ddl: make test stable (#3091)

ddl/reorg_test.go

@@ -60,25 +60,27 @@ func (s *testDDLSuite) TestReorg(c *C) {
 	err = ctx.Txn().Commit()
 	c.Assert(err, IsNil)
 
-	done := make(chan struct{})
 	rowCount := int64(10)
 	f := func() error {
 		d.setReorgRowCount(rowCount)
 		time.Sleep(4 * testLease)
-		close(done)
 		return nil
 	}
 	job := &model.Job{}
 	err = d.runReorgJob(job, f)
 	c.Assert(err, NotNil)
 
-	<-done
-	// Make sure the function of f is returned.
-	time.Sleep(5 * time.Millisecond)
-	err = d.runReorgJob(job, f)
+	// The longest to wait for 5 seconds to make sure the function of f is returned.
+	for i := 0; i < 1000; i++ {
+		time.Sleep(5 * time.Millisecond)
+		err = d.runReorgJob(job, f)
+		if err == nil {
+			c.Assert(job.RowCount, Equals, rowCount)
+			c.Assert(d.reorgRowCount, Equals, int64(0))
+			break
+		}
+	}
 	c.Assert(err, IsNil)
-	c.Assert(job.RowCount, Equals, rowCount)
-	c.Assert(d.reorgRowCount, Equals, int64(0))
 
 	d.Stop()
 	err = d.runReorgJob(job, func() error {