Thread safe collections in .NET

Question

What is the standard nowadays when one needs a thread safe collection (e.g. Set). Do I synchronize it myself, or is there an inherently thread safe collection?

Answer 1

Pre .net 4.0 most collections in .Net are not thread safe. You'll have to do some work yourself to handle the synchronization: http://msdn.microsoft.com/en-us/library/573ths2x.aspx

Quote from article:

Collections classes can be made thread safe using any of the following methods:

Create a thread-safe wrapper using the Synchronized method, and access the collection exclusively through that wrapper.

If the class does not have a Synchronized method, derive from the class and implement a Synchronized method using the SyncRoot property.

Use a locking mechanism, such as the lock statement in C# (SyncLock in Visual Basic), on the SyncRoot property when accessing the collection.

Sync Root Property
Lock Statement

Object thisLock = new Object();
......
lock (thisLock)
{
    // Critical code section
}

In .net 4.0 the introduced the System.Collections.Concurrent namespace

Blocking Collection
Concurrent Bag
Concurrent Queue
Concurrent Dictionary
Ordable Partitioner
Partitioner
Partitioner T