tailieunhanh - Lecture Operating systems: Internalsand design principles (7/e): Chapter 4 - William Stallings

Chapter 4 - Threads. This chapter examines some more advanced concepts related to process management, which are found in a number of contemporary operating systems. We show that the concept of process is more complex and subtle than presented so far and in fact embodies two separate and potentially independent concepts. | Operating Systems: Internals and Design Principles Chapter 4 Threads Seventh Edition By William Stallings Operating Systems: Internals and Design Principles The basic idea is that the several components in any complex system will perform particular subfunctions that contribute to the overall function. —THE SCIENCES OF THE ARTIFICIAL, Herbert Simon Processes and Threads ∗Processes have two characteristics: Resource Ownership Scheduling/Execution Process includes a virtual address space to hold the process image Follows an execution path that may be interleaved with other processes the OS performs a protection function to prevent unwanted interference between processes with respect to resources a process has an execution state (Running, Ready, etc.) and a dispatching priority and is scheduled and dispatched by the OS Processes and Threads The unit of dispatching is referred to as a thread or lightweight process The unit of resource ownership is referred to as a process or task Multithreading - The ability of an OS to support multiple, concurrent paths of execution within a single process Single Threaded Approaches A single thread of execution per process, in which the concept of a thread is not recognized, is referred to as a single-threaded approach MS-DOS is .