threadtest_ex2.cc

linux的例子,就是下载后到自己的机子上去运行

// 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"
#include "synch-sleep.h"
#include "BoundedBuffer.h"
#include "Table.h"
// testnum is set in main.cc
#define Maxsize 20
int testnum = 1;
DLList *A=new DLList();
Table *A2 = new Table(30);
Lock* lock = new Lock("list lock");
Condition* listEmpty = new Condition("list empty cond");
BoundedBuffer* buffer = new BoundedBuffer(Maxsize);

//----------------------------------------------------------------------
// SimpleThread
// 	Loop 5 times, yielding the CPU to another ready thread 
//	each iteration.
//
//	"which" is simply a number identifying the thread, for debugging
//	purposes.
//----------------------------------------------------------------------
extern int T,N,P;
void SimpleThread1(int which)
{
    int num;
    num=1;
    while(1){
	printf("*** thread %d looped %d times\n", which, num);
	num++;
	driver_insert(A,N,which);
	currentThread->Yield();
	A->Print();
	driver_remove(A,N,which);
	if(A->IsEmpty()||num==5) break;
    }
}
//----------------------------------------------------------------------
// ThreadTest1
// 	Set up a ping-pong between two threads, by forking a thread 
//	to call SimpleThread, and then calling SimpleThread ourselves.
//----------------------------------------------------------------------

void SimpleThread2(int which)
{
    int num = 0,i;
    char object[20], *obj;
    while(1) {
	printf("*** thread %d looped %d times ***\n",which,num);
	++num;
	switch(which){
	    case 1:   strcpy(object,"thread 1");break;
	    case 2:   strcpy(object,"thread 2");break;
	    case 3:   strcpy(object,"thread 3");break;
	    default:  object[0] = '\0';  
	}
	
	i = A2->Alloc(object);
	obj = (char *)A2->Get(i); 
        printf("(thread %d)index = %d :%s\n",which,i,obj);
	currentThread->Yield();
	obj = (char *)A2->Get(i);
        printf("(thread %d)index = %d :%s\n",which,i,obj);
	currentThread->Yield();
	if(num == 2) break;
    }
}

void SimpleThread3(int which)
{
    int num,length,i;
    char read[100],write[100];
    num=1;
    while(1){
	i = 0;
	while(i<100)
		read[i++] = '\0';
	printf("*** thread %d looped %d times\n", which, num);
	num++;
	if(which%2 == 0)
	{
		buffer->Read(read,5);
		printf("thread %d read %s\n",which,read);
		buffer->printbuffer();
		currentThread->Yield();
	}
	strcpy(write,"woshishui");
	length = strlen(write);
	buffer->Write(write,length);
	printf("thread %d write %s\n",which,write); 
	buffer->printbuffer();
	currentThread->Yield();
	if(which%2 == 1)
	{
		buffer->Read(read,5);
		printf("thread %d read %s\n",which,read);
		buffer->printbuffer();
		currentThread->Yield();
	}
	if(num==3) break;
    }
}

void
ThreadTest1()
{
    int i;
    DEBUG('t', "Entering ThreadTest1");

    for(i=1;i<=T;i++){
    	Thread *t1 = new Thread("forked thread");
    	switch(P)
    	{
    			case 1:t1->Fork(SimpleThread1,i);break;
    			case 2:t1->Fork(SimpleThread2,i);break;
    			case 3:t1->Fork(SimpleThread3,i);break;
	}
    }
}

//----------------------------------------------------------------------
// ThreadTest
// 	Invoke a test routine.
//----------------------------------------------------------------------

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