Пример #1
0
Файл: async.c Проект: L0op/qemu
static gboolean
aio_ctx_dispatch(GSource     *source,
                 GSourceFunc  callback,
                 gpointer     user_data)
{
    AioContext *ctx = (AioContext *) source;

    assert(callback == NULL);
    aio_dispatch(ctx);
    return true;
}
Пример #2
0
int pass_on(ProgramState *s) {
  SIGSELECT sigsel[] = {0,FM_READ_PTR_REPLY};
  union SIGNAL *sig;
  char child_read_buff[BUFSIZ], pipe_read_buff[BUFSIZ];
  struct aiocb child_read_req, pipe_read_req;
  int rfd, wfd = 0;
  FmHandle rfh, child_rfh;
  int outstanding_writes = 0, got_some = 0, child_done = 0;

  if ((rfd = sf_open(s->r_pipe, O_RDONLY, 0)) < 0) {
    ERRNO_ERR1(LOG_ERR,"Could not open FIFO '%s' for reading.\n", s->r_pipe);
    rfd = 0;
    return 1;
  }

  attach(NULL,s->progpid);

  /* Open the log file */
  erts_run_erl_log_open();

  efs_examine_fd(rfd,FLIB_FD_HANDLE,&rfh);
  efs_examine_fd(s->ifd,FLIB_FD_HANDLE,&child_rfh);

  READ_AIO(child_read_req,s->ifd,BUFSIZ,child_read_buff);
  READ_AIO(pipe_read_req,rfd,BUFSIZ,pipe_read_buff);

  while (1) {
    time_t now,last_activity;

    time(&last_activity);
    sig = receive_w_tmo(erts_run_erl_log_alive_minutes()*60000,sigsel);

    time(&now);

    if (sig) {
      erts_run_erl_log_activity(0,now,last_activity);
    } else {
      /* timeout */
      erts_run_erl_log_activity(1,now,last_activity);
      continue;
    }

    switch (sig->signo) {
    case OS_ATTACH_SIG: {
      if (rfd) { sf_close(rfd); rfd = 0; }
      free_buf(&sig);
      child_done = 1;
      /* Make sure to to let all outstanding write request finish */
      if (outstanding_writes)
	break;
      if (wfd) sf_close(wfd);
      return 0;
    }
    case FM_WRITE_PTR_REPLY: {
      if (sig->fm_write_ptr.status == EFS_SUCCESS) {
	if (sig->fm_write_ptr.actual < sig->fm_write_ptr.requested) {
	  WRITE_AIO(wfd, sig->fm_write_ptr.requested-sig->fm_write_ptr.actual,
		    sig->fm_write_ptr.buffer+sig->fm_write_ptr.actual);
	}
      } else {
	/* Assume to_erl has terminated. */
	sf_close(wfd);
	wfd = 0;
      }
      free((char*)sig->fm_write_ptr.buffer);
      aio_dispatch(sig);
      if ((--outstanding_writes == 0) && child_done) {
	if (wfd) sf_close(wfd);
	return 0;
      }
      break;
    }
    case FM_READ_PTR_REPLY: {
      /* Child fd */
      if (sig->fm_read_ptr.handle == child_rfh) {

	/* Child terminated */
	if (sig->fm_read_ptr.status != EFS_SUCCESS ||
	    sig->fm_read_ptr.actual == 0) {

	  if (rfd) { sf_close(rfd); rfd = 0; }

	  if (sig->fm_read_ptr.status != EFS_SUCCESS) {
	    ERROR0(LOG_ERR,"Erlang closed the connection.");
	    aio_dispatch(sig);
	    return 1;
	  }

	  /* child closed connection gracefully */
	  aio_dispatch(sig);
	  if (outstanding_writes) {
	    child_done = 1;
	    break;
	  }

	  if (wfd) sf_close(wfd);

	  return 0;
	} else {
	  erts_run_erl_log_write(sig->fm_read_ptr.buffer,
				 sig->fm_read_ptr.actual);
	  if (wfd) {
	    WRITE_AIO(wfd, sig->fm_read_ptr.actual, sig->fm_read_ptr.buffer);
	    outstanding_writes++;
	  }
	  aio_dispatch(sig);
	  READ_AIO(child_read_req, s->ifd,BUFSIZ, child_read_buff);
	}
      /* pipe fd */
      } else if (sig->fm_read_ptr.handle == rfh) {
	if (sig->fm_read_ptr.status != EFS_SUCCESS) {
	  if(rfd) sf_close(rfd);
	  if(wfd) sf_close(wfd);
	  aio_dispatch(sig);
	  ERRNO_ERR0(LOG_ERR,"Error in reading from FIFO.");
	  return 1;
	}
	if (sig->fm_read_ptr.actual == 0) {
	  /* to_erl closed its end of the pipe */
	  aio_dispatch(sig);
	  sf_close(rfd);
	  rfd = sf_open(s->r_pipe,O_RDONLY|DONT_BLOCK_PLEASE, 0);
	  if (rfd < 0) {
	    ERRNO_ERR1(LOG_ERR,"Could not open FIFO '%s' for reading.",
		       s->r_pipe);
	    rfd = 0;
	  } else {
	    READ_AIO(pipe_read_req,rfd,BUFSIZ,pipe_read_buff);
	  }
	  got_some = 0; /* reset for next session */
	} else {
	  int len = sig->fm_read_ptr.actual;
	  char *buffer = sig->fm_read_ptr.buffer;
	  if (!wfd) {
	    /* Try to open the write pipe to to_erl. Now that we got some data
	     * from to_erl, to_erl should already be reading this pipe - open
	     * should succeed. But in case of error, we just ignore it.
	     */
	    if ((wfd = sf_open(s->w_pipe, O_WRONLY|DONT_BLOCK_PLEASE, 0)) < 0) {
	      erts_run_erl_log_status("Client expected on FIFO %s, "
				      "but can't open (len=%d)\n",
				      s->w_pipe, sig->fm_read_ptr.actual);
	      sf_close(rfd);
	      rfd = sf_open(s->r_pipe, O_RDONLY|DONT_BLOCK_PLEASE, 0);
	      if (rfd < 0) {
		ERRNO_ERR1(LOG_ERR,"Could not open FIFO '%s' for reading.",
			   s->r_pipe);
		return 1;
	      }
	      wfd = 0;
	    } else {
#ifdef DEBUG
	      erts_run_erl_log_status("run_erl: %s opened for writing\n",
				      s->w_pipe);
#endif
	    }
	  }

	  if (!got_some && wfd && buffer[0] == '\014') {
	    char wbuf[30];
	    int wlen = sn_printf(wbuf,sizeof(wbuf),"[run_erl v%u-%u]\n",
				 RUN_ERL_HI_VER, RUN_ERL_LO_VER);
	    /* For some reason this, the first write aio seems to
	       not get an FM_WRITE_PTR_REPLY, so we do not do:
	       outstanding_writes++;
	    */
	    WRITE_AIO(wfd, wlen, wbuf);
	  }
	  got_some = 1;

	  /* Write the message */
#ifdef DEBUG
	  erts_run_erl_log_status("Pty master write; ");
#endif
	  len = erts_run_erl_extract_ctrl_seq(buffer,len, s->ofd);

	  if (len > 0) {
	    int wlen = erts_run_erl_write_all(s->ofd, buffer, len);
	    if (wlen != len) {
	      aio_dispatch(sig);
	      ERRNO_ERR0(LOG_ERR,"Error in writing to terminal.");
	      if(rfd) sf_close(rfd);
	      if(wfd) sf_close(wfd);
	      return 1;
	    }
	  }
#ifdef DEBUG
	  erts_run_erl_log_status("OK\n");
#endif
	  aio_dispatch(sig);
	  READ_AIO(pipe_read_req,rfd,BUFSIZ,pipe_read_buff);
	}
	}
      break;
    }
    default: {
      free_buf(&sig);
      break;
    }
    }
  }
}
Пример #3
0
int to_erl(int argc, char **argv)
{
    char  FIFO1[FILENAME_MAX], FIFO2[FILENAME_MAX];
    int i, len, wfd, rfd;
    char pipename[FILENAME_MAX];
    int pipeIx = 1;
    int force_lock = 0;
    int got_some = 0;

#ifdef __OSE__
    struct aiocb stdin_read_req, pipe_read_req;
    FmHandle stdin_fh, pipe_fh;
    char *stdin_buf, *pipe_buf;
    char *buf;
    union SIGNAL *sig;
#else /* __UNIX__ */
    char buf[BUFSIZ];
    fd_set readfds;
#endif

    if (argc >= 2 && argv[1][0]=='-') {
	switch (argv[1][1]) {
	case 'h':
	    usage(argv[0]);
	    exit(1);
	case 'F':
	    force_lock = 1;
	    break;
	default:
	    fprintf(stderr,"Invalid option '%s'\n",argv[1]);
	    exit(1);
	}
	pipeIx = 2;
    }

#ifdef DEBUG
    fprintf(stderr, "%s: pid is : %d\n", argv[0],(int)
#ifdef __OSE__
	    current_process()
#else /* __UNIX__ */
	    getpid()
#endif
	    );
#endif

    strn_cpy(pipename, sizeof(pipename),
	     (argv[pipeIx] ? argv[pipeIx] : PIPE_DIR));

    if(*pipename && pipename[strlen(pipename)-1] == '/') {
	/* The user wishes us to find a pipe name in the specified */
	/* directory */
	int highest_pipe_num = 0;
	DIR *dirp;
	struct dirent *direntp;

	dirp = opendir(pipename);
	if(!dirp) {
	    fprintf(stderr, "Can't access pipe directory %s: %s\n", pipename, strerror(errno));
	    exit(1);
	}

	/* Check the directory for existing pipes */

	while((direntp=readdir(dirp)) != NULL) {
	    if(strncmp(direntp->d_name,PIPE_STUBNAME,PIPE_STUBLEN)==0) {
		int num = atoi(direntp->d_name+PIPE_STUBLEN+1);
		if(num > highest_pipe_num)
		    highest_pipe_num = num;
	    }
	}
	closedir(dirp);
	strn_catf(pipename, sizeof(pipename), (highest_pipe_num?"%s.%d":"%s"),
		  PIPE_STUBNAME, highest_pipe_num);
    } /* if */

    /* read FIFO */
    sn_printf(FIFO1,sizeof(FIFO1),"%s.r",pipename);
    /* write FIFO */
    sn_printf(FIFO2,sizeof(FIFO2),"%s.w",pipename);

#ifndef __OSE__
    /* Check that nobody is running to_erl on this pipe already */
    if ((wfd = open (FIFO1, O_WRONLY|DONT_BLOCK_PLEASE, 0)) >= 0) {
	/* Open as server succeeded -- to_erl is already running! */
	close(wfd);
	fprintf(stderr, "Another to_erl process already attached to pipe "
			"%s.\n", pipename);
	if (force_lock) {
	    fprintf(stderr, "But we proceed anyway by force (-F).\n");
	}
	else {
	    exit(1);
	}
    }
#endif

    if ((rfd = open (FIFO1, O_RDONLY|DONT_BLOCK_PLEASE, 0)) < 0) {
#ifdef DEBUG
	fprintf(stderr, "Could not open FIFO %s for reading.\n", FIFO1);
#endif
	fprintf(stderr, "No running Erlang on pipe %s: %s\n", pipename, strerror(errno));
	exit(1);
    }
#ifdef DEBUG
    fprintf(stderr, "to_erl: %s opened for reading\n", FIFO1);
#endif

    if ((wfd = open (FIFO2, O_WRONLY|DONT_BLOCK_PLEASE, 0)) < 0) {
#ifdef DEBUG
	fprintf(stderr, "Could not open FIFO %s for writing.\n", FIFO2);
#endif
	fprintf(stderr, "No running Erlang on pipe %s: %s\n", pipename, strerror(errno));
	close(rfd);
	exit(1);
    }
#ifdef DEBUG
    fprintf(stderr, "to_erl: %s opened for writing\n", FIFO2);
#endif

#ifndef __OSE__
    fprintf(stderr, "Attaching to %s (^D to exit)\n\n", pipename);
#else
    fprintf(stderr, "Attaching to %s (^C to exit)\n\n", pipename);
#endif

#ifndef __OSE__
    /* Set break handler to our handler */
    signal(SIGINT,handle_ctrlc);

    /*
     * Save the current state of the terminal, and set raw mode.
     */
    if (tcgetattr(0, &tty_rmode) , 0) {
	fprintf(stderr, "Cannot get terminals current mode\n");
	exit(-1);
    }
    tty_smode = tty_rmode;
    tty_eof = '\004'; /* Ctrl+D to exit */
#ifdef DEBUG
    show_terminal_settings(&tty_rmode);
#endif
    tty_smode.c_iflag =
	1*BRKINT |/*Signal interrupt on break.*/
	    1*IGNPAR |/*Ignore characters with parity errors.*/
		1*ISTRIP |/*Strip character.*/
		    0;

#if 0
0*IGNBRK |/*Ignore break condition.*/
0*PARMRK |/*Mark parity errors.*/
0*INPCK  |/*Enable input parity check.*/
0*INLCR  |/*Map NL to CR on input.*/
0*IGNCR  |/*Ignore CR.*/
0*ICRNL  |/*Map CR to NL on input.*/
0*IUCLC  |/*Map upper-case to lower-case on input.*/
0*IXON   |/*Enable start/stop output control.*/
0*IXANY  |/*Enable any character to restart output.*/
0*IXOFF  |/*Enable start/stop input control.*/
0*IMAXBEL|/*Echo BEL on input line too long.*/
#endif

    tty_smode.c_oflag =
	1*OPOST  |/*Post-process output.*/
	    1*ONLCR  |/*Map NL to CR-NL on output.*/
#ifdef XTABS
		1*XTABS  |/*Expand tabs to spaces. (Linux)*/
#endif
#ifdef OXTABS
		    1*OXTABS  |/*Expand tabs to spaces. (FreeBSD)*/
#endif
#ifdef NL0
			1*NL0    |/*Select newline delays*/
#endif
#ifdef CR0
			    1*CR0    |/*Select carriage-return delays*/
#endif
#ifdef TAB0
				1*TAB0   |/*Select horizontal tab delays*/
#endif
#ifdef BS0
				    1*BS0    |/*Select backspace delays*/
#endif
#ifdef VT0
					1*VT0    |/*Select vertical tab delays*/
#endif
#ifdef FF0
					    1*FF0    |/*Select form feed delays*/
#endif
											    0;

#if 0
0*OLCUC  |/*Map lower case to upper on output.*/
0*OCRNL  |/*Map CR to NL on output.*/
0*ONOCR  |/*No CR output at column 0.*/
0*ONLRET |/*NL performs CR function.*/
0*OFILL  |/*Use fill characters for delay.*/
0*OFDEL  |/*Fill is DEL, else NULL.*/
0*NL1    |
0*CR1    |
0*CR2    |
0*CR3    |
0*TAB1   |
0*TAB2   |
0*TAB3   |/*Expand tabs to spaces.*/
0*BS1    |
0*VT1    |
0*FF1    |
#endif

    /* JALI: removed setting the tty_smode.c_cflag flags, since this is not */
    /* advisable if this is a *real* terminal, such as the console. In fact */
    /* this may hang the entire machine, deep, deep down (signalling break */
    /* or toggling the abort switch doesn't help) */

    tty_smode.c_lflag =
									0;

#if 0
0*ISIG   |/*Enable signals.*/
0*ICANON |/*Canonical input (erase and kill processing).*/
0*XCASE  |/*Canonical upper/lower presentation.*/
0*ECHO   |/*Enable echo.*/
0*ECHOE  |/*Echo erase character as BS-SP-BS.*/
0*ECHOK  |/*Echo NL after kill character.*/
0*ECHONL |/*Echo NL.*/
0*NOFLSH |/*Disable flush after interrupt or quit.*/
0*TOSTOP |/*Send SIGTTOU for background output.*/
0*ECHOCTL|/*Echo control characters as ^char, delete as ^?.*/
0*ECHOPRT|/*Echo erase character as character erased.*/
0*ECHOKE |/*BS-SP-BS erase entire line on line kill.*/
0*FLUSHO |/*Output is being flushed.*/
0*PENDIN |/*Retype pending input at next read or input character.*/
0*IEXTEN |/*Enable extended (implementation-defined) functions.*/
#endif

    tty_smode.c_cc[VMIN]      =0;/* Note that VMIN is the same as VEOF! */
    tty_smode.c_cc[VTIME]     =0;/* Note that VTIME is the same as VEOL! */
    tty_smode.c_cc[VINTR]     =3;

    tcsetattr(0, TCSADRAIN, &tty_smode);

#ifdef DEBUG
    show_terminal_settings(&tty_smode);
#endif

#endif /* !__OSE__ */
    /*
     * 	 "Write a ^L to the FIFO which causes the other end to redisplay
     *    the input line."
     * This does not seem to work as was intended in old comment above.
     * However, this control character is now (R12B-3) used by run_erl
     * to trigger the version handshaking between to_erl and run_erl
     * at the start of every new to_erl-session.
     */

    if (write(wfd, "\014", 1) < 0) {
	fprintf(stderr, "Error in writing ^L to FIFO.\n");
    }

#ifdef __OSE__
    /* we have a tiny stack so we malloc the buffers */
    stdin_buf = malloc(sizeof(char) * BUFSIZ);
    pipe_buf = malloc(sizeof(char) * BUFSIZ);

    efs_examine_fd(rfd,FLIB_FD_HANDLE,&pipe_fh);
    efs_examine_fd(0,FLIB_FD_HANDLE,&stdin_fh);
    READ_AIO(stdin_read_req,0,BUFSIZ,stdin_buf);
    READ_AIO(pipe_read_req,rfd,BUFSIZ,pipe_buf);
#endif

    /*
     * read and write
     */
    while (1) {
#ifndef __OSE__
	FD_ZERO(&readfds);
	FD_SET(0, &readfds);
	FD_SET(rfd, &readfds);
	if (select(rfd + 1, &readfds, NULL, NULL, NULL) < 0) {
	    if (recv_sig) {
		FD_ZERO(&readfds);
	    }
	    else {
		fprintf(stderr, "Error in select.\n");
		break;
	    }
	}
	len = 0;

	/*
	 * Read from terminal and write to FIFO
         */
	if (recv_sig) {
	    switch (recv_sig) {
	    case SIGINT:
		fprintf(stderr, "[Break]\n\r");
		buf[0] = '\003';
		len = 1;
		break;
	    case SIGWINCH:
		len = window_size_seq(buf,sizeof(buf));
		break;
	    default:
		fprintf(stderr,"Unexpected signal: %u\n",recv_sig);
	    }
	    recv_sig = 0;
	}
	else
#else /* __OSE__ */
	SIGSELECT sigsel[] = {0};
	sig = receive(sigsel);
	len = 0;
#endif
#ifndef __OSE__
	  if (FD_ISSET(0,&readfds)) {
	    len = read(0, buf, sizeof(buf));
#else /* __OSE__ */
	  if (sig->signo == FM_READ_PTR_REPLY &&
	      sig->fm_read_ptr.handle == stdin_fh) {
	    len = sig->fm_read_ptr.status == EFS_SUCCESS ? sig->fm_read_ptr.actual : -1;
	    buf = sig->fm_read_ptr.buffer;
#endif
	    if (len <= 0) {
		close(rfd);
		close(wfd);
		if (len < 0) {
		    fprintf(stderr, "Error in reading from stdin.\n");
		} else {
		    fprintf(stderr, "[EOF]\n\r");
		}
		break;
	    }
	    /* check if there is an eof character in input */
	    for (i = 0; i < len-1 && buf[i] != tty_eof; i++);
	    if (buf[i] == tty_eof) {
		fprintf(stderr, "[Quit]\n\r");
		break;
	    }
	}

	if (len) {
#ifdef DEBUG
	    if(write(1, buf, len));
#endif
	    if (write_all(wfd, buf, len) != len) {
		fprintf(stderr, "Error in writing to FIFO.\n");
		close(rfd);
		close(wfd);
		break;
	    }
	    STATUS("\" OK\r\n");
#ifdef __OSE__
	    aio_dispatch(sig);
	    READ_AIO(stdin_read_req, 0, BUFSIZ, stdin_buf);
#endif
	}

	/*
	 * Read from FIFO, write to terminal.
	 */
#ifndef __OSE__
	if (FD_ISSET(rfd, &readfds)) {
	    STATUS("FIFO read: ");
	    len = read(rfd, buf, BUFSIZ);
#else /* __OSE__ */
        if (sig->signo == FM_READ_PTR_REPLY &&
	    sig->fm_read_ptr.handle == pipe_fh) {
	    len = sig->fm_read_ptr.status == EFS_SUCCESS ? sig->fm_read_ptr.actual : -1;
	    buf = sig->fm_read_ptr.buffer;
#endif
	    if (len < 0 && errno == EAGAIN) {
		/*
		 * No data this time, but the writing end of the FIFO is still open.
		 * Do nothing.
		 */
		;
	    } else if (len <= 0) {
		/*
		 * Either an error or end of file. In either case, break out
		 * of the loop.
		 */
		close(rfd);
		close(wfd);
		if (len < 0) {
		    fprintf(stderr, "Error in reading from FIFO.\n");
		} else
		    fprintf(stderr, "[End]\n\r");
		break;
	    } else {
		if (!got_some) {
		    if ((len=version_handshake(buf,len,wfd)) < 0) {
			close(rfd);
			close(wfd);
			break;
		    }
#ifndef __OSE__
		    if (protocol_ver >= 1) {
			/* Tell run_erl size of terminal window */
			signal(SIGWINCH, handle_sigwinch);
			raise(SIGWINCH);
		    }
#endif
		    got_some = 1;
		}

		/*
		 * We successfully read at least one character. Write what we got.
		 */
		STATUS("Terminal write: \"");
		if (write_all(1, buf, len) != len) {
		    fprintf(stderr, "Error in writing to terminal.\n");
		    close(rfd);
		    close(wfd);
		    break;
		}
		STATUS("\" OK\r\n");
#ifdef __OSE__
		aio_dispatch(sig);
		READ_AIO(pipe_read_req, rfd, BUFSIZ, pipe_buf);
#endif
	    }
	}
    }

#ifndef __OSE__
    /*
     * Reset terminal characterstics
     * XXX
     */
    tcsetattr(0, TCSADRAIN, &tty_rmode);
#endif
    return 0;
}

/* Call write() until entire buffer has been written or error.
 * Return len or -1.
 */
static int write_all(int fd, const char* buf, int len)
{
    int left = len;
    int written;
    while (left) {
	written = write(fd,buf,left);
	if (written < 0) {
	    return -1;
	}
	left -= written;
	buf += written;
    }
    return len;
}

#ifndef __OSE__
static int window_size_seq(char* buf, size_t bufsz)
{
#ifdef TIOCGWINSZ
    struct winsize ws;
    static const char prefix[] = "\033_";
    static const char suffix[] = "\033\\";
    /* This Esc sequence is called "Application Program Command"
       and seems suitable to use for our own customized stuff. */

    if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) == 0) {
	int len = sn_printf(buf, bufsz, "%swinsize=%u,%u%s",
			    prefix, ws.ws_col, ws.ws_row, suffix);
	return len;
    }
#endif /* TIOCGWINSZ */
    return 0;
}
#endif /* !__OSE__ */

/*   to_erl                     run_erl
 *     |                           |
 *     |---------- '\014' -------->| (session start)
 *     |                           |
 *     |<---- "[run_erl v1-0]" ----| (version interval)
 *     |                           |
 *     |--- Esc_"version=1"Esc\ -->| (common version)
 *     |                           |
 */
static int version_handshake(char* buf, int len, int wfd)
{
    unsigned re_high=0, re_low;
    char *end = find_str(buf,len,"]\n");

    if (end && sscanf(buf,"[run_erl v%u-%u",&re_high,&re_low)==2) {
	char wbuf[30];
	int wlen;

	if (re_low > RUN_ERL_HI_VER || re_high < RUN_ERL_LO_VER) {
	    fprintf(stderr,"Incompatible versions: to_erl=v%u-%u run_erl=v%u-%u\n",
		    RUN_ERL_HI_VER, RUN_ERL_LO_VER, re_high, re_low);
	    return -1;
	}
	/* Choose highest common version */
	protocol_ver = re_high < RUN_ERL_HI_VER ? re_high : RUN_ERL_HI_VER;

	wlen = sn_printf(wbuf, sizeof(wbuf), "\033_version=%u\033\\",
			 protocol_ver);
	if (write_all(wfd, wbuf, wlen) < 0) {
	    fprintf(stderr,"Failed to send version handshake\n");
	    return -1;
	}
	end += 2;
	len -= (end-buf);
	memmove(buf,end,len);

    }
    else {  /* we assume old run_erl without version handshake */
	protocol_ver = 0;
    }

    if (re_high != RUN_ERL_HI_VER) {
	fprintf(stderr,"run_erl has different version, "
		"using common protocol level %u\n", protocol_ver);
    }

    return len;
}