288 lines
7.1 KiB
C++
288 lines
7.1 KiB
C++
// system.cc
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// Nachos initialization and cleanup routines.
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//
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// Copyright (c) 1992-1993 The Regents of the University of California.
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// All rights reserved. See copyright.h for copyright notice and limitation
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// of liability and disclaimer of warranty provisions.
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#include "copyright.h"
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#include "system.h"
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#include <locale.h>
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#ifdef __GLIBC__
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#include <malloc.h>
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#endif
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// This defines *all* of the global data structures used by Nachos.
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// These are all initialized and de-allocated by this file.
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Thread *currentThread; // the thread we are running now
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Thread *threadToBeDestroyed; // the thread that just finished
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Scheduler *scheduler; // the ready list
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Interrupt *interrupt; // interrupt status
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Statistics *stats; // performance metrics
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Timer *timer; // the hardware timer device,
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// for invoking context switches
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#ifdef FILESYS_NEEDED
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FileSystem *fileSystem;
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#endif
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#ifdef FILESYS
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SynchDisk *synchDisk;
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#endif
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#ifdef USER_PROGRAM // requires either FILESYS or FILESYS_STUB
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Machine *machine; // user program memory and registers
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#ifdef CHANGED // Define our consoledriver Object
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ConsoleDriver *consoledriver;
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PageProvider *pageProvider;
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#endif // CHANGED
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#endif // USER_PROGRAM
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#ifdef NETWORK
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PostOffice *postOffice;
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#endif
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// External definition, to allow us to take a pointer to this function
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extern void Cleanup ();
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//----------------------------------------------------------------------
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// TimerInterruptHandler
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// Interrupt handler for the timer device. The timer device is
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// set up to interrupt the CPU periodically (once every TimerTicks).
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// This routine is called each time there is a timer interrupt,
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// with interrupts disabled.
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//
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// Note that instead of calling Yield() directly (which would
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// suspend the interrupt handler, not the interrupted thread
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// which is what we wanted to context switch), we set a flag
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// so that once the interrupt handler is done, it will appear as
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// if the interrupted thread called Yield at the point it is
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// was interrupted.
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//
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// "dummy" is because every interrupt handler takes one argument,
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// whether it needs it or not.
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//----------------------------------------------------------------------
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static void
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TimerInterruptHandler (void *dummy)
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{
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(void) dummy;
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if (interrupt->getStatus () != IdleMode)
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interrupt->YieldOnReturn ();
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}
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//----------------------------------------------------------------------
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// Initialize
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// Initialize Nachos global data structures. Interpret command
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// line arguments in order to determine flags for the initialization.
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//
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// "argc" is the number of command line arguments (including the name
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// of the command) -- ex: "nachos -d +" -> argc = 3
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// "argv" is an array of strings, one for each command line argument
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// ex: "nachos -d +" -> argv = {"nachos", "-d", "+"}
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//----------------------------------------------------------------------
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void
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Initialize (int argc, char **argv)
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{
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int argCount;
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const char *debugArgs = "";
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bool randomYield = FALSE;
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#ifdef USER_PROGRAM
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bool debugUserProg = FALSE; // single step user program
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#endif
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#ifdef FILESYS_NEEDED
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bool format = FALSE; // format disk
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#endif
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#ifdef NETWORK
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double rely = 1; // network reliability
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int netname = 0; // UNIX socket name
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#endif
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setlocale(LC_CTYPE,"");
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#ifdef __GLIBC__
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#if (__GLIBC__ > 2) || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 4)
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/* Make free() fill freed memory, to trap bad code */
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mallopt(M_PERTURB, 0xfefefefe);
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#endif
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#endif
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ThrashStack();
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for (argc--, argv++; argc > 0; argc -= argCount, argv += argCount)
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{
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argCount = 1;
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if (!strcmp (*argv, "-d"))
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{
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if (argc == 1)
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debugArgs = "+"; // turn on all debug flags
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else
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{
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debugArgs = *(argv + 1);
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argCount = 2;
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}
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}
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else if (!strcmp (*argv, "-rs"))
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{
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int seed;
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ASSERT (argc > 1);
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seed = atoi (*(argv + 1));
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if (seed == 0)
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{
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fprintf(stderr,"-rs option needs a seed value\n");
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exit(EXIT_FAILURE);
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}
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RandomInit (seed); // initialize pseudo-random
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// number generator
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randomYield = TRUE;
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argCount = 2;
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}
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#ifdef USER_PROGRAM
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if (!strcmp (*argv, "-s"))
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debugUserProg = TRUE;
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#endif
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#ifdef FILESYS_NEEDED
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if (!strcmp (*argv, "-f"))
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format = TRUE;
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#endif
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#ifdef NETWORK
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if (!strcmp (*argv, "-l"))
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{
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ASSERT (argc > 1);
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rely = atof (*(argv + 1));
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argCount = 2;
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}
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else if (!strcmp (*argv, "-m"))
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{
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ASSERT (argc > 1);
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netname = atoi (*(argv + 1));
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argCount = 2;
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}
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#endif
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}
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DebugInit (debugArgs); // initialize DEBUG messages
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stats = new Statistics (); // collect statistics
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interrupt = new Interrupt; // start up interrupt handling
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scheduler = new Scheduler (); // initialize the ready queue
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if (randomYield) // start the timer (if needed)
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timer = new Timer (TimerInterruptHandler, 0, randomYield);
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threadToBeDestroyed = NULL;
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// We didn't explicitly allocate the current thread we are running in.
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// But if it ever tries to give up the CPU, we better have a Thread
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// object to save its state.
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currentThread = new Thread ("main");
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currentThread->SetMain ();
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interrupt->Enable ();
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CallOnUserAbort (Cleanup); // if user hits ctl-C
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#ifdef USER_PROGRAM
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machine = new Machine (debugUserProg); // this must come first
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#ifdef CHANGED
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pageProvider = new PageProvider((int)(MemorySize/PageSize));
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#endif //CHANGED
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#endif
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#ifdef FILESYS
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synchDisk = new SynchDisk ("DISK");
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#endif
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#ifdef FILESYS_NEEDED
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fileSystem = new FileSystem (format);
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#endif
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#ifdef NETWORK
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postOffice = new PostOffice (netname, rely, 10);
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#endif
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}
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//----------------------------------------------------------------------
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// Cleanup
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// Nachos is halting. De-allocate global data structures.
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//----------------------------------------------------------------------
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void
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Cleanup ()
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{
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static int cleaning;
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if (cleaning) {
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printf ("\nCtrl-C while cleaning, stopping here hard.\n");
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Exit (0);
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}
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cleaning = 1;
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printf ("\nCleaning up...\n");
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/* Allow more interrupts but prevent other threads from continuing to use
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* the system while we are waiting for the last interrupts */
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if (scheduler)
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scheduler->Stop();
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if (interrupt)
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interrupt->Enable();
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#ifdef NETWORK
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if (postOffice) {
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delete postOffice;
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postOffice = NULL;
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}
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#endif
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#ifdef USER_PROGRAM
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if (machine) {
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delete machine;
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machine = NULL;
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}
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#ifdef CHANGED
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if (consoledriver) {
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delete consoledriver;
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consoledriver = NULL;
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}
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if (pageProvider){
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delete pageProvider;
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pageProvider = NULL;
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}
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#endif
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#endif
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#ifdef FILESYS_NEEDED
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if (fileSystem) {
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delete fileSystem;
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fileSystem = NULL;
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}
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#endif
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#ifdef FILESYS
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if (synchDisk) {
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delete synchDisk;
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synchDisk = NULL;
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}
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#endif
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if (timer) {
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delete timer;
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timer = NULL;
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}
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if (scheduler) {
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delete scheduler;
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scheduler = NULL;
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}
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if (interrupt) {
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delete interrupt;
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interrupt = NULL;
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}
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if (stats) {
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delete stats;
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stats = NULL;
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}
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ThreadList.Remove(currentThread);
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Exit (0);
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}
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