Queue.Synchronized(Queue) 方法

定义

命名空间:

System.Collections

程序集:

System.Collections.NonGeneric.dll

Source:

Queue.cs

返回将包装原始队列并且是线程安全的新的 Queue。

public:
 static System::Collections::Queue ^ Synchronized(System::Collections::Queue ^ queue);

public static System.Collections.Queue Synchronized (System.Collections.Queue queue);

static member Synchronized : System.Collections.Queue -> System.Collections.Queue

Public Shared Function Synchronized (queue As Queue) As Queue

参数

queue

Queue

要同步的 Queue。

返回

Queue

同步的（线程安全）Queue 包装。

例外

ArgumentNullException

queue 为 null。

示例

下面的代码示例演示如何在整个枚举期间使用 SyncRoot 锁定集合。 此方法是一个 O(1) 操作。

Queue^ myCollection = gcnew Queue();
bool lockTaken = false;
try
{
    Monitor::Enter(myCollection->SyncRoot, lockTaken);
    for each (Object^ item in myCollection);
    {
        // Insert your code here.
    }
}
finally
{
    if (lockTaken)
    {
        Monitor::Exit(myCollection->SyncRoot);
    }
}

Queue myCollection = new Queue();
lock (myCollection.SyncRoot)
{
    foreach (object item in myCollection)
    {
        // Insert your code here.
    }
}

Dim myCollection As New Queue()
SyncLock myCollection.SyncRoot
    For Each item In myCollection
        ' Insert your code here.
    Next item
End SyncLock

以下示例演示如何同步 Queue，确定 是否 Queue 同步并使用同步的 Queue。

#using <system.dll>

using namespace System;
using namespace System::Collections;
int main()
{
   
   // Creates and initializes a new Queue.
   Queue^ myQ = gcnew Queue;
   myQ->Enqueue( "The" );
   myQ->Enqueue( "quick" );
   myQ->Enqueue( "brown" );
   myQ->Enqueue( "fox" );
   
   // Creates a synchronized wrapper around the Queue.
   Queue^ mySyncdQ = Queue::Synchronized( myQ );
   
   // Displays the sychronization status of both Queues.
   Console::WriteLine( "myQ is {0}.", myQ->IsSynchronized ? (String^)"synchronized" : "not synchronized" );
   Console::WriteLine( "mySyncdQ is {0}.", mySyncdQ->IsSynchronized ? (String^)"synchronized" : "not synchronized" );
}

/*
This code produces the following output.

myQ is not synchronized.
mySyncdQ is synchronized.
*/

using System;
using System.Collections;

public class SamplesQueue
{
    public static void Main()
    {
        // Creates and initializes a new Queue.
        Queue myQ = new Queue();
        myQ.Enqueue("The");
        myQ.Enqueue("quick");
        myQ.Enqueue("brown");
        myQ.Enqueue("fox");

        // Creates a synchronized wrapper around the Queue.
        Queue mySyncdQ = Queue.Synchronized(myQ);

        // Displays the sychronization status of both Queues.
        Console.WriteLine("myQ is {0}.", myQ.IsSynchronized ? "synchronized" : "not synchronized");
        Console.WriteLine("mySyncdQ is {0}.", mySyncdQ.IsSynchronized ? "synchronized" : "not synchronized");
    }
}
/*
This code produces the following output.

myQ is not synchronized.
mySyncdQ is synchronized.
*/

Imports System.Collections

Public Class SamplesQueue    
    
    Public Shared Sub Main()
        
        ' Creates and initializes a new Queue.
        Dim myQ As New Queue()
        myQ.Enqueue("The")
        myQ.Enqueue("quick")
        myQ.Enqueue("brown")
        myQ.Enqueue("fox")
        
        ' Creates a synchronized wrapper around the Queue.
        Dim mySyncdQ As Queue = Queue.Synchronized(myQ)
        
        ' Displays the sychronization status of both Queues.
        Dim msg As String
        If myQ.IsSynchronized Then
            msg = "synchronized"
        Else
            msg = "not synchronized"
        End If
        Console.WriteLine("myQ is {0}.", msg)
        If mySyncdQ.IsSynchronized Then
            msg = "synchronized"
        Else
            msg = "not synchronized"
        End If
        Console.WriteLine("mySyncdQ is {0}.", msg)
    End Sub
End Class

' This code produces the following output.
' 
' myQ is not synchronized.
' mySyncdQ is synchronized.

注解

此方法返回的包装器将在操作执行前锁定队列，以便以线程安全的方式执行此操作。

若要保证 的 Queue线程安全，必须仅通过此包装器执行所有操作。

枚举整个集合本质上不是一个线程安全的过程。 即使某个集合已同步，其他线程仍可以修改该集合，这会导致枚举数引发异常。 若要确保枚举过程中的线程安全性，可以在整个枚举期间锁定集合，或者捕获由其他线程进行的更改所导致的异常。

另请参阅

• IsSynchronized
• SyncRoot