Advanced C#: Thread-Safe Data with Concurrent Collections

Course details

A "thread-safe" class is one whose members are protected from situations in which one thread interrupts another thread. The standard .NET collection types are not thread safe, which can lead to a slew of problems, including race conditions, data corruption, and unexpected exceptions in modern multithreaded applications. In this course, instructor Walt Ritscher demonstrates how to work with the thread-safe concurrent collections to share data across threads and build more scalable applications. Using practical examples, Walt outlines the problems you can face when working in multithreaded applications and explains why concurrent collections are great at handling multiple threads. He explores how to work with the ConcurrentDictionary class, including how to update data in ConcurrentDictionary. Plus, learn about the producer-consumer pattern and how it relates to concurrent collections types, how to use BlockingCollection—a thread-safe collection class—and more.

Concepts

Introduction

Thread-safe data with concurrent collections
What you should know
How to access the sample code on GitHub

Defining the Problem

Collections and threads
Use Queue with single thread
Use Queue with multiple threads
Debug the Queue multiple-thread problem

Deconstruct the .NET Queue Class

Re-implement the sample with custom class
Examine the ExampleQueue code

Using Thread-Safe Code with Standard Collections

Rewrite the code to support thread locks
Use a lock statement and mutex to make thread-safe
Why locking is not a good solution
How the concurrent collections are better

Overview of Thread-Safe Collections

Compare standard and concurrent collections
Categories of collections

Work with the ConcurrentDictionary Class

Create a dictionary
Use TryAdd to add an item
Use TryRemove to remove an item
The GetOrAdd method to get or add an item

Updating Data in ConcurrentDictionary

Review the updated example application
Potential problems with updating an item
Use TryUpdate to update dictionary value
Use a while loop with TryUpdate
Use the AddOrUpdate method
Why ICollection and other interfaces are not thread-safe
Inspect your APIs for ICollection usage

Work with the Producer-Consumer Collections

Overview of the producer-consumer collections
Work with ConcurrentQueue
Work with the ConcurrentStack
Work with the ConcurrentBag

Using the BlockingCollection

Understand the BlockingCollection
Use the BlockingCollection with ConcurrentQueue
Use the CompleteAdding method
Use other collections with BlockingCollection
Read items with multiple consumers
Create items with multiple producers

Continuing Your Journey

Next steps