From: Dave Nadler <drn@nadler.com>
To: Freddie Chopin <freddie_chopin@op.pl>, newlib@sourceware.org
Subject: Re: Confusion about possibly unsafe malloc_r?
Date: Sun, 25 Jun 2017 14:28:00 -0000 [thread overview]
Message-ID: <e07056d6-34dd-55a9-e39c-6a0c8ad9aa98@nadler.com> (raw)
In-Reply-To: <1498371337.1704.1.camel@op.pl>
Thanks Freddie. If I understand your answer correctly, printf's call chain's
use of _GLOBAL_REENT should be OK because this particular memory is
protected by a global lock.
I studied the newlib documentation and looked in syscalls, but did not find
anything explaining how to implement "retargetable locks" as you mention.
I did understand that I must implement env_locks to use set_env/get_env,
and that I did not need to implement the corresponding malloc locks.
I read a half-dozen articles about embedding/porintg newlib and failed
to find this...
Could you point me at documentation (or sources) explaining how
to implement "retargetable locks"?
Thanks for the help!
Best Regards, Dave
On 6/25/2017 2:15 AM, Freddie Chopin wrote:
> On Sat, 2017-06-24 at 18:42 -0400, Dave Nadler wrote:
>> Is this OK? I'm paranoid about thread safety!
> Then it's worth mentioning that newlib and FreeRTOS will _NEVER_ be
> fully thread safe unless you are using a toolchain with retargetable
> locks and your project has support code for these locks.
>
> printf()-style families partially use global reent structure, this is
> expected. Trace the calls of the mentioned functions in newlib source
> and you'll see that sometimes _GLOBAL_REENT is used, sometimes thread's
> reent.
>
> Regards,
> FCh
--
Dave Nadler, USA East Coast voice (978) 263-0097,drn@nadler.com, Skype
Dave.Nadler1
next prev parent reply other threads:[~2017-06-25 14:28 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-24 22:42 Dave Nadler
2017-06-25 6:18 ` Freddie Chopin
2017-06-25 14:28 ` Dave Nadler [this message]
[not found] ` <a720c7bc-1795-ee25-d757-359e7d9942ec@nadler.com>
2017-06-27 18:26 ` Freddie Chopin
2017-06-27 20:07 ` Dave Nadler
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-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=e07056d6-34dd-55a9-e39c-6a0c8ad9aa98@nadler.com \
--to=drn@nadler.com \
--cc=freddie_chopin@op.pl \
--cc=newlib@sourceware.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).