src/xsmfns.c

   1 /* Session management module for systems which understand the X Session
   2    management protocol.
   3    Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008
   4      Free Software Foundation, Inc.
   5
   6 This file is part of GNU Emacs.
   7
   8 GNU Emacs is free software: you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation, either version 3 of the License, or
  11 (at your option) any later version.
  12
  13 GNU Emacs is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include <config.h>
  22
  23 #ifdef HAVE_X_SM
  24
  25 #include <X11/SM/SMlib.h>
  26 #include <X11/Xlib.h>
  27 #include <X11/Xutil.h>
  28
  29 #ifdef HAVE_STRING_H
  30 #include <string.h>
  31 #else
  32 #ifdef HAVE_STRINGS_H
  33 #include <strings.h>
  34 #endif
  35 #endif
  36
  37 #ifdef HAVE_UNISTD_H
  38 #include <unistd.h>
  39 #endif
  40 #ifdef HAVE_STDLIB_H
  41 #include <stdlib.h>
  42 #endif
  43
  44 #include <sys/param.h>
  45 #include <stdio.h>
  46
  47 #include "lisp.h"
  48 #include "systime.h"
  49 #include "sysselect.h"
  50 #include "frame.h"
  51 #include "termhooks.h"
  52 #include "termopts.h"
  53 #include "xterm.h"
  54
  55 /* The user login name.  */
  56
  57 extern Lisp_Object Vuser_login_name;
  58
  59 /* This is the event used when SAVE_SESSION_EVENT occurs.  */
  60
  61 static struct input_event emacs_event;
  62
  63 /* The descriptor that we use to check for data from the session manager.  */
  64
  65 static int ice_fd = -1;
  66
  67 /* A flag that says if we are in shutdown interactions or not.  */
  68
  69 static int doing_interact = False;
  70
  71 /* The session manager object for the session manager connection.  */
  72
  73 static SmcConn smc_conn;
  74
  75 /* The client session id for this session.  */
  76
  77 static char *client_id;
  78
  79 /* The full path name to the Emacs program.  */
  80
  81 static char *emacs_program;
  82
  83 /* The client session id for this session as a lisp object.  */
  84
  85 Lisp_Object Vx_session_id;
  86
  87 /* The id we had the previous session.  This is only available if we
  88    have been started by the session manager with SMID_OPT.  */
  89
  90 Lisp_Object Vx_session_previous_id;
  91
  92 /* The option we tell the session manager to start Emacs with when
  93    restarting Emacs.  The client_id is appended.  */
  94
  95 #define SMID_OPT "--smid="
  96
  97
  98 /* The option to start Emacs without the splash screen when
  99    restarting Emacs.  */
 100
 101 #define NOSPLASH_OPT "--no-splash"
 102
 103
 104 /* Handle any messages from the session manager.  If no connection is
 105    open to a session manager, just return 0.
 106    Otherwise returns 1 if SAVE_SESSION_EVENT is stored in buffer BUFP.  */
 107
 108 int
 109 x_session_check_input (bufp)
 110      struct input_event *bufp;
 111 {
 112   SELECT_TYPE read_fds;
 113   EMACS_TIME tmout;
 114
 115   if (ice_fd == -1) return 0;
 116
 117   FD_ZERO (&read_fds);
 118   FD_SET (ice_fd, &read_fds);
 119
 120   tmout.tv_sec = 0;
 121   tmout.tv_usec = 0;
 122
 123   /* Reset this so wo can check kind after callbacks have been called by
 124      IceProcessMessages.  The smc_interact_CB sets the kind to
 125      SAVE_SESSION_EVENT, but we don't know beforehand if that callback
 126      will be called.  */
 127   emacs_event.kind = NO_EVENT;
 128
 129   if (select (ice_fd+1, &read_fds,
 130               (SELECT_TYPE *)0, (SELECT_TYPE *)0, &tmout) < 0)
 131     {
 132       ice_fd = -1;
 133       return 0;
 134     }
 135
 136
 137   if (FD_ISSET (ice_fd, &read_fds))
 138     IceProcessMessages (SmcGetIceConnection (smc_conn),
 139                         (IceReplyWaitInfo *)0, (Bool *)0);
 140
 141
 142   /* Check if smc_interact_CB was called and we shall generate a
 143      SAVE_SESSION_EVENT.  */
 144   if (emacs_event.kind == NO_EVENT)
 145     return 0;
 146
 147   bcopy (&emacs_event, bufp, sizeof (struct input_event));
 148   return 1;
 149 }
 150
 151 /* Return non-zero if we have a connection to a session manager.  */
 152
 153 int
 154 x_session_have_connection ()
 155 {
 156   return ice_fd != -1;
 157 }
 158
 159 /* This is called when the session manager says it is OK to interact with the
 160    user.  Here we set the kind to SAVE_SESSION_EVENT so an event is generated.
 161    Then lisp code can interact with the user.  */
 162
 163 static void
 164 smc_interact_CB (smcConn, clientData)
 165      SmcConn smcConn;
 166      SmPointer clientData;
 167 {
 168   doing_interact = True;
 169   emacs_event.kind = SAVE_SESSION_EVENT;
 170 }
 171
 172 /* This is called when the session manager tells us to save ourselves.
 173    We set the required properties so the session manager can restart us,
 174    plus the current working directory property (not mandatory) so we
 175    are started in the correct directory.
 176
 177    If this is a shutdown and we can request to interact with the user,
 178    we do so, because we don't know what the lisp code might do.  */
 179
 180 static void
 181 smc_save_yourself_CB (smcConn,
 182                       clientData,
 183                       saveType,
 184                       shutdown,
 185                       interactStyle,
 186                       fast)
 187      SmcConn smcConn;
 188      SmPointer clientData;
 189      int saveType;
 190      Bool shutdown;
 191      int interactStyle;
 192      Bool fast;
 193 {
 194 #define NR_PROPS 5
 195
 196   SmProp *props[NR_PROPS];
 197   SmProp prop_ptr[NR_PROPS];
 198
 199   SmPropValue values[20];
 200   int val_idx = 0;
 201   int props_idx = 0;
 202
 203   char *cwd = NULL;
 204   char *smid_opt;
 205
 206   /* How to start a new instance of Emacs.  */
 207   props[props_idx] = &prop_ptr[props_idx];
 208   props[props_idx]->name = SmCloneCommand;
 209   props[props_idx]->type = SmLISTofARRAY8;
 210   props[props_idx]->num_vals = 1;
 211   props[props_idx]->vals = &values[val_idx++];
 212   props[props_idx]->vals[0].length = strlen (emacs_program);
 213   props[props_idx]->vals[0].value = emacs_program;
 214   ++props_idx;
 215
 216   /* The name of the program.  */
 217   props[props_idx] = &prop_ptr[props_idx];
 218   props[props_idx]->name = SmProgram;
 219   props[props_idx]->type = SmARRAY8;
 220   props[props_idx]->num_vals = 1;
 221   props[props_idx]->vals = &values[val_idx++];
 222   props[props_idx]->vals[0].length = strlen (SDATA (Vinvocation_name));
 223   props[props_idx]->vals[0].value = SDATA (Vinvocation_name);
 224   ++props_idx;
 225
 226   /* How to restart Emacs (i.e.: /path/to/emacs --smid=xxxx --no-splash).  */
 227   props[props_idx] = &prop_ptr[props_idx];
 228   props[props_idx]->name = SmRestartCommand;
 229   props[props_idx]->type = SmLISTofARRAY8;
 230   props[props_idx]->num_vals = 3; /* /path/to/emacs, --smid=xxx --no-splash  */
 231   props[props_idx]->vals = &values[val_idx];
 232   props[props_idx]->vals[0].length = strlen (emacs_program);
 233   props[props_idx]->vals[0].value = emacs_program;
 234
 235   smid_opt = xmalloc (strlen (SMID_OPT) + strlen (client_id) + 1);
 236   strcpy (smid_opt, SMID_OPT);
 237   strcat (smid_opt, client_id);
 238
 239   props[props_idx]->vals[1].length = strlen (smid_opt);
 240   props[props_idx]->vals[1].value = smid_opt;
 241
 242   props[props_idx]->vals[2].length = strlen (NOSPLASH_OPT);
 243   props[props_idx]->vals[2].value = NOSPLASH_OPT;
 244   val_idx += 3;
 245   ++props_idx;
 246
 247   /* User id.  */
 248   props[props_idx] = &prop_ptr[props_idx];
 249   props[props_idx]->name = SmUserID;
 250   props[props_idx]->type = SmARRAY8;
 251   props[props_idx]->num_vals = 1;
 252   props[props_idx]->vals = &values[val_idx++];
 253   props[props_idx]->vals[0].length = strlen (SDATA (Vuser_login_name));
 254   props[props_idx]->vals[0].value = SDATA (Vuser_login_name);
 255   ++props_idx;
 256
 257   cwd = get_current_dir_name ();
 258
 259   if (cwd)
 260     {
 261       props[props_idx] = &prop_ptr[props_idx];
 262       props[props_idx]->name = SmCurrentDirectory;
 263       props[props_idx]->type = SmARRAY8;
 264       props[props_idx]->num_vals = 1;
 265       props[props_idx]->vals = &values[val_idx++];
 266       props[props_idx]->vals[0].length = strlen (cwd);
 267       props[props_idx]->vals[0].value = cwd;
 268       ++props_idx;
 269     }
 270
 271
 272   SmcSetProperties (smcConn, props_idx, props);
 273
 274   xfree (smid_opt);
 275
 276   if (cwd)
 277     free (cwd);
 278
 279   /* See if we maybe shall interact with the user.  */
 280   if (interactStyle != SmInteractStyleAny
 281       || ! shutdown
 282       || saveType == SmSaveLocal
 283       || ! SmcInteractRequest (smcConn, SmDialogNormal, smc_interact_CB, 0))
 284     {
 285       /* No interaction, we are done saving ourself.  */
 286       SmcSaveYourselfDone (smcConn, True);
 287     }
 288 }
 289
 290 /* According to the SM specification, this shall close the connection.  */
 291
 292 static void
 293 smc_die_CB (smcConn, clientData)
 294      SmcConn smcConn;
 295      SmPointer clientData;
 296 {
 297   SmcCloseConnection (smcConn, 0, 0);
 298   ice_fd = -1;
 299 }
 300
 301 /* We don't use the next two but they are mandatory, leave them empty.
 302    According to the SM specification, we should not interact with the
 303    user between smc_save_yourself_CB is called and until smc_save_complete_CB
 304    is called.  It seems like a lot of job to implement this and it doesn't
 305    even seem necessary.  */
 306
 307 static void
 308 smc_save_complete_CB (smcConn, clientData)
 309      SmcConn smcConn;
 310      SmPointer clientData;
 311 {
 312   /* Empty */
 313 }
 314
 315 static void
 316 smc_shutdown_cancelled_CB (smcConn, clientData)
 317      SmcConn smcConn;
 318      SmPointer clientData;
 319 {
 320   /* Empty */
 321 }
 322
 323 /* Error handlers for SM and ICE.  We don't want to exit Emacs just
 324    because there is some error in the session management.  */
 325
 326 static void
 327 smc_error_handler (smcConn,
 328                    swap,
 329                    offendingMinorOpcode,
 330                    offendingSequence,
 331                    errorClass,
 332                    severity,
 333                    values)
 334      SmcConn smcConn;
 335      Bool swap;
 336      int offendingMinorOpcode;
 337      unsigned long offendingSequence;
 338      int errorClass;
 339      int severity;
 340      SmPointer values;
 341 {
 342   /* Empty  */
 343 }
 344
 345 static void
 346 ice_error_handler (iceConn,
 347                    swap,
 348                    offendingMinorOpcode,
 349                    offendingSequence,
 350                    errorClass,
 351                    severity,
 352                    values)
 353      IceConn iceConn;
 354      Bool swap;
 355      int offendingMinorOpcode;
 356      unsigned long offendingSequence;
 357      int errorClass;
 358      int severity;
 359      IcePointer values;
 360 {
 361   /* Empty  */
 362 }
 363
 364
 365 static void
 366 ice_io_error_handler (iceConn)
 367      IceConn iceConn;
 368 {
 369   /* Connection probably gone.  */
 370   ice_fd = -1;
 371 }
 372
 373 /* This is called when the ICE connection is created or closed.  The SM library
 374    uses ICE as it transport protocol.  */
 375
 376 static void
 377 ice_conn_watch_CB (iceConn, clientData, opening, watchData)
 378      IceConn iceConn;
 379      IcePointer clientData;
 380      Bool opening;
 381      IcePointer *watchData;
 382 {
 383   if (! opening)
 384     {
 385       ice_fd = -1;
 386       return;
 387     }
 388
 389   ice_fd = IceConnectionNumber (iceConn);
 390 #ifdef F_SETOWN
 391   fcntl (ice_fd, F_SETOWN, getpid ());
 392 #endif /* ! defined (F_SETOWN) */
 393
 394 #ifdef SIGIO
 395   if (interrupt_input)
 396     init_sigio (ice_fd);
 397 #endif /* ! defined (SIGIO) */
 398 }
 399
 400 /* Create the client leader window.  */
 401
 402 static void
 403 create_client_leader_window (dpyinfo, client_id)
 404      struct x_display_info *dpyinfo;
 405      char *client_id;
 406 {
 407   Window w;
 408   XClassHint class_hints;
 409   Atom sm_id;
 410
 411   w = XCreateSimpleWindow (dpyinfo->display,
 412                            dpyinfo->root_window,
 413                            -1, -1, 1, 1,
 414                            CopyFromParent, CopyFromParent, CopyFromParent);
 415
 416   class_hints.res_name = (char *) SDATA (Vx_resource_name);
 417   class_hints.res_class = (char *) SDATA (Vx_resource_class);
 418   XSetClassHint (dpyinfo->display, w, &class_hints);
 419   XStoreName (dpyinfo->display, w, class_hints.res_name);
 420
 421   sm_id = XInternAtom (dpyinfo->display, "SM_CLIENT_ID", False);
 422   XChangeProperty (dpyinfo->display, w, sm_id, XA_STRING, 8, PropModeReplace,
 423                    client_id, strlen (client_id));
 424
 425   dpyinfo->client_leader_window = w;
 426 }
 427
 428 /* Try to open a connection to the session manager.  */
 429
 430 void
 431 x_session_initialize (dpyinfo)
 432      struct x_display_info *dpyinfo;
 433 {
 434 #define SM_ERRORSTRING_LEN 512
 435   char errorstring[SM_ERRORSTRING_LEN];
 436   char* previous_id = NULL;
 437   SmcCallbacks callbacks;
 438   int  name_len = 0;
 439
 440   /* Check if we where started by the session manager.  If so, we will
 441      have a previous id.  */
 442   if (! EQ (Vx_session_previous_id, Qnil) && STRINGP (Vx_session_previous_id))
 443     previous_id = SDATA (Vx_session_previous_id);
 444
 445   /* Construct the path to the Emacs program.  */
 446   if (! EQ (Vinvocation_directory, Qnil))
 447     name_len += strlen (SDATA (Vinvocation_directory));
 448   name_len += strlen (SDATA (Vinvocation_name));
 449
 450   /* This malloc will not be freed, but it is only done once, and hopefully
 451      not very large   */
 452   emacs_program = xmalloc (name_len + 1);
 453   emacs_program[0] = '\0';
 454
 455   if (! EQ (Vinvocation_directory, Qnil))
 456     strcpy (emacs_program, SDATA (Vinvocation_directory));
 457   strcat (emacs_program, SDATA (Vinvocation_name));
 458
 459   /* The SM protocol says all callbacks are mandatory, so set up all
 460      here and in the mask passed to SmcOpenConnection.  */
 461   callbacks.save_yourself.callback = smc_save_yourself_CB;
 462   callbacks.save_yourself.client_data = 0;
 463   callbacks.die.callback = smc_die_CB;
 464   callbacks.die.client_data = 0;
 465   callbacks.save_complete.callback = smc_save_complete_CB;
 466   callbacks.save_complete.client_data = 0;
 467   callbacks.shutdown_cancelled.callback = smc_shutdown_cancelled_CB;
 468   callbacks.shutdown_cancelled.client_data = 0;
 469
 470   /* Set error handlers.  */
 471   SmcSetErrorHandler (smc_error_handler);
 472   IceSetErrorHandler (ice_error_handler);
 473   IceSetIOErrorHandler (ice_io_error_handler);
 474
 475   /* Install callback for when connection status changes.  */
 476   IceAddConnectionWatch (ice_conn_watch_CB, 0);
 477
 478   /* Open the connection to the session manager.  A failure is not
 479      critical, it usually means that no session manager is running.
 480      The errorstring is here for debugging.  */
 481   smc_conn = SmcOpenConnection (NULL, NULL, 1, 0,
 482                                 (SmcSaveYourselfProcMask|
 483                                  SmcDieProcMask|
 484                                  SmcSaveCompleteProcMask|
 485                                  SmcShutdownCancelledProcMask),
 486                                 &callbacks,
 487                                 previous_id,
 488                                 &client_id,
 489                                 SM_ERRORSTRING_LEN,
 490                                 errorstring);
 491
 492   if (smc_conn != 0)
 493     {
 494       Vx_session_id = make_string (client_id, strlen (client_id));
 495
 496 #ifdef USE_GTK
 497       /* GTK creats a leader window by itself, but we need to tell
 498          it about our client_id.  */
 499       gdk_set_sm_client_id (client_id);
 500 #else
 501       create_client_leader_window (dpyinfo, client_id);
 502 #endif
 503     }
 504 }
 505
 506 /* Ensure that the session manager is not contacted again. */
 507
 508 void
 509 x_session_close ()
 510 {
 511   ice_fd = -1;
 512 }
 513
 514
 515 DEFUN ("handle-save-session", Fhandle_save_session,
 516        Shandle_save_session, 1, 1, "e",
 517        doc: /* Handle the save_yourself event from a session manager.
 518 A session manager can tell Emacs that the window system is shutting down
 519 by sending Emacs a save_yourself message.  Emacs executes this function when
 520 such an event occurs.  This function then executes `emacs-session-save'.
 521 After that, this function informs the session manager that it can continue
 522 or abort shutting down the window system depending on the return value
 523 from `emacs-session-save'  If the return value is non-nil the session manager
 524 is told to abort the window system shutdown.
 525
 526 Do not call this function yourself. */)
 527      (event)
 528      Lisp_Object event;
 529 {
 530   /* Check doing_interact so that we don't do anything if someone called
 531      this at the wrong time. */
 532   if (doing_interact)
 533     {
 534       Bool cancel_shutdown = False;
 535
 536       cancel_shutdown = ! EQ (call0 (intern ("emacs-session-save")), Qnil);
 537
 538       SmcInteractDone (smc_conn, cancel_shutdown);
 539       SmcSaveYourselfDone (smc_conn, True);
 540
 541       doing_interact = False;
 542     }
 543
 544   return Qnil;
 545 }
 546
 547 \f
 548 /***********************************************************************
 549                             Initialization
 550  ***********************************************************************/
 551 void
 552 syms_of_xsmfns ()
 553 {
 554   DEFVAR_LISP ("x-session-id", &Vx_session_id,
 555     doc: /* The session id Emacs got from the session manager for this session.
 556 Changing the value does not change the session id used by Emacs.
 557 The value is nil if no session manager is running.
 558 See also `x-session-previous-id', `emacs-save-session-functions',
 559 `emacs-session-save' and `emacs-session-restore'." */);
 560   Vx_session_id = Qnil;
 561
 562   DEFVAR_LISP ("x-session-previous-id", &Vx_session_previous_id,
 563     doc: /* The previous session id Emacs got from session manager.
 564 If Emacs is running on a window system that has a session manager, the
 565 session manager gives Emacs a session id.  It is feasible for Emacs Lisp
 566 code to use the session id to save configuration in, for example, a file
 567 with a file name based on the session id.  If Emacs is running when the
 568 window system is shut down, the session manager remembers that Emacs was
 569 running and saves the session id Emacs had.
 570
 571 When the window system is started again, the session manager restarts
 572 Emacs and hands Emacs the session id it had the last time it was
 573 running.  This is now the previous session id and the value of this
 574 variable.  If configuration was saved in a file as stated above, the
 575 previous session id shall be used to reconstruct the file name.
 576
 577 The session id Emacs has while it is running is in the variable
 578 `x-session-id'.  The value of this variable and `x-session-id' may be the
 579 same, depending on how the session manager works.
 580
 581 See also `emacs-save-session-functions', `emacs-session-save' and
 582 `emacs-session-restore'." */);
 583   Vx_session_previous_id = Qnil;
 584
 585   defsubr (&Shandle_save_session);
 586 }
 587
 588 #endif /* HAVE_X_SM */
 589
 590 /* arch-tag: 56a2c58c-adfa-430a-b772-130abd29fd2e
 591    (do not change this comment) */