Is std::map find thread safe?

4 Answers. No, the C++ spec makes no guarantees on thread safety in the spec for operations on any STL containers.

Is STD unordered map thread safe?

No, the standard containers are not thread safe.

Is STD list thread safe?

Generally, yes. If every thread/path that modifies or reads the list locks the same mutex before doing so, then access to the list can be considered thread safe. Note that caveats apply if someone holds on to iterators, references or pointers to list items outside the scope of the lock.

Is map in C++ thread safe?

std::map thread-safety It isn’t thread safe, insert from two threads and you can end up in an inconstant state.

How do you make a map thread safe in C++?

6 Answers. You can use a shared_mutex beside your map to acquire shared or unique access. Generally, a write operation will require unique access, while read operations will require shared access. Any number of threads can acquire shared access, as long as no threads are holding unique access.

Is std::map Atomic?

std::atomic as a value of std::map std::atomic is a C++11 feature, you probably should not expect these things to work very well unless you are willing to use a compiler offering robust support for C++11.

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.)

What is shared mutex?

The shared_mutex class is a synchronization primitive that can be used to protect shared data from being simultaneously accessed by multiple threads. shared – several threads can share ownership of the same mutex.

How do I make a HashMap thread-safe?

You can make HashMap thread safe by wrapping it with Collections. synchronizedMap() . What’s the difference? @naXa ConcurrentHashMap allows concurrent access and a synchronized one doesn’t.

Is std :: string Atomic?

std::string certainly does not meet the std::atomic requirement that the template parameter T be trivially copyable, so the standard places no requirements on the implementation.

Are std::map containers thread-safe?

After learning that std::map containers are not inherently atomic and therefore not thread-safe (check out this related Stack Overflow question and usage example), I decided to create code that would allow concurrent access to the container.

Is find call on STL map thread safe?

Bookmark this question. Show activity on this post. Is find call on stl map thread safe? Show activity on this post. 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 it safe to use a thread to write to a map?

Elements in a map are stable, they do not get moved or invalidated unless the element is erased from the map. If only one thread is writing to a given object, and changes to the map itself are correctly synchronized, then I believe it will be safe. I’m sure it’s safe in practice, and I think it’s safe in theory too.

Is the SGI STL thread safe?

The SGI implementation of STL is thread-safe only in the sense that simultaneous accesses to distinct containers are safe, and simultaneous read accesses to to shared containers are safe.