Processes exchange information by sending interprocess messages. This chapter discusses the semantics of message passing, and OS responsibilities in buffering and delivery of interprocess messages. It also discusses how message passing is employed in higher-level protocols for providing electronic mail facility and in providing intertask communication in parallel or distributed programs. | Chapter 9 Message Passing Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Introduction Overview of Message Passing Implementing Message Passing Mailboxes Higher-Level Protocols Using Message Passing Case Studies in Message Passing 9. Operating Systems, by Dhananjay Dhamdhere Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Overview of Message Passing Message passing is one way in which processes interact with one another Processes may exist in the same computer or in different computers connected to a network Uses of message passing: Client-server paradigm Backbone of higher-level communication protocols Parallel and distributed programs 9. Operating Systems, by Dhananjay Dhamdhere Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Overview of Message Passing (continued) Two important issues in message passing are: Naming of processes Names may be explicitly indicated or deduced by the kernel in some manner Delivery of messages Whether | Chapter 9 Message Passing Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Introduction Overview of Message Passing Implementing Message Passing Mailboxes Higher-Level Protocols Using Message Passing Case Studies in Message Passing 9. Operating Systems, by Dhananjay Dhamdhere Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Overview of Message Passing Message passing is one way in which processes interact with one another Processes may exist in the same computer or in different computers connected to a network Uses of message passing: Client-server paradigm Backbone of higher-level communication protocols Parallel and distributed programs 9. Operating Systems, by Dhananjay Dhamdhere Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Overview of Message Passing (continued) Two important issues in message passing are: Naming of processes Names may be explicitly indicated or deduced by the kernel in some manner Delivery of messages Whether sender should be blocked until delivery What the order is in which messages are delivered to a destination process How exceptional conditions are handled 9. Operating Systems, by Dhananjay Dhamdhere Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Direct and Indirect Naming In direct naming, sender and receiver processes mention each other’s name In symmetric naming, both sender and receiver processes specify each other’s name In asymmetric naming, receiver does not name process from which it wishes to receive a message; kernel gives it a message sent to it by some process In indirect naming, processes do not mention each other’s name in send and receive statements 9. Operating Systems, by Dhananjay Dhamdhere Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Blocking and Nonblocking Sends A blocking send blocks sender process until message is delivered to destination process Synchronous message passing Simplifies design of concurrent processes A .
