threadtest.cc

本次实验的目的在于将nachos中的锁机制和条件变量的实现补充完整

// threadtest.cc 
//  Simple test case for the threads assignment.
//
//  Create two threads, and have them context switch
//  back and forth between themselves by calling Thread::Yield, 
//  to illustratethe inner workings of the thread system.
//
// Copyright (c) 1992-1993 The Regents of the University of California.
// All rights reserved.  See copyright.h for copyright notice and limitation 
// of liability and disclaimer of warranty provisions.

#include "copyright.h"
#include "system.h"
#include "dllist.h"

extern void Insertlist(int n,DLList  *list,int which);
extern void Insertlist_new(int n,DLList  *list,int which);
extern void Removelist(int n,DLList *list,int which);
extern void Removelist_new(int n,DLList *list,int which);

char choose;
// testnum is set in main.cc
int testnum = 1;
 DLList *list;
//extern DLList list;
//----------------------------------------------------------------------
// SimpleThread
//  Loop 5 times, yielding the CPU to another ready thread 
//  each iteration.
//
//  "which" is simply a number identifying the thread, for debugging
//  purposes.
//----------------------------------------------------------------------


void
SimpleThread(int which)
{   
      switch(choose)
      {
        case '1':
       Insertlist(3,list,which);
       Removelist(3,list,which);
          break;
       case '2':
          Insertlist_new(3,list,which);
          Removelist_new(3,list,which);
          break;
      }
             
                               
//  printf("*** thread %d \n", which);
        currentThread->Yield();
}
//----------------------------------------------------------------------
// ThreadTest1
//  Set up a ping-pong between two threads, by forking a thread 
//  to call SimpleThread, and then calling SimpleThread ourselves.
//----------------------------------------------------------------------

void
ThreadTest1()
{
    DEBUG('t', "Entering ThreadTest1");
    Thread *t =  new Thread("forked thread");
    t->Fork(SimpleThread, 1);
    SimpleThread(0);
}

//----------------------------------------------------------------------
// ThreadTest
//  Invoke a test routine.
//----------------------------------------------------------------------
void
ThreadTest()
{   
    while(1)
   { 
    printf("1.未加锁的演示结果\n2.加锁后的演示结果\n");
    choose = getchar();
    if(choose != '1' && choose !='2')
       printf("error\n");
    else break;
   }
 
switch (testnum) {
    case 1:
             list=new DLList();
         ThreadTest1();
    break;
    default:
    printf("No test specified.\n");
    break;
    }
}