zmq_socket()

Name

zmq_socket : 创建0MQ socket

Synopsis

void *zmq_socket(void *context, int type)

描述

zmq_socket(): 在一个特定的context中创建一个0MQ socket，返回一个不透明的句柄到新创建的socket中。

type: 指定socket类型。

新创建的socket初试时时未绑定的，不和任何相关联。为了建立一个信息流，socket必须首先zmq_connect()其中一个终端，或是zmq_bind();

与传统socket的不同：

传统socket提供的同步接口，要么是面向连接的可靠的字节流(SOCK_STREAM)，要么是无连接不可靠的数据包（SOCK_DGRAM）.

0MQ socket 是异步的，物理连接的安装和卸载，重连和有效地转发等对用户来说都是透明的，时间由0MQ自己控制。 消息会排队，当一个peer不能有效接收时。

传统socket ：严格的1-1(2个peer）、N-1（多个client，一个server）、1-N（多播）。

0MQ: ZMQ_PAIR是个特例。0MQ socket 可以连接到多个终端，使用zmq_connect();同时，可以结果多个终端的信息，使用zmq_bind().  N-N的模式

线程安全：

0MQ socket不是线程安全的。 Applications MUST NOT use a socket from multiple threads except after migrating a socket from one thread to another with a "full fence" memory barrier.

Socket类型

1. Request-reply pattern:Summary of ZMQ_REQ characteristicsCompatible peer socketsZMQ_REP, ZMQ_ROUTERDirectionBidirectionalSend/receive patternSend, Receive, Send, Receive, …Outgoing routing strategyRound-robinIncoming routing strategyLast peerAction in mute stateBlock
   Summary of ZMQ_REP characteristicsCompatible peer socketsZMQ_REQ, ZMQ_DEALERDirectionBidirectionalSend/receive patternReceive, Send, Receive, Send, …Incoming routing strategyFair-queuedOutgoing routing strategyLast peerAction in mute stateDrop
   Summary of ZMQ_DEALER characteristicsCompatible peer socketsZMQ_ROUTER, ZMQ_REP, ZMQ_DEALERDirectionBidirectionalSend/receive patternUnrestrictedOutgoing routing strategyRound-robinIncoming routing strategyFair-queuedAction in mute stateBlock
   

   
   

   Summary of ZMQ_ROUTER characteristicsCompatible peer socketsZMQ_DEALER, ZMQ_REQ, ZMQ_ROUTERDirectionBidirectionalSend/receive patternUnrestrictedOutgoing routing strategySee textIncoming routing strategyFair-queuedAction in mute stateDrop
   Summary of ZMQ_DEALER characteristicsCompatible peer socketsZMQ_ROUTER, ZMQ_REP, ZMQ_DEALERDirectionBidirectionalSend/receive patternUnrestrictedOutgoing routing strategyRound-robinIncoming routing strategyFair-queuedAction in mute stateBlock
   
2. Publish-subscribe pattern : 1-N （1 publisher，multiple subscribers

1. Summary of ZMQ_XSUB characteristicsCompatible peer socketsZMQ_PUB, ZMQ_XPUBDirectionUnidirectionalSend/receive patternReceive messages, send subscriptionsIncoming routing strategyFair-queuedOutgoing routing strategyN/AAction in mute stateDrop
   Summary of ZMQ_SUB characteristicsCompatible peer socketsZMQ_PUB, ZMQ_XPUBDirectionUnidirectionalSend/receive patternReceive onlyIncoming routing strategyFair-queuedOutgoing routing strategyN/AAction in mute stateDrop
   Summary of ZMQ_PUB characteristicsCompatible peer socketsZMQ_SUB, ZMQ_XSUBDirectionUnidirectionalSend/receive patternSend onlyIncoming routing strategyN/AOutgoing routing strategyFan outAction in mute stateDropSummary of ZMQ_XPUB characteristicsCompatible peer socketsZMQ_SUB, ZMQ_XSUBDirectionUnidirectionalSend/receive patternSend messages, receive subscriptionsIncoming routing strategyN/AOutgoing routing strategyFan outAction in mute stateDrop
   
2. pipeline pattern：ZMQ_PUSH、ZMQ_PULLSummary of ZMQ_PUSH characteristicsCompatible peer socketsZMQ_PULLDirectionUnidirectionalSend/receive patternSend onlyIncoming routing strategyN/AOutgoing routing strategyRound-robinAction in mute stateBlock
   

Summary of ZMQ_PULL characteristicsCompatible peer socketsZMQ_PUSHDirectionUnidirectionalSend/receive patternReceive onlyIncoming routing strategyFair-queuedOutgoing routing strategyN/AAction in mute stateBlock