Method shrink

datafusion/execution/src/memory_pool/pool.rs:46–48

(&self, _reservation: &MemoryReservation, shrink: usize)

    }

    fn shrink(&self, _reservation: &MemoryReservation, shrink: usize) {
        self.used.fetch_sub(shrink, Ordering::Relaxed);
    }

    fn try_grow(&self, reservation: &MemoryReservation, additional: usize) -> Result<()> {
        self.grow(reservation, additional);