Deadlock in tbb::concurrent_vector when resizing + growing.

[jdumas]

Hi. We've encountered a scary bug with TBB on the following code snippet:

tbb::concurrent_vector<int> v;
v.resize(382);
while (v.size() < 737) {
    v.emplace_back();
}
v.resize(27);
while (v.size() < 40) {
    v.emplace_back();
}

The problem is that the emplace_back() goes into an infinite loop at this line:

oneTBB/include/oneapi/tbb/concurrent_vector.h

Line 575 in ec39c54

spin_wait_while_eq(table[seg_index], segment_type(nullptr));

This happens with both oneTBB 2021.4.0 and 2021.5.0. The problem can be reproduced on godbolt:
https://godbolt.org/z/rsed7sYP7

I can reproduce the issue on both clang, gcc and msvc.

[pavelkumbrasev]

I can reproduce it. At a first glance, it looks like a bug in a segment table of concurrent_vector.

[pavelkumbrasev]

@jdumas Could you please recheck your case with current master? And if it fails, please reopen the issue.