openharmonyinsight/skills/oh-stability/memoryLeak/dynamic-memory-analyzer

Dynamic Memory Analyzer

Comprehensive memory management analysis for ace_engine codebase covering 17 critical scenarios.

Quick Start

Use this skill to analyze memory management in ace_engine codebase:

1. Statistical Analysis - Get overview metrics

   • Run: bash scripts/stats.sh <target-directory>
   • Review the output statistics

2. Pattern Detection - Identify specific issues

   • See PATTERNS.md for detection rules
   • Execute relevant grep/awk commands from the patterns

3. Generate Report - Document findings

   • Use REPORT_TEMPLATE.md as guide
   • Apply recommendations from FIXES.md

Core Scenarios

1. Basic Pairing

• new/delete pairing
• new[]/delete[] pairing
• Execution path coverage

2. Smart Pointers

• RefPtr usage patterns
• WeakPtr for cycles
• Raw/RefPtr mixing

3. Exception Safety

• Exception paths
• RAII patterns
• Try-catch coverage

4. Ownership Transfer

• Function returns
• Parameter passing
• Cross-module transfer

5. Container Pointers

• STL containers
• Cleanup logic
• Iterator safety

6. Singletons

• Singleton leaks
• Global pointers
• Static members

7. Callbacks

• EventHub callbacks
• Lambda captures
• Async cleanup

8. Multi-threading

• Cross-thread pointers
• Async tasks
• Thread-safe delete

9. Cross-layer

• Bridge layer
• FrameNode/UINode
• Pattern/RenderNode

10. Third-party

• Rosen pointers
• Skia pointers
• V8/ArkTS pointers

11. Special Patterns

• Factory pattern
• Builder pattern
• Observer pattern

12. Common Leaks

• Constructor/destructor
• Conditional branches
• Exception paths
• Loop issues

13. nullptr Handling

• delete nullptr safety
• Unnecessary checks
• new(std::nothrow)

14. Register/Unregister

• Registration pairing
• Exception safety
• Duplicate handling

15. Lifecycle Binding

• Parent/child cleanup
• Circular references
• FrameNode lifecycle

16. Assignment Updates

• Member assignment
• Exception safety
• Self-assignment

17. Function Returns

• Early returns
• Multiple paths
• CheckNull cleanup

Detailed Guidance

Statistical Analysis

See STATISTICS.md for comprehensive metrics and interpretation.

Pattern Detection

See PATTERNS.md for detection rules and examples.

Fix Recommendations

See FIXES.md for code examples and best practices.

Report Template

See REPORT_TEMPLATE.md for report structure.

Severity Levels

• 🔴 Critical: Definite leaks, double delete, use-after-free
• 🟠 High: Likely leaks, exception-unsafe, missing cleanup
• 🟡 Medium: Potential leaks, unclear ownership, inconsistent patterns
• 🟢 Low: Style issues, unnecessary checks, documentation gaps

Tools

Static Analysis

# clang-tidy
clang-tidy --checks=-*,clang-analyzer-* frameworks/**/*.cpp

# cppcheck
cppcheck --enable=all frameworks/

# Custom scripts
bash scripts/stats.sh
bash scripts/detect_patterns.sh

Runtime Detection

# AddressSanitizer
ASAN_OPTIONS=detect_leaks=1 ./test_executable

# LeakSanitizer
LSAN_OPTIONS=suppressions=lsan.supp ./test_executable

# Valgrind
valgrind --leak-check=full ./test_executable

Best Practices

✅ Always Do

• Use RefPtr/WeakPtr for ownership
• Use MakeRefPtr for creation
• Use CHECK_NULL_* macros
• Implement proper destructors
• Use RAII for resources
• Document ownership for returns
• Use WeakPtr to break cycles

❌ Never Do

• Delete RefPtr-managed pointers
• Forget to delete raw pointers
• Use delete instead of delete[]
• Mix raw/RefPtr without clear ownership
• Skip delete on exception paths
• Create RefPtr cycles
• Assume third-party ownership

⚠️ Be Careful

• Exception safety in new/delete pairs
• Ownership transfer across boundaries
• Callback memory management
• Cross-thread pointer sharing
• Container pointer cleanup
• Third-party library ownership