Contributing

Project Rules

Keep the public C API compatible with C99.
Preserve fixed-capacity, caller-owned storage semantics.
Do not add heap allocation, OS or RTOS dependencies, hidden locks, or generated code systems.
Keep access serialized per manager unless callers provide external synchronization.
Do not weaken runtime tests or remove compile-fail tests.
Do not create tags or releases unless explicitly requested.

Prefer CMake for package and consumer verification.
The checked-in include/mtimer_config.h is the source-tree default; build and install trees use a generated resolved configuration header.
Timer callbacks return void; error propagation must happen through caller-managed state.
longjmp out of a callback is unsupported and may leave the active-tick guard set.