From: eregontp@gmail.com
To: ruby-core@ruby-lang.org
Subject: [ruby-core:84851] [Ruby trunk Bug#14353] $SAFE should stay at least thread-local for compatibility
Date: Sat, 13 Jan 2018 19:33:42 +0000 (UTC) [thread overview]
Message-ID: <redmine.journal-69563.20180113193341.8faa3bc2018b27a8@ruby-lang.org> (raw)
In-Reply-To: redmine.issue-14353.20180113193325@ruby-lang.org
Issue #14353 has been updated by Eregon (Benoit Daloze).
Assignee set to ko1 (Koichi Sasada)
----------------------------------------
Bug #14353: $SAFE should stay at least thread-local for compatibility
https://bugs.ruby-lang.org/issues/14353#change-69563
* Author: Eregon (Benoit Daloze)
* Status: Open
* Priority: Normal
* Assignee: ko1 (Koichi Sasada)
* Target version:
* ruby -v:
* Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN
----------------------------------------
In #14250 $SAFE changed from a frame+thread-local variable to a process-wide global variable.
This feels wrong and breaks the most common usage of $SAFE in tests:
~~~ ruby
Thread.new {
$SAFE = 1
sth that should be checked to work under $SAFE==1
}.join
~~~
It is very clear this is incompatible given how many files (33!) had to be changed in r61510.
And it has wide ranging confusing side-effects, one example: https://travis-ci.org/ruby/spec/jobs/328524568
I agree frame-local is too much for $SAFE.
But removing thread-local seems to only introduce large incompatibilities.
It also makes it impossible to use it in a thread-safe way.
The common pattern (not necessarily for $SAFE, more often for $VERBOSE):
~~~ ruby
begin
old = $SAFE
$SAFE = 1
something under SAFE==1
ensure
$SAFE = old
end
~~~
is unsafe if two threads run it concurrently (The last thread executing `$SAFE = old` might restore to 1 even though it should be 0).
(Actually I believe most built-in variables (e.g. $VERBOSE) should be thread-local and not process-wide due to this)
Since $SAFE is being deprecated and removed, I don't see any reason to make it more incompatible than needed.
@ko1 Can we switch it back to thread-local for compatibility, avoiding headaches and keeping it usable with multiple threads?
--
https://bugs.ruby-lang.org/
next prev parent reply other threads:[~2018-01-13 19:33 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <redmine.issue-14353.20180113193325@ruby-lang.org>
2018-01-13 19:33 ` [ruby-core:84850] [Ruby trunk Bug#14353] $SAFE should stay at least thread-local for compatibility eregontp
2018-01-13 19:33 ` eregontp [this message]
2018-01-13 22:24 ` [ruby-core:84852] " shevegen
2018-01-16 3:14 ` [ruby-core:84886] " ko1
2018-01-16 17:14 ` [ruby-core:84892] " eregontp
2019-01-23 9:25 ` [ruby-core:91222] " v.ondruch
2019-02-07 5:23 ` [ruby-core:91447] " matz
2019-10-17 23:35 ` [ruby-core:95406] [Ruby master " merch-redmine
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-list from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://www.ruby-lang.org/en/community/mailing-lists/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=redmine.journal-69563.20180113193341.8faa3bc2018b27a8@ruby-lang.org \
--to=ruby-core@ruby-lang.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).