import type { Context } from "@steve.kite/stdlib";
/**
 * Remembers the process groups we started so shutdown can take them down.
 *
 * A background command outlives the shell that launched it, so a group has to
 * stay reapable long after its leader is gone.
 *
 * A group is identified by the number the operating system gave it, and that
 * number is reused once the group is gone. Every group is therefore dropped as
 * soon as it dies, and checked again immediately before it is signalled, which
 * narrows the window in which a recycled identifier could be mistaken for ours
 * to the gap between that check and the signal. Closing it entirely would take
 * a kernel handle on the group, which the platforms we support do not offer.
 */
export declare class ProcessGroupReaper {
    #private;
    retain(processGroupId: number): void;
    release(processGroupId: number): void;
    /** The groups we would take down right now, for tests and diagnostics. */
    pending(): readonly number[];
    /** Asks every surviving group to stop, then forces the ones that did not. */
    terminateAll(ctx: Context, forceAfterMs: number): Promise<void>;
}
/**
 * Signals a whole process group and nothing else.
 *
 * Unlike killing a process tree, there is deliberately no fall back to the bare
 * identifier: if the group is gone, the number may now belong to an unrelated
 * process, and signalling it would be someone else's problem.
 */
export declare function killProcessGroup(ctx: Context, processGroupId: number, signal: NodeJS.Signals): Promise<void>;
export declare function isProcessGroupAlive(processGroupId: number): boolean;