L-4.1: DEADLOCK concept | Example | Necessary condition | Operating
System
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Necessary Conditions for Deadlock
Understanding Deadlock Concept
Deadlock is a specific condition in multi-process, multi-resource computing systems where
two or more processes are unable to proceed because each is waiting for the other to
release a resource.
Necessary Conditions for Deadlock
Four necessary conditions must hold simultaneously for a deadlock to occur:
Mutual Exclusion: At least one resource must be held in a non-shareable mode. Only one
process can use the resource at any given instant of time.
Hold and Wait Condition: 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 by the process holding it, after
that process has completed its task.
Circular Wait: A set of processes are waiting for each other in a circular form. Each process
is waiting for a resource that the next process in the set holds.
Hold and Wait Condition
A process is in a hold and wait state if it is holding at least one resource and waiting for
additional resources held by other processes. This condition, combined with mutual
exclusion, can lead to a deadlock if the required resources are not available and the waiting
process does not release any of its currently held resources.
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System
Gate Smashers UCJihyK0A38SZ6SdJirEdIOw
Topics
Summary Copy Link
Necessary Conditions for Deadlock
Understanding Deadlock Concept
Deadlock is a specific condition in multi-process, multi-resource computing systems where
two or more processes are unable to proceed because each is waiting for the other to
release a resource.
Necessary Conditions for Deadlock
Four necessary conditions must hold simultaneously for a deadlock to occur:
Mutual Exclusion: At least one resource must be held in a non-shareable mode. Only one
process can use the resource at any given instant of time.
Hold and Wait Condition: 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 by the process holding it, after
that process has completed its task.
Circular Wait: A set of processes are waiting for each other in a circular form. Each process
is waiting for a resource that the next process in the set holds.
Hold and Wait Condition
A process is in a hold and wait state if it is holding at least one resource and waiting for
additional resources held by other processes. This condition, combined with mutual
exclusion, can lead to a deadlock if the required resources are not available and the waiting
process does not release any of its currently held resources.
Explore our developer-friendly HTML to PDF API Printed using PDFCrowd HTML to PDF
