lamothe4.txt

国外游戏开发者杂志1997年第七期配套代码

LISTING 4. An example of global message passing to control termination of threads.
// INCLUDES ////////////////////////////////////////////////////////////////////////////

#define WIN32_LEAN_AND_MEAN  // make sure certain headers are included correctly

#include <windows.h>         // include the standard windows stuff
#include <windowsx.h>        // include the 32 bit stuff
#include <conio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <math.h>
#include <io.h>
#include <fcntl.h>

// DEFINES /////////////////////////////////////////////////////////////////////////////

#define MAX_THREADS 3 

// PROTOTYPES //////////////////////////////////////////////////////////////////////////

DWORD WINAPI Printer_Thread(LPVOID data);

// GLOBALS /////////////////////////////////////////////////////////////////////////////

int terminate_threads = 0;  // global message flag to terminate
int active_threads    = 0;  // number of active threads

// FUNCTIONS ///////////////////////////////////////////////////////////////////////////

DWORD WINAPI Printer_Thread(LPVOID data)
{
// this thread function simply prints out data until it is told to terminate

for(;;)
    {
    printf("%d ",(int)data+1); // output a single character
    Sleep(100);                // sleep a little to slow things down
    // test for temination message

    if (terminate_threads)
      break;
    } // end for index

// decrement number of active threads

active_threads-;

// just return the data sent to the thread function

return((DWORD)data);

} // end Printer_Thread

// MAIN //////////////////////////////////////////////////////////////////////////////////

void main(void)
{

HANDLE thread_handle[MAX_THREADS];  // this holds the handles to the threads
DWORD  thread_id[MAX_THREADS];      // this holds the ids of the threads

// start with a blank line

printf("\nStarting Threads...\n");

// create the thread, IRL we would check for errors

for (int index=0; index<MAX_THREADS; index++)
	{
	thread_handle[index] = CreateThread(NULL,               	// default security
			                     0,		// default stack 
				Printer_Thread,     	// use this thread function
				(LPVOID)index,      	// user data sent to thread
				0,	    	// creation flags, 0=start now.
				&thread_id[index]);	// send id back in this var
	} // end for index

// now enter into printing loop, make sure this takes longer than threads,
// so threads finish first, note that primary thread prints 4

for (index=0; index<25; index++)
	{
	printf("4 ");
	Sleep(100);
	} // end for index

// at this point all the threads are still running, now if the keyboard is hit
// then a message will be sent to terminate all the threads and this thread
// will wait for all of the threads to message in 

while(!kbhit());

getch();

// wait for all threads to terminate, when all are terminated active_threads==0

while(active_threads);

// at this point the threads should all be dead, so close handles

for (index=0; index<MAX_THREADS; index++)
	CloseHandle(thread_handle[index]);

// end with a blank line

printf("\nAll threads terminated.\n");

} // end main

Sample output:

Starting Threads...
4 1 2 3 4 2 1 3 4 3 1 2 4 2 1 3 4 3 1 2 4 2 1 3 4 2 3 1 4 2 1 3 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 4 2 3 1 2 3 1 3 2 1 1 2 3 3 2 1 1 2 3 3 2 1 1 2 3 3 2 1 1 2 3 3 2 1 1 2 3 3 2 1 2 3 1 3 2 1 2 3 1 3 2 1 2 3 1 3 2 1 2 3 1 3 2 1 3 1 2 3 2 1 3 1 2 3 2 1 
All threads terminated.