C++ Runtime Jun 2026

Freestanding and exceptions: failfast with STL codebase? : r/cpp

(simplified for a class hierarchy A <- B ): c++ runtime

Understanding the runtime is crucial for writing performant software, debugging complex memory issues, and grasping how C++ differs from languages like C or Rust. Freestanding and exceptions: failfast with STL codebase

Windows uses a linked list of exception registration records on the stack ( fs:[0] on x86, __except_list on x64). Each function prolog pushes a EHRegistrationNode that points to a handler. The runtime ( RtlUnwind ) walks this list. The cost is similar: zero overhead in normal execution but complex metadata for each function containing try/catch blocks. Each function prolog pushes a EHRegistrationNode that points

Global objects with non‑constant initializers are constructed before main . The order across translation units is (the “static initialization order fiasco”). To mitigate this, the runtime uses:

The __cxa_guard_acquire function uses an atomic compare‑and‑swap and a mutex or futex to ensure only one thread constructs the object.