Chapter 7Processes

In a typical operating system, a process represents a program in execution along with associated system resources, which may be physical (such as processor cycles and memory) or abstract[1] (such as the number of files the process can open). The kernel provides an illusion of concurrent execution by scheduling resources between ready-to-run processes. On a multiprocessor or multicore system, more than one process may execute truly concurrently.

In their landmark 1965 paper,[2] Jack B. Dennis and Earl C. Van Horn defined a process as a “locus of control within an instruction sequence . . . an abstract entity which moves through the instructions of a procedure as the procedure is executed by a processor.”

In earlier chapters, ...

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