Delayed printf is a technique for low-overhead logging in real-time and embedded systems. Instead of formatting text at runtime, it stores the format string pointer and raw argument words into a compact buffer using C++11 variadic templates and an atomic fetch-and-add operation. A separate GDB Python script later reconstructs the formatted messages by reading strings from the executable or core dump. This approach supports logging from interrupt handlers and multiple threads without locks, and allows inspection of unflushed messages in live debug sessions or core dumps.
