session: Add failpoint session/beforeLoockKeys

[MyonKeminta]

What problem does this PR solve?

Problem Summary: Currently it's not very easy to construct a case in test that can stably get Running state transactions in TIDB_TRX tables. This PR adds a failpoint at a place just before starting acquiring locks. This helps in integration tests.

What is changed and how it works?

What's Changed: Adds failpoint github.com/pingcap/tidb/session/beforeLockKeys

Check List

Tests

• Integration test

Side effects

• None
  Documentation

• None

Release note

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• cfzjywxk
• longfangsong

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[longfangsong]

Currently it's not very easy to construct a case in test that can stably get Running state transactions in TIDB_TRX tables.

Can github.com/pingcap/tidb/session/mockStmtSlow (though might need a better name) archieve this goal?

[MyonKeminta]

Currently it's not very easy to construct a case in test that can stably get Running state transactions in TIDB_TRX tables.

Can github.com/pingcap/tidb/session/mockStmtSlow (though might need a better name) archieve this goal?

Its problem is that it also blocks the query to TIDB_TRX.

[cfzjywxk]

LGTM

[MyonKeminta]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 1878448

[ti-chi-bot]

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[ti-srebot]

cherry pick to release-5.2 in PR #27341