C# LocalDataStoreSlot, ThreadStatic, and ThreadLocal To Pass Thread Specific Data

Every thread will have isolated data. I try to show that concurrent web requests are coming to Controller classes and different data is passed to the threads. Lastly, don’t use with async/await, it is not working properly.

LocalDataStoreSlot

ThreadStatic

ThreadLocal

C# Asynchronous Programming Patterns

There are 3 Asynchronous Programming Patterns in C#.

1- Asynchronous Programming Model (APM)
2- Event-based Asynchronous Pattern (EAP)
3- Task-based Asynchronous Pattern (TAP)

 

1- Asynchronous Programming Model (APM)

Asynchronous Programming Model using Delegates

you can reach that article from Calling synchronous methods asynchronously

2- Event-based Asynchronous Pattern (EAP)

3- Task-based Asynchronous Pattern (TAP)

C# and RabbitMQ PubSub Example

Before you run the following C# code, run the below docker code to have a RabbitMQ applicaton locally.

docker run -d –hostname my-rabbit –name some-rabbit -p 8080:15672 -p 5672:5672 rabbitmq:3-management

After run Docker RabbitMQ container, you can reach from http://localhost:8080/ as shown in following picture.

Calling Synchronous Methods Asynchronously with different Patterns

The .NET Framework enables you to call any method asynchronously. Delegates enable you to call a synchronous method in an asynchronous manner. When you call a delegate synchronously, the Invoke method calls the target method directly on the current thread. If the BeginInvoke method is called, the common language runtime (CLR) queues the request and returns immediately to the caller. The target method is called asynchronously on a thread from the thread pool. The original thread, which submitted the request, is free to continue executing in parallel with the target method. If a callback method has been specified in the call to the BeginInvoke method, the callback method is called when the target method ends. In the callback method, the EndInvoke method obtains the return value and any input/output or output-only parameters. If no callback method is specified when calling BeginInvoke, EndInvoke can be called from the thread that called BeginInvoke.

There are several patterns to call a synchronous method asynchronously as shown below.

1- BeginInvoke and EndInvoke
2- WaitHandle
3- Polling
4- Callback

 

BeginInvoke and EndInvoke Pattern

As you see that first message written in console is worked in main thread (ThreadID is 1), But, DoWork() method is called asynchronously, so that, second message is worked on different thread (ThreadID is 3).

DoWork() method returns int value and without parameters, so that, BeginInvoke method shows two parameters(callback, @object) as shown in Figure-2

Notice that EndInvoke() method takes asyncResult variable returned by BeginInvoke() method and it also returns int value because of Func delegate in Figure-3.

Figure-1

Figure-2

Figure-3

Continue reading

File copying on Network showing with Asynchronous Progress Bar in Console Application

The following example demonstrate how to copy files from TcpClient to TcpListener on network asycnhronously. While copying files asynchronously, percentage of copied files are also updated asynchronously.

if cancellation is needed, application can be cancelled by Ctrl + c keys.

Continue reading

Asynchronous Progress Bar in Console Application

The following example demonstrate how to copy files from one directory to other directory asycnhronously. While copying files asynchronously, percentage of copied files are also updated asynchronously.

Notice the second picture, Total files count is 20. But, application could copy 17 files. Because, another process has been using those 3 files. I think you can solve this problem 🙂

if cancellation is needed, application can be cancelled by Ctrl + c keys. It is shown in the third picture.


Continue reading