C onsider the following code which uses Python to call the Unix ‘fork’ system call.
pid = os.fork()
if (pid0) :
# case 1
else :
# case 2

Select all of the following statements that are true (incorrect selections gain negative marks).

Question

C onsider the following code which uses Python to call the Unix ‘fork’ system call. 
   pid = os.fork()
  if (pid>0) :
       # case 1
  else :
       # case 2

Select all of the following statements that are true (incorrect selections gain negative marks).

Accepted Answer

The point in the program marked ‘case 2’ is reached in the child process; the value of the ‘pid’ variable is zero.

Accepted Answer

Fork can fail if there are no more process ids available for allocation by the operating system.

Answer

If fork succeeds there are 3 different processes involved: the original process that calls fork, the parent process and the child process (the new process).

Answer

The fork system call is used rarely. In normal use of Linux when using the shell fork is not used.

Answer

The fork call immediately causes all the memory pages owned by the process making the call to be copied for the new process.

Answer

Case 2 is not really needed as it only applies when the process id is zero and no (user) process has an id of zero. This case is only included for robustness.

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C onsider the following code which uses Python to call the Unix ‘fork’ system ca...

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