📝 Deadlocks Introduction in Operating System (45 MCQs)

📖 From Operating System • 7. Deadlocks • 45 questions available

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What is Deadlocks Introduction in Operating System?

Definition:
A deadlock is a situation where a set of processes are blocked because each process is holding a resource and waiting for another resource acquired by some other process, creating a permanent stalemate.

Example:
Process $P_1$ holds Resource $R_1$ and waits for $R_2$ , while Process $P_2$ holds $R_2$ and waits for $R_1$ , causing both to wait indefinitely.

Reason:
Understanding deadlocks is fundamental to OS design because they cause system halts and resource wastage, requiring specific mechanisms to ensure system liveness and reliability.

Easy

Medium

Hard

📝 All Deadlocks Introduction in Operating System MCQs

Q1. What is the fundamental condition that characterizes a deadlock in a multiprogramming environment?

A.A process is terminated due to a resource timeout.

B.A process is waiting indefinitely for resources held by other waiting processes. ✅

C.A process is continuously preempted by higher-priority processes.

D.A process has completed its execution but cannot release resources.

💡 Difficulty: easy | ✅ Correct: B

📖 Explanation: A deadlock occurs when a process cannot proceed because the resources it needs are being held by other processes that are themselves in a waiting state. This creates a circular dependency where no one can move forward, unlike termination, preemption, or completion scenarios.

Q2. In the context of deadlocks, what does a 'waiting state' for a process typically signify?

A.The process is waiting for its time slice to expire.

B.The process has finished its I/O operations.

C.The process is waiting for a resource that is currently unavailable. ✅

D.The process has been swapped out of main memory.

💡 Difficulty: easy | ✅ Correct: C

📖 Explanation: A process enters a waiting state when it requests a resource that is not immediately available. In the context of deadlocks, this waiting is indefinite because the resource is held by another waiting process, distinguishing it from temporary waits for I/O or CPU time.

Q3. Which of the following scenarios best exemplifies a deadlock as defined in operating system theory?

A.A high-priority process repeatedly preempts a low-priority process.

B.A process waits for a printer while another waits for a scanner, and neither will release its held resource. ✅

C.A process is terminated by the OS for exceeding its CPU time limit.

D.A process is paused so the system can perform a context switch.

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: This scenario perfectly illustrates a deadlock: two processes each hold one resource and need the other, creating a circular wait. This is the classic 'hold and wait' condition. The other options describe scheduling, termination, and normal context switching, not a deadlock.

Q4. A system has two processes, P1 and P2. P1 holds resource R1 and requests R2. P2 holds R2 and requests R1. Which condition is not yet met for this to be a definitive deadlock?

A.Hold and wait

B.Circular wait

C.Mutual exclusion

D.No preemption ✅

💡 Difficulty: medium | ✅ Correct: D

📖 Explanation: 'No preemption' is a condition where resources cannot be forcibly taken from a process. The scenario describes a potential deadlock, but if the OS could preempt resources (e.g., forcibly take R1 from P1), the deadlock could be avoided. The scenario already demonstrates hold-and-wait and circular wait. Mutual exclusion is assumed as resources are not shareable.

Q5. Consider a system with three processes and three resource types. The system enters a deadlock. What is the most direct consequence for the involved processes?

A.They will be automatically restarted by the operating system.

B.They will eventually time out and release their resources.

C.They will be unable to complete their execution and may wait indefinitely. ✅

D.They will continue executing with degraded performance.

💡 Difficulty: hard | ✅ Correct: C

📖 Explanation: The primary consequence of a deadlock is indefinite waiting. The processes involved will not complete their execution because they are blocked, waiting for resources that will never become available. Unlike a timeout or restart, deadlock is a permanent stall unless an external agent intervenes. Performance degradation implies progress, which is not the case.

Q6. A deadlock is often compared to a 'chicken-and-egg' problem. Which of the following statements best aligns with this analogy in an OS context?

A.The OS cannot allocate memory without first having the CPU, and vice versa.

B.Process A needs a file locked by Process B, which needs a record locked by Process A. ✅

C.A process cannot be created without memory, and memory cannot be allocated without a process.

D.The scheduler cannot run without processes, and processes cannot run without a scheduler.

💡 Difficulty: hard | ✅ Correct: B

📖 Explanation: The 'chicken-and-egg' analogy for deadlocks highlights the circular dependency. Option B perfectly describes this: A waits for B, and B waits for A, creating a cycle where neither can proceed. The other options describe bootstrapping or circular dependencies in system design, but not the classic resource allocation deadlock.

Q7. How does a finite number of resources in a system contribute to the occurrence of deadlocks?

A.It ensures resources are always allocated efficiently.

B.It creates the potential for competition where all resources can be exhausted. ✅

C.It simplifies the resource allocation algorithm.

D.It guarantees that a process will always find a resource.

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: A finite number of resources means they are a limited commodity. In a multiprogramming environment, many processes may compete for these limited resources. If all resources of a certain type are allocated, any new request for them will cause a process to wait, creating the potential for a deadlock.

Q8. The text describes a deadlock as a situation where a waiting process is 'never again able to change state.' What does this imply about the process's future?

A.It will eventually become a zombie process.

B.It will be moved to the ready queue after a timeout.

C.It cannot transition to running, ready, or terminated without external intervention. ✅

D.It will be swapped out to disk to free up memory.

💡 Difficulty: hard | ✅ Correct: C

📖 Explanation: This is a critical aspect of a deadlock. The process is permanently blocked. It cannot move to a 'running' state (needs resources), a 'ready' state (needs resources), or a 'terminated' state (cannot finish). This state is terminal without external intervention, such as a system administrator or the OS forcibly breaking the deadlock.

Q9. The Kansas legislature law requiring trains to stop and not start until the other has gone is used to illustrate what concept?

A.Mutual exclusion

B.Resource starvation

C.Deadlock ✅

D.Race condition

💡 Difficulty: easy | ✅ Correct: C

📖 Explanation: This law is a perfect, albeit humorous, illustration of a deadlock. Both trains are waiting for a condition (the other train moving) that can never be met, as it requires them to move first. This parallels two processes waiting for resources each other holds.

Q10. According to the text, what is the primary purpose of using the Kansas train law as an analogy for deadlocks?

A.To show how laws can prevent accidents.

B.To provide a simple, real-world example of a deadlock scenario. ✅

C.To critique the efficiency of early 20th-century legislation.

D.To illustrate the concept of race conditions.

💡 Difficulty: easy | ✅ Correct: B

📖 Explanation: The text explicitly uses this law as the 'best illustration' of a deadlock. It helps to simplify the abstract computer science concept of processes waiting on each other by using a relatable, everyday scenario of two trains at a crossing.

Q11. In the Kansas train law analogy, what represents the 'resources' that processes are waiting for?

A.The trains themselves

B.The train engineers

C.The railroad crossing

D.The permission to go first ✅

💡 Difficulty: medium | ✅ Correct: D

📖 Explanation: In the analogy, the 'resource' is the right-of-way or the permission to cross the intersection first. Each train (process) holds the resource (the permission to go) for itself but needs the other's resource (the other train to move) to proceed, which creates the deadlock.

Q12. If the Kansas train law were modified to state that the train that arrived first has the right to go first, which deadlock condition would this directly address?

A.Mutual exclusion

B.Hold and wait

C.No preemption

D.Circular wait ✅

💡 Difficulty: medium | ✅ Correct: D

📖 Explanation: A 'first-arrival' rule would break the circular wait. In a circular wait, each train is waiting for the other to go. If a priority (first arrival) is established, the chain of waiting is broken. One train can proceed, releasing the crossing for the other. 'Mutual exclusion' (only one can use the crossing), 'hold and wait' (both hold their position), and 'no preemption' (can't move them) are still present.

Q13. The text mentions the Kansas law from the 'early 20th century.' What is the likely purpose of mentioning this specific historical context?

A.To show that deadlocks are a modern computing problem.

B.To provide a concrete, dated reference to a known historical curiosity. ✅

C.To suggest that deadlocks were first identified by lawmakers.

D.To criticize the intelligence of historical legislators.

💡 Difficulty: hard | ✅ Correct: B

📖 Explanation: The specific historical reference adds color and credibility to the illustration. It grounds the analogy in a known, albeit unusual, piece of legislation, making the example more memorable and believable. It does not suggest deadlocks are historical, nor does it imply they were discovered by lawmakers.

Q14. Which of the following is a key limitation of using the Kansas train law as an analogy for computer deadlocks?

A.Trains are much larger than computer processes.

B.The law involves only two trains, while systems can have many processes.

C.The law was never actually enforced.

D.The law is a metaphor, not a direct equivalence. ✅

💡 Difficulty: hard | ✅ Correct: D

📖 Explanation: The question asks for the key *limitation* of the analogy. Any analogy is an imperfect comparison. The text uses this to illustrate the core concept of a circular wait, but a real computer deadlock involves many processes and resources, and is governed by a complex OS, not a simple law. This inherent limitation is a fundamental aspect of any analogy.

Q15. If a third train were added to the Kansas crossing scenario, and the rule remained that each must wait for the one ahead to move, the resulting situation would most accurately be described as a:

A.Chain reaction

B.Circular wait with multiple participants ✅

C.Race condition

D.Resource starvation

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: Adding more trains to a circular waiting scenario is a classic example of a circular wait with multiple participants. Each train (process) is holding its position (resource) and waiting for the next (another resource), creating a cycle that includes all three. 'Race condition' and 'resource starvation' are different concepts.

Q16. Why are deadlocks a significant concern specifically in a multiprogramming environment?

A.Multiprogramming eliminates all waiting states.

B.Several processes compete for a finite number of resources concurrently. ✅

C.Multiprogramming systems have infinite resources.

D.Processes in a multiprogramming system are independent.

💡 Difficulty: easy | ✅ Correct: B

📖 Explanation: The core of a multiprogramming environment is concurrent process execution. This leads to competition for finite resources. Without this competition and the potential for one process to hold a resource needed by another, the conditions for a deadlock would not be present.

Q17. In a system with a finite number of resources, what is the most critical factor that can lead to a deadlock?

A.The speed of the CPU.

B.The order in which resources are requested. ✅

C.The total amount of memory.

D.The number of users logged in.

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: While the number of resources is important, the *order* of requests is the key. If all processes request resources in a globally defined order, deadlocks can be prevented. A deadlock scenario (e.g., P1 holds R1 and requests R2, P2 holds R2 and requests R1) is a classic example of a problematic request order.

Q18. The text mentions that deadlock problems can 'only become more common' due to current trends. What is the primary reason for this prediction?

A.Modern operating systems are more complex than older ones.

B.The trends create more opportunities for resource contention and circular dependencies. ✅

C.Programmers today are less careful than those in the past.

D.Hardware is becoming less reliable.

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: The trends (more processes, multithreading, more resources, long-lived servers) all point to increased system complexity and interaction. More components and interactions mean more chances for processes to become entangled in a circular wait for resources, making deadlocks statistically more likely.

Q19. Which of the following modern computing trends is NOT mentioned in the text as a factor contributing to the increased likelihood of deadlocks?

A.Larger numbers of processes

B.Multithreaded programs

C.Increased use of cloud computing ✅

D.Long-lived file and database servers

💡 Difficulty: medium | ✅ Correct: C

📖 Explanation: The text specifically lists larger numbers of processes, multithreaded programs, many more resources, and long-lived servers as trends. While cloud computing can involve these elements, it is not directly mentioned in the provided text as a distinct trend causing deadlocks. The others are all explicitly cited.

Q20. What is the fundamental challenge that an operating system faces when managing resources in a multiprogramming environment that can lead to a deadlock?

A.Managing a finite number of resources among competing processes. ✅

B.Scheduling processes to maximize CPU utilization.

C.Allocating memory efficiently to avoid fragmentation.

D.Handling input/output operations from multiple devices.

💡 Difficulty: hard | ✅ Correct: A

📖 Explanation: The fundamental challenge is the finite nature of resources. The OS must decide how to allocate limited resources (CPU, memory, I/O devices) among a potentially large number of competing processes. This allocation, if not carefully managed, can lead to a situation where processes are waiting for resources held by each other, resulting in a deadlock.

Q21. How does the concept of a 'long-lived file and database server' contribute to the increased risk of deadlocks compared to a batch system?

A.Batch systems are inherently slower, so they have more time to recover.

B.Servers handle many concurrent requests, leading to more complex resource locking and higher contention. ✅

C.Batch systems use fewer resources overall.

D.Servers have more advanced deadlock detection mechanisms.

💡 Difficulty: hard | ✅ Correct: B

📖 Explanation: Long-lived servers handle many concurrent, persistent requests. This means they hold locks on resources (like database records or files) for longer periods. The increased overlap in resource access and the higher number of concurrent transactions create a much greater probability of encountering a circular wait for resources, making deadlocks more likely than in simpler batch systems.

Q22. In a multiprogramming environment, a process requests a resource that is unavailable. What is the immediate consequence for that process?

A.It is terminated immediately.

B.It enters a waiting state. ✅

C.It is given a higher priority.

D.It continues execution using a different resource.

💡 Difficulty: easy | ✅ Correct: B

📖 Explanation: When a requested resource is not available, the process cannot continue its execution. It is therefore placed into a waiting state by the operating system's scheduler. This is a normal and expected part of resource management, but it is this waiting that can lead to a deadlock if not resolved.

Q23. According to the text, who typically holds the primary responsibility for ensuring a program is deadlock-free?

A.The operating system developers

B.The computer hardware manufacturer

C.The application programmer ✅

D.The network administrator

💡 Difficulty: easy | ✅ Correct: C

📖 Explanation: The text explicitly states that 'it remains the responsibility of programmers to ensure that they design deadlock-free programs.' This clearly assigns the primary responsibility to the application programmer.

Q24. The text states that 'operating systems typically do not provide deadlock-prevention facilities.' What is the most likely reason for this?

A.Deadlock prevention is impossible to implement.

B.It is more efficient to handle deadlocks by simply restarting the system.

C.Prevention algorithms can limit resource utilization and degrade performance. ✅

D.Programmers are better equipped to handle this task.

💡 Difficulty: medium | ✅ Correct: C

📖 Explanation: Deadlock prevention often involves imposing restrictions on resource allocation, such as requiring processes to request all resources at once or ordering resource requests. These restrictions can significantly reduce resource utilization and overall system performance, which is why OSes often leave the problem to the programmer.

Q25. If an operating system does not prevent deadlocks, what is a likely alternative approach it might take to handle them?

A.It will ignore the problem entirely.

B.It will terminate one or more processes involved in the deadlock to break the cycle. ✅

C.It will automatically upgrade the hardware to provide more resources.

D.It will ask the user to manually resolve the conflict.

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: If prevention is not used, the OS might employ deadlock detection and recovery. A common recovery technique is to terminate one or more of the deadlocked processes, forcing them to release their resources and allowing the others to proceed. This breaks the circular wait.

Q26. The text mentions that 'some applications can identify programs that may deadlock.' This suggests that deadlock detection is:

A.Impossible to perform in any practical system.

B.A feature that is only available in third-party software.

C.A complex task that may be feasible in specific, controlled environments. ✅

D.A standard feature of all modern operating systems.

💡 Difficulty: hard | ✅ Correct: C

📖 Explanation: The phrase 'some applications can identify' suggests that while it is not a general feature, it is possible in certain contexts. This implies that deadlock detection is a complex but feasible task, often applied in specific, well-understood environments like database systems or certain real-time applications, rather than being a universal OS feature.

Q27. What is a key consequence of shifting the responsibility of deadlock prevention from the operating system to the programmer?

A.It reduces the overall complexity of the operating system.

B.It requires programmers to deeply understand resource management and concurrency. ✅

C.It makes programs more portable across different systems.

D.It completely eliminates the possibility of deadlocks.

💡 Difficulty: hard | ✅ Correct: B

📖 Explanation: When prevention is the programmer's task, they must be knowledgeable about the potential for deadlocks and design their code accordingly (e.g., using a specific resource request order). This requires a deep understanding of concurrency and resource management, which is a significant and challenging aspect of system-level programming.

Q28. In a situation where a deadlock occurs, and the operating system does not have a recovery mechanism, what is the most likely outcome for the deadlocked processes?

A.They will be swapped out to disk.

B.They will eventually time out and release their resources.

C.They will remain in a blocked state indefinitely until the system is restarted. ✅

D.They will be given higher priority to resolve the conflict.

💡 Difficulty: medium | ✅ Correct: C

📖 Explanation: If the OS cannot detect or recover from a deadlock, the processes involved will remain in a waiting state forever. They cannot proceed on their own. In many systems, this means the processes effectively hang, and the only way to resolve the situation is to manually terminate them or restart the system.

Q29. Which of the following is a potential drawback of an operating system actively preventing deadlocks?

A.It makes the system less secure.

B.It can lead to lower resource utilization and reduced system throughput. ✅

C.It makes the system more prone to race conditions.

D.It increases the complexity of the user interface.

💡 Difficulty: hard | ✅ Correct: B

📖 Explanation: Deadlock prevention often requires resource allocation policies that are inherently restrictive. For example, a process might have to request all its resources at startup, which can lead to a process holding resources it doesn't need yet, preventing other processes from using them and thus reducing overall system efficiency.

Q30. Based on the text, which of the following is a trend that is increasing the likelihood of deadlocks?

A.A decrease in the number of processes running concurrently.

B.A shift from batch processing to long-lived file and database servers. ✅

C.A reduction in the number of resources available within a system.

D.A move from multithreaded programs to single-threaded programs.

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: The text explicitly lists 'an emphasis on long-lived file and database servers rather than batch systems' as a trend that increases the risk. The other options represent trends that would likely decrease the risk or are contrary to the text's description.

Q31. How does an increase in the number of processes within a system contribute to a higher risk of deadlocks?

A.It increases the total amount of memory used.

B.It increases the likelihood of circular waits by creating more resource allocation combinations. ✅

C.It makes the system slower, giving more time for deadlocks to occur.

D.It decreases the availability of the CPU.

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: More processes mean more entities contending for resources. This combinatorially increases the number of possible allocation states. With more processes, the chance of them forming a cycle where each holds a resource needed by another (a circular wait) is significantly higher, thus increasing the risk of a deadlock.

Q32. The text suggests that the problem of deadlocks is not diminishing but is likely to grow. What is the most significant underlying reason for this?

A.Software developers are becoming less skilled.

B.System complexity and concurrency are increasing. ✅

C.Hardware is becoming more prone to failure.

D.Operating systems are becoming less efficient.

💡 Difficulty: hard | ✅ Correct: B

📖 Explanation: The core reason is the increasing complexity and concurrency in modern systems. More processes, threads, and shared resources lead to intricate interactions. This complexity makes it more challenging to design systems that are entirely free of deadlocks, and the probability of a deadlock occurring due to unforeseen interactions goes up.

Q33. What is the relationship between multithreaded programs and the increased risk of deadlocks?

A.Multithreading reduces the need for resource locks.

B.Threads within a program share resources, increasing the potential for contention. ✅

C.Multithreading inherently prevents deadlocks from occurring.

D.Threads are independent and do not compete for resources.

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: In a multithreaded program, threads within the same process can share resources (e.g., memory, files). This sharing necessitates synchronization mechanisms like mutexes and semaphores. If not used carefully, these locks can lead to deadlocks where two or more threads are waiting for locks held by each other.

Q34. Which of the following is an example of a system where the emphasis on 'long-lived' services might make deadlocks a significant concern?

A.A simple calculator application

B.A web server handling thousands of concurrent requests ✅

C.A single-user word processor

D.A batch payroll system that runs overnight

💡 Difficulty: hard | ✅ Correct: B

📖 Explanation: A web server is a prime example of a long-lived service. It handles many concurrent requests, each potentially accessing files, database connections, and other shared resources. If locks are not managed correctly, a deadlock can stall a web server, making it unresponsive to all users, which is a critical problem.

Q35. The text mentions 'many more resources within a system' as a trend. Why does having more resources potentially increase deadlock risk?

A.It makes the system more complex to manage, increasing the chance of allocation errors.

B.It creates more opportunities for processes to hold different combinations of resources, leading to circular waits. ✅

C.It simply provides more resources, which should reduce deadlock risk.

D.It increases the likelihood of a single point of failure.

💡 Difficulty: hard | ✅ Correct: B

📖 Explanation: A larger pool of resources means there are more possible combinations of resources that a process can hold. This significantly increases the complexity of the resource allocation state. With more combinations comes a higher probability of creating a cycle where Process A holds Resource X and wants Y, while Process B holds Y and wants X, etc.

Q36. In the resource request process, what happens if the resources a process requests are not available at that time?

A.The process is immediately terminated.

B.The process enters a waiting state. ✅

C.The process is given a different resource.

D.The request is ignored and the process continues.

💡 Difficulty: easy | ✅ Correct: B

📖 Explanation: This is a fundamental step. If a requested resource is unavailable, the OS cannot grant it. The process must then wait for the resource to become available, transitioning from the running state to a waiting or blocked state until the resource can be allocated.

Q37. A process successfully requests and obtains a resource. It then requests a second resource, which is unavailable. What is the state of the process and its resources?

A.The process waits, and it releases the first resource.

B.The process waits while still holding the first resource. ✅

C.The process is terminated.

D.The process releases both resources and restarts.

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: This is the classic 'hold and wait' condition. When a process requests a second resource and it's unavailable, it enters a waiting state. Crucially, the OS typically does not force it to release the first resource it already holds. This 'holding' while 'waiting' is a necessary condition for a deadlock.

Q38. If a process requests a resource that is currently held by a waiting process, what is the most likely outcome?

A.The request is granted immediately.

B.The requesting process also enters a waiting state, potentially creating a chain. ✅

C.The resource is forcibly taken from the waiting process.

D.The requesting process is terminated to prevent a deadlock.

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: This situation is the foundation of a deadlock. If process A waits for a resource held by process B, and B is itself waiting for a resource held by A (or another process), a circular chain of waiting processes is formed. This is the 'circular wait' condition that ultimately defines a deadlock.

Q39. What is the immediate outcome when a process requests a resource that is currently available?

A.The process is blocked.

B.The process is terminated.

C.The process is granted the resource and continues execution. ✅

D.The process is moved to a waiting queue.

💡 Difficulty: easy | ✅ Correct: C

📖 Explanation: If a resource is available, the OS allocates it to the requesting process. The process can then continue its execution, as its request has been satisfied. This is the standard, successful path in the request-allocation process.

Q40. Consider a system with two resources, R1 and R2. Process P1 holds R1 and requests R2. Process P2 holds R2 and requests R1. What is the critical condition that this scenario fulfills?

A.Mutual exclusion

B.Hold and wait

C.No preemption

D.Circular wait ✅

💡 Difficulty: medium | ✅ Correct: D

📖 Explanation: While this scenario fulfills all four conditions, the critical and defining one here is 'circular wait'. The processes form a cycle: P1 is waiting for a resource (R2) held by P2, and P2 is waiting for a resource (R1) held by P1. This cycle is the essence of the circular wait condition.

Q41. A process requests a resource that is unavailable, and the operating system's policy is to make the process release all resources it currently holds. Which deadlock condition is this policy designed to prevent?

A.Mutual exclusion

B.Hold and wait ✅

C.No preemption

D.Circular wait

💡 Difficulty: hard | ✅ Correct: B

📖 Explanation: The 'hold and wait' condition occurs when a process holds at least one resource and is waiting for another. By forcing a process to release all held resources before waiting, the OS directly breaks this condition. The process then either has all it needs or nothing, preventing the scenario where a process holds resources while waiting for more.

Q42. If a process holds a resource and requests another, but the second request can be satisfied, the process will continue. The request and allocation cycle continues until the process is done, at which point it releases all resources. This describes a standard, non-deadlock scenario that avoids which condition?

A.Mutual exclusion

B.Hold and wait (if it never has to wait) ✅

C.No preemption

D.Circular wait

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: If a process never has to wait for a resource it requests, it does not hold resources while waiting for others. The 'hold and wait' condition is only problematic when a process is forced to wait while holding resources. In this successful scenario, the process either gets all requested resources immediately or not at all, thus avoiding the 'hold and wait' condition that leads to deadlocks.

Q43. What is the final step in the typical resource life-cycle for a process that has completed its execution?

A.It requests more resources.

B.It releases all allocated resources. ✅

C.It is terminated by the operating system.

D.It enters a waiting state for new resources.

💡 Difficulty: easy | ✅ Correct: B

📖 Explanation: Once a process has finished its work and is ready to terminate, it is its responsibility (or the OS's) to release all resources it had been holding. This makes those resources available to other waiting processes and is a crucial part of resource management and preventing deadlocks in the long run.

Q44. In the process of resource allocation, which action directly triggers a process to enter a waiting state?

A.The process requests a resource that is not currently available. ✅

B.The process completes its execution.

C.The process releases a held resource.

D.The OS preempts the process to give CPU to another.

💡 Difficulty: easy | ✅ Correct: A

📖 Explanation: A process requests a resource. If the OS can grant the request, the process continues. If the resource is unavailable, the request cannot be granted, and the process is put into a waiting state by the OS scheduler. The process will remain there until the resource becomes available.

Q45. What is the role of the operating system when a process requests a resource that is currently being held by another process?

A.It terminates both processes immediately.

B.It grants the request and forces the other process to release the resource.

C.It denies the request and places the requesting process in a waiting state. ✅

D.It automatically upgrades the hardware to provide more resources.

💡 Difficulty: medium | ✅ Correct: C

📖 Explanation: When a resource is held by another process, the OS cannot grant the request. The requesting process has no choice but to wait. The OS will therefore deny the request and move the process to a waiting state, where it will remain until the resource becomes free. Whether this leads to a deadlock depends on the state of the process holding the resource.

🔗 Related Topics (MCQs)

📝 Deadlocks System Model in Operating System MCQs 📝 Deadlock Characterization in Operating System MCQs 📝 Necessary Conditions for Deadlock Characterization MCQs 📝 Methods for Handling Deadlocks in Operating System MCQs 📝 Mutual Exclusion Deadlock Prevention MCQs

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