pezkuwichain/pezkuwi-subxt
1
0
Fork 0
mirror of https://github.com/pezkuwichain/pezkuwi-subxt.git synced 2026-04-26 15:47:58 +00:00
Code Issues Packages Projects Releases Wiki Activity

Opt-out from fast instance reuse and foundation for other refactorings (#8394)

Browse Source 
* Establish the runtime_blob module

Seed it with the existing contents of the `util` module.

* Port wasmtime mutable globals instrumentation into runtime blob APIs

* Opt-out from fast instance reuse

* Minor clean up

* Spaces

* Docs clean up

* Apply suggestions from code review

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Factor out the expects

* Fix the suggestion

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
This commit is contained in:
Sergei Shulepov
2021-04-06 19:21:34 +03:00
committed by GitHub
parent 6a8c6b2b0a
commit b2a6ad0553
15 changed files with 592 additions and 285 deletions
Download Patch File Download Diff File Expand all files Collapse all files
substrate/client/executor/common/src/runtime_blob/mod.rs
+57
View File
@@ -0,0 +1,57 @@
// This file is part of Substrate.
// Copyright (C) 2021 Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
//! This module allows for inspection and instrumentation, i.e. modifying the module to alter it's
//! structure or behavior, of a wasm module.
//!
//! ## Instrumentation
//!
//! In ideal world, there would be no instrumentation. However, in the real world the execution
//! engines we use are somewhat limited in their APIs or abilities.
//!
//! To give you some examples:
//!
//! - wasmi allows reaching to non-exported mutable globals so that we could reset them.
//! Wasmtime doesn’t support that.
//!
//! We need to reset the globals because when we
//! execute the Substrate Runtime, we do not drop and create the instance anew, instead
//! we restore some selected parts of the state.
//!
//! - stack depth metering can be performed via instrumentation or deferred to the engine and say
//! be added directly in machine code. Implementing this in machine code is rather cumbersome so
//! instrumentation looks like a good solution.
//!
//! Stack depth metering is needed to make a wasm blob
//! execution deterministic, which in turn is needed by the Parachain Validation Function in Polkadot.
//!
//! ## Inspection
//!
//! Inspection of a wasm module may be needed to extract some useful information, such as to extract
//! data segment snapshot, which is helpful for quickly restoring the initial state of instances.
//! Inspection can be also useful to prove that a wasm module possesses some properties, such as,
//! is free of any floating point operations, which is a useful step towards making instances produced
//! from such a module deterministic.
mod data_segments_snapshot;
mod globals_snapshot;
mod runtime_blob;
pub use data_segments_snapshot::DataSegmentsSnapshot;
pub use globals_snapshot::{GlobalsSnapshot, ExposedMutableGlobalsSet, InstanceGlobals};
pub use runtime_blob::RuntimeBlob;