Timer Patterns Reference

Complete API reference for iOS timer mechanisms — Timer, DispatchSourceTimer, Combine Timer.publish, AsyncTimerSequence, and Task.sleep.

When to Use This Reference

Use this reference when:

• Looking up specific timer API syntax or parameters
• Understanding DispatchSourceTimer lifecycle state machine
• Choosing the right timer API for your use case
• Checking platform availability for timer APIs
• Debugging timer behavior with LLDB commands

Example Prompts

• "What's the API for Timer.publish in Combine?"
• "How do I schedule a DispatchSourceTimer with leeway?"
• "What RunLoop modes are available for Timer?"
• "How do I use ContinuousClock.timer for async polling?"
• "What's the platform availability for AsyncTimerSequence?"

What's Covered

• Timer API (scheduledTimer, tolerance, RunLoop modes, invalidate lifecycle)
• DispatchSourceTimer API (makeTimerSource, schedule, activate, suspend/resume/cancel, state machine)
• Combine Timer (Timer.publish, autoconnect, RunLoop mode parameter)
• AsyncTimerSequence (ContinuousClock.timer, SuspendingClock.timer, structured concurrency)
• Task.sleep patterns (one-shot delays vs repeating timers)
• LLDB timer inspection commands
• Platform availability matrix

Documentation Scope

This page documents the axiom-timer-patterns-ref skill — the API reference Claude uses for timer syntax and lifecycle details.

For decision trees and crash prevention: See Timer Safety Patterns for when to use which timer API and how to prevent DispatchSourceTimer crashes.

Related

• Timer Safety Patterns — Decision trees, crash patterns, SafeDispatchTimer wrapper (use this for "which timer should I use?" questions)
• Energy Optimization — Timer as energy subsystem (tolerance, coalescing)
• Memory Debugging — Timer retain cycle as leak pattern

Resources

Skills: axiom-timer-patterns, axiom-energy-ref, axiom-memory-debugging