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, 2009, 2010, 2011
   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_UNISTD_H
  30 #include <unistd.h>
  31 #endif
  32
  33 #include <sys/param.h>
  34 #include <stdio.h>
  35 #include <setjmp.h>
  36
  37 #include "lisp.h"
  38 #include "systime.h"
  39 #include "sysselect.h"
  40 #include "frame.h"
  41 #include "termhooks.h"
  42 #include "termopts.h"
  43 #include "xterm.h"
  44
  45 /* The user login name.  */
  46
  47 extern Lisp_Object Vuser_login_name;
  48
  49 /* This is the event used when SAVE_SESSION_EVENT occurs.  */
  50
  51 static struct input_event emacs_event;
  52
  53 /* The descriptor that we use to check for data from the session manager.  */
  54
  55 static int ice_fd;
  56
  57 /* A flag that says if we are in shutdown interactions or not.  */
  58
  59 static int doing_interact;
  60
  61 /* The session manager object for the session manager connection.  */
  62
  63 static SmcConn smc_conn;
  64
  65 /* The client session id for this session.  */
  66
  67 static char *client_id;
  68
  69 /* The full path name to the Emacs program.  */
  70
  71 static char *emacs_program;
  72
  73 /* The client session id for this session as a lisp object.  */
  74
  75 Lisp_Object Vx_session_id;
  76
  77 /* The id we had the previous session.  This is only available if we
  78    have been started by the session manager with SMID_OPT.  */
  79
  80 Lisp_Object Vx_session_previous_id;
  81
  82 /* The option we tell the session manager to start Emacs with when
  83    restarting Emacs.  The client_id is appended.  */
  84
  85 #define SMID_OPT "--smid="
  86
  87
  88 /* The option to start Emacs without the splash screen when
  89    restarting Emacs.  */
  90
  91 #define NOSPLASH_OPT "--no-splash"
  92
  93 static void
  94 ice_connection_closed ()
  95 {
  96   if (ice_fd >= 0)
  97     delete_keyboard_wait_descriptor (ice_fd);
  98   ice_fd = -1;
  99 }
 100
 101
 102 /* Handle any messages from the session manager.  If no connection is
 103    open to a session manager, just return 0.
 104    Otherwise returns 1 if SAVE_SESSION_EVENT is stored in buffer BUFP.  */
 105
 106 int
 107 x_session_check_input (bufp)
 108      struct input_event *bufp;
 109 {
 110   SELECT_TYPE read_fds;
 111   EMACS_TIME tmout;
 112   int ret;
 113
 114   if (ice_fd == -1) return 0;
 115   FD_ZERO (&read_fds);
 116   FD_SET (ice_fd, &read_fds);
 117
 118   tmout.tv_sec = 0;
 119   tmout.tv_usec = 0;
 120
 121   /* Reset this so wo can check kind after callbacks have been called by
 122      IceProcessMessages.  The smc_interact_CB sets the kind to
 123      SAVE_SESSION_EVENT, but we don't know beforehand if that callback
 124      will be called.  */
 125   emacs_event.kind = NO_EVENT;
 126
 127   ret = select (ice_fd+1, &read_fds,
 128                 (SELECT_TYPE *)0, (SELECT_TYPE *)0, &tmout);
 129
 130   if (ret < 0)
 131     {
 132       ice_connection_closed ();
 133     }
 134   else if (ret > 0 && FD_ISSET (ice_fd, &read_fds))
 135     {
 136       ret = IceProcessMessages (SmcGetIceConnection (smc_conn),
 137                                 (IceReplyWaitInfo *)0, (Bool *)0);
 138       if (ret != IceProcessMessagesSuccess)
 139         {
 140           /* Either IO error or Connection closed.  */
 141           if (ret == IceProcessMessagesIOError)
 142             IceCloseConnection (SmcGetIceConnection (smc_conn));
 143
 144           ice_connection_closed ();
 145         }
 146     }
 147
 148   /* Check if smc_interact_CB was called and we shall generate a
 149      SAVE_SESSION_EVENT.  */
 150   if (emacs_event.kind != NO_EVENT)
 151     bcopy (&emacs_event, bufp, sizeof (struct input_event));
 152
 153   return emacs_event.kind != NO_EVENT ? 1 : 0;
 154 }
 155
 156 /* Return non-zero if we have a connection to a session manager.  */
 157
 158 int
 159 x_session_have_connection ()
 160 {
 161   return ice_fd != -1;
 162 }
 163
 164 /* This is called when the session manager says it is OK to interact with the
 165    user.  Here we set the kind to SAVE_SESSION_EVENT so an event is generated.
 166    Then lisp code can interact with the user.  */
 167
 168 static void
 169 smc_interact_CB (smcConn, clientData)
 170      SmcConn smcConn;
 171      SmPointer clientData;
 172 {
 173   doing_interact = True;
 174   emacs_event.kind = SAVE_SESSION_EVENT;
 175   emacs_event.arg = Qnil;
 176 }
 177
 178 /* This is called when the session manager tells us to save ourselves.
 179    We set the required properties so the session manager can restart us,
 180    plus the current working directory property (not mandatory) so we
 181    are started in the correct directory.
 182
 183    If this is a shutdown and we can request to interact with the user,
 184    we do so, because we don't know what the lisp code might do.  */
 185
 186 static void
 187 smc_save_yourself_CB (smcConn,
 188                       clientData,
 189                       saveType,
 190                       shutdown,
 191                       interactStyle,
 192                       fast)
 193      SmcConn smcConn;
 194      SmPointer clientData;
 195      int saveType;
 196      Bool shutdown;
 197      int interactStyle;
 198      Bool fast;
 199 {
 200 #define NR_PROPS 5
 201
 202   SmProp *props[NR_PROPS];
 203   SmProp prop_ptr[NR_PROPS];
 204
 205   SmPropValue values[20];
 206   int val_idx = 0;
 207   int props_idx = 0;
 208
 209   char *cwd = NULL;
 210   char *smid_opt;
 211
 212   /* How to start a new instance of Emacs.  */
 213   props[props_idx] = &prop_ptr[props_idx];
 214   props[props_idx]->name = SmCloneCommand;
 215   props[props_idx]->type = SmLISTofARRAY8;
 216   props[props_idx]->num_vals = 1;
 217   props[props_idx]->vals = &values[val_idx++];
 218   props[props_idx]->vals[0].length = strlen (emacs_program);
 219   props[props_idx]->vals[0].value = emacs_program;
 220   ++props_idx;
 221
 222   /* The name of the program.  */
 223   props[props_idx] = &prop_ptr[props_idx];
 224   props[props_idx]->name = SmProgram;
 225   props[props_idx]->type = SmARRAY8;
 226   props[props_idx]->num_vals = 1;
 227   props[props_idx]->vals = &values[val_idx++];
 228   props[props_idx]->vals[0].length = strlen (SDATA (Vinvocation_name));
 229   props[props_idx]->vals[0].value = SDATA (Vinvocation_name);
 230   ++props_idx;
 231
 232   /* How to restart Emacs (i.e.: /path/to/emacs --smid=xxxx --no-splash).  */
 233   props[props_idx] = &prop_ptr[props_idx];
 234   props[props_idx]->name = SmRestartCommand;
 235   props[props_idx]->type = SmLISTofARRAY8;
 236   props[props_idx]->num_vals = 3; /* /path/to/emacs, --smid=xxx --no-splash  */
 237   props[props_idx]->vals = &values[val_idx];
 238   props[props_idx]->vals[0].length = strlen (emacs_program);
 239   props[props_idx]->vals[0].value = emacs_program;
 240
 241   smid_opt = xmalloc (strlen (SMID_OPT) + strlen (client_id) + 1);
 242   strcpy (smid_opt, SMID_OPT);
 243   strcat (smid_opt, client_id);
 244
 245   props[props_idx]->vals[1].length = strlen (smid_opt);
 246   props[props_idx]->vals[1].value = smid_opt;
 247
 248   props[props_idx]->vals[2].length = strlen (NOSPLASH_OPT);
 249   props[props_idx]->vals[2].value = NOSPLASH_OPT;
 250   val_idx += 3;
 251   ++props_idx;
 252
 253   /* User id.  */
 254   props[props_idx] = &prop_ptr[props_idx];
 255   props[props_idx]->name = SmUserID;
 256   props[props_idx]->type = SmARRAY8;
 257   props[props_idx]->num_vals = 1;
 258   props[props_idx]->vals = &values[val_idx++];
 259   props[props_idx]->vals[0].length = strlen (SDATA (Vuser_login_name));
 260   props[props_idx]->vals[0].value = SDATA (Vuser_login_name);
 261   ++props_idx;
 262
 263   cwd = get_current_dir_name ();
 264
 265   if (cwd)
 266     {
 267       props[props_idx] = &prop_ptr[props_idx];
 268       props[props_idx]->name = SmCurrentDirectory;
 269       props[props_idx]->type = SmARRAY8;
 270       props[props_idx]->num_vals = 1;
 271       props[props_idx]->vals = &values[val_idx++];
 272       props[props_idx]->vals[0].length = strlen (cwd);
 273       props[props_idx]->vals[0].value = cwd;
 274       ++props_idx;
 275     }
 276
 277
 278   SmcSetProperties (smcConn, props_idx, props);
 279
 280   xfree (smid_opt);
 281
 282   free (cwd);
 283
 284   /* See if we maybe shall interact with the user.  */
 285   if (interactStyle != SmInteractStyleAny
 286       || ! shutdown
 287       || saveType == SmSaveLocal
 288       || ! SmcInteractRequest (smcConn, SmDialogNormal, smc_interact_CB, 0))
 289     {
 290       /* No interaction, we are done saving ourself.  */
 291       SmcSaveYourselfDone (smcConn, True);
 292     }
 293 }
 294
 295 /* According to the SM specification, this shall close the connection.  */
 296
 297 static void
 298 smc_die_CB (smcConn, clientData)
 299      SmcConn smcConn;
 300      SmPointer clientData;
 301 {
 302   emacs_event.kind = SAVE_SESSION_EVENT;
 303   emacs_event.arg = Qt;
 304 }
 305
 306 /* We don't use the next two but they are mandatory, leave them empty.
 307    According to the SM specification, we should not interact with the
 308    user between smc_save_yourself_CB is called and until smc_save_complete_CB
 309    is called.  It seems like a lot of job to implement this and it doesn't
 310    even seem necessary.  */
 311
 312 static void
 313 smc_save_complete_CB (smcConn, clientData)
 314      SmcConn smcConn;
 315      SmPointer clientData;
 316 {
 317   /* Empty */
 318 }
 319
 320 static void
 321 smc_shutdown_cancelled_CB (smcConn, clientData)
 322      SmcConn smcConn;
 323      SmPointer clientData;
 324 {
 325   /* Empty */
 326 }
 327
 328 /* Error handlers for SM and ICE.  We don't want to exit Emacs just
 329    because there is some error in the session management.  */
 330
 331 static void
 332 smc_error_handler (smcConn,
 333                    swap,
 334                    offendingMinorOpcode,
 335                    offendingSequence,
 336                    errorClass,
 337                    severity,
 338                    values)
 339      SmcConn smcConn;
 340      Bool swap;
 341      int offendingMinorOpcode;
 342      unsigned long offendingSequence;
 343      int errorClass;
 344      int severity;
 345      SmPointer values;
 346 {
 347   /* Empty  */
 348 }
 349
 350 static void
 351 ice_error_handler (iceConn,
 352                    swap,
 353                    offendingMinorOpcode,
 354                    offendingSequence,
 355                    errorClass,
 356                    severity,
 357                    values)
 358      IceConn iceConn;
 359      Bool swap;
 360      int offendingMinorOpcode;
 361      unsigned long offendingSequence;
 362      int errorClass;
 363      int severity;
 364      IcePointer values;
 365 {
 366   /* Empty  */
 367 }
 368
 369
 370 static void
 371 ice_io_error_handler (iceConn)
 372      IceConn iceConn;
 373 {
 374   /* Connection probably gone.  */
 375   ice_connection_closed ();
 376 }
 377
 378 /* This is called when the ICE connection is created or closed.  The SM library
 379    uses ICE as it transport protocol.  */
 380
 381 static void
 382 ice_conn_watch_CB (iceConn, clientData, opening, watchData)
 383      IceConn iceConn;
 384      IcePointer clientData;
 385      Bool opening;
 386      IcePointer *watchData;
 387 {
 388   if (! opening)
 389     {
 390       ice_connection_closed ();
 391       return;
 392     }
 393
 394   ice_fd = IceConnectionNumber (iceConn);
 395 #ifdef F_SETOWN
 396   fcntl (ice_fd, F_SETOWN, getpid ());
 397 #endif /* ! defined (F_SETOWN) */
 398
 399 #ifdef SIGIO
 400   if (interrupt_input)
 401     init_sigio (ice_fd);
 402 #endif /* ! defined (SIGIO) */
 403
 404   add_keyboard_wait_descriptor (ice_fd);
 405 }
 406
 407 /* Create the client leader window.  */
 408
 409 static void
 410 create_client_leader_window (dpyinfo, client_id)
 411      struct x_display_info *dpyinfo;
 412      char *client_id;
 413 {
 414   Window w;
 415   XClassHint class_hints;
 416   Atom sm_id;
 417
 418   w = XCreateSimpleWindow (dpyinfo->display,
 419                            dpyinfo->root_window,
 420                            -1, -1, 1, 1,
 421                            CopyFromParent, CopyFromParent, CopyFromParent);
 422
 423   class_hints.res_name = (char *) SDATA (Vx_resource_name);
 424   class_hints.res_class = (char *) SDATA (Vx_resource_class);
 425   XSetClassHint (dpyinfo->display, w, &class_hints);
 426   XStoreName (dpyinfo->display, w, class_hints.res_name);
 427
 428   sm_id = XInternAtom (dpyinfo->display, "SM_CLIENT_ID", False);
 429   XChangeProperty (dpyinfo->display, w, sm_id, XA_STRING, 8, PropModeReplace,
 430                    client_id, strlen (client_id));
 431
 432   dpyinfo->client_leader_window = w;
 433 }
 434
 435 /* Try to open a connection to the session manager.  */
 436
 437 void
 438 x_session_initialize (dpyinfo)
 439      struct x_display_info *dpyinfo;
 440 {
 441 #define SM_ERRORSTRING_LEN 512
 442   char errorstring[SM_ERRORSTRING_LEN];
 443   char* previous_id = NULL;
 444   SmcCallbacks callbacks;
 445   int  name_len = 0;
 446
 447   ice_fd = -1;
 448   doing_interact = False;
 449
 450   /* Check if we where started by the session manager.  If so, we will
 451      have a previous id.  */
 452   if (! EQ (Vx_session_previous_id, Qnil) && STRINGP (Vx_session_previous_id))
 453     previous_id = SDATA (Vx_session_previous_id);
 454
 455   /* Construct the path to the Emacs program.  */
 456   if (! EQ (Vinvocation_directory, Qnil))
 457     name_len += strlen (SDATA (Vinvocation_directory));
 458   name_len += strlen (SDATA (Vinvocation_name));
 459
 460   /* This malloc will not be freed, but it is only done once, and hopefully
 461      not very large   */
 462   emacs_program = xmalloc (name_len + 1);
 463   emacs_program[0] = '\0';
 464
 465   if (! EQ (Vinvocation_directory, Qnil))
 466     strcpy (emacs_program, SDATA (Vinvocation_directory));
 467   strcat (emacs_program, SDATA (Vinvocation_name));
 468
 469   /* The SM protocol says all callbacks are mandatory, so set up all
 470      here and in the mask passed to SmcOpenConnection.  */
 471   callbacks.save_yourself.callback = smc_save_yourself_CB;
 472   callbacks.save_yourself.client_data = 0;
 473   callbacks.die.callback = smc_die_CB;
 474   callbacks.die.client_data = 0;
 475   callbacks.save_complete.callback = smc_save_complete_CB;
 476   callbacks.save_complete.client_data = 0;
 477   callbacks.shutdown_cancelled.callback = smc_shutdown_cancelled_CB;
 478   callbacks.shutdown_cancelled.client_data = 0;
 479
 480   /* Set error handlers.  */
 481   SmcSetErrorHandler (smc_error_handler);
 482   IceSetErrorHandler (ice_error_handler);
 483   IceSetIOErrorHandler (ice_io_error_handler);
 484
 485   /* Install callback for when connection status changes.  */
 486   IceAddConnectionWatch (ice_conn_watch_CB, 0);
 487
 488   /* Open the connection to the session manager.  A failure is not
 489      critical, it usually means that no session manager is running.
 490      The errorstring is here for debugging.  */
 491   smc_conn = SmcOpenConnection (NULL, NULL, 1, 0,
 492                                 (SmcSaveYourselfProcMask|
 493                                  SmcDieProcMask|
 494                                  SmcSaveCompleteProcMask|
 495                                  SmcShutdownCancelledProcMask),
 496                                 &callbacks,
 497                                 previous_id,
 498                                 &client_id,
 499                                 SM_ERRORSTRING_LEN,
 500                                 errorstring);
 501
 502   if (smc_conn != 0)
 503     {
 504       Vx_session_id = make_string (client_id, strlen (client_id));
 505
 506 #ifdef USE_GTK
 507       /* GTK creats a leader window by itself, but we need to tell
 508          it about our client_id.  */
 509       gdk_set_sm_client_id (client_id);
 510 #else
 511       create_client_leader_window (dpyinfo, client_id);
 512 #endif
 513     }
 514 }
 515
 516 /* Ensure that the session manager is not contacted again. */
 517
 518 void
 519 x_session_close ()
 520 {
 521   ice_connection_closed ();
 522 }
 523
 524
 525 DEFUN ("handle-save-session", Fhandle_save_session,
 526        Shandle_save_session, 1, 1, "e",
 527        doc: /* Handle the save_yourself event from a session manager.
 528 A session manager can tell Emacs that the window system is shutting down
 529 by sending Emacs a save_yourself message.  Emacs executes this function when
 530 such an event occurs.  This function then executes `emacs-session-save'.
 531 After that, this function informs the session manager that it can continue
 532 or abort shutting down the window system depending on the return value
 533 from `emacs-session-save'  If the return value is non-nil the session manager
 534 is told to abort the window system shutdown.
 535
 536 Do not call this function yourself. */)
 537      (event)
 538      Lisp_Object event;
 539 {
 540   int kill_emacs = CONSP (event) && CONSP (XCDR (event))
 541     && EQ (Qt, XCAR (XCDR (event)));
 542
 543   /* Check doing_interact so that we don't do anything if someone called
 544      this at the wrong time. */
 545   if (doing_interact && ! kill_emacs)
 546     {
 547       Bool cancel_shutdown = False;
 548
 549       cancel_shutdown = ! EQ (call0 (intern ("emacs-session-save")), Qnil);
 550
 551       SmcInteractDone (smc_conn, cancel_shutdown);
 552       SmcSaveYourselfDone (smc_conn, True);
 553
 554       doing_interact = False;
 555     }
 556   else if (kill_emacs)
 557     {
 558       /* We should not do user interaction here, but it is not easy to
 559          prevent.  Fix this in next version.  */
 560       Fkill_emacs (Qnil);
 561
 562       /* This will not be reached, but we want kill-emacs-hook to be run.  */
 563       SmcCloseConnection (smc_conn, 0, 0);
 564       ice_connection_closed ();
 565     }
 566
 567   return Qnil;
 568 }
 569
 570
 571 \f
 572 /***********************************************************************
 573                             Initialization
 574  ***********************************************************************/
 575 void
 576 syms_of_xsmfns ()
 577 {
 578   DEFVAR_LISP ("x-session-id", &Vx_session_id,
 579     doc: /* The session id Emacs got from the session manager for this session.
 580 Changing the value does not change the session id used by Emacs.
 581 The value is nil if no session manager is running.
 582 See also `x-session-previous-id', `emacs-save-session-functions',
 583 `emacs-session-save' and `emacs-session-restore'." */);
 584   Vx_session_id = Qnil;
 585
 586   DEFVAR_LISP ("x-session-previous-id", &Vx_session_previous_id,
 587     doc: /* The previous session id Emacs got from session manager.
 588 If Emacs is running on a window system that has a session manager, the
 589 session manager gives Emacs a session id.  It is feasible for Emacs Lisp
 590 code to use the session id to save configuration in, for example, a file
 591 with a file name based on the session id.  If Emacs is running when the
 592 window system is shut down, the session manager remembers that Emacs was
 593 running and saves the session id Emacs had.
 594
 595 When the window system is started again, the session manager restarts
 596 Emacs and hands Emacs the session id it had the last time it was
 597 running.  This is now the previous session id and the value of this
 598 variable.  If configuration was saved in a file as stated above, the
 599 previous session id shall be used to reconstruct the file name.
 600
 601 The session id Emacs has while it is running is in the variable
 602 `x-session-id'.  The value of this variable and `x-session-id' may be the
 603 same, depending on how the session manager works.
 604
 605 See also `emacs-save-session-functions', `emacs-session-save' and
 606 `emacs-session-restore'." */);
 607   Vx_session_previous_id = Qnil;
 608
 609   defsubr (&Shandle_save_session);
 610 }
 611
 612 #endif /* HAVE_X_SM */
 613
 614 /* arch-tag: 56a2c58c-adfa-430a-b772-130abd29fd2e
 615    (do not change this comment) */