ParallelLoopState.Stop 메서드

정의

시스템에서 편의상 빨리 수행하는 반복에서 Parallel 루프의 실행이 중단되도록 통신합니다.

public:
 void Stop();
public void Stop ();
member this.Stop : unit -> unit
Public Sub Stop ()

예외

Break() 메서드가 이미 호출되었습니다. Break()Stop()은 동일한 루프의 반복을 조합하여 사용할 수 없습니다.

예제

다음 예제에서는 루프를 최대 10,000회 병렬로 실행합니다. 각 반복은 1~1,000밀리초의 임의 간격으로 일시 중지됩니다. 임의로 생성된 값은 메서드가 호출되는 루프의 반복을 Stop 결정합니다. 예제의 출력에서 보여 주듯이 메서드를 호출 Stop 한 후에는 반복이 실행되지 않습니다.

using System;
using System.Threading;
using System.Threading.Tasks;

public class Example
{
   public static void Main()
   {
      var rnd = new Random();
      long stopIndex = rnd.Next(1, 11);

      Console.WriteLine("Will call Stop in iteration {0}\n", stopIndex);

      var result = Parallel.For(1, 10000, (i, state) => {
                                            Console.WriteLine("Beginning iteration {0}", i);
                                            int delay;
                                            Monitor.Enter(rnd);
                                               delay = rnd.Next(1, 1001);
                                            Monitor.Exit(rnd);
                                            Thread.Sleep(delay);
                                            
                                            if (i == stopIndex) {
                                               Console.WriteLine("Stop in iteration {0}", i);
                                               state.Stop();
                                               return;
                                            }

                                            if (state.IsStopped) {
                                               return;
                                            }

                                            Console.WriteLine("Completed iteration {0}", i);
                                       });
   }
}
// The example displays output like the following:
//       Will call Stop in iteration 5
//
//       Beginning iteration 1
//       Beginning iteration 9993
//       Beginning iteration 8744
//       Beginning iteration 6246
//       Beginning iteration 7495
//       Beginning iteration 3748
//       Beginning iteration 4997
//       Beginning iteration 2499
//       Beginning iteration 1250
//       Completed iteration 6246
//       Beginning iteration 6247
//       Completed iteration 3748
//       Beginning iteration 3749
//       Completed iteration 8744
//       Beginning iteration 8745
//       Completed iteration 7495
//       Beginning iteration 7496
//       Completed iteration 1250
//       Beginning iteration 1251
//       Completed iteration 2499
//       Beginning iteration 2500
//       Completed iteration 1
//       Beginning iteration 2
//       Completed iteration 2500
//       Beginning iteration 2501
//       Completed iteration 3749
//       Beginning iteration 3750
//       Completed iteration 6247
//       Beginning iteration 6248
//       Completed iteration 7496
//       Beginning iteration 7497
//       Completed iteration 3750
//       Beginning iteration 3751
//       Completed iteration 2
//       Beginning iteration 3
//       Completed iteration 9993
//       Beginning iteration 9994
//       Completed iteration 8745
//       Beginning iteration 8746
//       Completed iteration 4997
//       Completed iteration 9994
//       Beginning iteration 9995
//       Beginning iteration 4998
//       Completed iteration 6248
//       Beginning iteration 6249
//       Completed iteration 7497
//       Beginning iteration 7498
//       Completed iteration 1251
//       Beginning iteration 1252
//       Completed iteration 2501
//       Beginning iteration 2502
//       Completed iteration 9995
//       Beginning iteration 9996
//       Completed iteration 4998
//       Beginning iteration 4999
//       Completed iteration 2502
//       Beginning iteration 2503
//       Completed iteration 1252
//       Beginning iteration 1253
//       Completed iteration 7498
//       Beginning iteration 7499
//       Completed iteration 3751
//       Beginning iteration 3752
//       Completed iteration 9996
//       Beginning iteration 9997
//       Completed iteration 1253
//       Beginning iteration 1254
//       Completed iteration 9997
//       Beginning iteration 9998
//       Completed iteration 1254
//       Beginning iteration 1255
//       Completed iteration 6249
//       Beginning iteration 6250
//       Completed iteration 3
//       Beginning iteration 4
//       Completed iteration 4
//       Beginning iteration 5
//       Completed iteration 4999
//       Beginning iteration 5000
//       Completed iteration 8746
//       Beginning iteration 8747
//       Stop in iteration 5
Imports System.Threading
Imports System.Threading.Tasks

Module Example
   Public Sub Main()
      Dim rnd As New Random()
      Dim stopIndex As Long = rnd.Next(1, 11)

      Console.WriteLine("Will call Stop in iteration {0}", stopIndex)
      Console.WriteLine()

      Dim result = Parallel.For(1, 10000, Sub(i, state)
                                            Console.WriteLine("Beginning iteration {0}", i)
                                            Dim delay As Integer
                                            Monitor.Enter(rnd)
                                               delay = rnd.Next(1, 1001)
                                            Monitor.Exit(rnd)
                                            Thread.Sleep(delay)

                                            If i = stopIndex Then
                                               Console.WriteLine("Stop in iteration {0}", i)
                                               state.Stop()
                                               Return
                                            End If

                                            If state.IsStopped Then
                                               Return
                                            End If

                                            Console.WriteLine("Completed iteration {0}", i)
                                       End Sub)
    End Sub
End Module
' The example displays output like the following:
'       Will call Stop in iteration 5
'
'       Beginning iteration 1
'       Beginning iteration 9993
'       Beginning iteration 8744
'       Beginning iteration 6246
'       Beginning iteration 7495
'       Beginning iteration 3748
'       Beginning iteration 4997
'       Beginning iteration 2499
'       Beginning iteration 1250
'       Completed iteration 6246
'       Beginning iteration 6247
'       Completed iteration 3748
'       Beginning iteration 3749
'       Completed iteration 8744
'       Beginning iteration 8745
'       Completed iteration 7495
'       Beginning iteration 7496
'       Completed iteration 1250
'       Beginning iteration 1251
'       Completed iteration 2499
'       Beginning iteration 2500
'       Completed iteration 1
'       Beginning iteration 2
'       Completed iteration 2500
'       Beginning iteration 2501
'       Completed iteration 3749
'       Beginning iteration 3750
'       Completed iteration 6247
'       Beginning iteration 6248
'       Completed iteration 7496
'       Beginning iteration 7497
'       Completed iteration 3750
'       Beginning iteration 3751
'       Completed iteration 2
'       Beginning iteration 3
'       Completed iteration 9993
'       Beginning iteration 9994
'       Completed iteration 8745
'       Beginning iteration 8746
'       Completed iteration 4997
'       Completed iteration 9994
'       Beginning iteration 9995
'       Beginning iteration 4998
'       Completed iteration 6248
'       Beginning iteration 6249
'       Completed iteration 7497
'       Beginning iteration 7498
'       Completed iteration 1251
'       Beginning iteration 1252
'       Completed iteration 2501
'       Beginning iteration 2502
'       Completed iteration 9995
'       Beginning iteration 9996
'       Completed iteration 4998
'       Beginning iteration 4999
'       Completed iteration 2502
'       Beginning iteration 2503
'       Completed iteration 1252
'       Beginning iteration 1253
'       Completed iteration 7498
'       Beginning iteration 7499
'       Completed iteration 3751
'       Beginning iteration 3752
'       Completed iteration 9996
'       Beginning iteration 9997
'       Completed iteration 1253
'       Beginning iteration 1254
'       Completed iteration 9997
'       Beginning iteration 9998
'       Completed iteration 1254
'       Beginning iteration 1255
'       Completed iteration 6249
'       Beginning iteration 6250
'       Completed iteration 3
'       Beginning iteration 4
'       Completed iteration 4
'       Beginning iteration 5
'       Completed iteration 4999
'       Beginning iteration 5000
'       Completed iteration 8746
'       Beginning iteration 8747
'       Stop in iteration 5

루프의 반복은 메서드가 호출될 때 Stop 계속 실행될 가능성이 높기 때문에 각 반복은 메서드를 호출 IsStopped 하여 다른 반복이 메서드를 호출 Stop 했는지 여부를 확인합니다. 반환 true하는 경우 반복이 즉시 반환됩니다.

설명

메서드를 Stop 호출하면 아직 시작되지 않은 루프의 반복을 실행할 필요가 없음을 나타냅니다. 루프의 추가 반복을 효과적으로 취소합니다. 그러나 이미 실행을 시작한 반복은 중지되지 않습니다.

메서드를 Stop 호출하면 IsStopped 여전히 실행 중인 루프의 반복에 대해 속성이 반환 true 됩니다. 이는 장기 실행 반복에 특히 유용합니다. 이 반복은 속성을 확인하고 IsStopped 해당 값 true이 있으면 일찍 종료할 수 있습니다.

Stop 는 일반적으로 검색 기반 알고리즘에서 사용되며, 결과가 발견되면 다른 반복을 실행할 필요가 없습니다.

적용 대상

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