Added a basic test for wsrep_sync_wait system variable.

Also made some coding style related changes.

mysql-test/r/mysqld--help.result

@@ -862,8 +862,8 @@ The following options may be given as the first argument:
  variables
  (Defaults to on; use --skip-wsrep-auto-increment-control to disable.)
  --wsrep-causal-reads 
- Enable "strictly synchronous" semantics for read
- operations
+ (DEPRECATED) Setting this variable is equivalent to
+ setting wsrep_sync_wait READ flag
  --wsrep-certify-nonPK 
  Certify tables with no primary key
  (Defaults to on; use --skip-wsrep-certify-nonPK to disable.)
@@ -937,6 +937,11 @@ The following options may be given as the first argument:
  Address where node is waiting for SST contact
  --wsrep-start-position=name 
  global transaction position to start from 
+ --wsrep-sync-wait[=#] 
+ Ensure "synchronous" read view before executing an
+ operation of the type specified by bitmask: 1 -
+ READ(includes SELECT, SHOW and BEGIN/START TRANSACTION);
+ 2 - UPDATE and DELETE; 4 - INSERT and REPLACE
 
 Variables (--variable-name=value)
 allow-suspicious-udfs FALSE
@@ -1223,6 +1228,7 @@ wsrep-sst-donor-rejects-queries FALSE
 wsrep-sst-method rsync
 wsrep-sst-receive-address AUTO
 wsrep-start-position 00000000-0000-0000-0000-000000000000:-1
+wsrep-sync-wait 0
 
 To see what values a running MySQL server is using, type
 'mysqladmin variables' instead of 'mysqld --verbose --help'.

mysql-test/suite/sys_vars/r/wsrep_sync_wait_basic.result

+#
+# wsrep_sync_wait
+#
+# save the initial values
+SET @wsrep_sync_wait_global_saved = @@global.wsrep_sync_wait;
+SET @wsrep_sync_wait_session_saved = @@session.wsrep_sync_wait;
+# default
+SELECT @@global.wsrep_sync_wait;
+@@global.wsrep_sync_wait
+0
+SELECT @@session.wsrep_sync_wait;
+@@session.wsrep_sync_wait
+0
+
+# scope and valid values
+SET @@global.wsrep_sync_wait=0;
+SELECT @@global.wsrep_sync_wait;
+@@global.wsrep_sync_wait
+0
+SET @@global.wsrep_sync_wait=7;
+SELECT @@global.wsrep_sync_wait;
+@@global.wsrep_sync_wait
+7
+SET @@session.wsrep_sync_wait=0;
+SELECT @@session.wsrep_sync_wait;
+@@session.wsrep_sync_wait
+0
+SET @@session.wsrep_sync_wait=7;
+SELECT @@session.wsrep_sync_wait;
+@@session.wsrep_sync_wait
+7
+SET @@session.wsrep_sync_wait=default;
+SELECT @@session.wsrep_sync_wait;
+@@session.wsrep_sync_wait
+7
+SET @@session.wsrep_sync_wait=8;
+Warnings:
+Warning	1292	Truncated incorrect wsrep_sync_wait value: '8'
+SELECT @@session.wsrep_sync_wait;
+@@session.wsrep_sync_wait
+7
+
+# invalid values
+SET @@global.wsrep_sync_wait=NULL;
+ERROR 42000: Incorrect argument type to variable 'wsrep_sync_wait'
+SET @@global.wsrep_sync_wait='junk';
+ERROR 42000: Incorrect argument type to variable 'wsrep_sync_wait'
+SET @@session.wsrep_sync_wait=NULL;
+ERROR 42000: Incorrect argument type to variable 'wsrep_sync_wait'
+SET @@session.wsrep_sync_wait='junk';
+ERROR 42000: Incorrect argument type to variable 'wsrep_sync_wait'
+
+# restore the initial values
+SET @@global.wsrep_sync_wait = @wsrep_sync_wait_global_saved;
+SET @@session.wsrep_sync_wait = @wsrep_sync_wait_session_saved;
+# End of test

mysql-test/suite/sys_vars/t/wsrep_sync_wait_basic.test

+--source include/have_wsrep.inc
+
+--echo #
+--echo # wsrep_sync_wait
+--echo #
+
+--echo # save the initial values
+SET @wsrep_sync_wait_global_saved = @@global.wsrep_sync_wait;
+SET @wsrep_sync_wait_session_saved = @@session.wsrep_sync_wait;
+
+--echo # default
+SELECT @@global.wsrep_sync_wait;
+SELECT @@session.wsrep_sync_wait;
+
+--echo
+--echo # scope and valid values
+SET @@global.wsrep_sync_wait=0;
+SELECT @@global.wsrep_sync_wait;
+SET @@global.wsrep_sync_wait=7;
+SELECT @@global.wsrep_sync_wait;
+
+SET @@session.wsrep_sync_wait=0;
+SELECT @@session.wsrep_sync_wait;
+SET @@session.wsrep_sync_wait=7;
+SELECT @@session.wsrep_sync_wait;
+SET @@session.wsrep_sync_wait=default;
+SELECT @@session.wsrep_sync_wait;
+SET @@session.wsrep_sync_wait=8;
+SELECT @@session.wsrep_sync_wait;
+
+--echo
+--echo # invalid values
+--error ER_WRONG_TYPE_FOR_VAR
+SET @@global.wsrep_sync_wait=NULL;
+--error ER_WRONG_TYPE_FOR_VAR
+SET @@global.wsrep_sync_wait='junk';
+--error ER_WRONG_TYPE_FOR_VAR
+SET @@session.wsrep_sync_wait=NULL;
+--error ER_WRONG_TYPE_FOR_VAR
+SET @@session.wsrep_sync_wait='junk';
+
+--echo
+--echo # restore the initial values
+SET @@global.wsrep_sync_wait = @wsrep_sync_wait_global_saved;
+SET @@session.wsrep_sync_wait = @wsrep_sync_wait_session_saved;
+
+--echo # End of test

sql/sys_vars.cc

@@ -3865,19 +3865,20 @@ static Sys_var_mybool Sys_wsrep_certify_nonPK(
        CMD_LINE(OPT_ARG), DEFAULT(TRUE));
 
 static Sys_var_mybool Sys_wsrep_causal_reads(
-       "wsrep_causal_reads", "(DEPRECATED) setting this variable is equivalent to setting wsrep_sync_wait READ flag",
-       SESSION_VAR(wsrep_causal_reads), 
-       CMD_LINE(OPT_ARG), DEFAULT(FALSE),
+       "wsrep_causal_reads", "(DEPRECATED) Setting this variable is equivalent "
+       "to setting wsrep_sync_wait READ flag",
+       SESSION_VAR(wsrep_causal_reads), CMD_LINE(OPT_ARG), DEFAULT(FALSE),
        NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(0),
        ON_UPDATE(wsrep_causal_reads_update));
 
 static Sys_var_uint Sys_wsrep_sync_wait(
-       "wsrep_sync_wait", "Ensure \"synchronous\" read view before executing an operation of the type specified by bitmask: 1 - READ(includes SELECT, SHOW and BEGIN/START TRANSACTION); 2 - UPDATE and DELETE; 4 - INSERT and REPLACE",
-       SESSION_VAR(wsrep_sync_wait),
-       CMD_LINE(OPT_ARG),
+       "wsrep_sync_wait", "Ensure \"synchronous\" read view before executing "
+       "an operation of the type specified by bitmask: 1 - READ(includes "
+       "SELECT, SHOW and BEGIN/START TRANSACTION); 2 - UPDATE and DELETE; 4 - "
+       "INSERT and REPLACE",
+       SESSION_VAR(wsrep_sync_wait), CMD_LINE(OPT_ARG),
        VALID_RANGE(WSREP_SYNC_WAIT_NONE, WSREP_SYNC_WAIT_MAX),
-       DEFAULT(WSREP_SYNC_WAIT_NONE),
-       BLOCK_SIZE(1),
+       DEFAULT(WSREP_SYNC_WAIT_NONE), BLOCK_SIZE(1),
        NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(0),
        ON_UPDATE(wsrep_sync_wait_update));