unix_main.c

quakeIII源码这个不用我多说吧

/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.

Quake III Arena source code is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include <limits.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/stat.h>
#include <string.h>
#include <ctype.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <errno.h>
#ifdef __linux__ // rb010123
  #include <mntent.h>
#endif
#include <dlfcn.h>

#ifdef __linux__
  #include <fpu_control.h> // bk001213 - force dumps on divide by zero
#endif

// FIXME TTimo should we gard this? most *nix system should comply?
#include <termios.h>

#include "../game/q_shared.h"
#include "../qcommon/qcommon.h"
#include "../renderer/tr_public.h"

#include "linux_local.h" // bk001204

// Structure containing functions exported from refresh DLL
refexport_t re;

unsigned  sys_frame_time;

uid_t saved_euid;
qboolean stdin_active = qtrue;

// =============================================================
// tty console variables
// =============================================================

// enable/disabled tty input mode
// NOTE TTimo this is used during startup, cannot be changed during run
static cvar_t *ttycon = NULL;
// general flag to tell about tty console mode
static qboolean ttycon_on = qfalse;
// when printing general stuff to stdout stderr (Sys_Printf)
//   we need to disable the tty console stuff
// this increments so we can recursively disable
static int ttycon_hide = 0;
// some key codes that the terminal may be using
// TTimo NOTE: I'm not sure how relevant this is
static int tty_erase;
static int tty_eof;

static struct termios tty_tc;

static field_t tty_con;

// history
// NOTE TTimo this is a bit duplicate of the graphical console history
//   but it's safer and faster to write our own here
#define TTY_HISTORY 32
static field_t ttyEditLines[TTY_HISTORY];
static int hist_current = -1, hist_count = 0;

// =======================================================================
// General routines
// =======================================================================

// bk001207 
#define MEM_THRESHOLD 96*1024*1024

/*
==================
Sys_LowPhysicalMemory()
==================
*/
qboolean Sys_LowPhysicalMemory() {
  //MEMORYSTATUS stat;
  //GlobalMemoryStatus (&stat);
  //return (stat.dwTotalPhys <= MEM_THRESHOLD) ? qtrue : qfalse;
  return qfalse; // bk001207 - FIXME
}

/*
==================
Sys_FunctionCmp
==================
*/
int Sys_FunctionCmp(void *f1, void *f2) {
  return qtrue;
}

/*
==================
Sys_FunctionCheckSum
==================
*/
int Sys_FunctionCheckSum(void *f1) {
  return 0;
}

/*
==================
Sys_MonkeyShouldBeSpanked
==================
*/
int Sys_MonkeyShouldBeSpanked( void ) {
  return 0;
}

void Sys_BeginProfiling( void ) {
}

/*
=================
Sys_In_Restart_f

Restart the input subsystem
=================
*/
void Sys_In_Restart_f( void ) 
{
  IN_Shutdown();
  IN_Init();
}

// =============================================================
// tty console routines
// NOTE: if the user is editing a line when something gets printed to the early console then it won't look good
//   so we provide tty_Clear and tty_Show to be called before and after a stdout or stderr output
// =============================================================

// flush stdin, I suspect some terminals are sending a LOT of shit
// FIXME TTimo relevant?
void tty_FlushIn()
{
  char key;
  while (read(0, &key, 1)!=-1);
}

// do a backspace
// TTimo NOTE: it seems on some terminals just sending '\b' is not enough
//   so for now, in any case we send "\b \b" .. yeah well ..
//   (there may be a way to find out if '\b' alone would work though)
void tty_Back()
{
  char key;
  key = '\b';
  write(1, &key, 1);
  key = ' ';
  write(1, &key, 1);
  key = '\b';
  write(1, &key, 1);
}

// clear the display of the line currently edited
// bring cursor back to beginning of line
void tty_Hide()
{
  int i;
  assert(ttycon_on);
  if (ttycon_hide)
  {
    ttycon_hide++;
    return;
  }
  if (tty_con.cursor>0)
  {
    for (i=0; i<tty_con.cursor; i++)
    {
      tty_Back();
    }
  }
  ttycon_hide++;
}

// show the current line
// FIXME TTimo need to position the cursor if needed??
void tty_Show()
{
  int i;
  assert(ttycon_on);
  assert(ttycon_hide>0);
  ttycon_hide--;
  if (ttycon_hide == 0)
  {
    if (tty_con.cursor)
    {
      for (i=0; i<tty_con.cursor; i++)
      {
        write(1, tty_con.buffer+i, 1);
      }
    }
  }
}

// never exit without calling this, or your terminal will be left in a pretty bad state
void Sys_ConsoleInputShutdown()
{
  if (ttycon_on)
  {
    Com_Printf("Shutdown tty console\n");
    tcsetattr (0, TCSADRAIN, &tty_tc);
  }
}

void Hist_Add(field_t *field)
{
  int i;
  assert(hist_count <= TTY_HISTORY);
  assert(hist_count >= 0);
  assert(hist_current >= -1);
  assert(hist_current <= hist_count);
  // make some room
  for (i=TTY_HISTORY-1; i>0; i--)
  {
    ttyEditLines[i] = ttyEditLines[i-1];
  }
  ttyEditLines[0] = *field;
  if (hist_count<TTY_HISTORY)
  {
    hist_count++;
  }
  hist_current = -1; // re-init
}

field_t *Hist_Prev()
{
  int hist_prev;
  assert(hist_count <= TTY_HISTORY);
  assert(hist_count >= 0);
  assert(hist_current >= -1);
  assert(hist_current <= hist_count);
  hist_prev = hist_current + 1;
  if (hist_prev >= hist_count)
  {
    return NULL;
  }
  hist_current++;
  return &(ttyEditLines[hist_current]);
}

field_t *Hist_Next()
{
  assert(hist_count <= TTY_HISTORY);
  assert(hist_count >= 0);
  assert(hist_current >= -1);
  assert(hist_current <= hist_count);
  if (hist_current >= 0)
  {
    hist_current--;
  }
  if (hist_current == -1)
  {
    return NULL;
  }
  return &(ttyEditLines[hist_current]);
}

// =============================================================
// general sys routines
// =============================================================

#if 0
// NOTE TTimo this is not used .. looks interesting though? protection against buffer overflow kind of stuff?
void Sys_Printf (char *fmt, ...)
{
  va_list   argptr;
  char    text[1024];
  unsigned char   *p;

  va_start (argptr,fmt);
  vsprintf (text,fmt,argptr);
  va_end (argptr);

  if (strlen(text) > sizeof(text))
    Sys_Error("memory overwrite in Sys_Printf");

  for (p = (unsigned char *)text; *p; p++)
  {
    *p &= 0x7f;
    if ((*p > 128 || *p < 32) && *p != 10 && *p != 13 && *p != 9)
      printf("[%02x]", *p);
    else
      putc(*p, stdout);
  }
}
#endif

// single exit point (regular exit or in case of signal fault)
void Sys_Exit( int ex ) {
  Sys_ConsoleInputShutdown();

#ifdef NDEBUG // regular behavior

  // We can't do this 
  //  as long as GL DLL's keep installing with atexit...
  //exit(ex);
  _exit(ex);
#else

  // Give me a backtrace on error exits.
  assert( ex == 0 );
  exit(ex);
#endif
}


void Sys_Quit (void) {
  CL_Shutdown ();
  fcntl (0, F_SETFL, fcntl (0, F_GETFL, 0) & ~FNDELAY);
  Sys_Exit(0);
}

void Sys_Init(void)
{
  Cmd_AddCommand ("in_restart", Sys_In_Restart_f);

#if defined __linux__
#if defined __i386__
  Cvar_Set( "arch", "linux i386" );
#elif defined __alpha__
  Cvar_Set( "arch", "linux alpha" );
#elif defined __sparc__
  Cvar_Set( "arch", "linux sparc" );
#elif defined __FreeBSD__

#if defined __i386__ // FreeBSD
  Cvar_Set( "arch", "freebsd i386" );
#elif defined __alpha__
  Cvar_Set( "arch", "freebsd alpha" );
#else
  Cvar_Set( "arch", "freebsd unknown" );
#endif // FreeBSD

#else
  Cvar_Set( "arch", "linux unknown" );
#endif
#elif defined __sun__
#if defined __i386__
  Cvar_Set( "arch", "solaris x86" );
#elif defined __sparc__
  Cvar_Set( "arch", "solaris sparc" );
#else
  Cvar_Set( "arch", "solaris unknown" );
#endif
#elif defined __sgi__
#if defined __mips__
  Cvar_Set( "arch", "sgi mips" );
#else
  Cvar_Set( "arch", "sgi unknown" );
#endif
#else
  Cvar_Set( "arch", "unknown" );
#endif

  Cvar_Set( "username", Sys_GetCurrentUser() );

  IN_Init();

}

void  Sys_Error( const char *error, ...)
{ 
  va_list     argptr;
  char        string[1024];

  // change stdin to non blocking
  // NOTE TTimo not sure how well that goes with tty console mode
  fcntl (0, F_SETFL, fcntl (0, F_GETFL, 0) & ~FNDELAY);

  // don't bother do a show on this one heh
  if (ttycon_on)
  {
    tty_Hide();
  }

  CL_Shutdown ();

  va_start (argptr,error);
  vsprintf (string,error,argptr);
  va_end (argptr);
  fprintf(stderr, "Sys_Error: %s\n", string);

  Sys_Exit( 1 ); // bk010104 - use single exit point.
} 

void Sys_Warn (char *warning, ...)
{ 
  va_list     argptr;
  char        string[1024];

  va_start (argptr,warning);
  vsprintf (string,warning,argptr);
  va_end (argptr);

  if (ttycon_on)
  {
    tty_Hide();
  }

  fprintf(stderr, "Warning: %s", string);

  if (ttycon_on)
  {
    tty_Show();
  }
} 

/*
============
Sys_FileTime

returns -1 if not present
============
*/
int Sys_FileTime (char *path)
{
  struct  stat  buf;

  if (stat (path,&buf) == -1)
    return -1;

  return buf.st_mtime;
}

void floating_point_exception_handler(int whatever)
{
  signal(SIGFPE, floating_point_exception_handler);
}

// initialize the console input (tty mode if wanted and possible)
void Sys_ConsoleInputInit()
{
  struct termios tc;

  // TTimo 
  // https://zerowing.idsoftware.com/bugzilla/show_bug.cgi?id=390
  // ttycon 0 or 1, if the process is backgrounded (running non interactively)
  // then SIGTTIN or SIGTOU is emitted, if not catched, turns into a SIGSTP
  signal(SIGTTIN, SIG_IGN);
  signal(SIGTTOU, SIG_IGN);

  // FIXME TTimo initialize this in Sys_Init or something?
  ttycon = Cvar_Get("ttycon", "1", 0);
  if (ttycon && ttycon->value)
  {
    if (isatty(STDIN_FILENO)!=1)
    {
      Com_Printf("stdin is not a tty, tty console mode failed\n");
      Cvar_Set("ttycon", "0");
      ttycon_on = qfalse;
      return;
    }
    Com_Printf("Started tty console (use +set ttycon 0 to disable)\n");
    Field_Clear(&tty_con);
    tcgetattr (0, &tty_tc);
    tty_erase = tty_tc.c_cc[VERASE];
    tty_eof = tty_tc.c_cc[VEOF];
    tc = tty_tc;
    /*
     ECHO: don't echo input characters
     ICANON: enable canonical mode.  This  enables  the  special
              characters  EOF,  EOL,  EOL2, ERASE, KILL, REPRINT,
              STATUS, and WERASE, and buffers by lines.
     ISIG: when any of the characters  INTR,  QUIT,  SUSP,  or
              DSUSP are received, generate the corresponding sig