Recommended
Practice
1. In which of the following scenarios is the concept of 'Hold and Wait' most likely to cause a deadlock?
easy
Solution
Step 1: Understand 'Hold and Wait'
This condition requires a process to hold at least one resource while waiting to acquire additional resources. A process holds one resource and waits to acquire another resource already held by another process directly describes this scenario.Step 2: Analyze other options
A process requests all required resources at once before execution begins avoids hold and wait by requesting all resources upfront. A process releases all resources before requesting new ones releases resources before requesting new ones, preventing hold and wait. A process can forcibly preempt resources from other processes describes preemption, which is a different condition.Final Answer:
Option D -> Option DQuick Check:
Only a process holding one resource and waiting to acquire another resource already held by another process matches the hold and wait condition necessary for deadlock.
Hint: Hold and Wait means holding some resources while waiting for others [OK]
Common Mistakes:
- Confusing hold and wait with requesting all resources at once
- Thinking preemption is part of hold and wait
2. In which scenario is First-Come, First-Served (FCFS) scheduling most appropriate to use?
easy
Solution
Step 1: Understand FCFS characteristics
FCFS schedules processes in the order they arrive without preemption, making it simple and fair in terms of arrival order.Step 2: Analyze each option
A is incorrect because FCFS does not optimize for similar burst times; it just queues by arrival.
B is incorrect because FCFS can cause long waiting times if a long process arrives first.
C is incorrect because FCFS is non-preemptive and does not handle unpredictable arrivals well.
D is correct because FCFS's main advantage is simplicity and fairness in order, not responsiveness or waiting time optimization.Final Answer:
Option D -> Option DQuick Check:
FCFS is chosen for simplicity and fairness, not for minimizing waiting time or handling preemption.
Hint: FCFS = simple, fair order, not optimized for waiting time
Common Mistakes:
- Assuming FCFS minimizes average waiting time
- Confusing FCFS with preemptive scheduling
- Believing FCFS handles unpredictable arrivals efficiently
3. Which of the following statements best describes a limitation of FCFS scheduling related to waiting time and system responsiveness?
medium
Solution
Step 1: Evaluate each statement
A is correct because FCFS can cause long waiting times for short processes due to the convoy effect.
B is incorrect because FCFS does not guarantee the shortest average waiting time; algorithms like SJF do.
C is incorrect because FCFS is non-preemptive and does not allow preemption.
D is incorrect because FCFS scheduling complexity is O(n), simple queue processing.Step 2: Identify the limitation
The convoy effect causing long waiting times for short processes is a key limitation.Final Answer:
Option A -> Option AQuick Check:
FCFS is simple but can cause poor responsiveness due to the convoy effect.
Hint: FCFS = simple but convoy effect hurts short jobs
Common Mistakes:
- Believing FCFS minimizes average waiting time
- Confusing FCFS with preemptive algorithms
- Overestimating FCFS scheduling complexity
4. Which of the following statements about the FIFO page replacement algorithm is INCORRECT?
medium
Solution
Step 1: Understand FIFO Eviction Policy
FIFO evicts the oldest loaded page, not the least recently used.Step 2: Evaluate Each Option
FIFO can suffer from Belady's anomaly where increasing frames increases page faults is correct; Belady's anomaly can occur with FIFO.
FIFO always evicts the least recently used page is incorrect; FIFO does not track recency of use.
FIFO is simple to implement with a queue data structure is correct; FIFO uses a queue for eviction order.
FIFO does not consider how frequently or recently a page was accessed is correct; FIFO ignores frequency and recency.Final Answer:
Option A -> Option AQuick Check:
FIFO evicts by arrival order, not usage recency.
Hint: FIFO evicts oldest loaded page, not least recently used [OK]
Common Mistakes:
- Confusing FIFO with LRU eviction criteria
- Assuming FIFO tracks page usage
- Believing FIFO cannot have anomalies
5. Suppose a multithreaded application crashes due to a segmentation fault. Which of the following scenarios best explains why debugging is more challenging compared to a multi-process application?
hard
Solution
Step 1: Understand memory sharing in threads
Threads share the same address space, so a fault in one thread can corrupt shared data affecting others.Step 2: Contrast with processes
Processes have isolated memory, so faults are contained, making debugging easier.Step 3: Evaluate options
Because each thread has its own memory space, faults are isolated and easier to debug is false because threads share memory. Because thread context switches are slower, the fault is harder to reproduce is false; thread context switch speed does not affect fault reproducibility. Because processes share memory, faults propagate easily between them is false; processes do not share memory by default.Final Answer:
Option A -> Option AQuick Check:
Shared memory in threads complicates debugging due to data corruption [OK]
Hint: Shared memory means shared bugs [OK]
Common Mistakes:
- Assuming threads have isolated memory like processes
- Confusing context switch speed with debugging difficulty
- Believing processes share memory by default