Move tokio fork to MystenLabs repo, and add instructions to upgrade tokio (#57)

* Move tokio fork to MystenLabs repo, and add instructions to upgrade tokio

* Update README.md

Co-authored-by: stefan-mysten <135084671+stefan-mysten@users.noreply.github.com>

* Update README.md

Co-authored-by: stefan-mysten <135084671+stefan-mysten@users.noreply.github.com>

---------

Co-authored-by: stefan-mysten <135084671+stefan-mysten@users.noreply.github.com>

Author: mystenmark

README.md

@@ -5,6 +5,50 @@
 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 git@github.com:MystenLabs/tokio-msim-fork.git
+        $ cd tokio-msim-fork
+        $ git remote add upstream git@github.com: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
+
+2. 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`
+
+3. Usually, there are no merge conflicts. If there are, the scope of the fork is limited and things should be fixable.
+
+4. 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`.
+
+5. Now, in the sui repo, update the tokio version by editing Cargo.toml, or by running:
+
+        $ cargo update -p tokio --precise 1.43.0
+
+6. Test all the changes against your local msim repo - if there are build errors the rebasing may have gone wrong.
+
+- install simtest (if you already have it, skip this step): https://github.com/MystenLabs/sui/blob/main/scripts/simtest/install.sh
+
+        $ LOCAL_MSIM_PATH=/path/to/mysten-sim/repo cargo simtest
+
 ## Usage:
 
 TODO

msim-tokio/Cargo.toml

@@ -61,7 +61,7 @@ msim = { version = "0.1.0", path = "../msim" }
 [dependencies]
 tracing = "0.1"
 
-real_tokio = { git = "https://github.com/mystenmark/tokio-madsim-fork.git", rev = "d46208cb11118c0e6ab5dfea1a2265add36fbc15", package = "real_tokio", features = ["full"] }
+real_tokio = { git = "https://github.com/MystenLabs/tokio-msim-fork.git", rev = "d46208cb11118c0e6ab5dfea1a2265add36fbc15", package = "real_tokio", features = ["full"] }
 bytes = { version = "1.1" }
 futures = { version = "0.3.0", features = ["async-await"] }
 mio = { version = "0.8.1" }

msim/Cargo.toml

@@ -38,8 +38,8 @@ ahash = "0.7"
 downcast-rs = "1.2"
 libc = "0.2"
 naive-timer = "0.2"
-tokio = { git = "https://github.com/mystenmark/tokio-madsim-fork.git", rev = "d46208cb11118c0e6ab5dfea1a2265add36fbc15", package = "real_tokio", features = ["full"] }
-tokio-util = { git = "https://github.com/mystenmark/tokio-madsim-fork.git", rev = "d46208cb11118c0e6ab5dfea1a2265add36fbc15", features = ["full"] }
+tokio = { git = "https://github.com/MystenLabs/tokio-msim-fork.git", rev = "d46208cb11118c0e6ab5dfea1a2265add36fbc15", package = "real_tokio", features = ["full"] }
+tokio-util = { git = "https://github.com/MystenLabs/tokio-msim-fork.git", rev = "d46208cb11118c0e6ab5dfea1a2265add36fbc15", features = ["full"] }
 toml = "0.5"
 socket2 = "0.4"
 erasable = "1.2"
@@ -50,7 +50,7 @@ async-task = { git = "https://github.com/mystenmark/async-task", rev = "4e45b26e
 [dev-dependencies]
 criterion = "0.3"
 structopt = "0.3"
-tokio = { git = "https://github.com/mystenmark/tokio-madsim-fork.git", rev = "d46208cb11118c0e6ab5dfea1a2265add36fbc15", package = "real_tokio", features = ["full"] }
+tokio = { git = "https://github.com/MystenLabs/tokio-msim-fork.git", rev = "d46208cb11118c0e6ab5dfea1a2265add36fbc15", package = "real_tokio", features = ["full"] }
 
 [[bench]]
 name = "rpc"