[PATCH] D35704: added reset feature to dfsan

[Kostya Serebryany via Phabricator via llvm-commits]

kcc added inline comments.


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Comment at: lib/dfsan/dfsan.cc:179
+  // reset label count
+  atomic_store(&__dfsan_last_label, 0, memory_order_relaxed);
+}
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farahhariri wrote:
> kcc wrote:
> > Add some code to check-fail in case __dfsan_last_label has changed (i.e. to check that no other threads are messing around)
> > 
> > Then, add a test with threads that will trigger that check-fail.
> > Then, add a test with threads that will trigger that check-fail.
> 
> That means I will have to add a flaky test that sometimes passes and sometimes fails.
> I cannot guarantee that the scheduler will switch context between the atomic store and 
> the check-fail to another thread, and then switch back to the check-fail. That's the only
> way to guarantee it will fail..
You can create a test that runs a very long loop in a thread and thus guarantee that the test will crash 9999999999999999 our of 100000000000000 times. 


https://reviews.llvm.org/D35704