Answer questions about operating systems b through e Direct

Answer questions about operating systems: b through e

Direct memory access is a technique that ................[] Is most effective for slow character devices. Cannot be used for block devices. Enables the associated controller to read and write data directly from/to primary memory with no CPU intervention during data transfer. None of the above. In a time-sharing system, an interrupt for a user\'s program is handled by ..............[] The user\'s program directly. Operating system for the user program. Hardware. User\'s current shell program. In a system where round robin is used for CPU scheduling, the following is true when a process cannot finish its computation during its current time quantum ................ [] The process will terminate itself. The process will be terminated by the operating system. The process\'s state will be changed from running to ready. None of the above. The following algorithm is proposed to solve the critical section problem between two processes P_1 and P_2. where lock is a shared variable. P_1 do {while (lock) {NULL;} lock = TRUE; critical section: lock=FALSE; reminder section;} while(TRUE); P_2 do {while(lock) {NULL;} lock = TRUE; critical section; lock=FALSE; reminder section;} while(TRUE); Which of the following statements is true regarding the proposed algorithm? ..........[] Mutual exclusion to the critical section is guaranteed. Both processes can be in their critical section at the same time. Lock should be initialized to TRUE. None of the above.

Solution

Answer

B) Direct memory access (DMA) is a technique of operating systems that enables the associate controllers to read/write data directly from / to main system memory (RAM) independently with no intervention from the central processing unit (CPU).

C) In time sharing system, an interrupt for user program is handled by User`s current shell program. If a user attempts to interfere with another user\'s program or execute an illegal instruction, It automatically generates a signal by a fault interrupt.

D) In a Operating System, where Round Robin scheduling is used, when a process cannot finish its computation in current quantum, the process`s state is changed from running to ready state and then job is resumed next time a time slot is assigned to that process.

E) Before using above given algorithum Lock should be initialzed to TRUE.