6 files changed, 71 insertions, 4 deletions

diff --git a/innobase/include/log0recv.h b/innobase/include/log0recv.h
index 51f14393d38..8f896756db9 100644
--- a/innobase/include/log0recv.h
+++ b/innobase/include/log0recv.h
@@ -258,6 +258,7 @@ struct recv_sys_struct{
 extern recv_sys_t*	recv_sys;
 extern ibool		recv_recovery_on;
 extern ibool		recv_no_ibuf_operations;
+extern ibool		recv_needed_recovery;
 
 /* States of recv_addr_struct */
 #define RECV_NOT_PROCESSED	71
diff --git a/innobase/include/mem0mem.h b/innobase/include/mem0mem.h
index 57fac93d3ac..89c5428f054 100644
--- a/innobase/include/mem0mem.h
+++ b/innobase/include/mem0mem.h
@@ -269,13 +269,24 @@ mem_realloc(
 	ulint   n,	/* in: desired number of bytes */
 	char*  	file_name,/* in: file name where called */
 	ulint 	line);  /* in: line where called */
+#ifdef MEM_PERIODIC_CHECK
+/**********************************************************************
+Goes through the list of all allocated mem blocks, checks their magic
+numbers, and reports possible corruption. */
 
+void
+mem_validate_all_blocks(void);
+/*=========================*/
+#endif
 
 /*#######################################################################*/
 	
 /* The info header of a block in a memory heap */
 
 struct mem_block_info_struct {
+	ulint   magic_n;/* magic number for debugging */
+	char	file_name[8];/* file name where the mem heap was created */
+	ulint	line;	/* line number where the mem heap was created */
 	UT_LIST_BASE_NODE_T(mem_block_t) base; /* In the first block in the
 			the list this is the base node of the list of blocks;
 			in subsequent blocks this is undefined */
@@ -299,9 +310,11 @@ struct mem_block_info_struct {
 			allocated buffer frame, which can be appended as a
 			free block to the heap, if we need more space;
 			otherwise, this is NULL */
-	ulint   magic_n;/* magic number for debugging */
-	char	file_name[8];/* file name where the mem heap was created */
-	ulint	line;	/* line number where the mem heap was created */
+#ifdef MEM_PERIODIC_CHECK	
+	UT_LIST_NODE_T(mem_block_t) mem_block_list;
+			/* List of all mem blocks allocated; protected
+			by the mem_comm_pool mutex */
+#endif
 };
 
 #define MEM_BLOCK_MAGIC_N	764741555
diff --git a/innobase/include/mem0pool.h b/innobase/include/mem0pool.h
index eb675b4a7f9..43707bd5f61 100644
--- a/innobase/include/mem0pool.h
+++ b/innobase/include/mem0pool.h
@@ -72,6 +72,18 @@ mem_pool_get_reserved(
 				/* out: reserved mmeory in bytes */
 	mem_pool_t*	pool);	/* in: memory pool */
 /************************************************************************
+Reserves the mem pool mutex. */
+
+void
+mem_pool_mutex_enter(void);
+/*======================*/
+/************************************************************************
+Releases the mem pool mutex. */
+
+void
+mem_pool_mutex_exit(void);
+/*=====================*/
+/************************************************************************
 Validates a memory pool. */
 
 ibool
diff --git a/innobase/include/row0mysql.h b/innobase/include/row0mysql.h
index 0346299bb10..48b6ba8a715 100644
--- a/innobase/include/row0mysql.h
+++ b/innobase/include/row0mysql.h
@@ -251,6 +251,24 @@ row_table_add_foreign_constraints(
 	char*	name);		/* in: table full name in the normalized form
 				database_name/table_name */
 /*************************************************************************
+The master thread in srv0srv.c calls this regularly to drop tables which
+we must drop in background after queries to them have ended. Such lazy
+dropping of tables is needed in ALTER TABLE on Unix. */
+
+ulint
+row_drop_tables_for_mysql_in_background(void);
+/*=========================================*/
+					/* out: how many tables dropped
+					+ remaining tables in list */
+/*************************************************************************
+Get the background drop list length. NOTE: the caller must own the kernel
+mutex! */
+
+ulint
+row_get_background_drop_list_len_low(void);
+/*======================================*/
+					/* out: how many tables in list */
+/*************************************************************************
 Drops a table for MySQL. If the name of the dropped table ends to
 characters INNODB_MONITOR, then this also stops printing of monitor
 output by the master thread. */
@@ -426,7 +444,7 @@ struct row_prebuilt_struct {
 					fetched row in fetch_cache */
 	ulint		n_fetch_cached;	/* number of not yet fetched rows
 					in fetch_cache */
-	mem_heap_t*	blob_heap;	/* in SELECTS BLOB fields are copied
+	mem_heap_t*	blob_heap;	/* in SELECTS BLOB fie lds are copied
 					to this heap */
 	mem_heap_t*	old_vers_heap;	/* memory heap where a previous
 					version is built in consistent read */
diff --git a/innobase/include/srv0srv.h b/innobase/include/srv0srv.h
index 05989c6410e..01986c759d7 100644
--- a/innobase/include/srv0srv.h
+++ b/innobase/include/srv0srv.h
@@ -249,6 +249,12 @@ mutex, for performace reasons). */
 void
 srv_active_wake_master_thread(void);
 /*===============================*/
+/***********************************************************************
+Wakes up the master thread if it is suspended or being suspended. */
+
+void
+srv_wake_master_thread(void);
+/*========================*/
 /*************************************************************************
 Puts an OS thread to wait if there are too many concurrent threads
 (>= srv_thread_concurrency) inside InnoDB. The threads wait in a FIFO queue. */
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