ahrightos-process

ahrightos-process contains the portable process-management primitives used by the AhRightOS teaching kernel: PID allocation, saved contexts, process control blocks, process states, and the round-robin scheduler.

The crate is no_std outside tests and intentionally avoids QEMU-specific entry code, so students can unit-test process behavior on the host before booting the full kernel.

ProcessContext publishes layout constants used by the RISC-V context-switch assembly, and the crate tests assert that the ABI offsets stay stable.

Lifecycle contracts

• Parent child lists are de-duplicated so repeated bookkeeping cannot create phantom children.
• RoundRobinScheduler::find_zombie_child is the reap path used by wait.
• has_living_children intentionally excludes zombies: a zombie is reapable state, not a runnable/blocking child. This prevents wait from blocking after all remaining children have exited.
• Kernel ELF loading now rejects non-ET_EXEC files and entry points outside PT_LOAD segments; AhRightOS does not claim a full Linux execve model yet.

flowchart LR
    Kernel[ahrightos-kernel] --> Process[ahrightos-process]
    Process --> PID[ProcessId]
    Process --> PCB[ProcessControlBlock]
    Process --> Context[ProcessContext]
    Process --> Scheduler[RoundRobinScheduler]