fix(profiler): initialize memory collector until after libdatadog

[sanchda]

The current implementation of this system has a pretty negligent state initialization sequence.

In particular, the memory allocation profiler relies on libdatadog in some circumstances, and should be initialized after it.

Checklist

• [X] PR author has checked that all the criteria below are met
• The PR description includes an overview of the change
• The PR description articulates the motivation for the change
• The change includes tests OR the PR description describes a testing strategy
• The PR description notes risks associated with the change, if any
• Newly-added code is easy to change
• The change follows the library release note guidelines
• The change includes or references documentation updates if necessary
• Backport labels are set (if applicable)

Reviewer Checklist

• [ ] Reviewer has checked that all the criteria below are met
• Title is accurate
• All changes are related to the pull request's stated goal
• Avoids breaking API changes
• Testing strategy adequately addresses listed risks
• Newly-added code is easy to change
• Release note makes sense to a user of the library
• If necessary, author has acknowledged and discussed the performance implications of this PR as reported in the benchmarks PR comment
• Backport labels are set in a manner that is consistent with the release branch maintenance policy

[github-actions[bot]]

CODEOWNERS have been resolved as:

ddtrace/releasenotes/notes/fix-profiler-memalloc-init-f097d604fb2af519.yaml  @DataDog/apm-python
ddtrace/profiling/profiler.py                                           @DataDog/profiling-python

[pr-commenter[bot]]

Benchmarks

Benchmark execution time: 2024-11-18 17:59:57

Comparing candidate commit 7ac81aa13181dd861dd5f06b4ba16d9a88c463fe in PR branch sanchda/fix_memalloc_init with baseline commit 343ba22bbe4010edb9206950fca5dc21c35d3d58 in branch main.

Found 3 performance improvements and 0 performance regressions! Performance is the same for 385 metrics, 2 unstable metrics.

scenario:iast_aspects-ospathnormcase_aspect

• 🟩 execution_time [-236.396ns; -201.062ns] or [-8.906%; -7.575%]

scenario:iast_aspects-replace_aspect

• 🟩 execution_time [-595.803ns; -537.658ns] or [-8.256%; -7.450%]

scenario:iast_aspects-split_aspect

• 🟩 execution_time [-182.833ns; -145.773ns] or [-10.006%; -7.978%]

[juanjux]

Only semi-related, you can mostly ignore this: When reading Collector I thought this was an implementation of some unused/free memory collector, not a class to get memory data, maybe MemorySampler or something similar would be a better name?