The dynamic strategy of deadlock avoidance that attempts to ensure that resources are never allocated in such a way as to place a system in an unsafe state.
avoidance
One of four conditions for deadlock through which each process
involved is waiting for a resource being held by another; each process is blocked and
can’t continue, resulting in deadlock.
circular wait
A problem occurring when the resources needed by some jobs to finish execution are held by other jobs, which, in turn, are waiting for other resources to become available. Also called deadly embrace.
deadlock
the process of examining the state of an operating system to determine whether a deadlock exists.
detection
a graphic model representing various states of resource allocations
directed graphs
a locked system whereby two (or more) processes continually block the forward progress of the others without making any forward progress themselves. It is
similar to a deadlock except that neither process is blocked or obviously waiting; both
are in a continuous state of change.
livelock
a technique used to guarantee the integrity of the data in a database through which the user locks out all other users while working with the database.
locking
one of four conditions for deadlock in which only one process is
allowed to have access to a resource.
mutual exclusion:
one of four conditions for deadlock in which a process is allowed to
hold on to resources while it is waiting for other resources to finish execution.
no preemption
a design strategy for an operating system where resources are managed in such a way that some of the necessary conditions for deadlock do not hold.
prevention
(1) the need for algorithms to resolve conflicts between
processors in a multiprocessing environment; or (2) the need to ensure that events occur in the proper order even if they are carried out by several processes
process synchronization
a synchronization problem between two processes vying for the same resource.
race
the steps that must be taken, when deadlock is detected, by breaking the circle of waiting processes
recovery
one of four conditions for deadlock in which each process refuses to
relinquish the resources it holds until its execution is completed even though it isn’t using them because it’s waiting for other resources
resource holding
the situation in which the system has enough available resources to
guarantee the completion of at least one job running on the system
safe state
a technique developed to speed I/O by collecting in a disk file either input received from slow input devices or output going to slow output devices, such as printers
spooling
the result of conservative allocation of resources in which a single job is prevented from execution because it’s kept waiting for resources that never become available
starvation
a situation in which the system has too few available resources to guarantee the completion of at least one job running on the system. It can lead to deadlock.
unsafe state
an expendable job that is selected for removal from a deadlocked system to provide more resources to the waiting jobs and resolve the deadlock.
victim
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Chapter 1103
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Chapter 25
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Review Questions13
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Chapter 361
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Chapter 441
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Key Terms79
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Chapter 527
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Chapter 5 key terms19
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Chapter 3 Key Terms32
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Chapter 4 Key Terms37
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Chapter 2 Key Terms18
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Chapter 1 Key Terms32
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Chapter 645
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Chapter 6 Key Terms25
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Chapter 756
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Chapter 7 Key Terms42
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Chapter 8 Key Terms33
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Chapter 847
