C# 使用多个元素阻止集合?
生产者-消费者集合[1][2]的所有C#实现似乎都有一个模糊相似的接口:C# 使用多个元素阻止集合?,c#,.net,producer-consumer,C#,.net,Producer Consumer,生产者-消费者集合[1][2]的所有C#实现似乎都有一个模糊相似的接口: private Queue<T> items; public void Produce(T item) public T Consume() 专用队列项目; 公共产品(T项) 公共消费 有没有像下面这样的实现 private Queue<T> items; public void Produce(T[] item) public T[] Consume(int count) 专用队列项目;
private Queue<T> items;
public void Produce(T item)
public T Consume()
专用队列项目;
公共产品(T项)
公共消费
有没有像下面这样的实现
private Queue<T> items;
public void Produce(T[] item)
public T[] Consume(int count)
专用队列项目;
公共无效产品(T[]项)
公共T[]消耗(整数计数)
希望这能让我一次生产/消费不同数量的物品,而不需要过多的每件物品锁定。这对于生产/消费大量项目似乎是必要的,但我还没有找到任何实现
[1]
[2]
希望这能让我一次生产/消费不同数量的物品,而不需要过多的每件物品锁定
你可以使用这个类;尽管它没有添加或获取多个项的方法,但它在内部不使用锁。根据您想要实现的具体内容,有多种可能的方法 这里有接口的实现。据我所知,.NET framework中此接口的唯一线程安全实现是 此类允许您拥有阻塞或非阻塞生产者和消费者。通过在构造函数中为集合提供容量限制,生产者端在阻塞和非阻塞之间设置。正如该方法的文件所述: 如果在初始化此实例时指定了有界容量,则Add调用可能会阻塞,直到有空间存储提供的项为止 对于获取项目,您可以使用不同的
Take
和TryTake
方法,或者使用非常方便的方法创建IEnumerable
,创建IEnumerator
,该方法在获取下一个值时使用BlockingCollection
中的一个元素,并在源集合中阻塞是空的。直到调用并且集合不接受任何新数据为止。此时,所有使用可枚举实例的实例都将停止阻塞,并报告不再有数据(只要所有剩余数据都已使用)
因此,您基本上可以实现这样的消费者:
BlockingCollection<...> bc = ...
foreach (var item in bc.GetConsumingEnumerable())
{
// do something with your item
}
BlockingCollection bc=。。。
foreach(bc.GetConsumingEnumerable()中的变量项)
{
//对你的物品做点什么
}
这样的使用者可以在多个线程中启动,因此如果您选择,您可以有多个线程从源代码中读取。您可以创建任意数量的使用枚举
您应该知道,这个集合实际上只是一个包装器。有一个构造函数允许您设置使用的集合类型。默认情况下。这意味着默认情况下集合的行为类似于此队列,并且是先进先出集合,以防您只使用一个生产者和一个消费者
尽管如此,还是有另一种选择。如果您不需要阻塞部分(或者您想自己实现阻塞部分),如果您不需要集合中元素的任何顺序,那么就有了。此集合非常有效地处理来自多个线程的访问。它在包装中使用较小的集合。因此,每个线程都使用自己的存储,只有当线程自身存储中的项目用完时,它才会开始从另一个线程存储中获取项目
在您的用例中,使用此集合可能会使用例的生成和消费顺序变得有趣。因此,您首先添加所有项目,一旦完成,您将使用所有项目,这两个项目都有多个线程。正是出于这一需要,我自己创建了一个方法扩展。请注意,如果至少从队列中删除了一个元素,则此调用将记录任何其他异常,并返回这一个元素以防止丢失任何内容
public static class BlockingCollectionMethodExtensions
{
public static List<T> FetchAtLeastOneBlocking<T>(this BlockingCollection<T> threadSafeQueue, int maxCount, ICommonLog log)
{
var resultList = new List<T>();
// Take() will block the thread until new elements appear
// It will also throw an InvalidOperationException when blockingCollection is Completed
resultList.Add(threadSafeQueue.Take());
try
{
// Fetch more unblocking
while (threadSafeQueue.Count > 0 && resultList.Count < maxCount)
{
T item;
bool success = false;
success = threadSafeQueue.TryTake(out item);
if (success)
{
resultList.Add(item);
}
else
{
}
}
}
catch (Exception ex)
{
log.Fatal($"Unknown error fetching more elements. Continuing to process the {resultList.Count} already fetched items.", ex);
}
return resultList;
}
}
公共静态类BlockingCollectionMethodExtensions
{
公共静态列表FetchAtlastoneBlocking(此BlockingCollection threadSafeQueue、int-maxCount、ICommonLog日志)
{
var resultList=新列表();
//Take()将阻止线程,直到出现新元素
//当blockingCollection完成时,它还将抛出InvalidOperationException
Add(threadSafeQueue.Take());
尝试
{
//获取更多解锁
while(threadSafeQueue.Count>0&&resultList.Count
以及相应的测试:
public class BlockingCollectionMethodExtensionsTest : UnitTestBase
{
[Fact]
public void FetchAtLeastOneBlocking_FirstEmpty_ThenSingleEntryAdded_ExpectBlocking_Test()
{
var queue = new BlockingCollection<int>();
var startEvent = new ManualResetEvent(initialState: false);
var completedEvent = new ManualResetEvent(initialState: false);
List<int> fetchResult = null;
var thread = new Thread(() =>
{
startEvent.Set();
fetchResult = queue.FetchAtLeastOneBlocking<int>(maxCount: 3, log: null);
completedEvent.Set();
});
thread.Start();
var startedSuccess = startEvent.WaitOne(TimeSpan.FromSeconds(2)); // Wait until started
Assert.True(startedSuccess);
// Now wait for 2 seconds to ensure that nothing will be fetched
Thread.Sleep(TimeSpan.FromSeconds(1));
Assert.Null(fetchResult);
// Add a new element and verify that the fetch method succeeded
queue.Add(78);
var completedSuccess = completedEvent.WaitOne(timeout: TimeSpan.FromSeconds(2));
Assert.True(completedSuccess);
Assert.NotNull(fetchResult);
Assert.Single(fetchResult);
Assert.Equal(78, fetchResult.Single());
}
[Fact]
public void FetchAtLeastOneBlocking_FirstEmpty_ThenCompleted_ExpectOperationException_Test()
{
var queue = new BlockingCollection<int>();
Exception catchedException = null;
var startEvent = new ManualResetEvent(initialState: false);
var exceptionEvent = new ManualResetEvent(initialState: false);
List<int> fetchResult = null;
var thread = new Thread(() =>
{
startEvent.Set();
try
{
fetchResult = queue.FetchAtLeastOneBlocking<int>(maxCount: 3, log: null);
}
catch (Exception ex)
{
catchedException = ex;
exceptionEvent.Set();
}
});
thread.Start();
var startedSuccess = startEvent.WaitOne(TimeSpan.FromSeconds(2)); // Wait until started
Assert.True(startedSuccess);
// Now wait for 2 seconds to ensure that nothing will be fetched
Thread.Sleep(TimeSpan.FromSeconds(1));
Assert.Null(fetchResult);
// Now complete the queue and assert that fetching threw the expected exception
queue.CompleteAdding();
// Wait for the exception to be thrown
var exceptionSuccess = exceptionEvent.WaitOne(TimeSpan.FromSeconds(2));
Assert.True(exceptionSuccess);
Assert.NotNull(catchedException);
Assert.IsType<InvalidOperationException>(catchedException);
}
[Fact]
public void FetchAtLeastOneBlocking_SingleEntryExists_ExpectNonblocking_Test()
{
var queue = new BlockingCollection<int>();
// Add a new element and verify that the fetch method succeeded
queue.Add(78);
var startEvent = new ManualResetEvent(initialState: false);
var completedEvent = new ManualResetEvent(initialState: false);
List<int> fetchResult = null;
var thread = new Thread(() =>
{
startEvent.Set();
fetchResult = queue.FetchAtLeastOneBlocking<int>(maxCount: 3, log: null);
completedEvent.Set();
});
thread.Start();
var startedSuccess = startEvent.WaitOne(TimeSpan.FromSeconds(2)); // Wait until started
Assert.True(startedSuccess);
// Now wait for expected immediate completion
var completedSuccess = completedEvent.WaitOne(timeout: TimeSpan.FromSeconds(2));
Assert.True(completedSuccess);
Assert.NotNull(fetchResult);
Assert.Single(fetchResult);
Assert.Equal(78, fetchResult.Single());
}
[Fact]
public void FetchAtLeastOneBlocking_MultipleEntriesExist_ExpectNonblocking_Test()
{
var queue = new BlockingCollection<int>();
// Add a new element and verify that the fetch method succeeded
queue.Add(78);
queue.Add(79);
var startEvent = new ManualResetEvent(initialState: false);
var completedEvent = new ManualResetEvent(initialState: false);
List<int> fetchResult = null;
var thread = new Thread(() =>
{
startEvent.Set();
fetchResult = queue.FetchAtLeastOneBlocking<int>(maxCount: 3, log: null);
completedEvent.Set();
});
thread.Start();
var startedSuccess = startEvent.WaitOne(TimeSpan.FromSeconds(2)); // Wait until started
Assert.True(startedSuccess);
// Now wait for expected immediate completion
var completedSuccess = completedEvent.WaitOne(timeout: TimeSpan.FromSeconds(2));
Assert.True(completedSuccess);
Assert.NotNull(fetchResult);
Assert.Equal(2, fetchResult.Count);
Assert.Equal(78, fetchResult[0]);
Assert.Equal(79, fetchResult[1]);
}
[Fact]
public void FetchAtLeastOneBlocking_MultipleEntriesExist_MaxCountExceeded_ExpectNonblocking_Test()
{
var queue = new BlockingCollection<int>();
// Add a new element and verify that the fetch method succeeded
queue.Add(78);
queue.Add(79);
queue.Add(80);
queue.Add(81);
var startEvent = new ManualResetEvent(initialState: false);
var completedEvent = new ManualResetEvent(initialState: false);
List<int> fetchResult = null;
var thread = new Thread(() =>
{
startEvent.Set();
fetchResult = queue.FetchAtLeastOneBlocking<int>(maxCount: 3, log: null);
completedEvent.Set();
});
thread.Start();
var startedSuccess = startEvent.WaitOne(TimeSpan.FromSeconds(2)); // Wait until started
Assert.True(startedSuccess);
// Now wait for expected immediate completion
var completedSuccess = completedEvent.WaitOne(timeout: TimeSpan.FromSeconds(2));
Assert.True(completedSuccess);
Assert.NotNull(fetchResult);
Assert.Equal(3, fetchResult.Count);
Assert.Equal(78, fetchResult[0]);
Assert.Equal(79, fetchResult[1]);
Assert.Equal(80, fetchResult[2]);
}
}
公共类BlockingCollectionMethodExtensionTest:UnitTestBase
{
[事实]
public void FetchAtLeastOneBlocking\u FirstEmpty\u然后singleentryadded\u ExpectBlocking\u Test()
{
var queue=new BlockingCollection();
var startEvent=新手动重置事件(初始状态:false);
var completedEvent=新的手动重置事件(初始状态:false);
List fetchResult=null;
变量线程=新线程(()=>
{
startEvent.Set();
fetchResult=queue.FetchAtlastoneBlocking(maxCount:3,log:null);
completedEvent.Set();
});
thread.Start();
var startedSuccess=startEvent.WaitOne(TimeSpan.FromSeconds(2));//等待启动
断言.True(startedSuccess);
//现在等待2秒钟以确保不会提取任何内容
线程睡眠(TimeSpan.FromSeconds(1));
Assert.Null(fetchResult);
//添加一个新的元素