FOR FREE CONTENT
- Introduction: OS
- Booting Process
- Command Interpreter
- Dual mode of operation
- System Calls
- Difference between system call and library call
- Interrupt and Trap
- Introduction
- Scheduling Criteria, Terms and Concepts
- Different Type Scheduling Algorithms
- Longest Job First
- Longest Remaining Time First
- Highest Response Ratio Next (HRRN)
- Priority Scheduling
- Least Completed Next (LCN) Scheduling
- Multi-Level Queue Scheduling
- Multilevel Feedback Queue Scheduling
- Guaranteed Scheduling
- Fair Share Scheduling
- Lottery Scheduling
- Multi-Processor Scheduling
- Deadline Scheduling
- Rate-Monotonic Scheduling
- POSIX Real-Time Scheduling
- Priority Inversion
- Proportional Share Scheduling
- Comparison table of Scheduling Algorithm
- Algorithm Evaluation for Scheduling
- Important concept of MM
- Memory Representation as Address
- Memory layout for a Process
- Logical and Physical Address Space
- Necessity of Memory Management
- Introduction
- Concept of Non-contiguous memory allocation
- Basic concept of Paging
- Address Translation
- Process of Paging Method
- Calculation of Offset for paging
- Calculation of Logical Address Bit and number of Pages
- Calculation of Physical Address Bit and number of Frames
- Calculation of Page Table Size
- Organization of MMU
- Why Page size power of 2
- Paging Address Calculation: example1
- Paging Numeric Problem: Example2
- Paging Address Calculation: Example3
- Paging Address Calculation: Question1
- Some Important Question 2
- Paging Address Translation: Question3
- UGC NET Paging Question
- GATE Paging Question
- Number of information at Page Entry
- Exams Question on Page Entry Information
- Exam Question: Page Entry Information
- Calculates Page Table Entry Size
- Calculates Page Size
- Calculation of Optimal Page Size
- Question on Optimal Page Size
- Hashed Page Table with Example
- Inverted Page Table with Gate Question
- Question on Inverted Page Table
- Multi-Level Paging
- Multi-level paging: Example1
- Multi-level paging: Example2
- Allocation of Frames
- Subject Mock
Dining Philosopher Question-NET and GATE
Question GATE-2000
Let m[0] .........m[4] be mutexes (binary semaphore) and P0 ..... P4 be processes. Suppose each process P[i] executes the following:
wait (m[i]) ; wait (m[i+1] mod 4)
CS
release (m[i]); release (m[i+1] mod 4)
Which situation could be came
a) Thrashing
b) Deadlock
c) Starvation but no deadlock
d) None
Answer:
This is question is related to the dining philosopher problem. (See Dining Philosopher problem)
P means Down or Wait operation of binary semaphore.
P or Down operation cannot execute by two processes together for a single semaphore variable. If one process already runs a P or Down operation, then for the next process P or Down operation will be blocked for the same semaphore variable.
How it executes as per the above code P0, P1, P2, P3, P4
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As if we know very well that this situation can be deadlock because this is exactly a dining philosopher problem.
Let take an example where deadlock will occur.
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So, it is a deadlock. Option b is correct.
UGC NET Paper –III 52
Dining philosopher’s problem is a
a) Producer-Consumer problem
b) Classical IPC problem
c) Starvation problem
d) Synchronization problem.
Answer:
a) It is not a producer-consumer problem because the producer-consumer problem is a different classical problem.
Option a wrong.
b) We discuss all classical problems above and the Dining philosopher problem is one of the classical problems. (See Dining philosopher problem).
So, Option b is correct.
c) No obviously dining philosopher is not a starvation problem because it removes deadlock. For more details (See Dining philosopher problem).
Option c is wrong.
d) Dining philosopher problem is doing synchronization because it removes deadlock but it is a category of the classical problem.
So, Option b is a more correct answer than d.
