test: fix TestTaskError and TestMultiError flaky tests

[Rustin170506]

What problem does this PR solve?

close https://github.com/pingcap/ticdc/issues/2469

What is changed and how it works?

In one case, it did happen that isCancelled was used to the next event before it was updated, and ErrCh immediately received an error, just as cancel was called during the execution of AddEvent, which is why I encountered this unstable test. I was able to reproduce the problem occasionally after increasing the number of events and limiting resources locally.

Check List

Tests

• Unit test

Code changes

None

Side effects

None

Related changes

• Need to cherry-pick to the release branch

Release note

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• amyangfei
• overvenus

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[overvenus]

LGTM, could you check if we have handle context canceled error properly when we call AddEvent in other files?

[ben1009]

/run-integration-tests
/run-kafka-tests

[ben1009]

/run-integration-tests
/run-kafka-tests

[Rustin170506]

/hold

[Rustin170506]

LGTM, could you check if we have handle context canceled error properly when we call AddEvent in other files?

@overvenus It looks like calls elsewhere will return this error directly.

[Rustin170506]

@amyangfei @ben1009 I think it ready for review.
Could you please take a look? Thanks!

[Rustin170506]

I have tested this many times by limiting resources to 1C locally and it works.

[Rustin170506]

/unhold

[ti-chi-bot]

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

Commit hash: b5fb17d

[Rustin170506]

/run-unit-tests

[Rustin170506]

/run-kafka-tests

[Rustin170506]

/run-integration-tests

[Rustin170506]

/run-kafka-tests

[Rustin170506]

/run-integration-tests

[Rustin170506]

/run-integration-tests
/run-kafka-tests

[Rustin170506]

/run-all-tests

[codecov-commenter]

Codecov Report

Merging #2779 (3795a2e) into master (11e574c) will increase coverage by 1.5274%.
The diff coverage is 55.4627%.

@@               Coverage Diff                @@
##             master      #2779        +/-   ##
================================================
+ Coverage   55.3406%   56.8681%   +1.5274%     
================================================
  Files           164        180        +16     
  Lines         19754      18877       -877     
================================================
- Hits          10932      10735       -197     
+ Misses         7790       7174       -616     
+ Partials       1032        968        -64     

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #2817.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #2818.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #2819.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #2820.