main.cc

美国加州大学操作系统课程实验平台Nachos

// main.cc 
//	Driver code to initialize, selftest, and run the 
//	operating system kernel.  
//
// Usage: nachos -d <debugflags> -rs <random seed #>
//              -s -x <nachos file> -ci <consoleIn> -co <consoleOut>
//              -f -cp <unix file> <nachos file>
//              -p <nachos file> -r <nachos file> -l -D
//              -n <network reliability> -m <machine id>
//              -z -K -C -N
//
//    -d causes certain debugging messages to be printed (see debug.h)
//    -rs causes Yield to occur at random (but repeatable) spots
//    -z prints the copyright message
//    -s causes user programs to be executed in single-step mode
//    -x runs a user program
//    -ci specify file for console input (stdin is the default)
//    -co specify file for console output (stdout is the default)
//    -n sets the network reliability
//    -m sets this machine's host id (needed for the network)
//    -K run a simple self test of kernel threads and synchronization
//    -C run an interactive console test
//    -N run a two-machine network test (see Kernel::NetworkTest)
//
//    Filesystem-related flags:
//    -f forces the Nachos disk to be formatted
//    -cp copies a file from UNIX to Nachos
//    -p prints a Nachos file to stdout
//    -r removes a Nachos file from the file system
//    -l lists the contents of the Nachos directory
//    -D prints the contents of the entire file system 
//
//  Note: the file system flags are not used if the stub filesystem
//        is being used
//
// Copyright (c) 1992-1996 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.

#define MAIN
#include "copyright.h"
#undef MAIN

#include "main.h"
#include "filesys.h"
#include "openfile.h"
#include "sysdep.h"

#ifdef TUT

#include "tut.h"
//implements callbacks for unit test
#include "tut_reporter.h"
namespace tut
{
    test_runner_singleton runner;
}

#endif TUT

// global variables
Kernel *kernel;
Debug *debug;


//----------------------------------------------------------------------
// Cleanup
//	Delete kernel data structures; called when user hits "ctl-C".
//----------------------------------------------------------------------

static void 
Cleanup(int x) 
{     
    cerr << "\nCleaning up after signal " << x << "\n";
    delete kernel; 
}

//-------------------------------------------------------------------
// Constant used by "Copy" and "Print"
//   It is the number of bytes read from the Unix file (for Copy)
//   or the Nachos file (for Print) by each read operation
//-------------------------------------------------------------------
static const int TransferSize = 128;


#ifndef FILESYS_STUB
//----------------------------------------------------------------------
// Copy
//      Copy the contents of the UNIX file "from" to the Nachos file "to"
//----------------------------------------------------------------------

static void
Copy(char *from, char *to)
{
    int fd;
    OpenFile* openFile;
    int amountRead, fileLength;
    char *buffer;

// Open UNIX file
    if ((fd = OpenForReadWrite(from,FALSE)) < 0) {       
        printf("Copy: couldn't open input file %s\n", from);
        return;
    }

// Figure out length of UNIX file
    Lseek(fd, 0, 2);            
    fileLength = Tell(fd);
    Lseek(fd, 0, 0);

// Create a Nachos file of the same length
    DEBUG('f', "Copying file " << from << " of size " << fileLength <<  " to file " << to);
    if (!kernel->fileSystem->Create(to, fileLength)) {   // Create Nachos file
        printf("Copy: couldn't create output file %s\n", to);
        Close(fd);
        return;
    }
    
    openFile = kernel->fileSystem->Open(to);
    ASSERT(openFile != NULL);
    
// Copy the data in TransferSize chunks
    buffer = new char[TransferSize];
    while ((amountRead=ReadPartial(fd, buffer, sizeof(char)*TransferSize)) > 0)
        openFile->Write(buffer, amountRead);    
    delete [] buffer;

// Close the UNIX and the Nachos files
    delete openFile;
    Close(fd);
}

#endif // FILESYS_STUB

//----------------------------------------------------------------------
// Print
//      Print the contents of the Nachos file "name".
//----------------------------------------------------------------------

void
Print(char *name)
{
    OpenFile *openFile;    
    int i, amountRead;
    char *buffer;

    if ((openFile = kernel->fileSystem->Open(name)) == NULL) {
        printf("Print: unable to open file %s\n", name);
        return;
    }
    
    buffer = new char[TransferSize];
    while ((amountRead = openFile->Read(buffer, TransferSize)) > 0)
        for (i = 0; i < amountRead; i++)
            printf("%c", buffer[i]);
    delete [] buffer;

    delete openFile;            // close the Nachos file
    return;
}



//----------------------------------------------------------------------
// main
// 	Bootstrap the operating system kernel.  
//	
//	Initialize kernel data structures
//	Call some test routines
//	Call "Run" to start an initial user program running
//
//	"argc" is the number of command line arguments (including the name
//		of the command) -- ex: "nachos -d +" -> argc = 3 
//	"argv" is an array of strings, one for each command line argument
//		ex: "nachos -d +" -> argv = {"nachos", "-d", "+"}
//----------------------------------------------------------------------

int
main(int argc, char **argv)
{
    int i;
    char *debugArg = "";
    char *userProgName = NULL;        // default is not to execute a user prog
    bool threadTestFlag = false;
    bool consoleTestFlag = false;
    bool networkTestFlag = false;
#ifndef FILESYS_STUB
    char *copyUnixFileName = NULL;    // UNIX file to be copied into Nachos
    char *copyNachosFileName = NULL;  // name of copied file in Nachos
    char *printFileName = NULL; 
    char *removeFileName = NULL;
    bool dirListFlag = false;
    bool dumpFlag = false;
#endif //FILESYS_STUB

    // some command line arguments are handled here.
    // those that set kernel parameters are handled in
    // the Kernel constructor
    for (i = 1; i < argc; i++) {
        if (strcmp(argv[i], "-d") == 0) {
	    ASSERT(i + 1 < argc);   // next argument is debug string
            debugArg = argv[i + 1];
	    i++;
	}
	else if (strcmp(argv[i], "-z") == 0) {
            cout << copyright << "\n";
	}
	else if (strcmp(argv[i], "-x") == 0) {
	    ASSERT(i + 1 < argc);
	    userProgName = argv[i + 1];
	    i++;
	}
	else if (strcmp(argv[i], "-K") == 0) {
	    threadTestFlag = TRUE;
	}
	else if (strcmp(argv[i], "-C") == 0) {
	    consoleTestFlag = TRUE;
	}
	else if (strcmp(argv[i], "-N") == 0) {
	    networkTestFlag = TRUE;
	}
#ifndef FILESYS_STUB
	else if (strcmp(argv[i], "-cp") == 0) {
	    ASSERT(i + 2 < argc);
	    copyUnixFileName = argv[i + 1];
	    copyNachosFileName = argv[i + 2];
	    i += 2;
	}
	else if (strcmp(argv[i], "-p") == 0) {
	    ASSERT(i + 1 < argc);
	    printFileName = argv[i + 1];
	    i++;
	}
	else if (strcmp(argv[i], "-r") == 0) {
	    ASSERT(i + 1 < argc);
	    removeFileName = argv[i + 1];
	    i++;
	}
	else if (strcmp(argv[i], "-l") == 0) {
	    dirListFlag = true;
	}
	else if (strcmp(argv[i], "-D") == 0) {
	    dumpFlag = true;
	}
#endif //FILESYS_STUB
	else if (strcmp(argv[i], "-u") == 0) {
            cout << "Partial usage: nachos [-z -d debugFlags]\n";
            cout << "Partial usage: nachos [-x programName]\n";
	    cout << "Partial usage: nachos [-K] [-C] [-N]\n";
#ifndef FILESYS_STUB
            cout << "Partial usage: nachos [-cp UnixFile NachosFile]\n";
            cout << "Partial usage: nachos [-p fileName] [-r fileName]\n";
            cout << "Partial usage: nachos [-l] [-D]\n";
#endif //FILESYS_STUB
	}

    }
    debug = new Debug(debugArg);
    
    DEBUG(dbgThread, "Entering main");

#ifdef TUT
    ::tut::callback * clbk = new tut::reporter(cout);
    ::tut::runner.get().set_callback(clbk);  
    ::tut::runner.get().run_tests(); //run all unit tests
#endif 
    
    kernel = new Kernel(argc, argv);

    kernel->Initialize();

    CallOnUserAbort(Cleanup);		// if user hits ctl-C

    // at this point, the kernel is ready to do something
    // run some tests, if requested
    if (threadTestFlag) {
      kernel->ThreadSelfTest();  // test threads and synchronization
    }
    if (consoleTestFlag) {
      kernel->ConsoleTest();   // interactive test of the synchronized console
    }
    if (networkTestFlag) {
      kernel->NetworkTest();   // two-machine test of the network
    }

#ifndef FILESYS_STUB
    if (removeFileName != NULL) {
      kernel->fileSystem->Remove(removeFileName);
    }
    if (copyUnixFileName != NULL && copyNachosFileName != NULL) {
      Copy(copyUnixFileName,copyNachosFileName);
    }
    if (dumpFlag) {
      kernel->fileSystem->Print();
    }
    if (dirListFlag) {
      kernel->fileSystem->List();
    }
    if (printFileName != NULL) {
      Print(printFileName);
    }
#endif // FILESYS_STUB

    // finally, run an initial user program if requested to do so
    if (userProgName != NULL) {
      AddrSpace *space = new AddrSpace;
      ASSERT(space != (AddrSpace *)NULL);
      if (space->Load(userProgName)) {  // load the program into the space
	space->Execute();              // run the program
	ASSERTNOTREACHED();            // Execute never returns
      }
    }

    // If we don't run a user program, we may get here.
    // Calling "return" would terminate the program.
    // Instead, call Halt, which will first clean up, then
    //  terminate.
    kernel->interrupt->Halt();
    
    ASSERTNOTREACHED();
}