Mercurial > hg
view tests/test-pending.t @ 49000:dd6b67d5c256 stable
rust: fix unsound `OwningDirstateMap`
As per the previous patch, `OwningDirstateMap` is unsound. Self-referential
structs are difficult to implement correctly in Rust since the compiler is
free to move structs around as much as it wants to. They are also very rarely
needed in practice, so the state-of-the-art on how they should be done within
the Rust rules is still a bit new.
The crate `ouroboros` is an attempt at providing a safe way (in the Rust sense)
of declaring self-referential structs. It is getting a lot attention and was
improved very quickly when soundness issues were found in the past: rather than
relying on our own (limited) review circle, we might as well use the de-facto
common crate to fix this problem. This will give us a much better chance of
finding issues should any new ones be discovered as well as the benefit of
fewer `unsafe` APIs of our own.
I was starting to think about how I would present a safe API to the old struct
but soon realized that the callback-based approach was already done in
`ouroboros`, along with a lot more care towards refusing incorrect structs.
In short: we don't return a mutable reference to the `DirstateMap` anymore, we
expect users of its API to pass a `FnOnce` that takes the map as an argument.
This allows our `OwningDirstateMap` to control the input and output lifetimes
of the code that modifies it to prevent such issues.
Changing to `ouroboros` meant changing every API with it, but it is relatively
low churn in the end. It correctly identified the example buggy modification of
`copy_map_insert` outlined in the previous patch as violating the borrow rules.
Differential Revision: https://phab.mercurial-scm.org/D12429
author | Raphaël Gomès <rgomes@octobus.net> |
---|---|
date | Tue, 05 Apr 2022 10:55:28 +0200 |
parents | ef6cab7930b3 |
children |
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Verify that pending changesets are seen by pretxn* hooks but not by other processes that access the destination repo while the hooks are running. The hooks (python and external) both reject changesets after some think time, during which another process runs pull. Each hook creates a file ('notify') to indicate to the controlling process that it is running; the process removes the file to indicate the hook can terminate. init env vars $ d=`pwd` $ maxwait=20 utility to run the test - start a push in the background and run pull $ dotest() { > rm -f notify > printf 'push '; hg -R child-push tip --template '{node}\n' > hg -R child-push -q push > push.out 2>&1 & > > # wait for hook to create the notify file > i=$maxwait > while [ ! -f notify -a $i != 0 ]; do > sleep 1 > i=`expr $i - 1` > done > > # run pull > hg -R child-pull -q pull > rc=$? > > # tell hook to finish; notify should exist. > rm notify > wait > > cat push.out > printf 'pull '; hg -R child-pull tip --template '{node}\n' > return $rc > } python hook $ cat <<EOF > reject.py > import os > import time > def rejecthook(ui, repo, hooktype, node, **opts): > ui.write(b'hook %s\\n' % repo[b'tip'].hex()) > # create the notify file so caller knows we're running > fpath = os.path.join('$d', 'notify') > f = open(fpath, 'w') > f.close() > # wait for ack - caller should delete the notify file > i = int("$maxwait") > while os.path.exists(fpath) and i > 0: > time.sleep(1) > i -= 1 > return True # reject the changesets > EOF external hook $ cat <<EOF > reject.sh > printf 'hook '; hg tip --template '{node}\\n' > # create the notify file so caller knows we're running > fpath=$d/notify > touch \$fpath > # wait for ack - caller should delete the notify file > i=$maxwait > while [ -f \$fpath -a \$i != 0 ]; do > sleep 1 > i=\`expr \$i - 1\` > done > exit 1 # reject the changesets > EOF create repos $ hg init parent $ hg clone -q parent child-push $ hg clone -q parent child-pull $ echo a > child-push/a $ hg -R child-push add child-push/a $ hg -R child-push commit -m a -d '1000000 0' test python hook $ cat <<EOF > parent/.hg/hgrc > [extensions] > reject = $d/reject.py > [hooks] > pretxnchangegroup = python:reject.rejecthook > EOF $ dotest push 29b62aeb769fdf78d8d9c5f28b017f76d7ef824b hook 29b62aeb769fdf78d8d9c5f28b017f76d7ef824b transaction abort! rollback completed abort: pretxnchangegroup hook failed pull 0000000000000000000000000000000000000000 test external hook $ cat <<EOF > parent/.hg/hgrc > [hooks] > pretxnchangegroup = sh $d/reject.sh > EOF $ dotest push 29b62aeb769fdf78d8d9c5f28b017f76d7ef824b hook 29b62aeb769fdf78d8d9c5f28b017f76d7ef824b transaction abort! rollback completed abort: pretxnchangegroup hook exited with status 1 pull 0000000000000000000000000000000000000000 Test that pending on transaction without changegroup see the normal changegroup( (issue4609) $ cat <<EOF > parent/.hg/hgrc > [hooks] > pretxnchangegroup= > pretxnclose = hg tip -T "tip: {node|short}\n" > [phases] > publishing=False > EOF setup $ cd parent $ echo a > a $ hg add a $ hg commit -m a tip: cb9a9f314b8b actual test $ hg phase --public . tip: cb9a9f314b8b