Chapter 26 Flashcards
When in a bridge crossing problem, a lane of cars jammed and whole car lane goes back, what it is technically called
preempt the resource or roll back
Does starvation possible in bridge crossing
Yes
How a process utilize a resource
request -> use -> release
What is system model
In system model there are some processes and there are some resources. Processes uses resources and at the end they release resources.
Does resource type instances are identical to each other
Yes
What 4 conditions that become true to create a deadlocks
- Mutual Exclusion
- Hold and wait
- Circular wait
- No preemption
What is Mutual Exclusion
Every process using a resource mutually exclusively. Means not sharing the resource. Only one process can use a resource at a time.
What is no preemption
A process has a resource but it can not be preempt. It means resource can not be taken from it by force and give to some one else.
What is hold and wait
A process has a resource and wants that another process give him his resource.
What is circular wait
Processes are waiting in a circle. All processes want resource from another process.
What is resource allocation graph
We can know from it, when the system has a deadlock
What is deadlock prevention
If any of one condition among 4 conditions does not exists, then it is called deadlock prevention.
What are 2 things in edge set of resource allocation graph
- Request edges
2. Assignment edges
What is assignment edge in resource allocation graph
Instance assignment to process
What is request edge in resource allocation graph
From a process to a resource type
