Method _instantiate

crates/wasmtime/src/runtime/component/instance.rs:1163–1209

(
        &self,
        mut store: impl AsContextMut<Data = T>,
        asyncness: Asyncness,
    )

    }

    async fn _instantiate(
        &self,
        mut store: impl AsContextMut<Data = T>,
        asyncness: Asyncness,
    ) -> Result<Instance> {
        let store = store.as_context_mut();
        store.0.set_async_required(self.asyncness);
        store
            .engine()
            .allocator()
            .increment_component_instance_count()?;

        // Helper structure to pair the above increment with a decrement should
        // anything fail below.
        let mut decrement = DecrementComponentInstanceCountOnDrop {
            store,
            enabled: true,
        };

        let mut instantiator =
            Instantiator::new(&self.component, decrement.store.0, &self.imports)?;
        instantiator.run(&mut decrement.store, asyncness).await?;

        let instance = Instance::from_wasmtime(decrement.store.0, instantiator.id);
        decrement.store.0.push_component_instance(instance);

        // Everything has passed, don't decrement the instance count and let the
        // destructor for the `Store` handle that at this point.
        decrement.enabled = false;
        return Ok(instance);

        struct DecrementComponentInstanceCountOnDrop<'a, T: 'static> {
            store: StoreContextMut<'a, T>,
            enabled: bool,
        }

        impl<T> Drop for DecrementComponentInstanceCountOnDrop<'_, T> {
            fn drop(&mut self) {
                if self.enabled {
                    self.store
                        .engine()
                        .allocator()
                        .decrement_component_instance_count();
                }
            }
        }
    }
}