casper: document that most libcasper and cap_net functions are not thread-safe
ClosedPublic
Actions

Authored by asomers on Dec 6 2023, 5:24 PM.

Details

Reviewers

Commits

rG0125d6a23ba9: libcasper: document that most libcasper functions are not thread-safe
rGcf037972ea88: libcasper: document that most libcasper functions are not thread-safe

Summary

Because internally they all use cap_xfer_nvlist. cap_xfer_nvlist sends
and then receives data over a unix domain socket and associated with the
cap_channel_t argument. So absent synchronization, two threads may not
use the same cap_channel_t argument or they risk receiving the other's
reply.

MFC after: 2 weeks
Sponsored by: Axcient

Diff Detail

Repository

rG FreeBSD src repository

Lint

Lint Passed

Unit

No Test Coverage

Build Status

Buildable 54822
Build 51711: arc lint + arc unit

Event Timeline

asomers created this revision.Dec 6 2023, 5:24 PM

Herald added a subscriber: imp. · View Herald TranscriptDec 6 2023, 5:24 PM

asomers requested review of this revision.Dec 6 2023, 5:24 PM

Harbormaster completed remote builds in B54819: Diff 131075.Dec 6 2023, 5:24 PM

@oshogbo do you agree with this wording? If so I'll add it to the other casper services' man pages and update the revision.

LGTM, thank you for working on this.

Add reentrancy notices to the other casper service man pages, too.

Harbormaster completed remote builds in B54822: Diff 131081.Dec 6 2023, 10:20 PM

@oshogbo I've updated all of them now. But do you think that this is too pedantic? Maybe I'm just a cossetted Rust programmer who expects that everything is thread-safe by default.