MDEV-12534 Use atomic operations whenever available

Allow 64-bit atomic operations on 32-bit systems,
only relying on HAVE_ATOMIC_BUILTINS_64, disregarding
the width of the register file.

Define UNIV_WORD_SIZE correctly on all systems, including Windows.
In MariaDB 10.0 and 10.1, it was incorrectly defined as 4 on
64-bit Windows.

Define HAVE_ATOMIC_BUILTINS_64 on Windows
(64-bit atomics are available on both 32-bit and 64-bit Windows
platforms; the operations were unnecessarily disabled even on
64-bit Windows).

MONITOR_OS_PENDING_READS, MONITOR_OS_PENDING_WRITES: Enable by default.

os_file_n_pending_preads, os_file_n_pending_pwrites,
os_n_pending_reads, os_n_pending_writes: Remove.
Use the monitor counters instead.

os_file_count_mutex: Remove. On a system that does not support
64-bit atomics, monitor_mutex will be used instead.

1 files changed, 47 insertions, 15 deletions

diff --git a/storage/innobase/include/srv0mon.h b/storage/innobase/include/srv0mon.h
index 2d90f47eefe..09af5d4159b 100644
--- a/storage/innobase/include/srv0mon.h
+++ b/storage/innobase/include/srv0mon.h
@@ -2,6 +2,7 @@
 
 Copyright (c) 2010, 2013, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2012, Facebook Inc.
+Copyright (c) 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it
 under the terms of the GNU General Public License as published by the
@@ -541,22 +542,30 @@ on the counters */
 
 /** Increment a monitor counter under mutex protection.
 Use MONITOR_INC if appropriate mutex protection already exists.
+@param mutex	mutex to acquire and release
 @param monitor	monitor to be incremented by 1
-@param mutex	mutex to acquire and relese */
-# define MONITOR_MUTEX_INC(mutex, monitor)				\
+@param enabled	whether the monitor is enabled */
+#define MONITOR_MUTEX_INC_LOW(mutex, monitor, enabled)			\
 	ut_ad(!mutex_own(mutex));					\
-	if (MONITOR_IS_ON(monitor)) {					\
+	if (enabled) {							\
 		mutex_enter(mutex);					\
 		if (++MONITOR_VALUE(monitor) > MONITOR_MAX_VALUE(monitor)) { \
 			MONITOR_MAX_VALUE(monitor) = MONITOR_VALUE(monitor); \
 		}							\
 		mutex_exit(mutex);					\
 	}
+/** Increment a monitor counter under mutex protection.
+Use MONITOR_INC if appropriate mutex protection already exists.
+@param mutex	mutex to acquire and release
+@param monitor	monitor to be incremented by 1 */
+#define MONITOR_MUTEX_INC(mutex, monitor)				\
+	MONITOR_MUTEX_INC_LOW(mutex, monitor, MONITOR_IS_ON(monitor))
 /** Decrement a monitor counter under mutex protection.
 Use MONITOR_DEC if appropriate mutex protection already exists.
+@param mutex	mutex to acquire and release
 @param monitor	monitor to be decremented by 1
-@param mutex	mutex to acquire and relese */
-# define MONITOR_MUTEX_DEC(mutex, monitor)				\
+@param enabled	whether the monitor is enabled */
+#define MONITOR_MUTEX_DEC_LOW(mutex, monitor, enabled)			\
 	ut_ad(!mutex_own(mutex));					\
 	if (MONITOR_IS_ON(monitor)) {					\
 		mutex_enter(mutex);					\
@@ -565,13 +574,20 @@ Use MONITOR_DEC if appropriate mutex protection already exists.
 		}							\
 		mutex_exit(mutex);					\
 	}
+/** Decrement a monitor counter under mutex protection.
+Use MONITOR_DEC if appropriate mutex protection already exists.
+@param mutex	mutex to acquire and release
+@param monitor	monitor to be decremented by 1 */
+#define MONITOR_MUTEX_DEC(mutex, monitor)				\
+	MONITOR_MUTEX_DEC_LOW(mutex, monitor, MONITOR_IS_ON(monitor))
 
 #if defined HAVE_ATOMIC_BUILTINS_64
 /** Atomically increment a monitor counter.
 Use MONITOR_INC if appropriate mutex protection exists.
-@param monitor	monitor to be incremented by 1 */
-# define MONITOR_ATOMIC_INC(monitor)					\
-	if (MONITOR_IS_ON(monitor)) {					\
+@param monitor	monitor to be incremented by 1
+@param enabled	whether the monitor is enabled */
+# define MONITOR_ATOMIC_INC_LOW(monitor, enabled)			\
+	if (enabled) {					\
 		ib_uint64_t	value;					\
 		value  = os_atomic_increment_uint64(			\
 			(ib_uint64_t*) &MONITOR_VALUE(monitor),	 1);	\
@@ -584,9 +600,10 @@ Use MONITOR_INC if appropriate mutex protection exists.
 
 /** Atomically decrement a monitor counter.
 Use MONITOR_DEC if appropriate mutex protection exists.
-@param monitor	monitor to be decremented by 1 */
-# define MONITOR_ATOMIC_DEC(monitor)					\
-	if (MONITOR_IS_ON(monitor)) {					\
+@param monitor	monitor to be decremented by 1
+@param enabled	whether the monitor is enabled */
+# define MONITOR_ATOMIC_DEC_LOW(monitor, enabled)			\
+	if (enabled) {							\
 		ib_uint64_t	value;					\
 		value = os_atomic_decrement_uint64(			\
 			(ib_uint64_t*) &MONITOR_VALUE(monitor), 1);	\
@@ -617,14 +634,29 @@ srv_mon_free(void);
 
 /** Atomically increment a monitor counter.
 Use MONITOR_INC if appropriate mutex protection exists.
-@param monitor	monitor to be incremented by 1 */
-# define MONITOR_ATOMIC_INC(monitor) MONITOR_MUTEX_INC(&monitor_mutex, monitor)
+@param monitor	monitor to be incremented by 1
+@param enabled	whether the monitor is enabled */
+# define MONITOR_ATOMIC_INC_LOW(monitor, enabled)		\
+	MONITOR_MUTEX_INC_LOW(&monitor_mutex, monitor, enabled)
 /** Atomically decrement a monitor counter.
 Use MONITOR_DEC if appropriate mutex protection exists.
-@param monitor	monitor to be decremented by 1 */
-# define MONITOR_ATOMIC_DEC(monitor) MONITOR_MUTEX_DEC(&monitor_mutex, monitor)
+@param monitor	monitor to be decremented by 1
+@param enabled	whether the monitor is enabled */
+# define MONITOR_ATOMIC_DEC_LOW(monitor, enabled)		\
+	MONITOR_MUTEX_DEC_LOW(&monitor_mutex, monitor, enabled)
 #endif /* HAVE_ATOMIC_BUILTINS_64 */
 
+/** Atomically increment a monitor counter if it is enabled.
+Use MONITOR_INC if appropriate mutex protection exists.
+@param monitor	monitor to be incremented by 1 */
+#define MONITOR_ATOMIC_INC(monitor)				\
+	MONITOR_ATOMIC_INC_LOW(monitor, MONITOR_IS_ON(monitor))
+/** Atomically decrement a monitor counter if it is enabled.
+Use MONITOR_DEC if appropriate mutex protection exists.
+@param monitor	monitor to be decremented by 1 */
+#define MONITOR_ATOMIC_DEC(monitor)				\
+	MONITOR_ATOMIC_DEC_LOW(monitor, MONITOR_IS_ON(monitor))
+
 #define	MONITOR_DEC(monitor)						\
 	if (MONITOR_IS_ON(monitor)) {					\
 		MONITOR_VALUE(monitor)--;				\