Re: [PATCH] hashmap: add API to disable item counting when threaded

["Martin Ågren" <martin.agren@gmail.com>]

On 5 September 2017 at 18:39, Jeff Hostetler <git@jeffhostetler.com> wrote:
>
>
> On 9/1/2017 7:50 PM, Jonathan Nieder wrote:
>>
>> Hi,
>>
>> Johannes Schindelin wrote:
>>>
>>> On Wed, 30 Aug 2017, Jeff Hostetler wrote:
>>
>>
>>>> This is to address concerns raised by ThreadSanitizer on the mailing
>>>> list about threaded unprotected R/W access to map.size with my previous
>>>> "disallow rehash" change (0607e10009ee4e37cb49b4cec8d28a9dda1656a4).
>>
>>
>> Nice!
>>
>> What does the message from TSan look like?  (The full message doesn't
>> need to go in the commit message, but a snippet can help.)  How can I
>> reproduce it?
>
>
> I'll let Martin common on how to run TSan; I'm just going on
> what he reported in the "tsan: t3008..." message from the URL
> I quoted.  I didn't think to copy that text into the commit
> message because it is just stack traces and too long, but I
> could include a snippet.

I ran the test suite with ThreadSanitizer:

$ make SANITIZE=thread test

Any failures were then inspected:

$ cd t
$ ./t3008-ls-files-lazy-init-name-hash.sh --verbose

That can be done with or without ma/ts-cleanups. That series adds a file
.tsan-suppressions, which can be used by defining the environment
variable

TSAN_OPTIONS="suppressions=/some/absolute/path/.tsan-suppressions"

in order to suppress some findings which are indeed races, but which are
"not a problem in practice".

Martin