Bug#59307 Valgrind: uninitialized value in rw_lock_set_writer_id_and_recursion_flag()

rw_lock_create_func(): Initialize lock->writer_thread, so that Valgrind
will not complain even when Valgrind instrumentation is not enabled.
Flag lock->writer_thread uninitialized, so that Valgrind can complain
when it is used uninitialized.

rw_lock_set_writer_id_and_recursion_flag(): Revert the bogus Valgrind
instrumentation that was pushed in the first attempt to fix this bug.

mysql-test/suite/innodb_plugin/r/innodb_bug59307.result

+CREATE TABLE t1 (
+t1_int INT,
+t1_time TIME
+) ENGINE=innodb;
+CREATE TABLE t2 (
+t2_int int PRIMARY KEY,
+t2_int2 INT
+) ENGINE=INNODB;
+INSERT INTO t2 VALUES ();
+Warnings:
+Warning	1364	Field 't2_int' doesn't have a default value
+INSERT INTO t1 VALUES ();
+SELECT *
+FROM t1 AS t1a
+WHERE NOT EXISTS
+(SELECT *
+FROM t1 AS t1b
+WHERE t1b.t1_int NOT IN
+(SELECT t2.t2_int
+FROM t2
+WHERE t1b.t1_time LIKE t1b.t1_int
+OR t1b.t1_time <> t2.t2_int2
+AND 6=7
+)
+)
+;
+t1_int	t1_time
+DROP TABLE t1,t2;

mysql-test/suite/innodb_plugin/t/innodb_bug59307.test

+-- source include/have_innodb_plugin.inc
+# Bug #59307 uninitialized value in rw_lock_set_writer_id_and_recursion_flag()
+# when Valgrind instrumentation (UNIV_DEBUG_VALGRIND) is not enabled
+
+CREATE TABLE t1 (
+  t1_int INT,
+  t1_time TIME
+) ENGINE=innodb;
+
+CREATE TABLE t2 (
+  t2_int int PRIMARY KEY,
+  t2_int2 INT
+) ENGINE=INNODB;
+
+INSERT INTO t2 VALUES ();
+INSERT INTO t1 VALUES ();
+
+SELECT *
+FROM t1 AS t1a
+WHERE NOT EXISTS
+  (SELECT *
+   FROM t1 AS t1b
+   WHERE t1b.t1_int NOT IN
+     (SELECT t2.t2_int
+      FROM t2
+      WHERE t1b.t1_time LIKE t1b.t1_int
+      OR t1b.t1_time <> t2.t2_int2
+      AND 6=7
+ )
+)
+;
+DROP TABLE t1,t2;

storage/innodb_plugin/ChangeLog

+2011-02-15	The InnoDB Team
+
+	* sync/sync0rw.c, innodb_bug59307.test:
+	Bug#59307 Valgrind: uninitialized value in
+	rw_lock_set_writer_id_and_recursion_flag()
+
 2011-02-14	The InnoDB Team
 
 	* handler/handler0alter.cc:

storage/innodb_plugin/include/sync0rw.ic

@@ -280,7 +280,6 @@ rw_lock_set_writer_id_and_recursion_flag(
 	local_thread = lock->writer_thread;
 	success = os_compare_and_swap_thread_id(
 		&lock->writer_thread, local_thread, curr_thread);
-	UNIV_MEM_VALID(&success, sizeof(success));
 	ut_a(success);
 	lock->recursive = recursive;
 

storage/innodb_plugin/sync/sync0rw.c

@@ -260,6 +260,9 @@ rw_lock_create_func(
 	contains garbage at initialization and cannot be used for
 	recursive x-locking. */
 	lock->recursive = FALSE;
+	/* Silence Valgrind when UNIV_DEBUG_VALGRIND is not enabled. */
+	memset((void*) &lock->writer_thread, 0, sizeof lock->writer_thread);
+	UNIV_MEM_INVALID(&lock->writer_thread, sizeof lock->writer_thread);
 
 #ifdef UNIV_SYNC_DEBUG
 	UT_LIST_INIT(lock->debug_list);