childKillWindows

fn childKillWindows(t: *Threaded, child: *process.Child, exit_code: windows.UINT) !void {
    _ = t; // TODO cancelation
    const handle = child.id.?;
    _ = windows.ntdll.RtlReportSilentProcessExit(handle, @fromBackingInt(@intCast(exit_code)));
    switch (windows.ntdll.NtTerminateProcess(handle, @fromBackingInt(@intCast(exit_code)))) {
        .SUCCESS, .PROCESS_IS_TERMINATING => {
            _ = windows.ntdll.NtWaitForSingleObject(handle, .FALSE, null);
            childCleanupWindows(child);
        },
        .ACCESS_DENIED => {
            // Usually when TerminateProcess triggers a ACCESS_DENIED error, it
            // indicates that the process has already exited, but there may be
            // some rare edge cases where our process handle no longer has the
            // PROCESS_TERMINATE access right, so let's do another check to make
            // sure the process is really no longer running:
            const minimal_timeout: windows.LARGE_INTEGER = -1;
            return switch (windows.ntdll.NtWaitForSingleObject(handle, .FALSE, &minimal_timeout)) {
                windows.NTSTATUS.WAIT_0 => error.AlreadyTerminated,
                else => error.AccessDenied,
            };
        },
        else => |status| return windows.unexpectedStatus(status),
    }
}