Module task 

The one Windows login task that keeps a managed WSL distribution alive, and the four operations on it: render, register, query, remove.

What the task promises, and what it does not

WSL distributions are registered per user, so nothing that runs before a user logs on can start one. The 2026-09-06 review closed exactly this defect: an earlier design promised boot availability that Windows cannot deliver. So this is a LogonTrigger task for one named principal, and 02-target-architecture.md states the consequence in the product’s own words — “unattended Linux availability after that user’s logon, not before any interactive logon after a Windows reboot”.

There is no shell text in the action, at any layer

The other half of that review closed a design that composed systemctl and a keep-alive through a shell string. The action here is

<Command>...\runner-manager-wsl-supervisor-VERSION.exe</Command>
<Arguments>...\runner-manager-wsl-VERSION.exe wsl-host supervise --distribution Ubuntu ...</Arguments>

Task Scheduler has no Arguments vector — the element is a single string that Windows splits with CommandLineToArgvW — so LifecycleTask::action_arguments builds the vector and LifecycleTask::rendered_arguments quotes each element with the same function the service installer uses. A distribution called My Ubuntu is therefore "My Ubuntu" in the document and one argument again on the way out. What is not there is a cmd /c, a &&, a ;, or anything else a shell would interpret, and no_shell_text_reaches_the_task_document is the test that keeps it that way.

wsl-host supervise is the hidden Windows companion. It starts the Linux-only wsl-host hold, restarts that child when the named distribution is recovered, and owns the bounded recovery watchdog. Running in the distribution owner’s interactive token is essential: an SCM service under LocalSystem cannot see another account’s WSL registrations.

A task this did not create is never touched

The name is derived from the distribution, so two workstations agree on it and a re-run updates the task rather than accumulating copies. That same determinism means the name could collide with something an operator made by hand — and on the target workstation there is a hand-created task doing this job today (01-current-architecture.md). So every mutating operation reads the task back first and refuses unless its description carries PRODUCT_MARKER. wsl detach removing somebody else’s keep-alive task would be precisely the destructive behaviour the review renamed the command to avoid.

Structs

Detached

What LifecycleTaskControl::detach did, and what it deliberately did not.

LifecycleTask

Everything needed to render the task.

LifecycleTaskControl

Registering, reading and removing the product’s lifecycle task.

LifecycleTaskIdentity

The stable, per-distribution name of the product’s lifecycle task.

RegisteredTask

What Task Scheduler says about a task that is registered.

Constants

HOLD_ARGUMENTS

The hidden Linux command the task runs.

LIFECYCLE_TASK_PREFIX

The prefix every product-owned lifecycle task name starts with.

PRODUCT_MARKER

The string that says a task is this product’s.