C # TPL Learning (4 programs)

Program Ⅰ: Create a new thread from the task class

Using system;using system.collections.generic;using system.linq;using system.text;using  system.threading;using system.threading.tasks;namespace test000{    class  Program    {        /// <summary>         /// task Class Package          /// </summary>        class MyTask         {            /  <summary>            ///  First task class, count per second, Count 5 times             /// </ summary>            public static  VOID&NBSP;T1 () &NBSP;&NBSP;&NBSP;&NBsp;        {                 console.writeline ("task #{0}: begin!",  Task.CurrentId );                for  ( int i = 0; i < 5; i++)                  {                     thread.sleep (;     )                console.writeline (" Task #{0}: {1} ",  task.currentid, i);                 }               &nbsP; console.writeline ("task #{0}: terminated!",  task.currentid);             }             /// <summary>            // /  second task class, count per second, Count 5 times             /// < /summary>            public static  Void t2 ()             {                 console.writeline ("Task #{0 }: begin! ",  task.currentid);                 thread.sleep (+);                 for  (int i = 0; i < 5; i++)                  {                     thread.sleep (;  )                    Console.WriteLine ("Task #{0}: {1}",  task.currentid, i);                 }                 console.writeline ("task #{0}: terminated!",  task.currentid);            }         }        static void  Main (String[] args) &NBSP;&Nbsp;      {             //set up two task            task tsk1 =  new task (MYTASK.T1);             Console.WriteLine ("Task #{0}: constructed!",  tsk1. ID);             task tsk2 = new  task (MYTASK.T2);             Console.WriteLine ("Task #{0}: constructed!",  tsk1. ID);             //Run task             tsk1. Start ();             tsk2. Start ();             //wait for task to run end   &Nbsp;         waitall (TSK1,&NBSP;TSK2);             console.readline ();         }        /// <summary>         ///  wait for all task run to end         /// </summary >        /// <param name= "Tsks" > Waiting task Class </param >        public static void waitall (Params Task [] tsks)         {             foreach  (var t in tsks)              {                 T.wait ();            }         }    }}

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Program Ⅱ: Start a task by TaskFactory and receive the return value of the task

Using system;using system.collections.generic;using system.linq;using system.text;using  System.Threading.Tasks;namespace Test001{    class Program     {        /// <summary>         /// task Class Package         /// </summary >        class MyTask         {            /// <summary>             ///  for 1+2+...+n and              /// </summary>             /// <param name= "n" > Number n</param>             /// <returns></returns>             public static int sum (object n)              {                 int x =  (int) n;                 int sum = 0;                 for  (int i =  1; i <= x; i++)                  {                     sum += i;                 }                 return sum;            }         }        static void  Main (String[] args)         {             task<int> tsk = task<int>. Factory.startnew (mytask.sum, 100);             console.writeline ("result is: "  + tsk. Result);             console.readline ();         }    }}

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Program Ⅲ: Call multiple tasks in parallel through the invoke function of the parallel class

Creating a new task with a lambda expression in this program

Using system;using system.collections.generic;using system.linq;using system.text;using  system.threading;using system.threading.tasks;namespace test002{    class  Program    {        static void  Main (String[] args)         {             Parallel.Invoke                  (                      ()  =>                     {                          console.writeline ("Task #{0}: begin! ",  task.currentid);                         for  (int i  = 0; i < 5; i++)                          {                              thread.sleep (;          )                    Console.WriteLine ("Task #{0}: {1}",  task.currentid, i);                          }                         console.writeline ("task #{0}: terminated!",  task.currentid);                     },                       ()  =>                     {                         console.writeline ("Task #{0}:  begin! ",  task.currentid);                         thread.sleep (+);                         for  ( int i = 0; i < 5; i++)                          {                              thread.sleep (;       )                       console.writeline ("Task #{0}: {1}",  task.currentid, i);                          }                   &nbsP;     console.writeline ("task #{0}: terminated!",  Task.CurrentId);                      }                ) ;             console.readline ();         }    }}

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Program Ⅳ: multiple tasks are called in parallel by the for and Foeeach functions of the parallel class

In this procedure, the elapsed time of the Stopwatch class statistic program segment

As you can see from the example, not all loops are valid for parallelization. In general, using sequential loops is faster than parallel loops for small loops or loops that perform very simple operations

using system;using system.collections.generic;using system.diagnostics;using system.linq; Using system.text;using system.threading.tasks;namespace test003{    class  Program    {        /// <summary>         ///  Example Function         /  </summary>        /// <param name= "n" > Parameters </param>        public static void dosomething ( Int n)         {             int sum = 0;             for  (int i = 0; i < n * 100; i++)              {                 sum += i;             }        }         static void main (String[] args)         {             //timing tool, requires system.diagnostics             stopwatch sw = new stopwatch ()             //statistics The time that the function was called sequentially     &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;SW. Start ();            for  (int i =  100; i < 105; i++)             {                 dosomething (;           ) &NBSP;}&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;SW. Stop ();             console.writeline ("TotalTime:  {0} ", &NBSP;SW. elapsed.totalmilliseconds);             sw. Reset ();             console.writeline ("=========== ");             //statistics time of parallel call function     &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;SW. Start ();             parallel.for (100, 105,  dosomething);             sW.stop ();             console.writeline ("TotalTime:  {0} ", &NBSP;SW. elapsed.totalmilliseconds);             sw. Reset ();             console.writeline ("=========== ");             //statistics time of parallel call function     &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;SW. Start ();             parallel.foreach (new int[ 5] { 100, 101, 102, 103, 104 }, dosomething);     &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;SW. Stop ();             console.writeline ("TotalTime:  {0} ", &NBSP;SW. Elapsed.totalmilliseconds);            &nbsP;SW. Reset ();             console.readline ();         }    }}

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END

C # TPL Learning (4 programs)