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NSMessagePort


Inherits from:
NSPort : NSObject
Conforms to:
NSCoding
(NSPort)
NSCopying (NSPort)
NSObject (NSObject)
Declared in:
Foundation/NSPort.h




Class Description


NSMessagePort is a subclass of NSPort which can be used as an endpoint for Distributed Object connections (or raw messaging). NSMessagePort allows for local (on the same machine) communication only. A companion class, NSSocketPort, allows for both local and remote communication, but may be more expensive than NSMessagePort for the local case; there is also no name registry service for NSSocketPorts -- clients and servers must agree on the TCP port numbers to use beforehand.

A subclass of NSPort represents a particular flavor of data transport from one process to another. Note that instances of port subclasses cannot be mixed on a particular communication channel. For example, a client cannot connect to a server using NSMessagePort if the server only supports connections made with NSSocketPort. Also, you cannot transfer instances of NSMessagePort in a message to another process over a channel which is using NSSocketPorts as its endpoints; you can only pass NSSocketPorts on such a channel. These restrictions apply to any subclasses of NSPort, not just NSMessagePort and NSSocketPort. However, you are free to create other connections to a server using other subclasses of NSPort (assuming the server supports multiple transports) and send instances of that other subclass on that channel.




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