For example, a Printer is a non-sharable resource. A directory of Objective Type Questions covering all the Computer Science subjects. advertisement. Read only files are a good example of a sharable resource. 3. For a Hold and wait condition to prevail : A process must be not be holding a resource, but waiting for one to be freed, and then request to acquire it, A process must be holding at least one resource and waiting to acquire additional resources that are being held by other processes, A process must hold at least one resource and not be waiting to acquire additional resources. In this situation, mutual exclusion cannot be prevented. 2. In the blocking send, blocking receive: Answer. For non sharable resources like a printer, mutual exclusion : For sharable resources, mutual exclusion : To ensure that the hold and wait condition never occurs in the system, it must be ensured that : whenever a resource is requested by a process, it is not holding any other resources, each process must request and be allocated all its resources before it begins its execution, a process can request resources only when it has none. Resources are allocated to the process on non-sharable basis is (A) mutual exclusion (B) hold and wait (C) no pre-emption (D) circular wait 32. 10. 76. Mutual Exclusion. This condition is difficult to eliminate because some resources, such as the tape drive and printer, are inherently non-shareable.check this . processes that have previously been in the system, resources currently allocated to each process, future requests and releases of each process. is required. Cached and interleaved memories are ways of speeding up memory access between CPU’s and slower RAM. 1. Sharable resources, in contrast, do not require mutually exclusive access and thus cannot be involved in a deadlock. For sharable resources, mutual exclusion : If the resources are always preempted from the same process, __________ can occur. Hold and wait or partial allocation - The processes must hold the resources they have already been allocated while waiting for other (requested) resources. Cost factors of process termination include . none of the mentioned. Practice test for UGC NET Computer Science Paper. In general, however, it is not possible … Here you can access and discuss Multiple choice questions and answers for various compitative exams and interviews. The questions asked in this NET practice paper are from various previous year papers. ……………. is not required. The solution appears to do everything right: All accesses to the shared variables are protected by mutual exclusion, processes do not block themselves while in the mutual exclusion, new processes are prevented from using the resource if there are (or were) three active users, and the last process to depart unblocks up to three waiting processes. Mutual Exclusion. Attempt a small test to analyze your preparation level. A process holds at least one resource and requests another resource that is held by another process. The mutual exclusion condition must hold for non-sharable resources. can be defined as the permanent blocking of a set of processed that either complete for system resources or communicate with each other. Some resources can be made sharable, like a read-only file. That is, several processes cannot simultaneously share a single resource. The mutual exclusion condition must hold for non-sharable types of resources. For sharable resources, mutual exclusion : A. is required B. is not required C. None of these 18. Mutual exclusion condition must hold for non-sharable resources. For example, only one process can have access to a printer at a time, otherwise the output gets garbled up. Answer. 2. hold and wait: there must be a process holding one resource and waiting for another. If each process needs a maximum of 2 units, then, Consider a computer system with 6 tape drives and 'n' processes completing for them. Mutual exclusion means resources are (at least one) in non-sharable mode only. This condition is difficult to eliminate because some resources, such as the tap drive and printer, are inherently non-shareable. Operating System Concepts –9th Edition 7.6 Silberschatz, Galvin and Gagne ©2013 Deadlock Characterization Mutual exclusion: only one process at a time can use a resource Hold and wait: a process holding at least one resource is waiting to acquire additional resources held by other processes No preemption: a resource can be released only voluntarily Read-only files are a good example of a sharable resource. Mutual exclusion - The resources involved must be unshareable; otherwise, the processes would not be prevented from using the resource when necessary. Mutual exclusion is one of the conditions for a deadlock to occur. This will help identify : A system has 3 processes sharing 4 resources. For sharable resources, mutual exclusion : is required is not required depends on the operating system none of the mentioned. If several processes attempt to open a read only file at the same time, they can be granted simultaneous access to the file. The number of resources requested by a process : Deadlock prevention is a set of methods : Every time a request for allocation cannot be granted immediately, the detection algorithm is invoked. Hold and wait or partial allocation - The processes must hold the resources they have already been allocated while waiting for other (requested) resources. Question. This condition is difficult to eliminate because some resources, such as the tape drive and printer, are inherently non-shareable.check this. No Preemption: A resource cannot be taken from a process unless the process releases the resource. 1. mutual exclusion: at least one process must be held in a non-sharable mode. That is, several processes cannot simultaneously share a single resource. User Generated Resources Requiring Mutual Exclusion Examples of user-generated resources requiring mutual exclusion include (but are not limited to) Data pools. Note that shareable resources like If the process had to release its resources when a new resource or … several processes cannot simultaneously share a single resource. 2. It must be holding true for non-shareable resources .Non-sharable resources include printer, memory space etc. That is, several processes cannot simultaneously share a single resource. These resources are shared by 3 processes A, B, C, which have peak time demands of 3, 4, 6 respectively. The mutual exclusion condition must hold for non-sharable resources. A directory of Objective Type Questions covering all the Computer Science subjects. Significance of mutual execution: Prevents race around condition. What is the maximum value of 'n' for the system to be deadlock free? For example, a printer cannot be simultaneously shared by several processes. 1: – Mutual exclusion: – If we can share resources, then we can prevent mutual exclusion. 31. Hold and wait. The minimum value of 'm' that ensures that deadlock will never occur is. No preemption: resources cannot be preempted. Search Google: Answer: (b). 2. is not required. This GATE exam includes questions from previous year GATE papers. Attempt a small test to analyze your preparation level. Mutual Exclusion: One or more than one resource are non-sharable (Only one process can use at a time) Hold and Wait: A process is holding at least one resource and waiting for resources. The questions asked in this NET practice paper are from various previous year papers. Deadlock prevention is a set of methods : to ensure that at least one of the necessary conditions cannot hold, to ensure that all of the necessary conditions do not hold, to decide if the requested resources for a process have to be given or not.