Applying the CLR's thread pool

As you all know, the creation and destruction of this thread requires a lot of performance overhead, and when there are more and different tasks that need to be done, consider using a thread pool to manage those threads. Each process on a Windows NT-based operating system contains a thread pool, where there are many threads that can be used at any time, and when the application is in use, a thread that already exists is removed from the thread pool and is not destroyed immediately after the use of a thread is complete. Instead, it is placed in the thread pool to wait for the next use.

In C #, through system. Threading.threadpool provides the following common methods and instructions.

Method name	Description
Bindhandle	Binds an operating system handle to ThreadPool.
GetAvailableThreads	Retrieves the difference between the maximum number of threads returned by the GetMaxThreads method and the number of currently active threads.
GetMaxThreads	Retrieves the number of thread pool requests that are active at the same time, and all requests that are greater than this number remain queued until the thread pool threads become available.
GetMinThreads	Retrieves the number of idle threads that the thread pool maintains in the new request forecast.
QueueUserWorkItem	The method is queued for execution, and this method executes when the thread pool threads become available.
RegisterWaitForSingleObject	Registers the delegate that is waiting for WaitHandle.
SetMaxThreads	Sets the number of requests for a thread pool that can be active at the same time. All requests that are greater than this number remain queued until the thread pool threads become available.
SetMinThreads	Sets the number of idle threads that the thread pool maintains in the new request forecast.
Unsafequeueuserworkitem	Register a delegate waiting for WaitHandle.
Unregisterwaitforsingleobject	Queues the specified delegate to the thread pool.

As an example:

 Static voidMain (string[] args) {            intintworkthreads; intintcompletionportthreads; Threadpool.getmaxthreads ( outIntworkthreads, outintcompletionportthreads); Console.WriteLine ("maximum number of worker threads: {0}, max I/O threads: {1}", intworkthreads,intcompletionportthreads); //gets information about the maximum number of threads.              for(inti =0; I <3; i++) {ThreadPool.QueueUserWorkItem (testthreadpool);//request threads in the thread pool. } console.readline (); }        Static voidTestthreadpool (Objectobj) {             for(inti =0; I <3; i++)            {                //Thread.CurrentThread.ManagedThreadId Gets the identity of the running thread. Console.WriteLine ("thread pool, the unique identity of the running thread is {0}", Thread.CurrentThread.ManagedThreadId); } thread.sleep ( -); }

Threads running in the thread pool are background threads, that is, the IsBackground property of all threads in the thread pool is set to true, the background thread does not affect the end of the application, and the foreground thread has a significant effect on the end of the application. Because the application exits must wait for all foreground threads to end.

Applying the CLR's thread pool