unstable test in testPrepareSerialSuite.TestPrepareCache

[zhouqiang-cl]

Bug Report

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2021-06-22T14:28:16.669Z] FAIL: prepare_test.go:53: testPrepareSerialSuite.TestPrepareCache

[2021-06-22T14:28:16.669Z] 

[2021-06-22T14:28:16.669Z] prepare_test.go:138:

[2021-06-22T14:28:16.669Z]     ...

[2021-06-22T14:28:16.669Z] /home/jenkins/agent/workspace/tidb-unit-test-nightly/go/src/github.com/pingcap/tidb/util/testleak/leaktest.go:168:

[2021-06-22T14:28:16.669Z]     c.Errorf("Test %s check-count %d appears to have leaked: %v", c.TestName(), cnt, g)

[2021-06-22T14:28:16.669Z] ... Error: Test testPrepareSerialSuite.TestPrepareCache check-count 50 appears to have leaked: github.com/pingcap/tidb/domain.(*Domain).globalBindHandleWorkerLoop.func1(0xc39b7094a0)

[2021-06-22T14:28:16.669Z] 	/home/jenkins/agent/workspace/tidb-unit-test-nightly/go/src/github.com/pingcap/tidb/domain/domain.go:1005 +0x12a

[2021-06-22T14:28:16.669Z] created by github.com/pingcap/tidb/domain.(*Domain).globalBindHandleWorkerLoop

[2021-06-22T14:28:16.669Z] 	/home/jenkins/agent/workspace/tidb-unit-test-nightly/go/src/github.com/pingcap/tidb/domain/domain.go:996 +0x5f

[2021-06-22T14:28:16.669Z] 

[2021-06-22T14:28:16.669Z] 

1. Minimal reproduce step (Required)

in ci https://ci.pingcap.net/blue/organizations/jenkins/tidb-unit-test-nightly/detail/tidb-unit-test-nightly/1731/pipeline

2. What did you expect to see? (Required)

3. What did you see instead (Required)

4. What is your TiDB version? (Required)

master

[zimulala]

PTAL @winoros

[ti-srebot]

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