自学教程：C++ unlock_unit函数代码示例

static voidalready_open (st_parameter_open *opp, gfc_unit * u, unit_flags * flags){  if ((opp->common.flags & IOPARM_OPEN_HAS_FILE) == 0)    {      edit_modes (opp, u, flags);      return;    }  /* If the file is connected to something else, close it and open a     new unit.  */  if (!compare_file_filename (u, opp->file, opp->file_len))    {#if !HAVE_UNLINK_OPEN_FILE      char *path = NULL;      if (u->file && u->flags.status == STATUS_SCRATCH)	{	  path = (char *) gfc_alloca (u->file_len + 1);	  unpack_filename (path, u->file, u->file_len);	}#endif      if (sclose (u->s) == FAILURE)	{	  unlock_unit (u);	  generate_error (&opp->common, LIBERROR_OS,			  "Error closing file in OPEN statement");	  return;	}      u->s = NULL;      if (u->file)	free_mem (u->file);      u->file = NULL;      u->file_len = 0;#if !HAVE_UNLINK_OPEN_FILE      if (path != NULL)	unlink (path);#endif      u = new_unit (opp, u, flags);      if (u != NULL)	unlock_unit (u);      return;    }  edit_modes (opp, u, flags);}

intPREFIX(fgetc) (const int * unit, char * c, gfc_charlen_type c_len){  int ret;  gfc_unit * u = find_unit (*unit);  if (u == NULL)    return -1;  fbuf_reset (u);  if (u->mode == WRITING)    {      sflush (u->s);      u->mode = READING;    }  memset (c, ' ', c_len);  ret = sread (u->s, c, 1);  unlock_unit (u);  if (ret < 0)    return ret;  if (ret != 1)    return -1;  else    return 0;}

voidst_inquire (st_parameter_inquire *iqp){  gfc_unit *u;  library_start (&iqp->common);  if ((iqp->common.flags & IOPARM_INQUIRE_HAS_FILE) == 0)    {      u = find_unit (iqp->common.unit);      inquire_via_unit (iqp, u);    }  else    {      u = find_file (iqp->file, iqp->file_len);      if (u == NULL)	inquire_via_filename (iqp);      else	inquire_via_unit (iqp, u);    }  if (u != NULL)    unlock_unit (u);  library_end ();}

voidst_rewind (st_parameter_filepos *fpp){  gfc_unit *u;  library_start (&fpp->common);  u = find_unit (fpp->common.unit);  if (u != NULL)    {      if (u->flags.access == ACCESS_DIRECT)	generate_error (&fpp->common, LIBERROR_BAD_OPTION,			"Cannot REWIND a file opened for DIRECT access");      else	{	  /* If there are previously written bytes from a write with ADVANCE="no",	     add a record marker before performing the ENDFILE.  */	  if (u->previous_nonadvancing_write)	    finish_last_advance_record (u);	  u->previous_nonadvancing_write = 0;	  fbuf_reset (u);	  u->last_record = 0;	  if (sseek (u->s, 0, SEEK_SET) < 0)	    generate_error (&fpp->common, LIBERROR_OS, NULL);	  /* Handle special files like /dev/null differently.  */	  if (!is_special (u->s))	    {	      /* We are rewinding so we are not at the end.  */	      u->endfile = NO_ENDFILE;	    }	  else	    {	      /* Set this for compatibilty with g77 for /dev/null.  */	      if (file_length (u->s) == 0  && stell (u->s) == 0)		u->endfile = AT_ENDFILE;	      /* Future refinements on special files can go here.  */	    }	  u->current_record = 0;	  u->strm_pos = 1;	  u->read_bad = 0;	}      /* Update position for INQUIRE.  */      u->flags.position = POSITION_REWIND;      unlock_unit (u);    }  library_end ();}

static gfc_offsetgf_ftell (int unit){  gfc_unit * u = find_unit (unit);  if (u == NULL)    return -1;  int pos = fbuf_reset (u);  if (pos != 0)    sseek (u->s, pos, SEEK_CUR);  gfc_offset ret = stell (u->s);  unlock_unit (u);  return ret;}

static voidalready_open (st_parameter_open *opp, gfc_unit * u, unit_flags * flags){  if ((opp->common.flags & IOPARM_OPEN_HAS_FILE) == 0)    {      edit_modes (opp, u, flags);      return;    }  /* If the file is connected to something else, close it and open a     new unit.  */  if (!compare_file_filename (u, opp->file, opp->file_len))    {      if (sclose (u->s) == -1)	{	  unlock_unit (u);	  generate_error (&opp->common, LIBERROR_OS,			  "Error closing file in OPEN statement");	  return;	}      u->s = NULL; #if !HAVE_UNLINK_OPEN_FILE      if (u->filename && u->flags.status == STATUS_SCRATCH)	remove (u->filename);#endif     free (u->filename);     u->filename = NULL;      u = new_unit (opp, u, flags);      if (u != NULL)	unlock_unit (u);      return;    }  edit_modes (opp, u, flags);}

GFC_LOGICAL_8isatty_l8 (int *unit){  gfc_unit *u;  GFC_LOGICAL_8 ret = 0;  u = find_unit (*unit);  if (u != NULL)    {      ret = (GFC_LOGICAL_8) stream_isatty (u->s);      unlock_unit (u);    }  return ret;}

voidttynam (char ** name, gfc_charlen_type * name_len, int unit){  gfc_unit *u;  u = find_unit (unit);  if (u != NULL)    {      *name = xmalloc (TTY_NAME_MAX);      int err = stream_ttyname (u->s, *name, TTY_NAME_MAX);      if (err == 0)	{	  *name_len = strlen (*name);	  unlock_unit (u);	  return;	}      free (*name);      unlock_unit (u);    }  *name_len = 0;  *name = NULL;}

voidfseek_sub (int * unit, GFC_IO_INT * offset, int * whence, int * status){  gfc_unit * u = find_unit (*unit);  ssize_t result = -1;  if (u != NULL)    {      result = sseek(u->s, *offset, *whence);      unlock_unit (u);    }  if (status)    *status = (result < 0 ? -1 : 0);}

voidst_endfile (st_parameter_filepos *fpp){  gfc_unit *u;  library_start (&fpp->common);  u = find_unit (fpp->common.unit);  if (u != NULL)    {      if (u->flags.access == ACCESS_DIRECT)	{	  generate_error (&fpp->common, LIBERROR_OPTION_CONFLICT,			  "Cannot perform ENDFILE on a file opened"			  " for DIRECT access");	  goto done;	}      /* If there are previously written bytes from a write with ADVANCE="no",	 add a record marker before performing the ENDFILE.  */      if (u->previous_nonadvancing_write)	finish_last_advance_record (u);      u->previous_nonadvancing_write = 0;      if (u->current_record)	{	  st_parameter_dt dtp;	  dtp.common = fpp->common;	  memset (&dtp.u.p, 0, sizeof (dtp.u.p));	  dtp.u.p.current_unit = u;	  next_record (&dtp, 1);	}      unit_truncate (u, stell (u->s), &fpp->common);      u->endfile = AFTER_ENDFILE;      if (0 == stell (u->s))        u->flags.position = POSITION_REWIND;    done:      unlock_unit (u);    }  library_end ();}

voidflush_i8 (GFC_INTEGER_8 *unit){  gfc_unit *us;  /* flush all streams */  if (unit == NULL)    flush_all_units ();  else    {      us = find_unit (*unit);      if (us != NULL)	{	  sflush (us->s);	  unlock_unit (us);	}    }}

voidttynam_sub (int *unit, char * name, gfc_charlen_type name_len){  gfc_unit *u;  int nlen;  int err = 1;  u = find_unit (*unit);  if (u != NULL)    {      err = stream_ttyname (u->s, name, name_len);      if (err == 0)	{	  nlen = strlen (name);	  memset (&name[nlen], ' ', name_len - nlen);	}      unlock_unit (u);    }  if (err != 0)    memset (name, ' ', name_len);}

voidst_flush (st_parameter_filepos *fpp){  gfc_unit *u;  library_start (&fpp->common);  u = find_unit (fpp->common.unit);  if (u != NULL)    {      /* Make sure format buffer is flushed.  */      if (u->flags.form == FORM_FORMATTED)        fbuf_flush (u, u->mode);      sflush (u->s);      unlock_unit (u);    }  else    /* FLUSH on unconnected unit is illegal: F95 std., 9.3.5. */     generate_error (&fpp->common, LIBERROR_BAD_OPTION,			"Specified UNIT in FLUSH is not connected");  library_end ();}

voidst_endfile (st_parameter_filepos *fpp){  gfc_unit *u;  library_start (&fpp->common);  u = find_unit (fpp->common.unit);  if (u != NULL)    {      if (u->flags.access == ACCESS_DIRECT)	{	  generate_error (&fpp->common, LIBERROR_OPTION_CONFLICT,			  "Cannot perform ENDFILE on a file opened "			  "for DIRECT access");	  goto done;	}      if (u->flags.access == ACCESS_SEQUENTIAL      	  && u->endfile == AFTER_ENDFILE)	{	  generate_error (&fpp->common, LIBERROR_OPTION_CONFLICT,			  "Cannot perform ENDFILE on a file already "			  "positioned after the EOF marker");	  goto done;	}      /* If there are previously written bytes from a write with ADVANCE="no",	 add a record marker before performing the ENDFILE.  */      if (u->previous_nonadvancing_write)	finish_last_advance_record (u);      u->previous_nonadvancing_write = 0;      if (u->current_record)	{	  st_parameter_dt dtp;	  dtp.common = fpp->common;	  memset (&dtp.u.p, 0, sizeof (dtp.u.p));	  dtp.u.p.current_unit = u;	  next_record (&dtp, 1);	}      unit_truncate (u, stell (u->s), &fpp->common);      u->endfile = AFTER_ENDFILE;      if (0 == stell (u->s))        u->flags.position = POSITION_REWIND;    }  else    {      if (fpp->common.unit < 0)	{	  generate_error (&fpp->common, LIBERROR_BAD_OPTION,			  "Bad unit number in statement");	  return;	}      u = find_or_create_unit (fpp->common.unit);      if (u->s == NULL)	{	  /* Open the unit with some default flags.  */	  st_parameter_open opp;	  unit_flags u_flags;	  memset (&u_flags, '/0', sizeof (u_flags));	  u_flags.access = ACCESS_SEQUENTIAL;	  u_flags.action = ACTION_READWRITE;	  /* Is it unformatted?  */	  if (!(fpp->common.flags & (IOPARM_DT_HAS_FORMAT | IOPARM_DT_LIST_FORMAT				     | IOPARM_DT_IONML_SET)))	    u_flags.form = FORM_UNFORMATTED;	  else	    u_flags.form = FORM_UNSPECIFIED;	  u_flags.delim = DELIM_UNSPECIFIED;	  u_flags.blank = BLANK_UNSPECIFIED;	  u_flags.pad = PAD_UNSPECIFIED;	  u_flags.decimal = DECIMAL_UNSPECIFIED;	  u_flags.encoding = ENCODING_UNSPECIFIED;	  u_flags.async = ASYNC_UNSPECIFIED;	  u_flags.round = ROUND_UNSPECIFIED;	  u_flags.sign = SIGN_UNSPECIFIED;	  u_flags.status = STATUS_UNKNOWN;	  u_flags.convert = GFC_CONVERT_NATIVE;	  opp.common = fpp->common;	  opp.common.flags &= IOPARM_COMMON_MASK;	  u = new_unit (&opp, u, &u_flags);	  if (u == NULL)	    return;	  u->endfile = AFTER_ENDFILE;	}    }  done:    unlock_unit (u);  library_end ();//.........这里部分代码省略.........

//.........这里部分代码省略.........  flags.position = !(cf & IOPARM_OPEN_HAS_POSITION) ? POSITION_UNSPECIFIED :    find_option (&opp->common, opp->position, opp->position_len,		 position_opt, "Bad POSITION parameter in OPEN statement");  flags.status = !(cf & IOPARM_OPEN_HAS_STATUS) ? STATUS_UNSPECIFIED :    find_option (&opp->common, opp->status, opp->status_len,		 status_opt, "Bad STATUS parameter in OPEN statement");  /* First, we check wether the convert flag has been set via environment     variable.  This overrides the convert tag in the open statement.  */  conv = get_unformatted_convert (opp->common.unit);  if (conv == GFC_CONVERT_NONE)    {      /* Nothing has been set by environment variable, check the convert tag.  */      if (cf & IOPARM_OPEN_HAS_CONVERT)	conv = find_option (&opp->common, opp->convert, opp->convert_len,			    convert_opt,			    "Bad CONVERT parameter in OPEN statement");      else	conv = compile_options.convert;    }    /* We use big_endian, which is 0 on little-endian machines     and 1 on big-endian machines.  */  switch (conv)    {    case GFC_CONVERT_NATIVE:    case GFC_CONVERT_SWAP:      break;          case GFC_CONVERT_BIG:      conv = big_endian ? GFC_CONVERT_NATIVE : GFC_CONVERT_SWAP;      break;          case GFC_CONVERT_LITTLE:      conv = big_endian ? GFC_CONVERT_SWAP : GFC_CONVERT_NATIVE;      break;          default:      internal_error (&opp->common, "Illegal value for CONVERT");      break;    }  flags.convert = conv;  if (flags.position != POSITION_UNSPECIFIED      && flags.access == ACCESS_DIRECT)    generate_error (&opp->common, LIBERROR_BAD_OPTION,		    "Cannot use POSITION with direct access files");  if (flags.access == ACCESS_APPEND)    {      if (flags.position != POSITION_UNSPECIFIED	  && flags.position != POSITION_APPEND)	generate_error (&opp->common, LIBERROR_BAD_OPTION,			"Conflicting ACCESS and POSITION flags in"			" OPEN statement");      notify_std (&opp->common, GFC_STD_GNU,		  "Extension: APPEND as a value for ACCESS in OPEN statement");      flags.access = ACCESS_SEQUENTIAL;      flags.position = POSITION_APPEND;    }  if (flags.position == POSITION_UNSPECIFIED)    flags.position = POSITION_ASIS;  if ((opp->common.flags & IOPARM_LIBRETURN_MASK) == IOPARM_LIBRETURN_OK)    {      if ((opp->common.flags & IOPARM_OPEN_HAS_NEWUNIT))	opp->common.unit = get_unique_unit_number(opp);      else if (opp->common.unit < 0)	{	  u = find_unit (opp->common.unit);	  if (u == NULL) /* Negative unit and no NEWUNIT-created unit found.  */	    generate_error (&opp->common, LIBERROR_BAD_OPTION,			    "Bad unit number in OPEN statement");	}      if (u == NULL)	u = find_or_create_unit (opp->common.unit);      if (u->s == NULL)	{	  u = new_unit (opp, u, &flags);	  if (u != NULL)	    unlock_unit (u);	}      else	already_open (opp, u, &flags);    }      if ((opp->common.flags & IOPARM_OPEN_HAS_NEWUNIT)      && (opp->common.flags & IOPARM_LIBRETURN_MASK) == IOPARM_LIBRETURN_OK)    *opp->newunit = opp->common.unit;    library_end ();}

//.........这里部分代码省略.........	}      generate_error (&opp->common, LIBERROR_BAD_OPTION,		      "FILE parameter must not be present in OPEN statement");      goto fail;    case STATUS_OLD:    case STATUS_NEW:    case STATUS_REPLACE:    case STATUS_UNKNOWN:      if ((opp->common.flags & IOPARM_OPEN_HAS_FILE))	break;      opp->file = tmpname;      opp->file_len = snprintf(opp->file, sizeof (tmpname), "fort.%d", 			       (int) opp->common.unit);      break;    default:      internal_error (&opp->common, "new_unit(): Bad status");    }  /* Make sure the file isn't already open someplace else.     Do not error if opening file preconnected to stdin, stdout, stderr.  */  u2 = NULL;  if ((opp->common.flags & IOPARM_OPEN_HAS_FILE) != 0)    u2 = find_file (opp->file, opp->file_len);  if (u2 != NULL      && (options.stdin_unit < 0 || u2->unit_number != options.stdin_unit)      && (options.stdout_unit < 0 || u2->unit_number != options.stdout_unit)      && (options.stderr_unit < 0 || u2->unit_number != options.stderr_unit))    {      unlock_unit (u2);      generate_error (&opp->common, LIBERROR_ALREADY_OPEN, NULL);      goto cleanup;    }  if (u2 != NULL)    unlock_unit (u2);  /* Open file.  */  s = open_external (opp, flags);  if (s == NULL)    {      char *path, *msg;      size_t msglen;      path = (char *) gfc_alloca (opp->file_len + 1);      msglen = opp->file_len + 51;      msg = (char *) gfc_alloca (msglen);      unpack_filename (path, opp->file, opp->file_len);      switch (errno)	{	case ENOENT: 	  snprintf (msg, msglen, "File '%s' does not exist", path);	  break;	case EEXIST:	  snprintf (msg, msglen, "File '%s' already exists", path);	  break;	case EACCES:	  snprintf (msg, msglen, 		    "Permission denied trying to open file '%s'", path);

//.........这里部分代码省略.........		    "OPEN statement must have a STATUS of OLD or UNKNOWN");      else	generate_error (&opp->common, LIBERROR_BAD_OPTION,		    "OPEN statement must have a STATUS of OLD or UNKNOWN");    }  if (u->flags.form == FORM_UNFORMATTED)    {      if (flags->delim != DELIM_UNSPECIFIED)	generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,			"DELIM parameter conflicts with UNFORMATTED form in "			"OPEN statement");      if (flags->blank != BLANK_UNSPECIFIED)	generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,			"BLANK parameter conflicts with UNFORMATTED form in "			"OPEN statement");      if (flags->pad != PAD_UNSPECIFIED)	generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,			"PAD parameter conflicts with UNFORMATTED form in "			"OPEN statement");      if (flags->decimal != DECIMAL_UNSPECIFIED)	generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,			"DECIMAL parameter conflicts with UNFORMATTED form in "			"OPEN statement");      if (flags->encoding != ENCODING_UNSPECIFIED)	generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,			"ENCODING parameter conflicts with UNFORMATTED form in "			"OPEN statement");      if (flags->round != ROUND_UNSPECIFIED)	generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,			"ROUND parameter conflicts with UNFORMATTED form in "			"OPEN statement");      if (flags->sign != SIGN_UNSPECIFIED)	generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,			"SIGN parameter conflicts with UNFORMATTED form in "			"OPEN statement");    }  if ((opp->common.flags & IOPARM_LIBRETURN_MASK) == IOPARM_LIBRETURN_OK)    {      /* Change the changeable:  */      if (flags->blank != BLANK_UNSPECIFIED)	u->flags.blank = flags->blank;      if (flags->delim != DELIM_UNSPECIFIED)	u->flags.delim = flags->delim;      if (flags->pad != PAD_UNSPECIFIED)	u->flags.pad = flags->pad;      if (flags->decimal != DECIMAL_UNSPECIFIED)	u->flags.decimal = flags->decimal;      if (flags->encoding != ENCODING_UNSPECIFIED)	u->flags.encoding = flags->encoding;      if (flags->async != ASYNC_UNSPECIFIED)	u->flags.async = flags->async;      if (flags->round != ROUND_UNSPECIFIED)	u->flags.round = flags->round;      if (flags->sign != SIGN_UNSPECIFIED)	u->flags.sign = flags->sign;    }  /* Reposition the file if necessary.  */  switch (flags->position)    {    case POSITION_UNSPECIFIED:    case POSITION_ASIS:      break;    case POSITION_REWIND:      if (sseek (u->s, 0, SEEK_SET) != 0)	goto seek_error;      u->current_record = 0;      u->last_record = 0;      test_endfile (u);      break;    case POSITION_APPEND:      if (sseek (u->s, 0, SEEK_END) < 0)	goto seek_error;      if (flags->access != ACCESS_STREAM)	u->current_record = 0;      u->endfile = AT_ENDFILE;	/* We are at the end.  */      break;    seek_error:      generate_error (&opp->common, LIBERROR_OS, NULL);      break;    }  unlock_unit (u);}

voidst_backspace (st_parameter_filepos *fpp){  gfc_unit *u;  library_start (&fpp->common);  u = find_unit (fpp->common.unit);  if (u == NULL)    {      generate_error (&fpp->common, LIBERROR_BAD_UNIT, NULL);      goto done;    }  /* Direct access is prohibited, and so is unformatted stream access.  */  if (u->flags.access == ACCESS_DIRECT)    {      generate_error (&fpp->common, LIBERROR_OPTION_CONFLICT,		      "Cannot BACKSPACE a file opened for DIRECT access");      goto done;    }  if (u->flags.access == ACCESS_STREAM && u->flags.form == FORM_UNFORMATTED)    {      generate_error (&fpp->common, LIBERROR_OPTION_CONFLICT,                      "Cannot BACKSPACE an unformatted stream file");      goto done;    }  /* Make sure format buffer is flushed and reset.  */  if (u->flags.form == FORM_FORMATTED)    {      int pos = fbuf_reset (u);      if (pos != 0)        sseek (u->s, pos, SEEK_CUR);    }    /* Check for special cases involving the ENDFILE record first.  */  if (u->endfile == AFTER_ENDFILE)    {      u->endfile = AT_ENDFILE;      u->flags.position = POSITION_APPEND;      sflush (u->s);    }  else    {      if (stell (u->s) == 0)	{	  u->flags.position = POSITION_REWIND;	  goto done;		/* Common special case */	}      if (u->mode == WRITING)	{	  /* If there are previously written bytes from a write with	     ADVANCE="no", add a record marker before performing the	     BACKSPACE.  */	  if (u->previous_nonadvancing_write)	    finish_last_advance_record (u);	  u->previous_nonadvancing_write = 0;	  unit_truncate (u, stell (u->s), &fpp->common);	  u->mode = READING;        }      if (u->flags.form == FORM_FORMATTED)	formatted_backspace (fpp, u);      else	unformatted_backspace (fpp, u);      u->flags.position = POSITION_UNSPECIFIED;      u->endfile = NO_ENDFILE;      u->current_record = 0;      u->bytes_left = 0;    } done:  if (u != NULL)    unlock_unit (u);  library_end ();}