process.cc

来自「M5,一个功能强大的多处理器系统模拟器.很多针对处理器架构,性能的研究都使用它作」· CC 代码 · 共 719 行 · 第 1/2 页

/*
 * Copyright (c) 2001, 2002, 2003, 2004, 2005
 * The Regents of The University of Michigan
 * All Rights Reserved
 *
 * This code is part of the M5 simulator.
 *
 * Permission is granted to use, copy, create derivative works and
 * redistribute this software and such derivative works for any
 * purpose, so long as the copyright notice above, this grant of
 * permission, and the disclaimer below appear in all copies made; and
 * so long as the name of The University of Michigan is not used in
 * any advertising or publicity pertaining to the use or distribution
 * of this software without specific, written prior authorization.
 *
 * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION FROM THE
 * UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY PURPOSE, AND
 * WITHOUT WARRANTY BY THE UNIVERSITY OF MICHIGAN OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE. THE REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE
 * LIABLE FOR ANY DAMAGES, INCLUDING DIRECT, SPECIAL, INDIRECT,
 * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM
 * ARISING OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
 * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGES.
 *
 * Authors: Nathan L. Binkert
 *          Steven K. Reinhardt
 *          Ali G. Saidi
 */

#include <unistd.h>
#include <fcntl.h>
#include <string>

#include "arch/remote_gdb.hh"
#include "base/intmath.hh"
#include "base/loader/object_file.hh"
#include "base/loader/symtab.hh"
#include "base/statistics.hh"
#include "config/full_system.hh"
#include "cpu/thread_context.hh"
#include "mem/page_table.hh"
#include "mem/physical.hh"
#include "mem/translating_port.hh"
#include "params/Process.hh"
#include "params/LiveProcess.hh"
#include "sim/process.hh"
#include "sim/process_impl.hh"
#include "sim/stats.hh"
#include "sim/syscall_emul.hh"
#include "sim/system.hh"

#include "arch/isa_specific.hh"
#if THE_ISA == ALPHA_ISA
#include "arch/alpha/linux/process.hh"
#include "arch/alpha/tru64/process.hh"
#elif THE_ISA == SPARC_ISA
#include "arch/sparc/linux/process.hh"
#include "arch/sparc/solaris/process.hh"
#elif THE_ISA == MIPS_ISA
#include "arch/mips/linux/process.hh"
#elif THE_ISA == ARM_ISA
#include "arch/arm/linux/process.hh"
#else
#error "THE_ISA not set"
#endif


using namespace std;
using namespace TheISA;

//
// The purpose of this code is to fake the loader & syscall mechanism
// when there's no OS: thus there's no resone to use it in FULL_SYSTEM
// mode when we do have an OS
//
#if FULL_SYSTEM
#error "process.cc not compatible with FULL_SYSTEM"
#endif

// current number of allocated processes
int num_processes = 0;

Process::Process(ProcessParams * params)
    : SimObject(params), system(params->system), checkpointRestored(false),
    max_stack_size(params->max_stack_size)
{
    string in = params->input;
    string out = params->output;

    // initialize file descriptors to default: same as simulator
    int stdin_fd, stdout_fd, stderr_fd;

    if (in == "stdin" || in == "cin")
        stdin_fd = STDIN_FILENO;
    else if (in == "None")
        stdin_fd = -1;
    else
        stdin_fd = Process::openInputFile(in);

    if (out == "stdout" || out == "cout")
        stdout_fd = STDOUT_FILENO;
    else if (out == "stderr" || out == "cerr")
        stdout_fd = STDERR_FILENO;
    else if (out == "None")
        stdout_fd = -1;
    else
        stdout_fd = Process::openOutputFile(out);

    stderr_fd = (stdout_fd != STDOUT_FILENO) ? stdout_fd : STDERR_FILENO;

    M5_pid = system->allocatePID();
    // initialize first 3 fds (stdin, stdout, stderr)
    Process::FdMap *fdo = &fd_map[STDIN_FILENO];
    fdo->fd = stdin_fd;
    fdo->filename = in;
    fdo->flags = O_RDONLY;
    fdo->mode = -1;
    fdo->fileOffset = 0;

    fdo =  &fd_map[STDOUT_FILENO];
    fdo->fd = stdout_fd;
    fdo->filename = out;
    fdo->flags =  O_WRONLY | O_CREAT | O_TRUNC;
    fdo->mode = 0774;
    fdo->fileOffset = 0;

    fdo = &fd_map[STDERR_FILENO];
    fdo->fd = stderr_fd;
    fdo->filename = "STDERR";
    fdo->flags = O_WRONLY;
    fdo->mode = -1;
    fdo->fileOffset = 0;


    // mark remaining fds as free
    for (int i = 3; i <= MAX_FD; ++i) {
        Process::FdMap *fdo = &fd_map[i];
        fdo->fd = -1;
    }

    mmap_start = mmap_end = 0;
    nxm_start = nxm_end = 0;
    pTable = new PageTable(this);
    // other parameters will be initialized when the program is loaded
}


void
Process::regStats()
{
    using namespace Stats;

    num_syscalls
        .name(name() + ".PROG:num_syscalls")
        .desc("Number of system calls")
        ;
}

//
// static helper functions
//
int
Process::openInputFile(const string &filename)
{
    int fd = open(filename.c_str(), O_RDONLY);

    if (fd == -1) {
        perror(NULL);
        cerr << "unable to open \"" << filename << "\" for reading\n";
        fatal("can't open input file");
    }

    return fd;
}


int
Process::openOutputFile(const string &filename)
{
    int fd = open(filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0774);

    if (fd == -1) {
        perror(NULL);
        cerr << "unable to open \"" << filename << "\" for writing\n";
        fatal("can't open output file");
    }

    return fd;
}


int
Process::registerThreadContext(ThreadContext *tc)
{
    // add to list
    int myIndex = threadContexts.size();
    threadContexts.push_back(tc);

    RemoteGDB *rgdb = new RemoteGDB(system, tc);
    GDBListener *gdbl = new GDBListener(rgdb, 7000 + myIndex);
    gdbl->listen();
    //gdbl->accept();

    remoteGDB.push_back(rgdb);

    // return CPU number to caller
    return myIndex;
}

void
Process::startup()
{
    if (threadContexts.empty())
        fatal("Process %s is not associated with any CPUs!\n", name());

    // first thread context for this process... initialize & enable
    ThreadContext *tc = threadContexts[0];

    // mark this context as active so it will start ticking.
    tc->activate(0);

    Port *mem_port;
    mem_port = system->physmem->getPort("functional");
    initVirtMem = new TranslatingPort("process init port", this,
            TranslatingPort::Always);
    mem_port->setPeer(initVirtMem);
    initVirtMem->setPeer(mem_port);
}

void
Process::replaceThreadContext(ThreadContext *tc, int tcIndex)
{
    if (tcIndex >= threadContexts.size()) {
        panic("replaceThreadContext: bad tcIndex, %d >= %d\n",
              tcIndex, threadContexts.size());
    }

    threadContexts[tcIndex] = tc;
}

// map simulator fd sim_fd to target fd tgt_fd
void
Process::dup_fd(int sim_fd, int tgt_fd)
{
    if (tgt_fd < 0 || tgt_fd > MAX_FD)
        panic("Process::dup_fd tried to dup past MAX_FD (%d)", tgt_fd);

    Process::FdMap *fdo = &fd_map[tgt_fd];
    fdo->fd = sim_fd;
}


// generate new target fd for sim_fd
int
Process::alloc_fd(int sim_fd, string filename, int flags, int mode, bool pipe)
{
    // in case open() returns an error, don't allocate a new fd
    if (sim_fd == -1)
        return -1;

    // find first free target fd
    for (int free_fd = 0; free_fd <= MAX_FD; ++free_fd) {
        Process::FdMap *fdo = &fd_map[free_fd];
        if (fdo->fd == -1) {
            fdo->fd = sim_fd;
            fdo->filename = filename;
            fdo->mode = mode;
            fdo->fileOffset = 0;
            fdo->flags = flags;
            fdo->isPipe = pipe;
            fdo->readPipeSource = 0;
            return free_fd;
        }
    }

    panic("Process::alloc_fd: out of file descriptors!");
}


// free target fd (e.g., after close)
void
Process::free_fd(int tgt_fd)
{
    Process::FdMap *fdo = &fd_map[tgt_fd];
    if (fdo->fd == -1)
        warn("Process::free_fd: request to free unused fd %d", tgt_fd);

    fdo->fd = -1;
    fdo->filename = "NULL";
    fdo->mode = 0;
    fdo->fileOffset = 0;
    fdo->flags = 0;
    fdo->isPipe = false;
    fdo->readPipeSource = 0;
}


// look up simulator fd for given target fd
int
Process::sim_fd(int tgt_fd)
{
    if (tgt_fd > MAX_FD)
        return -1;

    return fd_map[tgt_fd].fd;
}

Process::FdMap *
Process::sim_fd_obj(int tgt_fd)
{
    if (tgt_fd > MAX_FD)
        panic("sim_fd_obj called in fd out of range.");

    return &fd_map[tgt_fd];
}
bool
Process::checkAndAllocNextPage(Addr vaddr)
{
    // if this is an initial write we might not have
    if (vaddr >= stack_min && vaddr < stack_base) {
        pTable->allocate(roundDown(vaddr, VMPageSize), VMPageSize);
        return true;
    }

    // We've accessed the next page of the stack, so extend the stack
    // to cover it.
    if (vaddr < stack_min && vaddr >= stack_base - max_stack_size) {
        while (vaddr < stack_min) {
            stack_min -= TheISA::PageBytes;
            if(stack_base - stack_min > max_stack_size)
                fatal("Maximum stack size exceeded\n");
            if(stack_base - stack_min > 8*1024*1024)
                fatal("Over max stack size for one thread\n");
            pTable->allocate(stack_min, TheISA::PageBytes);
            warn("Increasing stack size by one page.");
        };
        return true;
    }
    return false;
}

 // find all offsets for currently open files and save them
void
Process::fix_file_offsets() {
    Process::FdMap *fdo_stdin = &fd_map[STDIN_FILENO];
    Process::FdMap *fdo_stdout = &fd_map[STDOUT_FILENO];
    Process::FdMap *fdo_stderr = &fd_map[STDERR_FILENO];
    string in = fdo_stdin->filename;
    string out = fdo_stdout->filename;

    // initialize file descriptors to default: same as simulator
    int stdin_fd, stdout_fd, stderr_fd;

    if (in == "stdin" || in == "cin")
        stdin_fd = STDIN_FILENO;
    else if (in == "None")
        stdin_fd = -1;