Fixed race condition between StartETW() and StopETW()

[iglendd]

The fix is based on the few following facts

• StartETW() will be block on call to C.StartEtwSubscription()
• StartETW() will be unblocked by call StopETW() and specifically C.StopEtwSubscription()
• etwCallbackC() will not be invoked after ETW session is stopped (C.StopEtwSubscription() is completed and C.StartEtwSubscription() is unllocked)

What does this PR do?

Fixes race condition in the ETW package by adding mutex for access a global map.

Motivation

Fix the bug

Additional Notes

n/a

Possible Drawbacks / Trade-offs

n/a

Describe how to test/QA your changes

Make sure that all unit and kitchen tests are passing.

Reviewer's Checklist

• If known, an appropriate milestone has been selected; otherwise the Triage milestone is set.
• Use the major_change label if your change either has a major impact on the code base, is impacting multiple teams or is changing important well-established internals of the Agent. This label will be use during QA to make sure each team pay extra attention to the changed behavior. For any customer facing change use a releasenote.
• A release note has been added or the changelog/no-changelog label has been applied.
• Changed code has automated tests for its functionality.
• Adequate QA/testing plan information is provided. Except if the qa/skip-qa label, with required either qa/done or qa/no-code-change labels, are applied.
• At least one team/.. label has been applied, indicating the team(s) that should QA this change.
• If applicable, docs team has been notified or an issue has been opened on the documentation repo.
• If applicable, the need-change/operator and need-change/helm labels have been applied.
• If applicable, the k8s/<min-version> label, indicating the lowest Kubernetes version compatible with this feature.
• If applicable, the config template has been updated.

[pr-commenter]

Bloop Bleep... Dogbot Here

Regression Detector Results

Run ID: a450e818-b10e-450a-96ad-782d00d600bd
Baseline: 351a7fa
Comparison: 7c1e756
Total CPUs: 7

Performance changes are noted in the perf column of each table:

• ✅ = significantly better comparison variant performance
• ❌ = significantly worse comparison variant performance
• ➖ = no significant change in performance

No significant changes in experiment optimization goals

Confidence level: 90.00%
Effect size tolerance: |Δ mean %| ≥ 5.00%

There were no significant changes in experiment optimization goals at this confidence level and effect size tolerance.

Experiments ignored for regressions

Regressions in experiments with settings containing erratic: true are ignored.

perf	experiment	goal	Δ mean %	Δ mean % CI
➖	file_tree	memory utilization	+0.28	[+0.18, +0.38]
➖	idle	memory utilization	-0.09	[-0.14, -0.04]
➖	file_to_blackhole	% cpu utilization	-0.18	[-6.71, +6.34]

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI
➖	process_agent_standard_check_with_stats	memory utilization	+0.48	[+0.43, +0.54]
➖	file_tree	memory utilization	+0.28	[+0.18, +0.38]
➖	process_agent_real_time_mode	memory utilization	+0.05	[+0.01, +0.10]
➖	trace_agent_json	ingress throughput	+0.03	[+0.01, +0.06]
➖	trace_agent_msgpack	ingress throughput	+0.02	[+0.00, +0.03]
➖	uds_dogstatsd_to_api	ingress throughput	+0.00	[-0.03, +0.03]
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.00	[-0.06, +0.06]
➖	idle	memory utilization	-0.09	[-0.14, -0.04]
➖	file_to_blackhole	% cpu utilization	-0.18	[-6.71, +6.34]
➖	process_agent_standard_check	memory utilization	-0.19	[-0.25, -0.13]
➖	otel_to_otel_logs	ingress throughput	-0.41	[-1.12, +0.31]
➖	tcp_syslog_to_blackhole	ingress throughput	-0.65	[-0.71, -0.60]
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	-1.00	[-2.39, +0.39]

Explanation

A regression test is an A/B test of target performance in a repeatable rig, where "performance" is measured as "comparison variant minus baseline variant" for an optimization goal (e.g., ingress throughput). Due to intrinsic variability in measuring that goal, we can only estimate its mean value for each experiment; we report uncertainty in that value as a 90.00% confidence interval denoted "Δ mean % CI".

For each experiment, we decide whether a change in performance is a "regression" -- a change worth investigating further -- if all of the following criteria are true:

1. Its estimated |Δ mean %| ≥ 5.00%, indicating the change is big enough to merit a closer look.

2. Its 90.00% confidence interval "Δ mean % CI" does not contain zero, indicating that if our statistical model is accurate, there is at least a 90.00% chance there is a difference in performance between baseline and comparison variants.

3. Its configuration does not mark it "erratic".

[julien-lebot]

/merge

[dd-devflow]

🚂 MergeQueue

This merge request is not mergeable yet, because of pending checks/missing approvals. It will be added to the queue as soon as checks pass and/or get approvals.
Note: if you pushed new commits since the last approval, you may need additional approval.
You can remove it from the waiting list with /remove command.

Use /merge -c to cancel this operation!

[dd-devflow]

🚂 MergeQueue

Added to the queue.

This build is going to start soon! (estimated merge in less than 47m)

Use /merge -c to cancel this operation!

[pducolin]

❓ question
Should this be len(subs) ?

[iglendd]

Yes!!! Thank you, creating another PR