dotnet/runtime

Audit usages of Marshal.AllocHGlobal for ones that can be replaced with NativeMemory.Alloc

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#54,297 opened on Jun 16, 2021

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area-Interop-coreclrhelp wanted

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Description

#54006 introduced new NativeMemory APIs that wrap malloc, calloc, realloc, and aligned_alloc. We should audit existing usages of Marshal.AllocHGlobal for cases where it can be safely replaced with malloc.

Notably cases like StringToPtrHGlobal do not qualify as they are documented to be a call to LocalAlloc on Windows. However, on Unix and in cases where this is not a definitive contract, it should be safe to replace these calls with faster ones to NativeMemory.

Contributor guide

Research direction
Examine each usage of Marshal.AllocHGlobal in the codebase, identify those that are not on Windows or not documented as LocalAlloc, and replace with NativeMemory.Alloc where safe, then verify performance and correctness.
Tech stack
csharp
Domain
performance
Issue type
Refactor
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Mostly clear
Prerequisites
Git
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60