操作系统课程设计nachosproject2源代码.docVIP

修改UserProcess， UserKernel和 LotteryScheduler package nachos.userprog; import nachos.machine.*; import nachos.threads.*; import nachos.userprog.*; import java.io.EOFException; import java.util.ArrayList; import java.util.LinkedList; /* * Encapsulates（封装） the state of a user process that is not contained in its * user thread (or threads). This includes its address translation state, a file * table, and information about the program being executed. This class is * extended by other classes to support additional functionality (such as * additional syscalls). * 将用户进程的状态封装起来而不是包含用户的线程。这包括地址的转换状态，文件表，以及程序执行的信息。 * 这个类有其他的类扩展以便支持额外的功能 */ public class UserProcess { /* * Allocate a new process. */ public UserProcess() { pid=numOfProcess++; numOfRunningProcess++; //线程创建后，键盘输入流和显示输出流在不调用open方法的情况下自动打开 openfile[0]=UserKernel.console.openForReading(); openfile[1]=UserKernel.console.openForWriting(); } /** * Allocate and return a new process of the correct class. The class name is * specified by the ttnachos.conf/tt key * ttKernel.processClassName/tt. * * @return a new process of the correct class. */ public static UserProcess newUserProcess() {//调用了上面的构造器创建一个进程 return (UserProcess) Lib.constructObject(Machine.getProcessClassName()); } /** * Execute the specified program with the specified arguments. Attempts to * load the program, and then forks a thread to run it. * * @param name * the name of the file containing the executable. * @param args * the arguments to pass to the executable. * @return tttrue/tt if the program was successfully executed. * 用特定参数执行一个特定的线程，尝试加载程序，然后创建线程执行它 */ public boolean execute(String name, String[] args) { if (!load(name, args)) return false;// 如果不能导入就返回false，程序执行失败 thread=new UThread(this);// 产生新的用户线程，并执行 thread.setName(name).fork(); return true; } /** * Load the executable with the specified name into this process, and