Which STL container has a thread-safe insertion process?

Question

Which STL container has a thread safe insertion process? I want several threads to simultaneously insert in the same container. Any implementation other than STL (i.e., Boost) is welcome!

Answer 1

The STL containers are not thread safe. You have to impose that yourself, should you so wish, with your own synchronisation.

Answer 2

I am trying to avoid the critical region in multi-threading because it deteriorates the performance !

On the contrary, it improves performance. Because the kind of locking a container class can do is only the very fine-grained kind, having to acquire the lock for each simple operation. That's expensive. When you take care of locking, you have the luxury of acquiring the lock and perform many operations. That does not improve the odds for concurrency but greatly reduces the locking overhead. You can choose the strategy that makes most sense for your app, it isn't forced on you.

Add to this that it is next to impossible to write a thread-safe container implementation that isn't either prone to deadlock or very expensive. Iterators are the problem. The library writer has to choose between taking a lock for the life time of the iterator (risking deadlock) or needs to update all live iterators when another thread changes the collection (expensive). Only the expensive choice is safe. Again, you choose the strategy that makes most sense, the expensive choice is not forced on you.