TAILIEUCHUNG - Lecture Operating system concepts (Fifth edition): Module 7 - Avi Silberschatz, Peter Galvin

Module 7 - Deadlocks. After studying this chapter you will be able to develop a description of deadlocks, which prevent sets of concurrent processes from completing their tasks; to present a number of different methods for preventing or avoiding deadlocks in a computer system. | Module 7: Deadlocks System Model Deadlock Characterization Methods for Handling Deadlocks Deadlock Prevention Deadlock Avoidance Deadlock Detection Recovery from Deadlock Combined Approach to Deadlock Handling Operating System Concepts The Deadlock Problem A set of blocked processes each holding a resource and waiting to acquire a resource held by another process in the set. Example System has 2 tape drives. P1 and P2 each hold one tape drive and each needs another one. Example semaphores A and B, initialized to 1 P0 P1 wait (A); wait(B) wait (B); wait(A) Operating System Concepts Bridge Crossing Example Traffic only in one direction. Each section of a bridge can be viewed as a resource. If a deadlock occurs, it can be resolved if one car backs up (preempt resources and rollback). Several cars may have to be backed upif a deadlock occurs. Starvation is possible. Operating System Concepts System Model Resource types R1, R2, . . ., Rm CPU cycles, memory space, I/O devices Each resource

• Hệ điều hành
• Operating system concepts
• Lecture Operating system concepts
• Operating system
• Hệ điều hành
• Computer system organization
• Handling deadlocks
• Operating system services
• Operating system structures
• Operating system design
• Operating system structure
• Operating System Debugging
• Operating System Generation
• Types of System Calls
• Computer system structures
• File system interface
• File system implementation
• Computer system architecture
• The Linux system