字典的线程安全<TKey, TValue>

Question

If I initialize a generic dictionary once, and no further adds/updates/removes are allowed, is it safe to have multiple threads reading from it with no locking (assuming that the dictionary is initialized before the readers are started)?

There is a note in the help for the non-generic HashTable that says that it is safe for multiple readers, but I did not see something similar for the Generic Dictionary.

Answer 1

For your future reference, the documentation is here:

http://msdn.microsoft.com/en-us/library/xfhwa508.aspx

It says:

A Dictionary can support multiple readers concurrently, as long as the collection is not modified. Even so, enumerating through a collection is intrinsically not a thread-safe procedure. In the rare case where an enumeration contends with write accesses, the collection must be locked during the entire enumeration. To allow the collection to be accessed by multiple threads for reading and writing, you must implement your own synchronization.

Answer 2

Yes, it's safe if you don't modify the dictionary any more. Thread safety is only an issue in read/write scenarios