Reference no: EM13159705
Deadlock can be defined as the permanent blocking of a set of processes that either compete for system resources or communicate with each other. A set of processes is deadlocked when each process in the set is blocked awaiting an event (typically the freeing up of some requested resource) that can only be triggered by another blocked process in the set. Deadlock is permanent because none of the events is ever triggered. Unlike other problems in concurrent process management, there is no efficient solution in the general case. All deadlocks involve conflicting needs for resources by two or more processes.
The strategy of deadlock prevention is, simply put, to design a system in such a way that the possibility of deadlock is excluded.
Deadlock detection strategies do not limit resource access or restrict process actions. With deadlock detection, requested resources are granted to processes whenever possible. Periodically, the operating system performs an algorithm that allows it to detect the circular wait condition. Once deadlock has been detected, some strategy is needed for recovery.
In deadlock prevention, we constrain resource requests to prevent at least one of the four conditions of deadlock (Mutual exclusion, Hold and wait, No preemption, Circular wait). This is either done indirectly, by preventing one of the three necessary policy conditions (mutual exclusion, hold and wait, no preemption), or directly, by preventing circular wait. This leads to inefficient use of resources and inefficient execution of processes.
Deadlock avoidance, on the other hand, allows the three necessary conditions but makes judicious choices to assure that the deadlock point is never reached. As such, avoidance allows more concurrency than prevention. With deadlock avoidance, a decision is made dynamically whether the current resource allocation request will, if granted, potentially lead to a deadlock. Deadlock avoidance thus requires knowledge of future process resource requests. Two approaches to deadlock avoidance are:
- Do not start a process if its demands might lead to deadlock.
- Do not grant an incremental resource request to a process if this allocation might lead to deadlock.
Discuss these approaches
|
Impact on the british parliament
: Explain the impact on the British parliament due to the The Powder Treason. List the key periods when milling production reflected the needs of warfare between 1700 and 1900.
|
|
What would be an ascus from this cross look like
: In examining a large sample pf yeast colonies on a petri dish, ageneticist finds an abnormal-looking colony that is very small.This small colony was crossed with wild type, and products ofmeiosis were spread on a plate to produce colonies. In tota..
|
|
Probablity that in next week exactly seven claims filed
: A life insurance policy has determined that each week an average of seven claims is filed in its Nashville branch. What is the probablity that durning the next week exactly seven claims will be filed?
|
|
What will the concentration of hconh2 be at equilibrium
: If a reaction vessel initially contains only co and NH3 at concentrations of 1.00 m and 2.00m , respectively, what will the concentration of HCONH2 be at equilibrium?
|
|
Deadlock prevention
: In deadlock prevention , we constrain resource requests to prevent at least one of the four conditions of deadlock (Mutual exclusion, Hold and wait, No preemption, Circular wait). This is either done indirectly, by preventing one of the three necess..
|
|
Elements of persuasion
: What are the elements of persuasion? What forms of persuasion and group influence principles are harnessed by new religious movements? with at least a word count of 200-300 words.
|
|
State octane highest boiling point
: Which of the following compounds is expected to have the highest boiling point? octane, 2,3-dimethylhexane, 2,2,3,3-tetramethylbutane
|
|
Prefatory parts of a formal report
: What are some prefatory parts of a formal report or proposal? How does the reader use these parts?
|
|
Probablity that there are no tremors in a one-month period
: What is the probablity that there are no tremors in a 1-month period? What is the probability tha there are more than 5 tremors in a 6-month period?
|