The documentation of the on_idle hook states that "Any implementation should always respect _remaining_weight and never consume (and therefore return) more than this amount."

In the contracts pallet, the implementation is as follows:

impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
    fn on_idle(_block: BlockNumberFor<T>, mut remaining_weight: Weight) -> Weight {
        use migration::MigrateResult::*;
        // ...


Let's consider a scenario where process_deletion_queue_batch entirely consumes the remaining_weight. In this case, the return value of on_idle will exceed the authorized limit when adding the overhead weight T::WeightInfo::on_process_deletion_queue_batch().

Intuitively, I would rather have done:


To ensure that the return value of on_idle never exceeds the remaining_weight.

Is there something I'm missing?

1 Answer 1


It appears that I was missing the let base_weight = T::WeightInfo::on_process_deletion_queue_batch(); statement in the deletion_budget(weight_limit: Weight) function, which is called within the process_deletion_queue_batch(weight_limit: Weight) function. As a result, the returned weight will never exceed the remaining_weight.

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