[eventd] eventd unit test is not stable

[Junchao-Mellanox]

Description

There is statistical failure in eventd unit test:

16:10:15  [ RUN      ] eventd.proxy
16:10:15  Proxy TEST started
16:10:15  tests/eventd_ut.cpp:170: Failure
16:10:15  Expected equality of these values:
16:10:15    1
16:10:15    rc
16:10:15      Which is: 36
16:10:15  tests/eventd_ut.cpp:279: Failure
16:10:15  Expected equality of these values:
16:10:15    rd_cevts_sz
16:10:15      Which is: 6
16:10:15    wr_evts.size()
16:10:15      Which is: 5
16:10:15  eventd_proxy is tested GOOD
16:10:15  [  FAILED  ] eventd.proxy (1603 ms)

Steps to reproduce the issue:

1. build eventd

Describe the results you received:

eventd.proxy failed

Describe the results you expected:

no faillure

Output of show version:

commit hash: 7bdf8d4bb26709001cf95397c6a8e617986dd7fd

Output of show techsupport:

(paste your output here or download and attach the file here )

Additional information you deem important (e.g. issue happens only occasionally):

[anamehra]

We have also observed this error intermittently recently causing multiple build failures. It works with retyr most of the time but sometime requires multiple retires.

@abdosi , @yejianquan , for you viz

[zbud-msft]

PR fix: #21200, ETA for merge: 12/20

[zbud-msft]

Hi @Junchao-Mellanox, is it possible for you take changes in #21200 and see if there is any flakiness in eventd builds on your side? I have ran ~25 image builds and have not seen any flakiness with these changes.

[Junchao-Mellanox]

sure, will try