Check MACH_PORT_VALID on return from pthread_mach_thread_np

[indragiek]

📜 Description

pthread_mach_thread_np can return invalid values so check for those and return nullptr from ThreadHandle. That means changing the call sites for ThreadHandle::current() to check for a null pointer value.

💡 Motivation and Context

We don't have a solid repro for #3354 but this is one of the potential causes. In any case it doesn't hurt to add the check.

💚 How did you test it?

Run tests

📝 Checklist

You have to check all boxes before merging:

• 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

[philipphofmann]

@indragiek, good catch 👍 . CI is broken, and it would be great to add or change some tests for these changes if possible.

[armcknight]

Reading the logic again in SentryBacktrace.cpp which contains the callsite for the function we've modified is a bit unclear to me, given the name allExcludingCurrent. Reading it starting at the loop, it looks like we're going to do work on all the other threads except the current one, which is true, but we do still have to retain the current thread in order to know what thread we're running on, and the callsite tells me we threw out that info when we actually didn't.

TL;DR I would propose we rename allExcludingCurrent to currentAndOtherThreads.

[philipphofmann]

Once we have some tests, I will approve this PR. The rest LGTM.

[codecov]

Codecov Report

Attention: Patch coverage is 81.13208% with 10 lines in your changes missing coverage. Please review.

Project coverage is 91.165%. Comparing base (1734d1b) to head (6fac4d6).
Report is 343 commits behind head on main.

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #3520       +/-   ##
=============================================
+ Coverage   89.241%   91.165%   +1.923%     
=============================================
  Files          529       609       +80     
  Lines        57780     47846     -9934     
  Branches     20687         0    -20687     
=============================================
- Hits         51564     43619     -7945     
+ Misses        5300      4227     -1073     
+ Partials       916         0      -916     

Files	Coverage Δ
Sources/Sentry/PrivateSentrySDKOnly.mm	90.714% <100.000%> (+3.558%)	⬆️
Sources/Sentry/SentryThreadHandle.cpp	62.727% <100.000%> (-6.504%)	⬇️
Sources/Sentry/SentryTransactionContext.mm	100.000% <100.000%> (ø)
...yCrash/Recording/Monitors/SentryCrashMonitorType.c	0.000% <ø> (ø)
...entryCrash/Recording/Tools/SentryCrashSignalInfo.c	100.000% <ø> (ø)
...sts/SentryProfilerTests/SentryThreadHandleTests.mm	95.789% <100.000%> (+2.932%)	⬆️
Tests/SentryTests/SentryCrash/CrashReport.swift	100.000% <100.000%> (+6.666%)	⬆️
Tests/SentryTests/SentryInterfacesTests.m	100.000% <100.000%> (ø)
...rding/Monitors/SentryCrashMonitor_CPPException.cpp	20.408% <0.000%> (-10.223%)	⬇️
Tests/SentryProfilerTests/SentryBacktraceTests.mm	95.744% <88.888%> (+0.939%)	⬆️
... and 2 more

... and 607 files with indirect coverage changes

---

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[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1208.50 ms	1221.08 ms	12.58 ms
Size	21.58 KiB	671.08 KiB	649.50 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
52e4912	1216.25 ms	1226.69 ms	10.44 ms
742d4b6	1230.41 ms	1247.23 ms	16.83 ms
297f460	1234.81 ms	1255.27 ms	20.45 ms
becc941	1221.90 ms	1240.37 ms	18.47 ms
340fb46	1224.60 ms	1239.27 ms	14.67 ms
3297d6e	1195.69 ms	1212.35 ms	16.65 ms
0d32275	1215.31 ms	1240.19 ms	24.88 ms
4d3df92	1218.27 ms	1248.30 ms	30.03 ms
b15521e	1224.44 ms	1251.13 ms	26.68 ms
e5dcbd5	1223.47 ms	1243.90 ms	20.43 ms

App size

Revision	Plain	With Sentry	Diff
52e4912	21.58 KiB	418.14 KiB	396.56 KiB
742d4b6	21.58 KiB	546.20 KiB	524.62 KiB
297f460	21.58 KiB	629.83 KiB	608.24 KiB
becc941	21.58 KiB	419.82 KiB	398.24 KiB
340fb46	21.58 KiB	418.78 KiB	397.20 KiB
3297d6e	21.58 KiB	418.44 KiB	396.86 KiB
0d32275	22.84 KiB	403.14 KiB	380.29 KiB
4d3df92	22.85 KiB	413.45 KiB	390.60 KiB
b15521e	21.58 KiB	573.18 KiB	551.60 KiB
e5dcbd5	22.85 KiB	414.09 KiB	391.24 KiB

[philipphofmann]

@armcknight, I guess after resolving the conflicts, I can review this?