What is a zombie process?

What is a zombie process?

• A. A process that is waiting for an input
• B. A completed process that still has an entry in the process table
• C. A process that is currently using excessive resources
• D. An inactive process that can be restarted

Answer: (B)

A zombie process refers specifically to a completed process that still has an entry in the process table because it has not yet been cleared by its parent process. When a process terminates, it does not immediately remove its entry from the operating system's process table; instead, it retains the information needed for the parent process to read the exit status. This state allows the parent process to retrieve exit information about the completed child process. Once the parent has acknowledged the termination by calling wait(), the operating system can then remove the entry, thus allowing the resources to be freed up. In contrast, a process that is waiting for input refers to a different state where the process is still pending and has not completed execution—this does not describe a zombie. A process using excessive resources is also unrelated to the definition of a zombie; instead, it might be described as resource-hogging or potentially in a state of being run or runnable. An inactive process that can be restarted does not capture the essence of a zombie either, as a zombie process is not inactive in the traditional sense; it has finished execution but remains in the process table. Understanding these distinctions helps clarify the unique role and lifecycle stage that a zombie process occupies within the operating system.

A zombie process refers specifically to a completed process that still has an entry in the process table because it has not yet been cleared by its parent process. When a process terminates, it does not immediately remove its entry from the operating system's process table; instead, it retains the information needed for the parent process to read the exit status. This state allows the parent process to retrieve exit information about the completed child process. Once the parent has acknowledged the termination by calling wait(), the operating system can then remove the entry, thus allowing the resources to be freed up.

In contrast, a process that is waiting for input refers to a different state where the process is still pending and has not completed execution—this does not describe a zombie. A process using excessive resources is also unrelated to the definition of a zombie; instead, it might be described as resource-hogging or potentially in a state of being run or runnable. An inactive process that can be restarted does not capture the essence of a zombie either, as a zombie process is not inactive in the traditional sense; it has finished execution but remains in the process table.

Understanding these distinctions helps clarify the unique role and lifecycle stage that a zombie process occupies within the operating system.