ThreadPool class is used to manage a set of readily available threads to be used by a process. We can use ThreadPool class for creating threads when we require large number of short living threads. A short living thread is a thread that is created to perform a single task and then terminated.We can use ThreadPool class when it is not necessary to have full control over each individual threads.
Note: There is a limit of 25 threads in a thread pool. That means if you
start 50 threads then only 25 threads is active at a time. As soon as a
thread finishes another thread is active from thread pool.
Avoiding uses of ThreadPool class when following situation raise
1. Requires a foreground thread.
2. Requires a thread to have a particular priority.
3. Have task that can block threads for long period of time. The threadpool has a maximum number of threads, so a large number of threadsfrom the thread pool being blocked might prevent task from starting.
4. Need to have stable identity associated with thread.
5. Need to place threads into a single threaded apartment.
Implementation of ThreadPool class
static void Main(string args)
//Call QueueUserWorkItem method of ThreadPool claas
//to send Thread in ThreadPool and pass object of
Console.WriteLine("Main Thread Started.");
Console.WriteLine("Main Thread Exists.");
/// This method is passed to WaitCallback delegate.
/// This method is used to print numbers from 1 to 50.
/// Main thread exists in two case either time fiven in main sleep
/// method over of number is printed from 1 to 50.
/// <param name="stateInfo"></param>
static void ThreadProc(object stateInfo)
Console.WriteLine("Welcome from thread pool. I will count from 1 to 50");
for (int i = 1; i <= 50; i++)
Execute above program to see the output.