Solution:

Process creation:

• A process may create several new processes, via a create-process system call, during the course of execution.

• The creating process is called a parent process, and the new processes are called the children of that process. Each of these new processes may in turn create other processes, forming a tree of processes.

• When a process creates a subprocess, that subprocess may be able to obtain its resources directly from the operatiiig system, or it may be constrained to a subset of the resources of the parent process.

• The parent may have to partition its resources among its children, or it may be able to share some resources (such as memory or files) among several of its children.

• It is easy to construct a process tree similar to what is shown in Figure by recursively tracing parent processes all the way to the in it process.

• In general, a process will need certain resources (CPU time, memory, files, I/O devices) to accomplish its task.

• Restricting a child process to a subset of the parent's resources prevents any process from overloading the system by creating too many sub-processes.

• In addition to the various physical and logical resources that a process obtains when it is created, initialization data (input) may be passed along by the parent process to the child process.

  Creating a separate process using the Win32 API:

  # include <stdio.h>  i
  
  # include <windows.h>
  
  int main(VOID)
  
  {
  STARTUPINFO si;
  
  PROCESS_INFORMATION pi;
  
  // allocate memory
  
  ZeroMemory(&si, sizeof (si)) ;
  
  si.cb = sizeof (si) ;
  
  ZeroMemory(&pi, sizeof(pi));
  
  // create child process
  
  if (!CreateProcess(NULL, // use command line
  
  "C:\\WINDOWS\\system32\\mspaint.exe", // command line
  
  NULL, // don't inherit process handle
  
  NULL, // don't inherit thread handle
  
  FALSE, // disable handle inheritance
  
  0, //no creation flags
  
  NULL, // use parent's environment block
  
  NULL, // use parent's existing directory
  
  &si,
  
  fprintf(stderr, "Create Process Failed");
  
  return -1;
  
  }
  
  // parent will wait for the child to complete
  
  WaitForSingleObject(pi.hProcess, INFINITE);
  
  printf("Child Complete");
  
  // close handles
  
  CloseHandle(pi.hProcess);
  
  CloseHandle(pi.hThread);
  
  }
  

• The first two parameters passed to CreateProcess () are the application name and command line parameters.

• If the application name is NULL, the command line parameter specifies the application to load. In this instance we are loading the Microsoft Windows mspaint.exe application.

• Beyond these two initial parameters, we use the default parameters for inheriting process and thread handles as well as specifying no creation flags.