ConcurrentBag<T> 类

定义

generic <typename T>
public ref class ConcurrentBag : System::Collections::Concurrent::IProducerConsumerCollection<T>, System::Collections::Generic::IEnumerable<T>, System::Collections::Generic::IReadOnlyCollection<T>, System::Collections::ICollection

generic <typename T>
public ref class ConcurrentBag : System::Collections::Concurrent::IProducerConsumerCollection<T>, System::Collections::Generic::IEnumerable<T>

generic <typename T>
public ref class ConcurrentBag : System::Collections::Concurrent::IProducerConsumerCollection<T>, System::Collections::Generic::IEnumerable<T>, System::Collections::Generic::IReadOnlyCollection<T>

generic <typename T>
public ref class ConcurrentBag : System::Collections::Concurrent::IProducerConsumerCollection<T>, System::Collections::Generic::IEnumerable<T>, System::Collections::ICollection

public class ConcurrentBag<T> : System.Collections.Concurrent.IProducerConsumerCollection<T>, System.Collections.Generic.IEnumerable<T>, System.Collections.Generic.IReadOnlyCollection<T>, System.Collections.ICollection

[System.Runtime.InteropServices.ComVisible(false)]
[System.Serializable]
public class ConcurrentBag<T> : System.Collections.Concurrent.IProducerConsumerCollection<T>, System.Collections.Generic.IEnumerable<T>

[System.Runtime.InteropServices.ComVisible(false)]
[System.Serializable]
public class ConcurrentBag<T> : System.Collections.Concurrent.IProducerConsumerCollection<T>, System.Collections.Generic.IEnumerable<T>, System.Collections.Generic.IReadOnlyCollection<T>

public class ConcurrentBag<T> : System.Collections.Concurrent.IProducerConsumerCollection<T>, System.Collections.Generic.IEnumerable<T>, System.Collections.ICollection

public class ConcurrentBag<T> : System.Collections.Concurrent.IProducerConsumerCollection<T>, System.Collections.Generic.IEnumerable<T>, System.Collections.Generic.IReadOnlyCollection<T>

type ConcurrentBag<'T> = class
    interface IProducerConsumerCollection<'T>
    interface seq<'T>
    interface IEnumerable
    interface ICollection
    interface IReadOnlyCollection<'T>

[<System.Runtime.InteropServices.ComVisible(false)>]
[<System.Serializable>]
type ConcurrentBag<'T> = class
    interface IProducerConsumerCollection<'T>
    interface seq<'T>
    interface ICollection
    interface IEnumerable

[<System.Runtime.InteropServices.ComVisible(false)>]
[<System.Serializable>]
type ConcurrentBag<'T> = class
    interface IProducerConsumerCollection<'T>
    interface seq<'T>
    interface IEnumerable
    interface ICollection
    interface IReadOnlyCollection<'T>

type ConcurrentBag<'T> = class
    interface IProducerConsumerCollection<'T>
    interface seq<'T>
    interface ICollection
    interface IEnumerable

Public Class ConcurrentBag(Of T)
Implements ICollection, IEnumerable(Of T), IProducerConsumerCollection(Of T), IReadOnlyCollection(Of T)

Public Class ConcurrentBag(Of T)
Implements IEnumerable(Of T), IProducerConsumerCollection(Of T)

Public Class ConcurrentBag(Of T)
Implements IEnumerable(Of T), IProducerConsumerCollection(Of T), IReadOnlyCollection(Of T)

Public Class ConcurrentBag(Of T)
Implements ICollection, IEnumerable(Of T), IProducerConsumerCollection(Of T)

类型参数

继承

Object

ConcurrentBag<T>

属性

ComVisibleAttribute SerializableAttribute

实现

IProducerConsumerCollection<T> IEnumerable<T> IReadOnlyCollection<T> ICollection IEnumerable

示例

以下示例演示如何从 /> 中添加和删除项：

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Threading.Tasks;
using System.Threading;

class ConcurrentBagDemo
{
    // Demonstrates:
    //      ConcurrentBag<T>.Add()
    //      ConcurrentBag<T>.IsEmpty
    //      ConcurrentBag<T>.TryTake()
    //      ConcurrentBag<T>.TryPeek()
    static void Main()
    {
        // Add to ConcurrentBag concurrently
        ConcurrentBag<int> cb = new ConcurrentBag<int>();
        List<Task> bagAddTasks = new List<Task>();
        for (int i = 0; i < 500; i++)
        {
            var numberToAdd = i;
            bagAddTasks.Add(Task.Run(() => cb.Add(numberToAdd)));
        }

        // Wait for all tasks to complete
        Task.WaitAll(bagAddTasks.ToArray());

        // Consume the items in the bag
        List<Task> bagConsumeTasks = new List<Task>();
        int itemsInBag = 0;
        while (!cb.IsEmpty)
        {
            bagConsumeTasks.Add(Task.Run(() =>
            {
                int item;
                if (cb.TryTake(out item))
                {
                    Console.WriteLine(item);
                    Interlocked.Increment(ref itemsInBag);
                }
            }));
        }
        Task.WaitAll(bagConsumeTasks.ToArray());

        Console.WriteLine($"There were {itemsInBag} items in the bag");

        // Checks the bag for an item
        // The bag should be empty and this should not print anything
        int unexpectedItem;
        if (cb.TryPeek(out unexpectedItem))
            Console.WriteLine("Found an item in the bag when it should be empty");
    }
}

module ConcurrentBagDemo

open System.Collections.Concurrent
open System.Threading.Tasks
open System.Threading

// Demonstrates:
//      ConcurrentBag<T>.Add()
//      ConcurrentBag<T>.IsEmpty
//      ConcurrentBag<T>.TryTake()
//      ConcurrentBag<T>.TryPeek()

// Add to ConcurrentBag concurrently
let cb = ConcurrentBag<int>()

let bagAddTasks =
    [| for i = 0 to 499 do
           let numberToAdd = i
           task { cb.Add numberToAdd } :> Task |]

// Wait for all tasks to complete
Task.WaitAll bagAddTasks

// Consume the items in the bag
let mutable itemsInBag = 0

let bagConsumeTasks =
    [| while not cb.IsEmpty do
           task {
               let mutable item = 0

               if cb.TryTake &item then
                   printfn $"{item}"
                   Interlocked.Increment &itemsInBag |> ignore
           }
           :> Task |]

Task.WaitAll bagConsumeTasks

printfn $"There were {itemsInBag} items in the bag"

// Checks the bag for an item
// The bag should be empty and this should not print anything
let mutable unexpectedItem = 0

if cb.TryPeek &unexpectedItem then
    printfn "Found an item in the bag when it should be empty"

Imports System.Collections.Concurrent

Module ConcurrentBagDemo
    ' Demonstrates:
    ' ConcurrentBag<T>.Add()
    ' ConcurrentBag<T>.IsEmpty
    ' ConcurrentBag<T>.TryTake()
    ' ConcurrentBag<T>.TryPeek()
    Sub Main()
        ' Add to ConcurrentBag concurrently
        Dim cb As New ConcurrentBag(Of Integer)()
        Dim bagAddTasks As New List(Of Task)()
        For i = 1 To 500
            Dim numberToAdd As Integer = i
            bagAddTasks.Add(Task.Run(Sub() cb.Add(numberToAdd)))
        Next

        ' Wait for all tasks to complete
        Task.WaitAll(bagAddTasks.ToArray())

        ' Consume the items in the bag
        Dim bagConsumeTasks As New List(Of Task)()
        Dim itemsInBag As Integer = 0
        While Not cb.IsEmpty
            bagConsumeTasks.Add(Task.Run(Sub()
                                             Dim item As Integer
                                             If cb.TryTake(item) Then
                                                 Console.WriteLine(item)
                                                 itemsInBag = itemsInBag + 1
                                             End If
                                         End Sub))
        End While

        Task.WaitAll(bagConsumeTasks.ToArray())

        Console.WriteLine($"There were {itemsInBag} items in the bag")

        ' Checks the bag for an item
        ' The bag should be empty and this should not print anything
        Dim unexpectedItem As Integer
        If cb.TryPeek(unexpectedItem) Then
            Console.WriteLine("Found an item in the bag when it should be empty")
        End If
    End Sub
End Module

注解

包可用于在排序无关紧要时存储对象，与集不同，包支持重复项。 ConcurrentBag<T> 是一种线程安全包实现，针对同一线程将同时生成和使用存储在包中的数据的方案进行优化。

ConcurrentBag<T> 接受 null 为引用类型的有效值。

有关详细信息，请参阅FAQ 的条目：所有新的并发集合是否都是无锁的？与 .NET 博客并行编程。

线程安全性

所有公共成员和受保护的成员 ConcurrentBag<T> 都是线程安全的，并且可以同时从多个线程使用。 但是，实现（包括扩展方法）通过其中一个接口 ConcurrentBag<T> 访问的成员不能保证线程安全，并且可能需要由调用方同步。

另请参阅

• 线程安全集合