kandev/docs/plans/desktop-orphaned-backend-lock/task-01-proclive-shared-helper.md

id, title, status, wave, depends_on, plan, spec, parallelism

id	title	status	wave	depends_on	plan	spec	parallelism
01-proclive-shared-helper	Shared process-liveness helper	done	1		plan.md	../../specs/desktop/requirements/desktop-tauri-app.md	sequential

Task 01: Shared process-liveness helper

Promote the existing private processAlive probe out of internal/system/storage/tempartifacts into internal/common/proclive so the launcher watchdog (task 02) and the ownership-lock diagnostics (task 04) consume one implementation instead of adding a second and third copy.

This is a pure move plus re-export. Do not change the probe's behavior.

Inputs

• Plan section "Shared process liveness (internal/common/proclive, new)".
• Existing implementation to move: apps/backend/internal/system/storage/tempartifacts/process_alive_unix.go and process_alive_windows.go.
• Its only current call site: tempartifacts/registry.go:209.
• apps/backend/AGENTS.md, "Cross-tier shared code belongs in internal/common/", which is why this lands as a shared package rather than being duplicated.

Implementation

Create apps/backend/internal/common/proclive/ with:

• proclive.go holding only the package doc comment. State that known=false means the platform cannot determine liveness and that callers must treat that as "do not act", since both consumers depend on that reading.
• proclive_unix.go (//go:build !windows) and proclive_windows.go (//go:build windows), each exporting:

func Alive(pid int64) (alive, known bool)

Move the two existing bodies verbatim, changing only the package clause and the identifier from processAlive to Alive. Keep the int64 parameter: it matches tempartifacts' artifact.OwnerPID exactly and avoids a 32-bit truncation question at the boundary. Keep the Windows comment explaining why it returns unknown.

Then delete both tempartifacts/process_alive_*.go files and update registry.go:209 to call proclive.Alive(artifact.OwnerPID). Update registry_test.go:119 the same way. Do not change any surrounding reconciliation logic.

Acceptance

• internal/common/proclive exports Alive(pid int64) (alive, known bool) with Unix and Windows implementations, and both tempartifacts/process_alive_*.go files are gone.
• tempartifacts calls proclive.Alive and its existing tests pass unchanged.
• No behavior change: signal 0 on Unix with EPERM treated as alive and ESRCH as gone, (false, false) on Windows.

Verification

cd apps/backend && go test ./internal/common/proclive/... ./internal/system/storage/tempartifacts/...

cd apps/backend && gofmt -l internal/common/proclive internal/system/storage/tempartifacts

The gofmt invocation must print nothing; the pre-commit hook fails the commit otherwise.

Files likely touched

• apps/backend/internal/common/proclive/proclive.go (new)
• apps/backend/internal/common/proclive/proclive_unix.go (new)
• apps/backend/internal/common/proclive/proclive_windows.go (new)
• apps/backend/internal/common/proclive/proclive_test.go (new)
• apps/backend/internal/system/storage/tempartifacts/process_alive_unix.go (delete)
• apps/backend/internal/system/storage/tempartifacts/process_alive_windows.go (delete)
• apps/backend/internal/system/storage/tempartifacts/registry.go
• apps/backend/internal/system/storage/tempartifacts/registry_test.go

Dependencies

None.

Tests to write

In proclive_test.go, table-driven:

• The current process (int64(os.Getpid())) reports (true, true) on Unix.
• A reaped child reports (false, true) on Unix. Start a real short-lived process with os/exec, Wait for it so the PID is fully released, then probe. Guard this case with //go:build !windows or a runtime.GOOS skip, since Windows returns unknown by design.
• 0 and a negative PID report (false, true) on Unix without touching the platform call.

Output contract

Report the moved files, the migrated call sites, the exact commands run with their outcomes, and confirmation that no tempartifacts behavior changed. Update this file's status and ## Results, and the matching checkbox in plan.md.

Results

• Added internal/common/proclive with Unix signal-zero and Windows unknown implementations, plus Unix tests for the current process, a reaped child, and non-positive PIDs.
• Migrated tempartifacts production and test call sites to proclive.Alive; removed the duplicated platform files.
• cd apps/backend && go test ./internal/common/proclive/... ./internal/system/storage/tempartifacts/... passed (ok for both packages).
• gofmt -w internal/common/proclive internal/system/storage/tempartifacts completed successfully.
• Cleanup: the subprocess used by the liveness test is reaped with Wait; no temporary capture files or external resources remain.
• Security/trust and external side-effect boundaries: none.