is the map find thread-safe?

Test environment gcc4.8.2

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Iterator Find (const key_type& k);

Const_iterator Find (const key_type& k) const;

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Unordered_map has two corresponding find functions I infer that the second one is safe and the first one is not thread safe.

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Auto iter = _map.find (key)

Core in OpenMP multithreaded environment, thanks to Glog for error message output

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***? aborted?at?1412933723? (unix?time)? Try? " [Email protected] "? if?you?are?using? gnu?date?***

Pc:[email protected]??????????? 0x8d1d65?std::equal_to<>::operator () ()

***? SIGSEGV? (@0x8)? Received?by? pid?3216? (tid?0x7f7c3902d700)? From? pid?8;? stack?trace:?***

[Email protected]????? 0x7f7c4b769150? (unknown)

[Email protected]??????????? 0x8d1d65?std::equal_to<>::operator () ()

[Email protected]??????????? 0x8e231b?std::__detail::_equal_helper<>::_s_equals ()

[Email protected]??????????? 0x8dbbb0?std::__detail::_hashtable_base<>::_m_equals ()

[Email protected]??????????? 0x8d1e63?std::_hashtable<>::_m_find_before_node ()

[Email protected]??????????? 0x8c432e?std::_hashtable<>::_m_find_node ()

[Email protected]??????????? 0x8b2bca?std::_hashtable<>::find ()

[Email protected]??????????? 0x89adcd?std::unordered_map<>::find ()

[Email protected]??????????? 0x87af21?gezi::lrumap<>::find ()

[Email protected]??????????? 0x85c6ab?gezi::timermap<>::count ()

[Email protected]??????????? 0x7ee705?run ()

[Email protected]??????????? 0x7f1893?_z3runv._omp_fn.3

[Email protected]????? 0x7f7c4a65641a?gomp_thread_start

[Email protected]????? 0x7f7c4b7611c1?start_thread

[Email protected]????? 0x7f7c49b6c0ad?__clone

Segmentation?fault

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Since I may need to modify iter->second, I cannot use const_iterator

Increase

Iterator Iter;

#pragma omp critical

iter = _map.find (key);

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The program is running normally.

is the map find thread-safe?