有一个已配置的ActorSystem
,其演员按层次结构组织如下:
/user
/processes
/process1
/process2
/process3
为了生成这个方案,我使用下一个C#代码:
// in entry point
IActorRef processesCoordinatorActorRef = ActorSystem.ActorOf(Props.Create<ProcessesCoordinatorActor>(), "processes");
// in ProcessesCoordinatorActor.cs:
IActorRef processOneActorRef = Context.ActorOf(Props.Create<ProccessActor>(), "process1");
IActorRef processTwoActorRef = Context.ActorOf(Props.Create<ProccessActor>(), "process2");
IActorRef processThreeActorRef = Context.ActorOf(Props.Create<ProccessActor>(), "process3");
我的问题是我想从入口点代码(ProcessActor之外)向process1
,process2
或process3
添加一个子actor。
但是现在我的双手被束缚了,因为IActorRef
隐藏了某些演员实例。
我该如何解决?
答案 0 :(得分:9)
必须在父actor的Context
中创建子actor。如果您想从外部触发发生的事情,只需向父母发送消息并让它创建子动作(例如CreateChildActor
)。没有办法在一个地方创建一个演员,然后让它被“收养”为另一个演员的孩子。
一般情况下(并且不知道你真正想要做什么),我的预感是从顶级/入口点代码创建演员级别的层次结构并不是一个很好的方向。您应该让层次结构中的父级角色完成创建和supervising children的工作。
如果您无法从入口点触发此过程,则可以使用CreateChildActor
将ActorSelection
发送到层次结构中的任意位置和/或将其解析为IActorRef
。< / p>
这是一个代码示例,展示了如何执行此操作,并让子流程在协调器准备就绪后通知协调器(also here as a Fiddle):
using System;
using System.Threading;
using Akka.Actor;
namespace ProcessActors
{
class Program
{
/// <summary>
/// Top-level process coordinator actor.
/// </summary>
public class ProcessesCoordinatorActor : ReceiveActor
{
public ProcessesCoordinatorActor()
{
Receive<CreateChildActor>(createRequest =>
{
Console.WriteLine("{0} creating child actor: {1}", Self.Path, createRequest.ChildName);
var child = Context.ActorOf(createRequest.ChildProps, createRequest.ChildName);
if (createRequest.ActorToNotify != null)
createRequest.ActorToNotify.Tell(new ReadyForWork(child));
});
Receive<ReadyForWork>(ready =>
{
Console.WriteLine("Coordinator sees worker ready: {0}", ready.Worker.Path);
});
ReceiveAny(o =>
{
Console.WriteLine("{0} received {1}", Self.Path, o);
});
}
}
/// <summary>
/// Actor for a given process.
/// </summary>
public class ProcessActor : ReceiveActor
{
public ProcessActor()
{
Receive<CreateChildActor>(createRequest =>
{
Console.WriteLine("{0} creating child actor: {1}", Self.Path, createRequest.ChildName);
var child = Context.ActorOf(createRequest.ChildProps, createRequest.ChildName);
if (createRequest.ActorToNotify != null)
createRequest.ActorToNotify.Tell(new ReadyForWork(child));
});
ReceiveAny(o =>
{
Console.WriteLine("{0} received {1}", Self.Path, o);
});
}
}
/// <summary>
/// Sub-process.
/// </summary>
public class SubprocessActor : ReceiveActor
{
public SubprocessActor()
{
ReceiveAny(o =>
{
Console.WriteLine("{0} received {1}", Self.Path, o);
});
}
}
public static void Main(string[] args)
{
using (var system = ActorSystem.Create("MyActorSystem"))
{
Console.WriteLine("Starting up.");
var coordinator = system.ActorOf(Props.Create(() => new ProcessesCoordinatorActor()), "processes");
var processProps = Props.Create(() => new ProcessActor());
// create process actors
coordinator.Tell(new CreateNewProcess("process1", processProps));
coordinator.Tell(new CreateNewProcess("process2", processProps));
coordinator.Tell(new CreateNewProcess("process3", processProps));
var subprocessProps = Props.Create(() => new SubprocessActor());
// tiny sleep to let everything boot
Thread.Sleep(TimeSpan.FromMilliseconds(50));
// get handle to an actor somewhere down in the hierarchy
var process1 = system.ActorSelection("/user/processes/process1").ResolveOne(TimeSpan.FromSeconds(1)).Result;
// create subprocess of process1 and notify the coordinator of new subprocess actor
process1.Tell(new CreateNewSubprocess("subprocess1", subprocessProps, coordinator));
Console.ReadLine();
}
}
#region Messages
/// <summary>
/// Command to create ChildProps actor and notify another actor about it.
/// </summary>
public class CreateChildActor
{
public CreateChildActor(string childName, Props childProps, IActorRef actorToNotify)
{
ChildName = childName;
ActorToNotify = actorToNotify;
ChildProps = childProps;
}
public CreateChildActor(string childName, Props childProps)
: this(childName, childProps, null)
{
}
public Props ChildProps { get; private set; }
public string ChildName { get; private set; }
public IActorRef ActorToNotify { get; private set; }
}
public class CreateNewProcess : CreateChildActor
{
public CreateNewProcess(string childName, Props childProps, IActorRef actorToNotify)
: base(childName, childProps, actorToNotify)
{
}
public CreateNewProcess(string childName, Props childProps)
: this(childName, childProps, null)
{
}
}
public class CreateNewSubprocess : CreateChildActor
{
public CreateNewSubprocess(string childName, Props childProps, IActorRef actorToNotify)
: base(childName, childProps, actorToNotify)
{
}
public CreateNewSubprocess(string childName, Props childProps)
: this(childName, childProps, null)
{
}
}
/// <summary>
/// Report to another actor when ready.
/// </summary>
public class ReadyForWork
{
public ReadyForWork(IActorRef worker)
{
Worker = worker;
}
public IActorRef Worker { get; private set; }
}
#endregion
}
}