Memory Debugging

Systematic memory leak diagnosis with Instruments. 5 leak patterns covering 90% of real-world issues.

When to use: App memory grows over time, seeing multiple instances of same class, crashes with memory limit exceeded, Instruments shows retain cycles

Key Features

• 5 comprehensive leak patterns
  • Delegate retain cycles
  • Closure capture cycles
  • Observer leaks
  • Cache accumulation
  • View controller leaks
• Instruments workflow (Leaks + Allocations)
• Stack trace analysis
• Quick diagnostic questions
• Reduces debugging from 2-3 hours to 15-30 min

Philosophy: Memory leaks follow predictable patterns. Systematic diagnosis is faster than trial-and-error.

Example Prompts

These are real questions developers ask that this skill answers:

• "My app crashes after 10-15 minutes of use but there are no error messages." → Covers systematic Instruments workflows to identify memory leaks vs normal memory pressure

• "I'm seeing memory jump from 50MB to 200MB+. Is this a leak or normal caching?" → Distinguishes between progressive leaks (continuous growth) and temporary spikes (caches that stabilize)

• "View controllers don't seem to be deallocating after dismiss. How do I find the retain cycle?" → Demonstrates Memory Graph Debugger to identify objects holding strong references

• "I have timers/observers and think they're leaking. How do I verify?" → Covers the 5 diagnostic patterns including timer and observer leak signatures

• "My app uses 200MB and I don't know if that's normal or multiple leaks." → Provides Instruments decision tree to distinguish normal memory use from actual leaks