Function nros_platform_timer_cancel 

pub unsafe extern "C" fn nros_platform_timer_cancel(
    handle: *mut c_void,
) -> i8

Cancel a previously-armed timer. Returns:

• 1 if cancellation prevented the callback from firing,
• 0 if the callback already fired (or the timer was already cancelled / destroyed),
• -1 on unrecoverable error.

Distinct from destroy — the handle remains valid after cancel and may be re-armed by the application’s own bookkeeping if the implementation supports it.