Revisão De SiSTEMas Operacionais

The correct answer is that the information is false because there was no distinction between professionals in the early days of the ENIAC. The same professionals were responsible for designing, programming, and operating the computer. Therefore, there would not have been a situation where operators intentionally introduced errors into the programs to cause problems for the programmers.

The correct answer is "Novo, Executando, Esperando, Pronto e Terminado". These states represent the generic states of a process. "Novo" (New) refers to a process that has been created but has not yet been executed. "Executando" (Executing) refers to a process that is currently being executed by the CPU. "Esperando" (Waiting) refers to a process that is waiting for a certain event or resource to become available. "Pronto" (Ready) refers to a process that is waiting to be assigned to a CPU for execution. "Terminado" (Terminated) refers to a process that has finished its execution.

During the second generation of computing (1955-1965), programmers developed their programs in Fortran or Assembly and recorded them on sets of punched cards. Operators would then group these programs into batches for execution on mainframes that cost millions of dollars. This scenario aligns with the characteristics of the second generation, where computers became more powerful, smaller, and more affordable, leading to increased use in business and scientific applications.

A seção crítica de um programa é a parte do código onde ocorre o acesso e a manipulação de recursos compartilhados por múltiplas threads ou processos. Essa seção é considerada crítica porque pode levar a uma condição de corrida, que é uma situação em que o resultado da execução depende da ordem de acesso concorrente aos recursos compartilhados. Portanto, a resposta correta é "Seção Crítica".

The correct answer is "Escalonador". The escalonador is responsible for selecting processes to be moved between queues or allocated for processing or I/O. It determines the order in which processes are executed and manages the allocation of resources to ensure efficient and fair utilization of the system's resources.

The correct answer states that the magnetic disks should be swapped with the optical disks in order for this hierarchy to be correctly represented. This means that the given hierarchy is not in the correct order, and the magnetic disks should be placed below the optical disks.

A resposta correta é "Contexto de Software, Contexto de Hardware, Espaço de Endereçamento e Seção de Texto". Essas são as partes que compõem um processo, incluindo o contexto de software e hardware, o espaço de endereçamento e a seção de texto. O contexto de software refere-se às informações relacionadas ao software em execução, enquanto o contexto de hardware se refere às informações relacionadas ao hardware em uso. O espaço de endereçamento é onde o processo armazena seus dados e instruções, e a seção de texto contém o código executável do programa.

A característica que NÃO é dos sistemas operacionais monoprogramáveis é que eles não utilizam os recursos do computador de forma economicamente eficiente.

The correct answer states that "No fundo, todo sistema é multiprogramável, já que diversos programas são carregáveis para a memória" which translates to "In essence, every system is multiprogrammable, since multiple programs can be loaded into memory." This statement is incorrect because not all systems are multiprogrammable. Some systems may only allow one program to be loaded and executed at a time. Therefore, this option is not a characteristic of multiprogrammable operating systems.

The system described in the question requires real-time processing to ensure that the cars can move as close together as possible and at the maximum speed allowed on the road. The system needs to make proactive adjustments for each car when the driver regains control or when there are defects in the vehicles. This indicates that the system has strict timing requirements and cannot tolerate any delays in processing. Therefore, it would be classified as "Tempo Real Crítico Rígido" (Real-Time Critical Hard).

A ocorrência de um deadlock requer a presença de exclusão mútua, não-preempção, espera circular e manter-e-esperar. No entanto, o progresso controlado não é uma das condições necessárias para a ocorrência de um deadlock. O progresso controlado refere-se à capacidade do sistema de garantir que pelo menos um processo em um conjunto de processos que competem por recursos seja capaz de avançar em direção à sua conclusão. Portanto, a opção "Progresso Controlado" não contém uma das condições necessárias para a ocorrência de um deadlock.

By dividing the memory into fixed-sized blocks (frames) and dividing the logical memory (process address space) into blocks of the same size (pages) and allowing pages to be loaded into any available frames, we are implementing memory paging.

The IBM System/360 was the first computer to introduce the techniques of circuitos integrados (integrated circuits) and multiprogramação (multiprogramming). Integrated circuits allowed for the miniaturization and increased efficiency of electronic components, while multiprogramming allowed for multiple programs to be executed simultaneously, improving the overall performance and utilization of the computer. These advancements were significant in the history of computer technology and greatly influenced the development of future systems.

Ser multiusuário ou monousuário é referente ao sistema como um todo e não aos serviços prestados pelo sistema.
Apenas sistemas multiprogramáveis podem ser multiusuário, pois é necessário prever a execução de processos concorrentes para cada usuário.

Em Windows NT, as chamadas de sistema são realizadas por intermédio da API Win32

A troca de contexto ocorre quando o kernel salva o contexto de um processo que estava em execução no PCB (bloco de controle de processo) e carrega o contexto salvo do processo escalonado. Durante a troca de contexto, o kernel realiza a transição de um processo em execução para outro processo, permitindo que vários processos sejam executados de forma concorrente em um sistema operacional multitarefa.

The correct answer is "Memória compartilhada e Troca de Mensagens". This is because these two models, shared memory and message passing, are the fundamental ways in which processes can communicate with each other. Shared memory involves multiple processes accessing and modifying the same memory space, allowing for efficient and fast communication. On the other hand, message passing involves processes sending and receiving messages to communicate, which can be more flexible and secure. Both models are widely used in inter-process communication and have their own advantages and disadvantages.

Ser multiusuário ou monousuário é referente ao sistema como um todo e não aos serviços prestados pelo sistema

The option "Quando ocorre um deadlock" does not indicate a circumstance in which scheduling decisions can occur. Deadlock refers to a situation where two or more processes are unable to proceed because each is waiting for the other to release a resource. Scheduling decisions, on the other hand, involve determining which process should be executed next based on various factors such as priority, time slice, or resource availability. Therefore, deadlock occurrence is not a valid circumstance for scheduling decisions.

A condição de corrida ocorre quando o resultado da execução de um conjunto de processos é afetado pela ordem de execução das instruções de cada processo. Isso pode levar a resultados inconsistentes ou indeterminados, pois os processos podem competir por recursos compartilhados ou executar em paralelo sem sincronização adequada. Portanto, a resposta correta é "Condição de Corrida".

The correct answer is "Uma ou mais UCP, controladores de dispositivos e adaptadores conectados por um barramento comum que fornece acesso a uma memória compartilhada." This is because the hardware of computers is designed in a way that allows for easy integration with operating systems. In a general-purpose computer, there would be one or more central processing units (UCP), device controllers, and adapters connected through a common bus that provides access to a shared memory. This arrangement allows for efficient communication and coordination between different hardware components.

The solution adopted to control the degree of risk of potentially harmful instructions is the implementation of a dual mode. The system operates normally in user mode, but potentially harmful instructions are executed in privileged mode, which provides a higher level of control over hardware and software. This allows for the separation of privileges and ensures that only authorized users with administrative rights can execute potentially harmful instructions, reducing the risk to other users and the system as a whole.

The correct answer is "Surto de UCP; Surto de E/S". In this context, "Surto de UCP" refers to the burst of CPU activity, indicating that the process is actively using the CPU. "Surto de E/S" refers to the burst of input/output activity, indicating that the process is waiting for input/output operations to be completed. Therefore, the process alternates between these two forms of operation.

The correct answer states that mechanisms determine how to implement a specific functionality, while policies indicate which functionalities should be implemented. This means that mechanisms are responsible for the technical implementation details, while policies define the overall guidelines and objectives of the system.

A unidade básica de utilização da UCP é a thread. Uma thread é uma sequência de instruções que pode ser executada independentemente por um processador. Ela representa uma unidade de trabalho dentro de um processo e permite que várias tarefas sejam executadas simultaneamente, melhorando a eficiência do processamento.

A opção "Prevenção de deadlock" não contém um benefício do uso de threads porque a prevenção de deadlock não é um benefício direto do uso de threads. O deadlock é um problema que ocorre quando dois ou mais processos ficam bloqueados, aguardando a liberação de recursos que estão sendo utilizados por outros processos. Embora o uso de threads possa potencialmente contribuir para a ocorrência de deadlock, a prevenção de deadlock é uma preocupação relacionada à programação concorrente em geral, não exclusivamente ao uso de threads.

The given answer states that IBM took advantage of a cooperation agreement with Microsoft to gain privileged access to the source code of Windows NT and used it in the development of OS/2. This statement is not true because it was actually Microsoft who took advantage of their cooperation with IBM to acquire a operating system from Seattle Computer Products and provide it to IBM. Therefore, the given answer is incorrect.

Unix was developed at Bell Labs, AT&T, as a version of Multics.

Registradores locais são usados para armazenar dados importantes e resultados temporários. O uso de registradores é conveniente porque o tempo de acesso à memória principal é muito menor do que o tempo necessário para executar instruções.

The statement that is not true is "Os sistemas operacionais podem implementar quantidade ilimitada de interrupções" which translates to "Operating systems can implement an unlimited number of interrupts." This statement is false because operating systems have a limited number of interrupt vectors available, which restricts the number of interrupts that can be implemented.

This question is asking for the classification of an operating system that consists of multiple computers interconnected by a dedicated fiber optic network, where some computers only monitor the activities of others and only take action in the event of a failure. The correct answer is "Multicomputer in asymmetric cluster" because this classification accurately describes the system where the computers in the cluster have different roles and responsibilities, with some acting as monitors and others as active nodes.

The correct answer is "Ela está incorreta. Para corrigí-la é necessário eliminar os critérios IV e VII." This is because the statement incorrectly includes criteria IV (Disponibilidade) and VII (Confiabilidade), which are not relevant for evaluating scheduling algorithms.

Vetores assíncronos não é uma das soluções adotadas para tentar resolver problemas de sincronização de processos. As outras opções mencionadas, como a Solução de Peterson, Semáforos, Monitores e Hardware de Sincronismo, são todas abordagens utilizadas para lidar com a sincronização de processos. No entanto, vetores assíncronos não é uma técnica comumente empregada nesse contexto.

Memória Virtual é a técnica que permite separar a memória lógica e a memória física, permitindo carregar mais e maiores processos do que a memória física comportaria. Ela carrega para a memória física apenas as páginas necessárias para a execução dos processos naquele momento.

The correct answer is "starvation; por prioridade; aging ou envelhecimento". This is because the question is discussing the issue of indefinite blocking or starvation that can occur with the implementation of a scheduling algorithm. It mentions that this issue occurred between 1967 and 1973 with an IBM 7094 at MIT. The solution to this problem is implementing the technique of priority-based scheduling with aging or envelhecimento.

The correct answer is LRU. LRU stands for Least Recently Used and it is a viable memory page replacement algorithm. It works by replacing the page that has not been used for the longest period of time, ensuring that the most recently used pages remain in memory. This algorithm is commonly used in operating systems to optimize memory usage and improve performance.

The correct answer is that the statement "O registrador limite aponta para o endereço final da memória principal de um processo" is not true. The register limit does not point to the final address of the main memory of a process. Instead, it contains the space occupied in the main memory by a process.

The correct answer is that the algorithm to which Round Robin is similar is FCFS, not SJF. This means that Round Robin scheduling algorithm shares similarities with the First-Come, First-Served (FCFS) scheduling algorithm, rather than the Shortest Job First (SJF) algorithm.

Deadlock is a situation where multiple processes are unable to proceed because each is waiting for a resource that is held by another process, resulting in a circular dependency. In this scenario, all processes are waiting for an event that will never occur because they are dependent on each other. This can lead to a system freeze or a significant decrease in performance.

The correct answer is "Refere-se a qualquer sistema que utilize armazenamento de arquivos ou de aplicativos na Internet". This option is not true in relation to cloud systems because cloud systems are not limited to just storage of files or applications. Cloud systems also involve the allocation of computational resources, scalability, and availability over a network like the Internet.

In this scenario, the correct answer is "Multiprocessador assimétrico" (Asymmetric Multiprocessor). This is because the question describes a system where multiple processors share a common bus and each processor can receive a specific task under the control of a master processor. In an asymmetric multiprocessor system, the processors have different capabilities and responsibilities, with one acting as the master and the others as slaves, performing specific tasks assigned by the master.

A transição "Esperando para Executando" não é encontrada entre as transições genéricas de estados de processos. As transições genéricas de estados de processos são: Novo para Pronto, Pronto para Executando, Executando para Bloqueado, Bloqueado para Pronto, Executando para Pronto e Terminado.

A process cannot select which process should take its place and exchange positions with it. This would violate the scheduling algorithm and the order of execution.

The correct answer is "multiprogramação; I/O-Bound; cálculos; CPU-Bound; menos". The long-term scheduler is responsible for controlling the degree of multiprogramming, which is achieved by balancing the mix between I/O-Bound processes (that consume more time performing I/O operations than executing calculations) and CPU-Bound processes (that generate frequent I/O requests, using more time for calculations). In this case, the correct option fills the gaps correctly and respectively, stating that the long-term scheduler controls the degree of multiprogramming, prioritizing I/O-Bound processes over CPU-Bound processes to minimize the time spent on calculations.

The given correct answer is FCFS. The "efeito comboio" refers to a situation in process scheduling where a long process is followed by several short processes. In FCFS (First-Come, First-Served) scheduling, the processes are executed in the order they arrive, which can lead to the "efeito comboio" as the long process will block subsequent processes from executing until it completes.

The correct answer is "Ocorrer somente nos casos A e D". This means that non-preemptive scheduling should only occur when a process makes a request for I/O (case A) or when a process finishes execution (case D). In non-preemptive scheduling, a process will continue running until it voluntarily gives up the CPU, either by requesting I/O or by completing its execution. This ensures that a process is not interrupted or preempted by another process.

The given statement states that the simplest scheduling algorithm is the one that schedules the process that has been waiting the longest in the Ready Queue. This algorithm is known as FCFS (First-Come, First-Served).

Starvation refers to a situation where processes continue to execute but none of them make progress. In this state, certain processes may not receive the necessary resources or attention to complete their execution, causing them to be stuck indefinitely. This can occur when resources are allocated unfairly or when a higher priority process constantly takes precedence over others.

The correct answer is "Escalonador de Longo Prazo". O escalonador de longo prazo é responsável por mover os processos do estado Novo para a Fila de Prontos. Ele decide quais processos devem ser admitidos na memória principal e inicia o carregamento desses processos. Ele também é responsável por gerenciar a quantidade de processos na memória para otimizar o desempenho do sistema operacional.

The correct answer is SJF (Shortest Job First). This is because the given statement mentions that when the CPU is available, it will be allocated to the process with the shortest predicted duration of the next CPU burst. SJF scheduling algorithm selects the process with the shortest burst time, allowing the process with the shortest predicted duration to be executed first.