Describe How Unix And Linux Manage Orphan Processes

Question: Is a new browser process created by the Chrome browser for every new website that is visited? If not, when are new browser processes created?

Answer: No. There is only one browser processor created when Chrome is started. Although, Chrome creates a new renderer process for each website opened in a new tab.

Question: Name the characteristics of shared memory vs. message passing.

Answer: Shared Memory: Processes use system calls to create and gain access to regions of memory owned by other processes

Message Passing: Communicating processes exchange messages with one another to transfer information

Question: List the characteristics of the Mach operating system. (5)

Answer:

Question: Name and describe the different states in which a process can exist at any given time. (5)

Answer: 1. New: The process is being created

2. Running: Instructions are being executed

3. Waiting: The process is waiting for some event to occur

4. Ready: The process is waiting to be assigned to a processor

5. Terminated: The process has finished execution

Question: Why does fork() happen before exec()? What if exec() were executed first?

Answer: When fork() is called it creates an almost identical process called the child. When exec() is called it replaces the child with a new process, where this process is the new child of the parent process.

If exec() is executed first then the current parent process will be replaced with a new process.

Question: Describe how UNIX and Linux manage orphan processes.

Answer: UNIX and Linux assigne the init process as the new parent process to orphan processes. The init process periodically invokes wait(), thereby allowing the exit status of any orphaned process.

Question: What are names of the various types of pipes, and how are they used? (2)

Answer: Ordinary pipes: Allow two processes to communicate in standard producer - consumer fashion, but are uni-directional

Named pipes: Communication is bi-directional and several processes can use it for communication

Question: Do named pipes continue to exist in the system after the creating process has terminated? If so, how

are they shut down?

Answer: Yes they will continue to exist until it is explicitly deleted from the file system.

Question: Define a process control block list the three major categories that it contains.

Answer: The process control block serves as the repository for any information that may vary from process to process

Question: List the three major categories that a process control block contains

Answer: 1. Process state

2. Program counter

3. CPU registers