This article explains the architecture of Mach virtual memory in iOS, details its page‑based management, describes the core data structures and kernel APIs, analyzes the Objective‑C alloc implementation, and walks through the memory‑pressure (Jetsam) mechanism that triggers low‑memory warnings.
The article explains how iOS/macOS uses the XNU kernel's Mach micro‑kernel to represent processes, tasks and threads, describes the relationship between them, classifies hardware and software exceptions, shows how Mach exceptions are translated into Unix signals, and provides practical code examples for capturing both Mach exceptions and signals in a crash‑reporting framework.
This article provides an in‑depth technical overview of iOS RunLoop, explaining its relationship to threads, event loops, RunLoop modes, sources, timers, observers, and the underlying Mach message mechanisms, while including original source code excerpts for reference.
This article introduces the macOS vmmap utility, explains why a lightweight version was re‑implemented for iOS, and details the step‑by‑step code that obtains task handles, region data, dyld image information, formats and prints memory maps to aid reverse‑engineering on iOS devices.
