化零为整WCF(12) - 并发和限流(Concurrent和Throttle)

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化零为整WCF(12) - 并发和限流(Concurrent和Throttle)

作者：webabcd


介绍
WCF(Windows Communication Foundation) - 并发(Concurrent)：
    1、ConcurrencyMode.Single：单线程并发模式。系统自动加锁，无并发问题
    ・InstanceContextMode.PerCall：每个线程都会被分配一个新的实例
    ・InstanceContextMode.PerSession：每个Session被分配一个新的实例，每个Session内同时只会有一个线程操作实例
    ・InstanceContextMode.Single：唯一实例，并发调用只会有一个线程操作实例
    2、ConcurrencyMode.Reentrant：可重入的单线程并发模式。有可重入（回调）操作时，此模式才会生效，从回调返回的线程会进入队列尾部排队
    ・InstanceContextMode.PerCall：每个线程都会被分配一个新的实例，当有回调操作时如果使用Single并发模式的话就会产生死锁（1、调用服务端；2、回调客户端；3、返回服务端，1的时候锁定了，到3的时候就无法执行了，所以死锁了），此时应该用Reentrant并发模式
    ・InstanceContextMode.PerSession：每个Session被分配一个新的实例，每个Session内同时只会有一个线程操作实例，Session内可重入
    ・InstanceContextMode.Single：唯一实例，并发调用只会有一个线程操作实例，全局可重入
    3、ConcurrencyMode.Multiple：多线程并发模式。系统不会自动加锁，有并发问题
    ・InstanceContextMode.PerCall：每个线程都会被分配一个新的实例，无并发问题
    ・InstanceContextMode.PerSession：每个Session被分配一个新的实例，每个Session内多线程操作实例的话会有并发问题
    ・InstanceContextMode.Single：唯一实例，允许多线程并发操作实例，有并发问题

WCF(Windows Communication Foundation) - 限流(Throttle)：

<behaviors>
                <serviceBehaviors>
                        <behavior name="BehaviorPerCall">
                                <!--httpGetEnabled - 指示是否发布服务元数据以便使用 HTTP/GET 请求进行检索，如果发布 WSDL，则为 true，否则为 false，默认值为 false-->
                                <serviceMetadata httpGetEnabled="true"/>
                                <!--maxConcurrentCalls - 服务中同时存在的最大活动消息数，默认值为 16-->
                                <!--maxConcurrentInstances - 服务中同时存在的最大服务实例数，默认值为 Int32.MaxValue-->
                                <!--maxConcurrentSessions - 服务中同时存在的最大会话数，默认值为 10-->
                                <serviceThrottling maxConcurrentCalls="" maxConcurrentInstances="" maxConcurrentSessions="" />
                        </behavior>
                        <behavior name="BehaviorPerSession">
                                <serviceMetadata httpGetEnabled="true"/>
                                <serviceThrottling maxConcurrentCalls="" maxConcurrentInstances="" maxConcurrentSessions="" />
                        </behavior>
                        <behavior name="BehaviorSingle">
                                <serviceMetadata httpGetEnabled="true"/>
                                <serviceThrottling maxConcurrentCalls="" maxConcurrentInstances="1" maxConcurrentSessions="" />
                        </behavior>
                </serviceBehaviors>
        </behaviors>

 

示例（以ConcurrencyMode.Reentrant为例）
1、服务
IDuplexReentrant.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.ServiceModel;

namespace WCF.ServiceLib.Message
{
         /// <summary>
         /// IDuplexReentrant接口（演示ConcurrencyMode.Reentrant）
         /// </summary>
         /// <remarks>
        /// IDuplexReentrantCallback - 回调接口
        /// </remarks>
        [ServiceContract(CallbackContract = typeof(IDuplexReentrantCallback))]
         public interface IDuplexReentrant
        {
                 /// <summary>
                 /// Hello
                 /// </summary>
                 /// <param name="name">名字</param>
                [OperationContract]
                 void HelloDuplexReentrant( string name);
        }

         /// <summary>
         /// IDuplexReentrant回调接口
         /// </summary>
         public interface IDuplexReentrantCallback
        {
                 /// <summary>
                 /// Hello
                 /// </summary>
                 /// <param name="name"></param>
                [OperationContract]
                 void HelloDuplexReentrantCallback( string name);
        }
}

 

DuplexReentrant.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.ServiceModel;

namespace WCF.ServiceLib.Message
{
         /// <summary>
         /// DuplexReentrant类 （演示ConcurrencyMode.Reentrant）
         /// </summary>
         /// <remarks>
        /// ConcurrencyMode - 获取或设置一个值，该值指示服务是支持单线程、多线程还是支持可重入调用。默认值为 System.ServiceModel.ConcurrencyMode.Single。
        /// Single - 服务实例是单线程的，且不接受可重入调用。
        /// Reentrant - 服务实例是单线程的，且接受可重入调用。
        /// Multiple - 服务实例是多线程的。
        /// </remarks>
        [ServiceBehavior(ConcurrencyMode = ConcurrencyMode.Reentrant)]
         public class DuplexReentrant : IDuplexReentrant
        {
                 /// <summary>
                 /// Hello
                 /// </summary>
                 /// <param name="name">名字</param>
                 public void HelloDuplexReentrant( string name)
                {
                         // 声明回调接口
                        IDuplexReentrantCallback callback = OperationContext.Current.GetCallbackChannel<IDuplexReentrantCallback>();

                         // 调用回调接口中的方法
                        callback.HelloDuplexReentrantCallback(name);
                }
        }
}

 

 

2、宿主
DuplexReentrant.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.ServiceModel;

namespace WCF.ServiceHost2.Message
{
         /// <summary>
         /// host WCF.ServiceLib.Message.DuplexReentrant的类
         /// </summary>
         public class DuplexReentrant
        {
                 /// <summary>
                 /// 启动WCF.ServiceLib.Message.DuplexReentrant服务
                 /// </summary>
                 public void Launch()
                {
                         using (ServiceHost host = new ServiceHost( typeof(WCF.ServiceLib.Message.DuplexReentrant)))
                        {
                                host.Open();

                                Console.WriteLine( "服务已启动(WCF.ServiceLib.Message.DuplexReentrant)");
                                Console.WriteLine( "按<ENTER>停止服务");
                                Console.ReadLine();

                        }
                }
        }
}

 

App.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
        <system.serviceModel>
                <services>
                        <!--name - 提供服务的类名-->
                        <!--behaviorConfiguration - 指定相关的行为配置-->
                        <service name="WCF.ServiceLib.Message.DuplexReentrant" behaviorConfiguration="MessageBehavior">
                                <!--address - 服务地址-->
                                <!--binding - 通信方式-->
                                <!--contract - 服务契约-->
                                <endpoint address="Message/DuplexReentrant" binding="netTcpBinding" contract="WCF.ServiceLib.Message.IDuplexReentrant" />
                                <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
                                <host>
                                        <baseAddresses>
                                                <add baseAddress="http://localhost:12345/Message/DuplexReentrant"/>
                                                <add baseAddress="net.tcp://localhost:54321/"/>
                                        </baseAddresses>
                                </host>
                        </service>
                </services>
                <behaviors>
                        <serviceBehaviors>
                                <behavior name="MessageBehavior">
                                        <!--httpGetEnabled - 指示是否发布服务元数据以便使用 HTTP/GET 请求进行检索，如果发布 WSDL，则为 true，否则为 false，默认值为 false-->
                                        <serviceMetadata httpGetEnabled="true" />
                                        <serviceDebug includeExceptionDetailInFaults="true"/>
                                </behavior>
                        </serviceBehaviors>
                </behaviors>
        </system.serviceModel>
</configuration>

 

 

3、客户端
DuplexReentrant.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.ServiceModel;
using System.Windows.Forms;

namespace Client2.Message
{
         /// <summary>
         /// 演示Message.DuplexReentrant的类
         /// </summary>
         public class DuplexReentrant
        {
                 /// <summary>
                 /// Hello
                 /// </summary>
                 /// <param name="name">名字</param>
                 public void HelloDulexReentrant( string name)
                {
                        var ct = new Client2.Message.ReentrantCallbackType();
                        var ctx = new InstanceContext(ct);

                        var proxy = new MessageSvc.DuplexReentrant.DuplexReentrantClient(ctx);

                        proxy.HelloDuplexReentrant(name);
                }
        }
}

 

ReentrantCallbackType.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Windows.Forms;

namespace Client2.Message
{
         /// <summary>
         /// 实现回调接口
         /// </summary>
         /// <remarks>
        /// CallbackBehavior - 在客户端应用程序中配置回调服务实现
        /// UseSynchronizationContext - 如果对服务的所有调用都必须在 System.Threading.SynchronizationContext 指定的线程上运行，则为 true；否则为false。默认值为 true。
        /// </remarks>
        [System.ServiceModel.CallbackBehavior(UseSynchronizationContext = false)]
         public class ReentrantCallbackType : MessageSvc.DuplexReentrant.IDuplexReentrantCallback
        {
                 /// <summary>
                 /// Hello
                 /// </summary>
                 /// <param name="name">名字</param>
                 public void HelloDuplexReentrantCallback( string name)
                {
                        MessageBox.Show( "Hello: " + name);
                }
        }
}

 

App.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
        <system.serviceModel>
                <client>
                        <endpoint address="net.tcp://localhost:54321/Message/DuplexReentrant"
                                binding="netTcpBinding" contract="MessageSvc.DuplexReentrant.IDuplexReentrant">
                        </endpoint>
                </client>
        </system.serviceModel>
</configuration>

 

 

运行结果：
单击"btnDuplexReentrant"按钮后弹出提示框，显示"Hello: webabcd"


OK
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