From 7f2c249d127991b25a6d107e66204e3d3d641249 Mon Sep 17 00:00:00 2001
From: jianhaiqing <jwindy986@gmail.com>
Date: Thu, 28 May 2020 09:17:44 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0lock=5Fwait=5Ftimeout,?=
 =?UTF-8?q?=E6=8E=A7=E5=88=B6=E6=99=AE=E9=80=9ASQL=20=E6=89=A7=E8=A1=8C?=
 =?UTF-8?q?=E6=97=B6=E7=9A=84=E9=94=81=E7=AD=89=E5=BE=85=E8=B6=85=E6=97=B6?=
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MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 config/config.go              |  6 ++++++
 config/config.toml.default    |  5 +++++
 config/config.toml.example    |  5 +++++
 docs/options.md               |  1 +
 session/core.go               |  1 +
 session/session_inception.go  | 20 ++++++++++++++++++++
 sessionctx/variable/sysvar.go |  2 ++
 7 files changed, 40 insertions(+)

diff --git a/config/config.go b/config/config.go
index 6f4911190..858c18748 100644
--- a/config/config.go
+++ b/config/config.go
@@ -344,6 +344,11 @@ type Inc struct {
 	// 1  表示开启安全更新
 	SqlSafeUpdates int `toml:"sql_safe_updates" json:"sql_safe_updates"`
 
+	// 设置执行SQL时，会话变量
+	// 0 表示不做操作，基于远端数据库【默认值】
+	// > 0 值表示，会话在执行SQL 时获取锁超时的时间
+	LockWaitTimeout int `toml:"lock_wait_timeout" json:"lock_wait_timeout"`
+
 	// 支持的字符集
 	SupportCharset string `toml:"support_charset" json:"support_charset"`
 
@@ -719,6 +724,7 @@ var defaultConf = Config{
 		CheckFloatDouble:      false,
 		CheckIdentifierUpper:  false,
 		SqlSafeUpdates:        -1,
+		LockWaitTimeout:       -1,
 		SupportCharset:        "utf8,utf8mb4",
 		SupportEngine:         "innodb",
 		Lang:                  "en-US",
diff --git a/config/config.toml.default b/config/config.toml.default
index d97c79adf..9de018b31 100644
--- a/config/config.toml.default
+++ b/config/config.toml.default
@@ -74,6 +74,11 @@ explain_rule = "first"
 # 1  表示开启安全更新
 sql_safe_updates = -1
 
+# 设置执行SQL时，会话变量
+# -1 表示不做操作，基于远端数据库【默认值】
+# > 0 值表示，会话在执行SQL 时获取锁超时的时间
+lock_wait_timeout = -1
+
 support_charset = "utf8,utf8mb4"
 support_engine = "innodb"
 
diff --git a/config/config.toml.example b/config/config.toml.example
index d53997774..34a3456af 100644
--- a/config/config.toml.example
+++ b/config/config.toml.example
@@ -238,6 +238,11 @@ explain_rule = "first"
 # 1  表示开启安全更新
 sql_safe_updates = -1
 
+# 设置执行SQL时，会话变量
+# -1 表示不做操作，基于远端数据库【默认值】
+# > 0 值表示，会话在执行SQL 时获取锁超时的时间
+lock_wait_timeout = -1
+
 skip_grant_table = true
 
 support_charset = "utf8,utf8mb4"
diff --git a/docs/options.md b/docs/options.md
index 248357477..648908250 100644
--- a/docs/options.md
+++ b/docs/options.md
@@ -89,6 +89,7 @@ merge_alter_table   |  false    |   true,false     |  在多个改同一个表
 must_have_columns  `v0.6.3` | ''    |   string  | 用以指定建表时必须创建的列。多个列时以逗号分隔(`格式: 列名 [列类型,可选]`)
 skip_sqls `v1.0-rc3` | ''    |   string  | 指定不再审核的SQL.该参数指定要跳过的客户端/框架默认SQL,以实现客户端兼容
 sql_safe_updates               | -1              |  -1,0,1  | 安全更新.-1表示不做操作,基于远端数据库,0表示关闭安全更新,1表示开启安全更新
+lock_wait_timeout               | -1              |  -1, N+  | 会话在执行SQL 时获取锁超时的时间, -1 表示基于远端数据库，正整数表示获取锁的超时时间
 support_charset | utf8,utf8mb4              | string | 支持的字符集,多个时以逗号分隔
 support_collation `v0.7` | ''             | string | 支持的排序规则,多个时以逗号分隔
 support_engine `v1.0-rc4` | 'innodb'    |   string  | 支持的存储引擎类型.默认为`innodb`,此处可以设置多个,以逗号分隔,或者修改默认的存在引擎类型
diff --git a/session/core.go b/session/core.go
index 2b0e5463d..f87ef2152 100644
--- a/session/core.go
+++ b/session/core.go
@@ -497,6 +497,7 @@ func (s *session) checkOptions() error {
 
 	s.mysqlServerVersion()
 	s.setSqlSafeUpdates()
+	s.setLockWaitTimeout()
 
 	if s.opt.Backup && s.dbType == DBTypeTiDB {
 		s.appendErrorMessage("TiDB暂不支持备份功能.")
diff --git a/session/session_inception.go b/session/session_inception.go
index c096c14f4..1418f3c17 100644
--- a/session/session_inception.go
+++ b/session/session_inception.go
@@ -1873,6 +1873,26 @@ func (s *session) setSqlSafeUpdates() {
 	}
 }
 
+func (s *session) setLockWaitTimeout() {
+	log.Debug("setLockWaitTimeout")
+
+	var sql string
+	if s.inc.LockWaitTimeout > 0 {
+		sql = fmt.Sprintf("set session lock_wait_timeout=%d;", s.inc.LockWaitTimeout)
+	} else {
+		return
+	}
+
+	if _, err := s.exec(sql, true); err != nil {
+		log.Errorf("con:%d %v", s.sessionVars.ConnectionID, err)
+		if myErr, ok := err.(*mysqlDriver.MySQLError); ok {
+			s.appendErrorMessage(myErr.Message)
+		} else {
+			s.appendErrorMessage(err.Error())
+		}
+	}
+}
+
 func (s *session) checkBinlogIsOn() bool {
 	log.Debug("checkBinlogIsOn")
 
diff --git a/sessionctx/variable/sysvar.go b/sessionctx/variable/sysvar.go
index 90ac41af8..563c4cb3d 100644
--- a/sessionctx/variable/sysvar.go
+++ b/sessionctx/variable/sysvar.go
@@ -753,6 +753,8 @@ const (
 	ForeignKeyChecks = "foreign_key_checks"
 	// SQLSafeUpdates is the name for 'sql_safe_updates' system variable.
 	SQLSafeUpdates = "sql_safe_updates"
+	// LockWaitTimeout is the name for 'lock_wait_timeout' system variable.
+	LockWaitTimeout = "lock_wait_timeout"
 	// WarningCount is the name for 'warning_count' system variable.
 	WarningCount = "warning_count"
 	// ErrorCount is the name for 'error_count' system variable.