问题描述
根据《操作系统概念》一书，它说:
According to the book 'operating systems concepts', it says:
- 发送(P，消息):发送消息以处理P
- 接收(Q，消息)-从进程Q接收消息.
在不对称情况下，只有发件人为收件人命名；收件人不是 要求为发件人命名.在此方案中，发送和接收 原语定义如下:
In asymmetry only the sender names the recipient; the recipient is not required to name the sender. In this scheme, the send and receive primitives are defined as follows:
- 发送(P，消息):发送消息以处理P.
- receive(id，message):从任何进程接收消息；变量id设置为与之通信的进程的名称 已经发生了.
- Send(P, message): Send a message to process P.
- receive(id, message):Receive a message from any process; the variable id is set to the name of the process with which communication has taken place.
我不明白有什么区别?在非对称方案中，receive()调用是否不需要指定发件人ID?
I can't understand what is the difference? In asymmetric scheme, doesn't the receive() call need to specify the sender id?
推荐答案
区别在于receive()调用未指定发件人ID.这意味着发件人:收件人关系是多对一(N:1)，而对称情况是1:1.许多实现提供了辅助机制来模糊这种影响.
That the receive() call does not specify the sender id is the difference. The implication is that the sender:receiver relationship is many to one (N:1), whereas the symmetric case is 1:1. Many implementations offer secondary mechanisms to blur this implications.
在N:1的情况下，需要对处理多个同时发送者的机制进行一些解释.解释涉及政策:先到先得；随机的;优先级，容量:#线程，以及调度参数和约束的继承.
In the N:1 case, there needs to be some explanation of the mechanisms for handling multiple simultaneous senders. Explanations involve policy:first come first served; random; priority, capacity: #-threads, and perhaps inheritance of scheduling parameters and constraints.
在1:1情况下，不需要策略或容量，可以安全地假设继承是先天的.因此，1:1案例更适合自动化分析.
In the 1:1 case, there is no need for policy or capacity, and it is safe to assume inheritance is innate. Thusly, the 1:1 case is more amenable to automated analysis.
允许动态配置sender:receiver对的1:1系统可能比这些已识别系统更加复杂.在这种系统中，发送者可以通过实例化该发送者的接收者的某个过程来发现接收者.在这种安排中，发现策略，容量，继承属性更加复杂.
A 1:1 system that permits dynamic configuration of sender:receiver pairs can be even more complex than these identified systems. In this sort of system, a sender may discover a receiver by some process which instantiates a receiver for this sender. Uncovering the policy,capacity,inheritance attributes is more complex in this sort of arrangement.
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