C # multi-threaded programming-use a delegate to create a thread

Processes and threads

Process: A process contains resources, such as a Windows handle, a file system handle, or other core objects. Each process is allocated virtual memory. A process contains at least one thread. The Operating System Schedules threads.

Process Management resources include virtual memory and Windows handle.

 

Thread: Each thread has its own stack,ProgramCodeMemory and heap are shared by all threads in a process.

 

In. net, managed threads are defined by the Thread class. Managed threads are not necessarily mapped to an operating system thread.

 

Three ways to create a thread using a delegate

1. Pooling voting method

2. waithandle wait handle

3. asynchronous call asynchronous callback

 // Asynchronous delegation example  // Herbert  // For personal learning and use  Using System; Using System. Collections. Generic; Using System. LINQ;Using System. text; Using System. Threading; Using System. diagnostics; Namespace Asydelegate { Class Program { Public   Delegate   Int Takesawhiledelegate ( Int Data, Int MS ); Static   Int Takesawhile ( Int Data, Int MS) {console. writeline ("Takesawhile started" ); Thread. Sleep (MS); console. writeline ( "Talesawhile completed" ); Return ++ Data ;} Public   Static   Void Method1 (){ // Method 1              // Synchronouse method call              // Takesawhile (1, 3000)              // Asynchronous by using a delegate              // Iasyncresult can obtain the delegate information and verify whether the delegate has completed the task. Takesawhiledelegate DL = takesawhile; iasyncresult AR = DL. begininvoke (1, 3000, Null ,Null ); While (! Ar. iscompleted ){ // Do something else in the main thread Console. Write ( "." ); Thread. Sleep (50 );} Int Result = DL. endinvoke (AR); console. writeline ( "Result: {0 }" , Result );} Public   Static   Void Method2 (){ // Method 2 waiting for handle              // Synchronouse method call             // Takesawhile (1, 3000)              // Asynchronous by using a delegate              // Waitone () uses a time-out period as the first optional parameter and defines the maximum time to wait Takesawhiledelegate DL = takesawhile; iasyncresult AR = DL. begininvoke (1, 3000, Null , Null ); While ( True ){ // Do something else in the main thread Console. Write ( "." ); If (AR. asyncwaithandle. waitone (50, False ) {Console. writeline ( "Can get the result now" ); Break ;}} Int Result = DL. endinvoke (AR); console. writeline ( "Result: {0 }" , Result );} Public   Static   Void Takesawhilecompleted (iasyncresult AR ){ // Method 3: asynchronous callback              If (AR = Null ) Throw   New Argumentnullexception ( "Ar" ); Takesawhiledelegate d1 = ar. asyncstate As Takesawhiledelegate; trace. Assert (d1! = Null , "Invalid object type" ); Int Result = d1.endinvoke (AR); console. writeline ( "Result: {0 }" , Result );} Static   Void Main ( String [] ARGs) {stopwatch SW1 = New Stopwatch (); console. writeline ( "Method 1 pooling started :" ); Sw1.start (); program. Method1 (); sw1.stop (); console. writeline (sw1.elapsedmilliseconds. tostring (); stopwatch sw2 = New Stopwatch (); console. writeline ( "Method 2 wait handler started :" ); Sw2.start (); program. method2 (); sw2.stop (); console. writeline (sw2.elapsedmilliseconds. tostring (); stopwatch sw3 = New Stopwatch (); console. writeline ( "Method 3 asynchronize callback started :" ); Sw3.start (); takesawhiledelegate d1 = takesawhile; /*  D1.begininvoke (1, 3000, AR => {  Int result = d1.endinvoke (AR );  Console. writeline ("Result: {0}", result );  }), Null;  */ D1.begininvoke (1, 3000, takesawhilecompleted, D1 ); For ( Int I = 0; I <100; I ++) {console. Write ( "." ); Thread. Sleep (50);} console. writeline (sw3.elapsedmilliseconds. tostring (); console. readkey ();}}}

 

By comparing the running time, the voting method and asynchronous callback are easier to use. It seems that the voting method is less efficient, while asynchronous callback is the most efficient.