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.

PROF-13688

[datadog-official]

⚠️ Tests

✨ Fix all issues with Cursor

⚠️ Warnings

🧪 1028 Tests failed

    ❄️ Known flaky: Endpoints are sent() from com.datadog.appsec.php.integration.Laravel8xTests (Fix with Cursor)

    ❄️ Known flaky: Endpoints are sent() from com.datadog.appsec.php.integration.Symfony62Tests (Fix with Cursor)

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

DDTrace\Tests\Integration\PHPInstallerTest::testSearchPhpBinaries
Test code or tested code printed unexpected output: Searching for available php binaries, this operation might take a while.

View all

ℹ️ Info

❄️ No new flaky tests detected

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 91f9d71 | Docs | Datadog PR Page | Was this helpful? Give us feedback!}

[pr-commenter]

Benchmarks [ profiler ]

Benchmark execution time: 2026-02-12 08:02:42

Comparing candidate commit 91f9d71 in PR branch florian/heap-live-profiling with baseline commit de9c414 in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 27 metrics, 9 unstable metrics.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 62.20%. Comparing base (de9c414) to head (91f9d71).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3623      +/-   ##
==========================================
+ Coverage   62.11%   62.20%   +0.08%     
==========================================
  Files         141      141              
  Lines       13387    13387              
  Branches     1753     1753              
==========================================
+ Hits         8315     8327      +12     
+ Misses       4273     4263      -10     
+ Partials      799      797       -2     

see 2 files with indirect coverage changes

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[pr-commenter]

Benchmarks [ tracer ]

Benchmark execution time: 2026-02-06 08:47:53

Comparing candidate commit 49b5835 in PR branch florian/heap-live-profiling with baseline commit 6843f96 in branch master.

Found 1 performance improvements and 4 performance regressions! Performance is the same for 186 metrics, 3 unstable metrics.

scenario:ComposerTelemetryBench/benchTelemetryParsing

• 🟩 execution_time [-1.897µs; -1.103µs] or [-14.823%; -8.614%]

scenario:SamplingRuleMatchingBench/benchRegexMatching1

• 🟥 execution_time [+112.809ns; +149.391ns] or [+9.856%; +13.052%]

scenario:SamplingRuleMatchingBench/benchRegexMatching2

• 🟥 execution_time [+102.670ns; +152.930ns] or [+8.935%; +13.309%]

scenario:SamplingRuleMatchingBench/benchRegexMatching3

• 🟥 execution_time [+76.869ns; +117.931ns] or [+6.586%; +10.105%]

scenario:SamplingRuleMatchingBench/benchRegexMatching4

• 🟥 execution_time [+108.622ns; +151.178ns] or [+9.463%; +13.171%]