The Mysten Simulator

This is a fork of https://github.com/madsim-rs/madsim

The madsim project is building a tokio-like (but not 100% compatible) deterministic runtime. This fork modifies the original project to produce a drop-in replacement for tokio.

How to upgrade the tokio version:

1. Clone the tokio fork, add an upstream remote, and fetch

    $ git clone [email protected]:MystenLabs/tokio-msim-fork.git
    $ cd tokio-msim-fork
    $ git remote add upstream [email protected]:tokio-rs/tokio.git
    $ git fetch upstream --tags
   

2. See what our current version of tokio is - don't just look in Cargo.toml since we can be ahead of the version requested there.

    # cd sui
    # cargo tree -i tokio --depth 0
   

3. Now rebase the fork onto the tokio release you want to use.

    # make a new branch for the version we want to upgrade TO
    # start the branch from the current version, that we are upgrading FROM
    $ git checkout -b msim-1.43.0 msim-1.38.1
   
    # and rebase using the version tag
    $ git rebase tokio-1.43.0
   
    # push the rebased version to our repo and remember the current commit
    $ git push
    $ FORK_COMMIT=`git rev-parse HEAD`
   

4. Usually, there are no merge conflicts. If there are, the scope of the fork is limited and things should be fixable.

5. Now, in this repo

   1. Edit the version in msim-tokio/Cargo.toml to match the version we are upgrading to (1.43.0 in this example).
   2. Find all references to https://github.com/MystenLabs/tokio-msim-fork.git in Cargo.toml files in this repo and update the rev param to FORK_COMMIT.

6. Now, in the sui repo, update the tokio version by editing Cargo.toml, or by running:

    $ cargo update -p tokio --precise 1.43.0
   

7. Install simtest (if you already have it, skip this step): https://github.com/MystenLabs/sui/blob/main/scripts/simtest/install.sh

8. Test all the changes against your local msim repo - if there are build errors the rebasing may have gone wrong. Make sure to put the correct path for the LOCAL_MSIM_PATH variable. $ cd sui $ LOCAL_MSIM_PATH=/path/to/mysten-sim cargo simtest

9. If you're updating tokio because it needs to be updated in sui monorepo, then make sure to update all rev fields of msim in sui monorepo to point to the right commit from this repository (including script files!).

Usage:

TODO