学步园

#define THREAD_POOL_SIZE 3  //线程数目
#define NUM_TASKS 6 //任务数目

int main()
{
    HANDLE hThrds[THREAD_POOL_SIZE];
    int slot = 0;
    DWORD threadId;
    int i;
    DWORD rc;

    for (i=0; i < NUM_TASKS; i++)
    {
        Sleep(1000);
        /* Until we've used all threads in *
        * the pool, do not need to wait *
        * for one to exit */
        if (i >= THREAD_POOL_SIZE)
        {
            /* Wait for one thread to terminate */
            rc = WaitForMultipleObjects(THREAD_POOL_SIZE, hThrds, FALSE, INFINITE );
            
            slot = rc - WAIT_OBJECT_0;//0 to THREAD_POOL_SIZE -1
            if (slot >= 0 && slot < THREAD_POOL_SIZE)
            {
            	printf("Slot %d terminated\n", slot );
            }
            else
            {
                printf("Error or Timeout!\n");
		return 0；

            }
            if (hThrds[slot])
            {
                CloseHandle(hThrds[slot]);
                hThrds[slot] = NULL;
            }
        }

        /* Create a new thread in the given
        * available slot */

        //when slot is THREAD_POOL_SIZE, i is THREAD_POOL_SIZE too.
        //slot will be re-assigned between  0 to THREAD_POOL_SIZE -1. 
        hThrds[slot++] = CreateThread(NULL, 0, ThreadFunc, (LPVOID)slot, 0, &threadId);
        printf("Launched thread #%d (slot %d)\n", i, slot);
    }

    /* Now wait for all threads to terminate */
    rc = WaitForMultipleObjects(THREAD_POOL_SIZE, hThrds, TRUE, INFINITE );

    if (rc >= WAIT_OBJECT_0 && rc < WAIT_OBJECT_0 + THREAD_POOL_SIZE)
    {
        printf("All threads have terminated\n");
    }
    else
    {
        printf("Error or Timeout!\n");
    }
    for (slot=0; slot<THREAD_POOL_SIZE; slot++)
    {
        if (hThrds[slot])
        {
            CloseHandle(hThrds[slot]);
            hThrds[slot] = NULL;
        }
    }
    printf("All slots terminated\n");

    return EXIT_SUCCESS;
}