Question

Consider the following code snippet using the \texttt{fork() and \texttt{wait()} system calls. Assume that the code compiles and runs correctly, and that the system calls run successfully without any errors.} \begin{verbatim} int x = 3; while (x>0) { fork(); printf("hello"); wait(NULL); x--; } \end{verbatim} The total number of times the \texttt{printf} statement is executed is \_\_\_\_\_.

Answer 1

Step 1: Understand the behavior of the \texttt{fork()} system call. The \texttt{fork()} system call creates a new process (child) from the parent process. The total number of processes created depends on how many times \texttt{fork()} is executed. Step 2: Analyze the code. Initially, \( x = 3 \). In the first iteration of the \texttt{while} loop, one new process is created, leading to 2 processes. In the second iteration, each of these 2 processes creates a new process, resulting in \( 2 + 2 = 4 \) processes. In the third iteration, each of the 4 processes creates another process, resulting in \( 4 + 4 = 8 \) processes. Step 3: Count the total executions of \texttt{printf("hello")}.
Each process executes \texttt{printf("hello")} exactly once for each iteration of the loop. Summing across all iterations: \[ 2 + 4 + 8 = 14. \] Final Answer: \[ \boxed{14} \]