C++ tbb unsafe_erase() 并发访问怎么办

Posted 2021-10-13 软件工程小施同学

加锁

/*

NOTICE:

m_eraseMutex is used for eraseKey() method with tbb::concurrent_unordered_map

instance only. Because in that eraseKey() method, we use unsafe_erase() method to delete element

in tbb::concurrent_unordered_map instance. As "unsafe_" prefix says, the unsafe_erase() method

can NOT ensure concurrenty safety between different calls to this method, that's why we used a

mutex to ensure there is only one thread can erase element each time.

Additionally, by now no evidence shows that unsafe_erase() method would conflict with insert()

or find() method. To get furthur details about the data structure used in

tbb::concurrent_unordered_map, maybe you could read:

http://www.cs.ucf.edu/~dcm/Teaching/COT4810-Spring2011/Literature/SplitOrderedLists.pdf

*/

std::mutex m_eraseMutex;

void eraseKey(ConcurrentMap& _map, KeyType const& _key)

{

std::lock_guard<std::mutex> lock(m_eraseMutex);

_map.unsafe_erase(_key);

}