xsmfns.c 15.9 KB
Newer Older
1 2
/* Session management module for systems which understand the X Session
   management protocol.
3
   Copyright (C) 2002, 2002 Free Software Foundation, Inc.
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

This file is part of GNU Emacs.

GNU Emacs 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, or (at your option)
any later version.

GNU Emacs 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 GNU Emacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include <config.h>

#ifdef HAVE_X_SM

#include <X11/SM/SMlib.h>
#ifdef HAVE_STRING_H
#include <string.h>
#else
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#endif

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif

#include <sys/param.h>
43
#include <stdio.h>
44 45 46 47 48

#include "systime.h"
#include "sysselect.h"
#include "lisp.h"
#include "termhooks.h"
49
#include "termopts.h"
50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491

#ifndef MAXPATHLEN
#define MAXPATHLEN 1024
#endif /* not MAXPATHLEN */


/* The user login name.  */

extern Lisp_Object Vuser_login_name;

/* This is the event used when save_session occurs */

static struct input_event emacs_event;

/* The descriptor that we use to check for data from the session manager. */

static int ice_fd = -1;

/* A flag that says if we are in shutdown interactions or not. */

static int doing_interact = False;

/* The session manager object for the session manager connection */

static SmcConn smc_conn;

/* The client session id for this session */
static char *client_id;

/* The full path name to the Emacs program */
static char *emacs_program;

/* The client session id for this session as a lisp object. */

Lisp_Object Vx_session_id;

/* The id we had the previous session.  This is only available if we
   have been started by the session manager with SMID_OPT. */

Lisp_Object Vx_session_previous_id;

/* The option we tell the session manager to start Emacs with when
   restarting Emacs.  The client_id is appended. */

#define SMID_OPT "--smid="


/* Handle any messages from the session manager.  If no connection is
   open to a session manager, just return 0.
   Otherwise returns the number of events stored in buffer BUFP,
   which can hold up to *NUMCHARS characters.  At most one event is
   stored, an save_session_event. */
int
x_session_check_input (bufp, numchars)
     struct input_event *bufp;
     int *numchars;
{
  SELECT_TYPE read_fds;
  EMACS_TIME tmout;
  
  if (ice_fd == -1) return 0;
  
  FD_ZERO (&read_fds);
  FD_SET (ice_fd, &read_fds);
      
  tmout.tv_sec = 0;
  tmout.tv_usec = 0;
  
  /* Reset this so wo can check kind after callbacks have been called by
     IceProcessMessages.  The smc_interact_CB sets the kind to
     save_session_event, but we don't know beforehand if that callback
     will be called. */
  emacs_event.kind = no_event;

  if (select (ice_fd+1, &read_fds,
              (SELECT_TYPE *)0, (SELECT_TYPE *)0, &tmout) < 0)
    {
      ice_fd = -1;
      return 0;
    }
  

  if (FD_ISSET (ice_fd, &read_fds))
    IceProcessMessages (SmcGetIceConnection (smc_conn),
                        (IceReplyWaitInfo *)0, (Bool *)0);

  
  /* Check if smc_interact_CB was called and we shall generate a
     save_session event. */
  if (*numchars > 0 && emacs_event.kind != no_event)
    {
      bcopy (&emacs_event, bufp, sizeof (struct input_event));
      bufp++;
      (*numchars)--;

      return 1;
    }

  return 0;
}

/* Return non-zero if we have a connection to a session manager.*/
int
x_session_have_connection ()
{
  return ice_fd != -1;
}

/* This is called when the session manager says it is OK to interact with the
   user.  Here we set the kind to save_session so an event is generated.
   Then lisp code can interact with the user. */
static void
smc_interact_CB (smcConn, clientData)
     SmcConn smcConn;
     SmPointer clientData;
{
  doing_interact = True;
  emacs_event.kind = save_session_event;
}

/* This is called when the session manager tells us to save ourself.
   We set the required properties so the session manager can restart us,
   plus the current working directory property (not mandatory) so we
   are started in the correct directory.

   If this is a shutdown and we can request to interact with the user,
   we do so, because we don't know what the lisp code might do. */
static void
smc_save_yourself_CB (smcConn,
                      clientData,
                      saveType,
                      shutdown,
                      interactStyle,
                      fast)
     SmcConn smcConn;
     SmPointer clientData;
     int saveType;
     Bool shutdown;
     int interactStyle;
     Bool fast;
{
#define NR_PROPS 5
  
  SmProp *props[NR_PROPS];
  SmProp prop_ptr[NR_PROPS];
  
  SmPropValue values[20];
  int val_idx = 0;
  int props_idx = 0;
  
  char cwd[MAXPATHLEN+1];
  char *smid_opt;

  /* How to start a new instance of Emacs */
  props[props_idx] = &prop_ptr[props_idx];
  props[props_idx]->name = SmCloneCommand;
  props[props_idx]->type = SmLISTofARRAY8;
  props[props_idx]->num_vals = 1;
  props[props_idx]->vals = &values[val_idx++];
  props[props_idx]->vals[0].length = strlen (emacs_program);
  props[props_idx]->vals[0].value = emacs_program;
  ++props_idx;

  /* The name of the program */
  props[props_idx] = &prop_ptr[props_idx];
  props[props_idx]->name = SmProgram;
  props[props_idx]->type = SmARRAY8;
  props[props_idx]->num_vals = 1;
  props[props_idx]->vals = &values[val_idx++];
  props[props_idx]->vals[0].length = strlen (XSTRING (Vinvocation_name)->data);
  props[props_idx]->vals[0].value = XSTRING (Vinvocation_name)->data;
  ++props_idx;
  
  /* How to restart Emacs (i.e.: /path/to/emacs --smid=xxxx). */
  props[props_idx] = &prop_ptr[props_idx];
  props[props_idx]->name = SmRestartCommand;
  props[props_idx]->type = SmLISTofARRAY8;
  props[props_idx]->num_vals = 2; /* 2 values: /path/to/emacs, --smid=xxx */
  props[props_idx]->vals = &values[val_idx];
  props[props_idx]->vals[0].length = strlen (emacs_program);
  props[props_idx]->vals[0].value = emacs_program;

  smid_opt = xmalloc (strlen (SMID_OPT) + strlen (client_id) + 1);
  strcpy (smid_opt, SMID_OPT);
  strcat (smid_opt, client_id);
  
  props[props_idx]->vals[1].length = strlen (smid_opt);
  props[props_idx]->vals[1].value = smid_opt;
  val_idx += 2;
  ++props_idx;

  /* User id */
  props[props_idx] = &prop_ptr[props_idx];
  props[props_idx]->name = SmUserID;
  props[props_idx]->type = SmARRAY8;
  props[props_idx]->num_vals = 1;
  props[props_idx]->vals = &values[val_idx++];
  props[props_idx]->vals[0].length = strlen (XSTRING (Vuser_login_name)->data);
  props[props_idx]->vals[0].value = XSTRING (Vuser_login_name)->data;
  ++props_idx;

  /* The current directory property, not mandatory */
#ifdef HAVE_GETCWD
  if (getcwd (cwd, MAXPATHLEN+1) != 0)
#else
  if (getwd (cwd) != 0)
#endif
    {
      props[props_idx] = &prop_ptr[props_idx];
      props[props_idx]->name = SmCurrentDirectory;
      props[props_idx]->type = SmARRAY8;
      props[props_idx]->num_vals = 1;
      props[props_idx]->vals = &values[val_idx++];
      props[props_idx]->vals[0].length = strlen (cwd);
      props[props_idx]->vals[0].value = cwd;
      ++props_idx;
    }
  
  
  SmcSetProperties (smcConn, props_idx, props);

  xfree (smid_opt);

  /* See if we maybe shall interact with the user. */
  if (interactStyle != SmInteractStyleAny
      || ! shutdown
      || saveType == SmSaveLocal
      || ! SmcInteractRequest (smcConn, SmDialogNormal, smc_interact_CB, 0))
    {
      /* No interaction, we are done saving ourself. */
      SmcSaveYourselfDone (smcConn, True);
    }
}

/* According to the SM specification, this shall close the connection */
static void
smc_die_CB (smcConn, clientData)
     SmcConn smcConn;
     SmPointer clientData;
{
  SmcCloseConnection (smcConn, 0, 0);
  ice_fd = -1;
}

/* We don't use the next two but they are mandatory, leave them empty.
   According to the SM specification, we should not interact with the
   user between smc_save_yourself_CB is called and until smc_save_complete_CB
   is called.  It seems like a lot of job to implement this and it doesn't
   even seem necessary. */
static void
smc_save_complete_CB (smcConn, clientData)
     SmcConn smcConn;
     SmPointer clientData;
{
  /* Empty */
}

static void
smc_shutdown_cancelled_CB (smcConn, clientData)
     SmcConn smcConn;
     SmPointer clientData;
{
  /* Empty */
}

/* Error handlers for SM and ICE.  We don't wan't to exit Emacs just
   because there is some error in the session management. */
static void
smc_error_handler (smcConn,
                   swap,
                   offendingMinorOpcode,
                   offendingSequence,
                   errorClass,
                   severity,
                   values)
     SmcConn smcConn;
     Bool swap;
     int offendingMinorOpcode;
     unsigned long offendingSequence;
     int errorClass;
     int severity;
     SmPointer values;
{
  /* Empty */
}

static void
ice_error_handler (iceConn,
                   swap,
                   offendingMinorOpcode,
                   offendingSequence,
                   errorClass,
                   severity,
                   values)
     IceConn iceConn;
     Bool swap;
     int offendingMinorOpcode;
     unsigned long offendingSequence;
     int errorClass;
     int severity;
     IcePointer values;
{
  /* Empty */
}


static void
ice_io_error_handler (iceConn)
     IceConn iceConn;
{
  /* Connection probably gone. */
  ice_fd = -1;
}

/* This is called when the ICE connection is created or closed.  The SM library
   uses ICE as it transport protocol. */
static void
ice_conn_watch_CB (iceConn, clientData, opening, watchData)
     IceConn iceConn;
     IcePointer clientData;
     Bool opening;
     IcePointer *watchData;
{
  if (! opening)
    {
      ice_fd = -1;
      return;
    }
  
  ice_fd = IceConnectionNumber (iceConn);
#ifndef F_SETOWN_BUG
#ifdef F_SETOWN
#ifdef F_SETOWN_SOCK_NEG
  /* stdin is a socket here */
  fcntl (ice_fd, F_SETOWN, -getpid ());
#else /* ! defined (F_SETOWN_SOCK_NEG) */
  fcntl (ice_fd, F_SETOWN, getpid ());
#endif /* ! defined (F_SETOWN_SOCK_NEG) */
#endif /* ! defined (F_SETOWN) */
#endif /* F_SETOWN_BUG */

#ifdef SIGIO
  if (interrupt_input)
    init_sigio (ice_fd);
#endif /* ! defined (SIGIO) */
}

/* Try to open a connection to the session manager. */
void
x_session_initialize ()
{
#define SM_ERRORSTRING_LEN 512
  char errorstring[SM_ERRORSTRING_LEN];
  char* previous_id = NULL;
  SmcCallbacks callbacks;
  int  name_len = 0;
  
  /* Check if we where started by the session manager.  If so, we will
     have a previous id. */
  if (! EQ (Vx_session_previous_id, Qnil) && STRINGP (Vx_session_previous_id))
    previous_id = XSTRING (Vx_session_previous_id)->data;

  /* Construct the path to the Emacs program. */
  if (! EQ (Vinvocation_directory, Qnil))
    name_len += strlen (XSTRING (Vinvocation_directory)->data);
  name_len += strlen (XSTRING (Vinvocation_name)->data);

  /* This malloc will not be freed, but it is only done once, and hopefully
     not very large  */
  emacs_program = xmalloc (name_len + 1);
  emacs_program[0] = '\0';

  if (! EQ (Vinvocation_directory, Qnil))
    strcpy (emacs_program, XSTRING (Vinvocation_directory)->data);
  strcat (emacs_program, XSTRING (Vinvocation_name)->data);
  
  /* The SM protocol says all callbacks are mandatory, so set up all
     here and in the mask passed to SmcOpenConnection */
  callbacks.save_yourself.callback = smc_save_yourself_CB;
  callbacks.save_yourself.client_data = 0;
  callbacks.die.callback = smc_die_CB;
  callbacks.die.client_data = 0;
  callbacks.save_complete.callback = smc_save_complete_CB;
  callbacks.save_complete.client_data = 0;
  callbacks.shutdown_cancelled.callback = smc_shutdown_cancelled_CB;
  callbacks.shutdown_cancelled.client_data = 0;

  /* Set error handlers. */
  SmcSetErrorHandler (smc_error_handler);
  IceSetErrorHandler (ice_error_handler);
  IceSetIOErrorHandler (ice_io_error_handler);

  /* Install callback for when connection status changes. */
  IceAddConnectionWatch (ice_conn_watch_CB, 0);

  /* Open the connection to the session manager.  A failure is not
     critical, it usualy means that no session manager is running.
     The errorstring is here for debugging. */
  smc_conn = SmcOpenConnection (NULL, NULL, 1, 0,
                                (SmcSaveYourselfProcMask|
                                 SmcDieProcMask|
                                 SmcSaveCompleteProcMask|
                                 SmcShutdownCancelledProcMask),
                                &callbacks,
                                previous_id,
                                &client_id,
                                SM_ERRORSTRING_LEN,
                                errorstring);

  if (smc_conn != 0)
    Vx_session_id = make_string (client_id, strlen (client_id));
}


DEFUN ("handle-save-session", Fhandle_save_session,
       Shandle_save_session, 1, 1, "e",
       doc: /* Handle the save_yourself event from a session manager.
A session manager can tell Emacs that the window system is shutting down 
by sending Emacs a save_yourself message.  Emacs executes this function when
such an event occurs.  This function then executes `emacs-session-save'.
After that, this function informs the session manager that it can continue
or abort shutting down the window system depending on the return value
from `emacs-session-save'  If the return value is non-nil the session manager
is told to abort the window system shutdown.

Do not call this function yourself. */)
     (event)
     Lisp_Object event;
{
  /* Check doing_interact so that we don't do anything if someone called
     this at the wrong time. */
  if (doing_interact)
    {
      Bool cancel_shutdown = False;

      cancel_shutdown = ! EQ (call0 (intern ("emacs-session-save")), Qnil);

      SmcInteractDone (smc_conn, cancel_shutdown);
      SmcSaveYourselfDone (smc_conn, True);

      doing_interact = False;
    }
492 493

  return Qnil;
494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537
}


/***********************************************************************
			    Initialization
 ***********************************************************************/
void
syms_of_xsmfns ()
{
  DEFVAR_LISP ("x-session-id", &Vx_session_id,
    doc: /* The session id Emacs got from the session manager for this session.
Changing the value does not change the session id used by Emacs.
The value is nil if no session manager is running.
See also `x-session-previous-id', `emacs-save-session-functions',
`emacs-session-save' and `emacs-session-restore'." */);
  Vx_session_id = Qnil;

  DEFVAR_LISP ("x-session-previous-id", &Vx_session_previous_id,
    doc: /* The previous session id Emacs got from session manager.
If Emacs is running on a window system that has a session manager, the 
session manager gives Emacs a session id.  It is feasible for Emacs lisp 
code to use the session id to save configuration in, for example, a file 
with a file name based on the session id.  If Emacs is running when the 
window system is shut down, the session manager remembers that Emacs was 
running and saves the session id Emacs had.

When the window system is started again, the session manager restarts 
Emacs and hands Emacs the session id it had the last time it was 
running.  This is now the previous session id and the value of this 
variable.  If configuration was saved in a file as stated above, the 
previous session id shall be used to reconstruct the file name.

The session id Emacs has while it is running is in the variable 
`x-session-id'.  The value of this variable and `x-session-id' may be the
same, depending on how the session manager works.

See also `emacs-save-session-functions', `emacs-session-save' and
`emacs-session-restore'." */);
  Vx_session_previous_id = Qnil;
  
  defsubr (&Shandle_save_session);
}

#endif /* HAVE_X_SM */