*: pass make race (pingcap#1617)

ddl/ddl_worker.go

@@ -252,7 +252,9 @@ func (d *ddl) handleDDLJobQueue() error {
 
 			log.Warnf("[ddl] run DDL job %v", job)
 
+			d.m.RLock()
 			d.hook.OnJobRunBefore(job)
+			d.m.RUnlock()
 
 			// if run job meets error, we will save this error in job Error
 			// and retry later if the job is not cancelled.
@@ -281,7 +283,9 @@ func (d *ddl) handleDDLJobQueue() error {
 			return nil
 		}
 
+		d.m.RLock()
 		d.hook.OnJobUpdated(job)
+		d.m.RUnlock()
 
 		// here means the job enters another state (delete only, write only, public, etc...) or is cancelled.
 		// if the job is done or still running, we will wait 2 * lease time to guarantee other servers to update

ddl/index_test.go

@@ -671,7 +671,9 @@ func (s *testIndexSuite) TestDropIndex(c *C) {
 		oldIndexCol = index
 	}
 
+	d.m.Lock()
 	d.hook = tc
+	d.m.Unlock()
 
 	// Use local ddl for callback test.
 	s.d.close()

server/server_test.go

@@ -16,6 +16,7 @@ package server
 import (
 	"database/sql"
 	"encoding/json"
+	"fmt"
 	"net/http"
 	"strings"
 	"testing"
@@ -329,12 +330,13 @@ func runTestStatusAPI(c *C) {
 
 func runTestMultiPacket(c *C) {
 	runTests(c, dsn, func(dbt *DBTest) {
-		dbt.mustExec("set global max_allowed_packet=167772160") // 160M
+		dbt.mustExec(fmt.Sprintf("set global max_allowed_packet=%d", 1024*1024*160)) // 160M
 	})
 
 	runTests(c, dsn, func(dbt *DBTest) {
 		dbt.mustExec("create table test (a longtext)")
-		for i := 0; i < 100; i++ {
+		// When i == 30, packet size will be 16777215(2^24−1) bytes.
+		for i := 30; i < 32; i++ {
 			dbt.mustExec("insert into test values ('" + strings.Repeat("x", 1024*1024*16-i) + "')")
 		}
 	})

server/tidb_test.go

@@ -10,6 +10,7 @@
 // distributed under the License is distributed on an "AS IS" BASIS,
 // See the License for the specific language governing permissions and
 // limitations under the License.
+// +build !race
 
 package server