Summary

Message queues are one of three interprocess communication facilities added to UNIX with the release of System V. Once created, a message queue is maintained by the system. Unrelated processes, executing at different times, can use a message queue to pass information. Each message has an associated type that can be used to implement a rudimentary form of data multiplexing when multiple producers are involved. Message queues are created and accessed using the msgget system call. Messages are placed in the message queue with the msgsnd system call and retrieved from the queue with the msgrcv system call. Additional message queue manipulations are carried out with the msgctl system call. The msgctl system call returns information about the message queue, permits modification of access permissions, and allows the owner to remove the message queue facility.

Programs and Processes

Processing Environment

Using Processes

Primitive Communications

Pipes

Message Queues

Semaphores

Shared Memory

Remote Procedure Calls

Sockets

Threads

Appendix A. Using Linux Manual Pages

Appendix B. UNIX Error Messages

Appendix C. RPC Syntax Diagrams

Appendix D. Profiling Programs



Interprocess Communication in Linux
Interprocess Communications in Linux: The Nooks and Crannies
ISBN: 0130460427
EAN: 2147483647
Year: 2001
Pages: 136

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