sipherxyz/ue-memory-leak-hunter

UE Memory Leak Hunter

Analyze Unreal Engine memory reports to identify leaks, growth patterns, and optimization targets.

Quick Start

1. Generate memory report in editor/game: memreport -full
2. Provide the memreport file path
3. Get categorized analysis with actionable fixes

Workflow

Step 1: Collect Memory Data

Instruct user to generate memreport:

# In UE console
memreport -full

# Or for specific categories
memreport -class
memreport -obj

Default output: {Project}/Saved/Profiling/MemReports/

Step 2: Parse Memory Report

Read the memreport file and extract:

Object Count Section:

Class                          Count   NumBytes  MaxBytes  ResExcBytes  ResExcBytesMax
----------------------------------------------------------------------------------------------
Texture2D                      1523    892.45 MB ...
StaticMesh                     3421    456.78 MB ...
SkeletalMesh                   89      234.56 MB ...

Memory Pool Section:

FMalloc
    Used: 2.34 GB
    Peak: 2.89 GB
    Waste: 156 MB

Step 3: Analyze Patterns

Leak Indicators

| Pattern | Severity | Indicator | |---------|----------|-----------| | Object count growing over time | Critical | Compare sequential memreports | | Orphan UObjects without outer | High | Objects with Outer=None | | Pending kill objects not collected | High | Large PendingKill count | | Texture/Mesh duplicates | Medium | Same asset loaded multiple times | | Delegate binding growth | Medium | Multicast delegate arrays growing |

Memory Budget Violations

| Platform | Memory Budget | Alert Threshold | |----------|---------------|-----------------| | PS5 | 12 GB usable | >10 GB | | Xbox Series X | 13.5 GB usable | >11 GB | | PC (min spec) | 8 GB | >6 GB |

Step 4: Generate Report

Output format:

## Memory Analysis Report

### Executive Summary
- **Total Used**: {size}
- **Peak**: {peak}
- **Status**: {OK/WARNING/CRITICAL}

### Top Memory Consumers
| Rank | Class | Count | Size | % of Total |
|------|-------|-------|------|------------|
| 1 | {class} | {count} | {size} | {pct} |

### Leak Suspects
1. **{ClassName}** - {count} objects, {size}
   - Growth rate: +{n} per minute
   - Likely cause: {analysis}
   - Fix: {recommendation}

### Recommendations
1. {Priority 1 fix}
2. {Priority 2 fix}

Common Leak Patterns

1. Delegate Binding Leaks

// WRONG - Never unbound
BeginPlay() { SomeDelegate.AddDynamic(this, &MyClass::Handler); }

// CORRECT - Unbound in EndPlay
EndPlay() { SomeDelegate.RemoveDynamic(this, &MyClass::Handler); }

2. Timer Handle Leaks

// WRONG - Timer keeps reference
GetWorld()->GetTimerManager().SetTimer(Handle, this, &MyClass::Tick, 1.0f, true);

// CORRECT - Clear in EndPlay
EndPlay() { GetWorld()->GetTimerManager().ClearTimer(Handle); }

3. Async Load Leaks

// WRONG - Handle not stored
StreamableManager.RequestAsyncLoad(Path, Callback);

// CORRECT - Store and cancel
TSharedPtr<FStreamableHandle> Handle = StreamableManager.RequestAsyncLoad(Path, Callback);
// Cancel in destructor if still loading

4. Widget Leaks

// WRONG - Widget created but never removed
UUserWidget* W = CreateWidget<UUserWidget>(this, WidgetClass);
W->AddToViewport();

// CORRECT - Track and remove
if (ActiveWidget) { ActiveWidget->RemoveFromParent(); }
ActiveWidget = CreateWidget<UUserWidget>(this, WidgetClass);

Console Commands Reference

| Command | Purpose | |---------|---------| | memreport -full | Complete memory dump | | obj list class=Texture2D | List specific class | | obj gc | Force garbage collection | | gc.CollectGarbageEveryFrame 1 | Debug GC | | obj refs class=MyClass | Show references |

Integration with Project

For Huli/S2 project, check these common sources:

1. GAS Abilities: USipherGameplayAbility instances not ending properly
2. AI Characters: ASipherAICharacter pooling issues
3. VFX: Niagara systems not deactivating
4. Combo Graph: SipherComboGraph state accumulation
5. Hit Reactions: USipherHitReaction delegate leaks