. Net multithreaded (1) Task

Multithreading is an effective method to improve the efficiency of the program. Of course, for efficiency, more resources such as CPU, memory and so on need to be used.

Concurrency is two queues alternately using a coffee machine, parallel is two queues using two coffee machines at the same time , if serial, a queue using a coffee machine, then even if the person in front of constipation to go to the toilet for half a day, the back of the people can only death him back to pick up coffee, This efficiency is undoubtedly the lowest.

Both concurrency and parallelism can be a lot of threads, just to see if these threads can be executed by (multiple) CPUs at the same time, if it is possible to be parallel, and concurrency is a number of threads that are switched on and off by (a) CPU.

Run a thread

1  class Program2     {3         Static voidMain (string[] args)4         {5             NewThread (Go). Start ();//. NET 1.0 has started.6Task.Factory.StartNew (Go);//. NET 4.0 introduces the TPL7Task.run (NewAction (Go));//. NET 4.5 Adds a new run method8Console.WriteLine ("I am the main thread {0}", Thread.CurrentThread.ManagedThreadId.ToString ());9             varDayname = task.run<string> (() = {returnGetdayofthisweek ();});TenConsole.WriteLine ("today is: {0}", Dayname.result); One console.readline (); A              -         } -          Public Static voidGo () the         { -Console.WriteLine ("I'm another thread {0}", Thread.CurrentThread.ManagedThreadId.ToString ()); -         } -  +          Public Static stringGetdayofthisweek () -         { +             return string. Format ("result {0}", Thread.CurrentThread.ManagedThreadId.ToString ()); A         } at}

TaskFactory class

• Create a task and start the StartNew method immediately by calling

Task wait

• c Ontinuewhenany method. " > Create a task in one of the tasks in the array by calling finish after the start of the  ContinueWhenAny  method.

• continuewhenall method. " > Create a task in which all the tasks in the array have been completed by calling the start  ContinueWhenAll  method.

	AsyncState	Gets the state object provided when the Task was created, or null if not provided.
	Completedtask	Gets a task that has completed successfully.
	Creationoptions	Gets the taskcreationoptions used to create this task.
	CurrentID	Returns the ID of the currently executing Task.
	exception	task to end prematurely. " > get the  task that led to  AggregateException  early termination. task completed successfully or have not yet thrown no exceptions, this would return null ." >  if  task  completed successfully or has not thrown any exceptions, this will return   null .
	Factory	Provides access to the factory method used to create task and task<TResult> .
	Id	Gets The ID of this Task instance.
	IsCanceled	Gets Whether this Task instance has been executed because of the reason it was canceled.
	IsCompleted	Gets Whether this Task has completed.
	isfaulted	Gets whether the Task was completed because of an unhandled exception.
	Status	Gets the taskstatus for this task.

Https://msdn.microsoft.com/zh-cn/library/system.threading.tasks.task (v=vs.110). aspx

Of course, this does not take into account the operation of shared data, when multiple threads operate on the same data source, the uncontrolled order can have unintended consequences.

. Net multithreaded (1) Task