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Questions and Answers
What happens when a process running a user program in user mode needs a system service?
What happens when a process running a user program in user mode needs a system service?
- It executes a special procedure call within the user program.
- It executes a trap instruction to transfer control to the operating system. (correct)
- It bypasses the operating system and accesses the service directly.
- It switches to kernel mode automatically.
What is the mechanism used by a process to request a system service?
What is the mechanism used by a process to request a system service?
- Trap instruction (correct)
- Kernel execution
- Direct memory access
- User-level function call
In the context of system calls, what role does the operating system play?
In the context of system calls, what role does the operating system play?
- Transfers control to another user program upon request.
- Executes the user program directly without any intervention.
- Provides direct access to all system services from user programs.
- Determines the requested service, carries out the request, and returns control to the calling process. (correct)
What is the purpose of a trap instruction in the context of system calls?
What is the purpose of a trap instruction in the context of system calls?
How do C programs invoke system calls for requesting services?
How do C programs invoke system calls for requesting services?
What is the significance of return codes in system calls?
What is the significance of return codes in system calls?
What is the purpose of system calls in an operating system?
What is the purpose of system calls in an operating system?
In the context of system calls, what is the role of the operating system's kernel?
In the context of system calls, what is the role of the operating system's kernel?
Which of the following is a typical service provided by system calls in operating systems?
Which of the following is a typical service provided by system calls in operating systems?
What role do system calls play in maintaining the security and stability of an operating system?
What role do system calls play in maintaining the security and stability of an operating system?
When a user-level program makes a system call, how does the operating system's kernel respond?
When a user-level program makes a system call, how does the operating system's kernel respond?
Which programming language is commonly used to make system calls in user-level programs?
Which programming language is commonly used to make system calls in user-level programs?
What keeps track of the number of directory entries pointing to a file in UNIX?
What keeps track of the number of directory entries pointing to a file in UNIX?
In a monolithic system, what is responsible for invoking the requested service procedure?
In a monolithic system, what is responsible for invoking the requested service procedure?
What type of hypervisor is a practical type 2 hypervisor?
What type of hypervisor is a practical type 2 hypervisor?
Which OS structure involves separate user programs interacting with server programs over a network?
Which OS structure involves separate user programs interacting with server programs over a network?
What is removed from the disk if UNIX detects no entries to the file?
What is removed from the disk if UNIX detects no entries to the file?
What is the primary metric prefixes figure illustration in Tanenbaum's book referred to as?
What is the primary metric prefixes figure illustration in Tanenbaum's book referred to as?
