You asked: Is STL map thread safe?

Is STL vector thread safe?

Well, vector’s interface isn’t optimal for concurrent use. It is fine if the client has access to a lock, but for for the interface to abstract locking for each operation — no. In fact, vector’s interface cannot guarantee thread safety without an external lock (assuming you need operations which also mutate).

Is map insert thread safe?

No, std::map::insert is not thread-safe. There are many reasons why your example may not crash. Your threads may be running in a serial fashion due to the system scheduler, or because they finish very quickly (1000 iterations isn’t that much).

Is std::map find thread safe?

No, the C++ spec makes no guarantees on thread safety in the spec for operations on any STL containers. If thread safety is important, the you should provide your own locking.

Is reading a map thread safe C++?

Yes it is. See related post with same question about std::set: Is the C++ std::set thread-safe? Show activity on this post.

Why are vectors thread-safe?

Vector is a thread-safe collection – all its methods are synchronized by default. This is why it’s recommended to use ArrayList instead – it’s not thread-safe which results in a better performance for single-thread applications.

Is ArrayList thread-safe in Java?

Synchronization. Vectors are synchronized. Any method that touches the Vector ‘s contents is thread safe. ArrayList , on the other hand, is unsynchronized, making them, therefore, not thread safe.

Is std :: Unordered_map thread-safe?

std::unordered_map is a good fit for some multi-threaded situations. There are also other concurrent maps from Intel TBB: tbb:concurrent_hash_map . It supports fine-grained, per-key locking for insert/update, which is something that few other hashmaps can offer.

How do you make a map thread-safe in Java?

Legacy map

If a thread-safe implementation is not needed, it is recommended to use HashMap in place of Hashtable . If a thread-safe highly-concurrent implementation is desired, then it is recommended to use ConcurrentHashMap in place of Hashtable .

Would it be possible for multiple threads to operate on independent entries of an unordered map?

Would it be possible for multiple threads to operate on independent entries of an unordered map? True (there isn’t much difference between vector and map. They both need to be pre-populated with initial entries for the thread to operate on.) You just studied 24 terms!