Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

fix(Query): Fix wrong path response for k-shortest paths (#6437) #6655

Merged
merged 1 commit into from
Oct 5, 2020

Conversation

ahsanbarkati
Copy link
Contributor

@ahsanbarkati ahsanbarkati commented Oct 5, 2020

The k-shortest path query sometimes returns a wrong response. The cause
of this issue is inappropriate use of sync.pools. Whenever a valid path
is found a new variable is assigned with this route and that variable is
appended in the kroutes (which is then parsed to produce response).
But the route is also put in the sync.pool. Since the route is a
structure containing a pointer to slice along with other fields, when
it is fetched back from the pool in future then any mutation on this fetched
route causes modification in the kroutes, resulting in garbage response.

This issue is fixed by making a copy of the route struct rather
than just assigning it to a variable, which causes a shallow copy.

(cherry picked from commit 4792d8b)


This change is Reviewable

Docs Preview: Dgraph Preview

The k-shortest path query sometimes returns a wrong response. The cause
of this issue is inappropriate use of sync.pools. Whenever a valid path
is found a new variable is assigned with this route and that variable is
appended in the kroutes (which is then parsed to produce response).
But the route is also put in the sync.pool. Since the route is a
structure containing a pointer to slice along with other fields, when
it is fetched back from the pool in future then any mutation on this fetched
route causes modification in the kroutes, resulting in garbage response.

This issue is fixed by making a copy of the route struct rather
than just assigning it to a variable, which causes a shallow copy.

(cherry picked from commit 4792d8b)
@parasssh parasssh merged commit 537ced2 into release/v20.03 Oct 5, 2020
@parasssh parasssh deleted the ahsan/v20.03-kshortest branch October 5, 2020 23:59
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Development

Successfully merging this pull request may close these issues.

2 participants