The goal of this assignment is to learn about Win32 threads. A good description of the related system
services is given in "Win32 System Services" by Marshall Brain (2nd edition pages: 139-157, 191-193,
and 669-673; 3rd edition pages: 116-130, 151-155, and 549-555)
The assignment has three parts:
PART A - Create a simple thread
This part deals with a single thread, which has only one integer parameter. It simulates crawling of a turtle by
using a random number generator. (In part A there is only one turtle, but in parts B and C there will be several
turtles which participate in a race.)
Part A is entirely held in a single file, p21.cpp, which should have three sections of code:
1) Definition of global variables:
#define N 1 // Number of turtles (threads)
double distance[N]; // Current turtle distances from the goal [in]
double step; // Maximum step size of turtles
int dt; // Time needed for a turtle to make one step [ms]
2) Main program:
void main(int argc, char *argv[]){...}
3) Thread function:
void Turtle(DWORD id){...} // id is parameter passed to the thread
The main program gets the initial distance from the goal (distance[0]), the step size (step), and the step
time (dt) via command-line arguments. A typical invocation of the program should be like this:
p21 2 0.25 1000 // The turtle runs distance of 2 inches with steps
// no bigger than 1/4 inches, a step takes 1 sec
After data initialization, the main program creates a thread that emulates a slowly crawling turtle:
HANDLE h[N];
DWORD id[N] = {0};
DWORD ThreadID[N];
h[0] = CreateThread(0, 0,
(LPTHREAD_START_ROUTINE) Turtle,
(VOID *)id[0],
0, &ThreadID[0]);
The main program then enters an endless loop in which it outputs the current position of the turtle
(distance[0]) and goes to sleep for 900 ms (use the run time function Sleep(900) (after this call you
don’t have to check the success status). The loop should be terminated when the turtle reaches the goal, i.e.
when the thread exits. How the main program knows when the thread has exited? It uses system function
CS570 Operating Systems Spring 2004
Programming Assignment #2 Assigned: Feb 4 Due: Feb18
