Add thread information when a span is created

[markushi]

📜 Description

Add thread.id and thread.name to the span context.

💡 Motivation and Context

Fixes #2997

💚 How did you test it?

Add Unit test

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

🔮 Next steps

[github-actions]

	Fails
🚫	Please consider adding a changelog entry for the next release.

	Messages
📖	Do not forget to update Sentry-docs with your feature once the pull request gets approved.

Instructions and example for changelog

Please add an entry to CHANGELOG.md to the "Unreleased" section. Make sure the entry includes this PR's number.

Example:

## Unreleased

- Add thread information when a span is created ([#2998](https://github.com/getsentry/sentry-java/pull/2998))

If none of the above apply, you can opt out of this check by adding #skip-changelog to the PR description.

Generated by 🚫 dangerJS against ce0469b

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	399.27 ms	485.84 ms	86.57 ms
Size	1.72 MiB	2.29 MiB	576.75 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
c7e2fbc	372.00 ms	461.71 ms	89.71 ms
bc4be3b	360.40 ms	435.04 ms	74.64 ms
0bf143e	368.35 ms	437.47 ms	69.12 ms
86f0096	368.63 ms	446.92 ms	78.29 ms
99a51e2	405.11 ms	479.65 ms	74.54 ms
7ca9895	364.31 ms	460.46 ms	96.15 ms
c7e2fbc	393.98 ms	478.24 ms	84.27 ms
c7e2fbc	377.85 ms	426.35 ms	48.50 ms
86f0096	371.86 ms	439.78 ms	67.92 ms
4bf95dd	345.96 ms	414.24 ms	68.28 ms

App size

Revision	Plain	With Sentry	Diff
c7e2fbc	1.72 MiB	2.29 MiB	576.40 KiB
bc4be3b	1.72 MiB	2.29 MiB	576.53 KiB
0bf143e	1.72 MiB	2.29 MiB	576.50 KiB
86f0096	1.72 MiB	2.29 MiB	576.50 KiB
99a51e2	1.72 MiB	2.29 MiB	576.34 KiB
7ca9895	1.72 MiB	2.29 MiB	576.51 KiB
c7e2fbc	1.72 MiB	2.29 MiB	576.40 KiB
c7e2fbc	1.72 MiB	2.29 MiB	576.40 KiB
86f0096	1.72 MiB	2.29 MiB	576.50 KiB
4bf95dd	1.72 MiB	2.29 MiB	576.40 KiB

Previous results on branch: feat/starfish-span-mainthread-flag

Startup times

Revision	Plain	With Sentry	Diff
2f17022	376.33 ms	463.83 ms	87.50 ms
f9cd2b8	382.38 ms	455.80 ms	73.42 ms
2e5b9df	373.00 ms	445.30 ms	72.30 ms

App size

Revision	Plain	With Sentry	Diff
2f17022	1.72 MiB	2.29 MiB	576.71 KiB
f9cd2b8	1.72 MiB	2.29 MiB	576.55 KiB
2e5b9df	1.72 MiB	2.29 MiB	576.55 KiB

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Files	Coverage Δ
sentry/src/main/java/io/sentry/SentryTracer.java	95.07% <100.00%> (+0.08%)	⬆️

📢 Thoughts on this report? Let us know!.

[romtsn]

Did we agree to use the same blocked_main_thread key? I'd rather us choose something different, because we don't know for sure if it blocked the main thread, we know that it was just started there? Also, if we pick a different key, the current behavior for File I/O or DB spans will remain the same with blocked_main_thread.

[markushi]

Nope, this wasn't discussed yet - thanks for bringing this up. @shruthilayaj I think Roman has some good points here, would it make sense for you as well to have a separate flag for main thread flagging?

[shruthilayaj]

Yes, it makes sense to have these as separate flags!

[markushi]

A bit lengthy, but how about started_on_main_thread? Would also make it clear that the flag is determined on span start.

[romtsn]

This rfc https://github.com/getsentry/rfcs/pull/75/files got merged just a couple of days ago, so we probably should adhere to what is defined there. Here's the develop docs PR which adds the the new keys to the span data conventions getsentry/develop#1056, which means we have to send thread.id and thread.name, how does that sounds @shruthilayaj @markushi ?

[philipphofmann]

h: I just wanted to make the same comment ⬆️ . Thanks @romtsn.

[shruthilayaj]

👍
just to confirm, sending thread.id and thread.name in addition to started_on_main_thread flag right?

[romtsn]

mm, since in the RFC we say it's the thread the span originated from, I think thread.name: main would be the same thing pretty much, so we don't need both flags?

[shruthilayaj]

yeah makes sense, and will thread name always be standardized to main if it started on the main thread regardless of the SDK it's coming from? (just so we know if we just look for main or need to maintain some sort of map/allow list for extracting this info in relay)

[romtsn]

I'd start with just main, I guess we can expand it later. We can ensure that it's called main from the SDKs side