threadtest_ex1.cc

来自「linux的例子,就是下载后到自己的机子上去运行」· CC 代码 · 共 82 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"

// testnum is set in main.cc
int testnum = 1;
DLList *A=new DLList();

//----------------------------------------------------------------------
// 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;
void
SimpleThread(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();
	driver_print(A);
	driver_remove(A,N,which);
	if(A->IsEmpty()) break;
    }
}
//----------------------------------------------------------------------
// 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=1;i<=T;i++){
    	Thread *t1 = new Thread("forked thread");
    	t1->Fork(SimpleThread,i);
    }
}

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

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