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. 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. - . Reading Assignment. T. M. Pinkston, . “. Deadlock Characterization and Resolution in Interconnection Networks,. ”. Chapter 13 in . Deadlock Resolution in Computer Integrated Systems. , CRC Press 2004. 1. 7.1 System Model. 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. 2. Examples of resource types:. Reading Assignment. T. M. Pinkston, . “. Deadlock Characterization and Resolution in Interconnection Networks,. ”. Chapter 13 in . Deadlock Resolution in Computer Integrated Systems. , CRC Press 2004. By. Sarabpreet. Singh . Anand. Sarabpreet. Singh . Anand. SQL . Server . MVP. MCTS. , MCITP: Admin, MCT . certifications. Vice . President & . Co-Founder of SQLServerGeeks.com. Expert . in handling VLDBs & Disaster . 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. “A set of processes is deadlocked if each process in the set is waiting for an event that only another process in the set can cause.”. Detection. “Is this system deadlocked, and if so, which processes are involved?”. OPERATING SYSTEMS . DEADLOCKS. 7: Deadlocks. 2. What Is In This Chapter?. What is a deadlock?. Staying Safe: Preventing and Avoiding Deadlocks. Living Dangerously: Let the deadlock happen, then detect it and recover from it.. Chapter 7: Deadlocks Chapter 7: Deadlocks The Deadlock Problem System Model Deadlock Characterization Methods for Handling Deadlocks Deadlock Prevention Deadlock Avoidance Deadlock Detection Recovery from Deadlock