threadtest.cc

这是一个关于操作系统进程调度的实验

// 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 <cstdio>
#include <cstdlib>
#include <ctime>
#include "system.h"
#include "dllist.h"


using namespace std;


// testnum is set in main.cc
int testnum = 1;

//----------------------------------------------------------------------
// 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)
{
    int num;
    
    for (num = 0; num < 5; num++) {
	printf("*** thread %d looped %d times\n", which, num);
        currentThread->Yield();
    }
}
*/


void                                                                                            //<--
SimpleThread( int which )
{
	int key;
	Begin( which );
	if( Flag == 6 )
	{
		printf("SimpleThread interrupt!\n");
		currentThread->Yield();
	}
	End( which);
}

//----------------------------------------------------------------------
// ThreadTest1
// 	Set up a ping-pong between two threads, by forking a thread 
//	to call SimpleThread, and then calling SimpleThread ourselves.
//----------------------------------------------------------------------



void
ThreadTest1()
{
	int i;
	
	DEBUG('t', "Entering ThreadTest1");
	for( i = 0; i < Thread_num; i++ )
	{
		Thread *t = new Thread("forked thread");
		t->Fork(SimpleThread, i);
	}
//	SimpleThread(0);
}


/*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()
{
    switch (testnum) {
    case 1:
	ThreadTest1();
	break;
    default:
	printf("No test specified.\n");
	break;
    }
}