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

On 5 September 2017 at 18:39, Jeff Hostetler [off-list ref] wrote:

On 9/1/2017 7:50 PM, Jonathan Nieder wrote:

quoted

Hi,

Johannes Schindelin wrote:

quoted

On Wed, 30 Aug 2017, Jeff Hostetler wrote:

quoted

quoted

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