I/O Multiplexing: The idea of I/O multiplexing is to use “select” function to ask kernel to suspend process. It returns control to application only after one or more I/O events had occurred. It denotes waiting for a set of descriptors that is ready for reading. The “select” function would manipulate sets of type “fd_set”, that denotes descriptor sets. It takes two inputs: a descriptor set called “read set” and cardinality of read set. It blocks until at least one descriptor in read set is ready for reading. A descriptor “k” is ready for reading if and only if a request to read 1 byte from that descriptor would not block. The “fd_set” is been modified that points to argument “fdset” to indicate subset of read set called “ready set”. The value returned by function indicates cardinality of ready set.

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Chapter 12, Problem 12.23HW

Program Plan Intro

I/O Multiplexing:

The idea of I/O multiplexing is to use “select” function to ask kernel to suspend process.

It returns control to application only after one or more I/O events had occurred.

It denotes waiting for a set of descriptors that is ready for reading.

The “select” function would manipulate sets of type “fd_set”, that denotes descriptor sets.

It takes two inputs: a descriptor set called “read set” and cardinality of read set.

It blocks until at least one descriptor in read set is ready for reading.

A descriptor “k” is ready for reading if and only if a request to read 1 byte from that descriptor would not block.

The “fd_set” is been modified that points to argument “fdset” to indicate subset of read set called “ready set”.

The value returned by function indicates cardinality of ready set.

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