PoC: feat(profiling): add heap-live profiling for memory leak detection

[realFlowControl]

Warning

do not merge, this is PoC

Description

Track allocations that survive across profile exports using heap-live-samples and heap-live-size sample types. Samples are emitted in batches at export time.

Enable via DD_PROFILING_HEAP_LIVE_ENABLED or datadog.profiling.heap_live_enabled (default disabled), only works when allocation profiling is active.

Reviewer checklist

• Test coverage seems ok.
• Appropriate labels assigned.

[datadog-official]

⚠️ Tests

✨ Fix all issues with Cursor

⚠️ Warnings

🧪 1024 Tests failed

    testSearchPhpBinaries from integration.DDTrace\Tests\Integration\PHPInstallerTest (Fix with Cursor)

    testSimplePushAndProcess from laravel-58-test.DDTrace\Tests\Integrations\Laravel\V5_8\QueueTest (Fix with Cursor)

testSimplePushAndProcess from laravel-8x-test.DDTrace\Tests\Integrations\Laravel\V8_x\QueueTest (Datadog) (Fix with Cursor)

DDTrace\Tests\Integrations\Laravel\V8_x\QueueTest::testSimplePushAndProcess
Test code or tested code printed unexpected output: spanLinksTraceId: 6983b6fb000000003d83b3fea91105ff
tid: 6983b6fb00000000
hexProcessTraceId: 3d83b3fea91105ff
hexProcessSpanId: dc12bb8a2844335b
processTraceId: 4432584364602230271
processSpanId: 15857943439980376923

View all

ℹ️ Info

❄️ No new flaky tests detected

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 817465a | Docs | Datadog PR Page | Was this helpful? Give us feedback!}

[pr-commenter]

Benchmarks [ profiler ]

Benchmark execution time: 2026-02-04 21:17:07

Comparing candidate commit 817465a in PR branch florian/heap-live-profiling with baseline commit 6843f96 in branch master.

Found 1 performance improvements and 3 performance regressions! Performance is the same for 26 metrics, 6 unstable metrics.

scenario:php-profiler-exceptions-with-profiler

• 🟥 cpu_user_time [+14.699ms; +18.148ms] or [+20.519%; +25.335%]
• 🟥 execution_time [+15.690ms; +18.446ms] or [+16.702%; +19.635%]

scenario:php-profiler-exceptions-with-profiler-and-timeline

• 🟥 execution_time [+13.742ms; +16.398ms] or [+14.016%; +16.723%]

scenario:walk_stack/1

• 🟩 wall_time [-273.753ns; -269.156ns] or [-2.155%; -2.118%]

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 62.20%. Comparing base (6843f96) to head (817465a).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3623      +/-   ##
==========================================
- Coverage   62.21%   62.20%   -0.02%     
==========================================
  Files         141      141              
  Lines       13387    13387              
  Branches     1753     1753              
==========================================
- Hits         8329     8327       -2     
- Misses       4260     4263       +3     
+ Partials      798      797       -1     

see 1 file with indirect coverage changes

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 6843f96...817465a. Read the comment docs.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.