PPT-Deadlocks (part II) Deadlock avoidance – (not reasonable)

Deadlock detection Resource Allocation Graphs Resource Pool and C ounting Semaphores Dining Philosophers Problem Condition Variables Resource Tables Deadlock Definition A  deadlock  is a situation in which two or more competing actions are each waiting for the other to finish and thus neither ever does. Mark Stanovich. Operating Systems. COP 4610. Deadlocks. Resource:. Something a thread waits for. Deadlocks. : Occur when threads are waiting for resources with circular dependencies. Often involve . Detection and Avoidance. Prof. Sirer. CS 4410. Cornell University. System Model. There are non-shared computer resources. Maybe more than one instance. Printers, Semaphores, Tape drives, CPU. Processes need access to these resources. 1. 6. Deadlocks. 6.1 Deadlocks with Reusable and Consumable. . Resources. 6.2 Approaches to the Deadlock Problem . 6.3 A System Model . Resource Graphs . State Transitions. Deadlock States and Safe States . Concurrency: Deadlock and Starvation. Operating Systems:. Internals and Design Principles, 6/E. William Stallings. Patricia Roy. Manatee Community College, Venice, FL. ©2008, Prentice Hall. Dining Philosophers Problem. Tore Larsen. With slides from . T. Plagemann, C. . . Griwodz. , K. Li,. A. . Tanenbaum. and M. van Steen. Resources. Resource allocation is a central OS concern. Examples . of computer resources. CPU. Spring 2013. Deadlocks. Dan Tsafrir (13/5/2013). Partially based on slides by Hagit Attiya. OS (234123) - spring 2013 - deadlocks. 1. Text @ OS notes book. Much of the material appears in Section 3.2 in Feitelson’s OS notes book. DEADLOCKS. Manju Muralidharan . Priya. Objective. At the end of this presentation, you will know:. What is a Deadlock?. Preventing and Avoiding Deadlocks. Detecting Deadlocks. Recovery Schemes. 2. CS 561 Deadlocks. DEADLOCKS. To be discussed…. Definition of deadlock. Example of deadlock. Resource allocation graph. Strategies to handle deadlock. - . Deadlock Prevention. - . Deadlock Avoidance. - . cs550. Operating Systems. David . Monismith. Deadlock. Four requirements for deadlock . Hold and wait - process holds resource while waiting for more resources . Mutual Exclusion - resource can't be shared. Deadlocks – Problems and Solutions. CS. . 111. Operating . Systems . Peter Reiher. . Outline. The deadlock problem. Approaches to handling the problem. Handling general synchronization bugs. Simplifying synchronization. Reading Assignment. T. M. Pinkston, . “. Deadlock Characterization and Resolution in Interconnection Networks,. ”. Chapter 13 in . Deadlock Resolution in Computer Integrated Systems. , CRC Press 2004. In order to talk about deadlocks in a system, it’s helpful to have a model of the system. A . system consists of a set of resources. The resources can be grouped into types. Processes compete to have (unique) access to instances of the types. CSSE 332. Operating Systems. Rose-Hulman Institute of Technology. Approaches to deadlock handling. Deadlock Detection. Periodically run algorithm to detect circular waiting. After detecting deadlock,. Objectives. 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.