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, or (at your option)
  11 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; see the file COPYING.  If not, write to
  20 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21 Boston, MA 02110-1301, USA.  */
  22
  23 #include <config.h>
  24
  25 #ifdef HAVE_X_SM
  26
  27 #include <X11/SM/SMlib.h>
  28 #include <X11/Xlib.h>
  29 #include <X11/Xutil.h>
  30
  31 #ifdef HAVE_STRING_H
  32 #include <string.h>
  33 #else
  34 #ifdef HAVE_STRINGS_H
  35 #include <strings.h>
  36 #endif
  37 #endif
  38
  39 #ifdef HAVE_UNISTD_H
  40 #include <unistd.h>
  41 #endif
  42 #ifdef HAVE_STDLIB_H
  43 #include <stdlib.h>
  44 #endif
  45
  46 #include <sys/param.h>
  47 #include <stdio.h>
  48
  49 #include "lisp.h"
  50 #include "systime.h"
  51 #include "sysselect.h"
  52 #include "frame.h"
  53 #include "termhooks.h"
  54 #include "termopts.h"
  55 #include "xterm.h"
  56
  57 /* The user login name.  */
  58
  59 extern Lisp_Object Vuser_login_name;
  60
  61 /* This is the event used when SAVE_SESSION_EVENT occurs.  */
  62
  63 static struct input_event emacs_event;
  64
  65 /* The descriptor that we use to check for data from the session manager.  */
  66
  67 static int ice_fd = -1;
  68
  69 /* A flag that says if we are in shutdown interactions or not.  */
  70
  71 static int doing_interact = False;
  72
  73 /* The session manager object for the session manager connection.  */
  74
  75 static SmcConn smc_conn;
  76
  77 /* The client session id for this session.  */
  78
  79 static char *client_id;
  80
  81 /* The full path name to the Emacs program.  */
  82
  83 static char *emacs_program;
  84
  85 /* The client session id for this session as a lisp object.  */
  86
  87 Lisp_Object Vx_session_id;
  88
  89 /* The id we had the previous session.  This is only available if we
  90    have been started by the session manager with SMID_OPT.  */
  91
  92 Lisp_Object Vx_session_previous_id;
  93
  94 /* The option we tell the session manager to start Emacs with when
  95    restarting Emacs.  The client_id is appended.  */
  96
  97 #define SMID_OPT "--smid="
  98
  99
 100 /* The option to start Emacs without the splash screen when
 101    restarting Emacs.  */
 102
 103 #define NOSPLASH_OPT "--no-splash"
 104
 105
 106 /* Handle any messages from the session manager.  If no connection is
 107    open to a session manager, just return 0.
 108    Otherwise returns 1 if SAVE_SESSION_EVENT is stored in buffer BUFP.  */
 109
 110 int
 111 x_session_check_input (bufp)
 112      struct input_event *bufp;
 113 {
 114   SELECT_TYPE read_fds;
 115   EMACS_TIME tmout;
 116
 117   if (ice_fd == -1) return 0;
 118
 119   FD_ZERO (&read_fds);
 120   FD_SET (ice_fd, &read_fds);
 121
 122   tmout.tv_sec = 0;
 123   tmout.tv_usec = 0;
 124
 125   /* Reset this so wo can check kind after callbacks have been called by
 126      IceProcessMessages.  The smc_interact_CB sets the kind to
 127      SAVE_SESSION_EVENT, but we don't know beforehand if that callback
 128      will be called.  */
 129   emacs_event.kind = NO_EVENT;
 130
 131   if (select (ice_fd+1, &read_fds,
 132               (SELECT_TYPE *)0, (SELECT_TYPE *)0, &tmout) < 0)
 133     {
 134       ice_fd = -1;
 135       return 0;
 136     }
 137
 138
 139   if (FD_ISSET (ice_fd, &read_fds))
 140     IceProcessMessages (SmcGetIceConnection (smc_conn),
 141                         (IceReplyWaitInfo *)0, (Bool *)0);
 142
 143
 144   /* Check if smc_interact_CB was called and we shall generate a
 145      SAVE_SESSION_EVENT.  */
 146   if (emacs_event.kind == NO_EVENT)
 147     return 0;
 148
 149   bcopy (&emacs_event, bufp, sizeof (struct input_event));
 150   return 1;
 151 }
 152
 153 /* Return non-zero if we have a connection to a session manager.  */
 154
 155 int
 156 x_session_have_connection ()
 157 {
 158   return ice_fd != -1;
 159 }
 160
 161 /* This is called when the session manager says it is OK to interact with the
 162    user.  Here we set the kind to SAVE_SESSION_EVENT so an event is generated.
 163    Then lisp code can interact with the user.  */
 164
 165 static void
 166 smc_interact_CB (smcConn, clientData)
 167      SmcConn smcConn;
 168      SmPointer clientData;
 169 {
 170   doing_interact = True;
 171   emacs_event.kind = SAVE_SESSION_EVENT;
 172 }
 173
 174 /* This is called when the session manager tells us to save ourselves.
 175    We set the required properties so the session manager can restart us,
 176    plus the current working directory property (not mandatory) so we
 177    are started in the correct directory.
 178
 179    If this is a shutdown and we can request to interact with the user,
 180    we do so, because we don't know what the lisp code might do.  */
 181
 182 static void
 183 smc_save_yourself_CB (smcConn,
 184                       clientData,
 185                       saveType,
 186                       shutdown,
 187                       interactStyle,
 188                       fast)
 189      SmcConn smcConn;
 190      SmPointer clientData;
 191      int saveType;
 192      Bool shutdown;
 193      int interactStyle;
 194      Bool fast;
 195 {
 196 #define NR_PROPS 5
 197
 198   SmProp *props[NR_PROPS];
 199   SmProp prop_ptr[NR_PROPS];
 200
 201   SmPropValue values[20];
 202   int val_idx = 0;
 203   int props_idx = 0;
 204
 205   char *cwd = NULL;
 206   char *smid_opt;
 207
 208   /* How to start a new instance of Emacs.  */
 209   props[props_idx] = &prop_ptr[props_idx];
 210   props[props_idx]->name = SmCloneCommand;
 211   props[props_idx]->type = SmLISTofARRAY8;
 212   props[props_idx]->num_vals = 1;
 213   props[props_idx]->vals = &values[val_idx++];
 214   props[props_idx]->vals[0].length = strlen (emacs_program);
 215   props[props_idx]->vals[0].value = emacs_program;
 216   ++props_idx;
 217
 218   /* The name of the program.  */
 219   props[props_idx] = &prop_ptr[props_idx];
 220   props[props_idx]->name = SmProgram;
 221   props[props_idx]->type = SmARRAY8;
 222   props[props_idx]->num_vals = 1;
 223   props[props_idx]->vals = &values[val_idx++];
 224   props[props_idx]->vals[0].length = strlen (SDATA (Vinvocation_name));
 225   props[props_idx]->vals[0].value = SDATA (Vinvocation_name);
 226   ++props_idx;
 227
 228   /* How to restart Emacs (i.e.: /path/to/emacs --smid=xxxx --no-splash).  */
 229   props[props_idx] = &prop_ptr[props_idx];
 230   props[props_idx]->name = SmRestartCommand;
 231   props[props_idx]->type = SmLISTofARRAY8;
 232   props[props_idx]->num_vals = 3; /* /path/to/emacs, --smid=xxx --no-splash  */
 233   props[props_idx]->vals = &values[val_idx];
 234   props[props_idx]->vals[0].length = strlen (emacs_program);
 235   props[props_idx]->vals[0].value = emacs_program;
 236
 237   smid_opt = xmalloc (strlen (SMID_OPT) + strlen (client_id) + 1);
 238   strcpy (smid_opt, SMID_OPT);
 239   strcat (smid_opt, client_id);
 240
 241   props[props_idx]->vals[1].length = strlen (smid_opt);
 242   props[props_idx]->vals[1].value = smid_opt;
 243
 244   props[props_idx]->vals[2].length = strlen (NOSPLASH_OPT);
 245   props[props_idx]->vals[2].value = NOSPLASH_OPT;
 246   val_idx += 3;
 247   ++props_idx;
 248
 249   /* User id.  */
 250   props[props_idx] = &prop_ptr[props_idx];
 251   props[props_idx]->name = SmUserID;
 252   props[props_idx]->type = SmARRAY8;
 253   props[props_idx]->num_vals = 1;
 254   props[props_idx]->vals = &values[val_idx++];
 255   props[props_idx]->vals[0].length = strlen (SDATA (Vuser_login_name));
 256   props[props_idx]->vals[0].value = SDATA (Vuser_login_name);
 257   ++props_idx;
 258
 259   cwd = get_current_dir_name ();
 260
 261   if (cwd)
 262     {
 263       props[props_idx] = &prop_ptr[props_idx];
 264       props[props_idx]->name = SmCurrentDirectory;
 265       props[props_idx]->type = SmARRAY8;
 266       props[props_idx]->num_vals = 1;
 267       props[props_idx]->vals = &values[val_idx++];
 268       props[props_idx]->vals[0].length = strlen (cwd);
 269       props[props_idx]->vals[0].value = cwd;
 270       ++props_idx;
 271     }
 272
 273
 274   SmcSetProperties (smcConn, props_idx, props);
 275
 276   xfree (smid_opt);
 277
 278   if (cwd)
 279     free (cwd);
 280
 281   /* See if we maybe shall interact with the user.  */
 282   if (interactStyle != SmInteractStyleAny
 283       || ! shutdown
 284       || saveType == SmSaveLocal
 285       || ! SmcInteractRequest (smcConn, SmDialogNormal, smc_interact_CB, 0))
 286     {
 287       /* No interaction, we are done saving ourself.  */
 288       SmcSaveYourselfDone (smcConn, True);
 289     }
 290 }
 291
 292 /* According to the SM specification, this shall close the connection.  */
 293
 294 static void
 295 smc_die_CB (smcConn, clientData)
 296      SmcConn smcConn;
 297      SmPointer clientData;
 298 {
 299   SmcCloseConnection (smcConn, 0, 0);
 300   ice_fd = -1;
 301 }
 302
 303 /* We don't use the next two but they are mandatory, leave them empty.
 304    According to the SM specification, we should not interact with the
 305    user between smc_save_yourself_CB is called and until smc_save_complete_CB
 306    is called.  It seems like a lot of job to implement this and it doesn't
 307    even seem necessary.  */
 308
 309 static void
 310 smc_save_complete_CB (smcConn, clientData)
 311      SmcConn smcConn;
 312      SmPointer clientData;
 313 {
 314   /* Empty */
 315 }
 316
 317 static void
 318 smc_shutdown_cancelled_CB (smcConn, clientData)
 319      SmcConn smcConn;
 320      SmPointer clientData;
 321 {
 322   /* Empty */
 323 }
 324
 325 /* Error handlers for SM and ICE.  We don't want to exit Emacs just
 326    because there is some error in the session management.  */
 327
 328 static void
 329 smc_error_handler (smcConn,
 330                    swap,
 331                    offendingMinorOpcode,
 332                    offendingSequence,
 333                    errorClass,
 334                    severity,
 335                    values)
 336      SmcConn smcConn;
 337      Bool swap;
 338      int offendingMinorOpcode;
 339      unsigned long offendingSequence;
 340      int errorClass;
 341      int severity;
 342      SmPointer values;
 343 {
 344   /* Empty  */
 345 }
 346
 347 static void
 348 ice_error_handler (iceConn,
 349                    swap,
 350                    offendingMinorOpcode,
 351                    offendingSequence,
 352                    errorClass,
 353                    severity,
 354                    values)
 355      IceConn iceConn;
 356      Bool swap;
 357      int offendingMinorOpcode;
 358      unsigned long offendingSequence;
 359      int errorClass;
 360      int severity;
 361      IcePointer values;
 362 {
 363   /* Empty  */
 364 }
 365
 366
 367 static void
 368 ice_io_error_handler (iceConn)
 369      IceConn iceConn;
 370 {
 371   /* Connection probably gone.  */
 372   ice_fd = -1;
 373 }
 374
 375 /* This is called when the ICE connection is created or closed.  The SM library
 376    uses ICE as it transport protocol.  */
 377
 378 static void
 379 ice_conn_watch_CB (iceConn, clientData, opening, watchData)
 380      IceConn iceConn;
 381      IcePointer clientData;
 382      Bool opening;
 383      IcePointer *watchData;
 384 {
 385   if (! opening)
 386     {
 387       ice_fd = -1;
 388       return;
 389     }
 390
 391   ice_fd = IceConnectionNumber (iceConn);
 392 #ifdef F_SETOWN
 393   fcntl (ice_fd, F_SETOWN, getpid ());
 394 #endif /* ! defined (F_SETOWN) */
 395
 396 #ifdef SIGIO
 397   if (interrupt_input)
 398     init_sigio (ice_fd);
 399 #endif /* ! defined (SIGIO) */
 400 }
 401
 402 /* Create the client leader window.  */
 403
 404 static void
 405 create_client_leader_window (dpyinfo, client_id)
 406      struct x_display_info *dpyinfo;
 407      char *client_id;
 408 {
 409   Window w;
 410   XClassHint class_hints;
 411   Atom sm_id;
 412
 413   w = XCreateSimpleWindow (dpyinfo->display,
 414                            dpyinfo->root_window,
 415                            -1, -1, 1, 1,
 416                            CopyFromParent, CopyFromParent, CopyFromParent);
 417
 418   class_hints.res_name = (char *) SDATA (Vx_resource_name);
 419   class_hints.res_class = (char *) SDATA (Vx_resource_class);
 420   XSetClassHint (dpyinfo->display, w, &class_hints);
 421   XStoreName (dpyinfo->display, w, class_hints.res_name);
 422
 423   sm_id = XInternAtom (dpyinfo->display, "SM_CLIENT_ID", False);
 424   XChangeProperty (dpyinfo->display, w, sm_id, XA_STRING, 8, PropModeReplace,
 425                    client_id, strlen (client_id));
 426
 427   dpyinfo->client_leader_window = w;
 428 }
 429
 430 /* Try to open a connection to the session manager.  */
 431
 432 void
 433 x_session_initialize (dpyinfo)
 434      struct x_display_info *dpyinfo;
 435 {
 436 #define SM_ERRORSTRING_LEN 512
 437   char errorstring[SM_ERRORSTRING_LEN];
 438   char* previous_id = NULL;
 439   SmcCallbacks callbacks;
 440   int  name_len = 0;
 441
 442   /* Check if we where started by the session manager.  If so, we will
 443      have a previous id.  */
 444   if (! EQ (Vx_session_previous_id, Qnil) && STRINGP (Vx_session_previous_id))
 445     previous_id = SDATA (Vx_session_previous_id);
 446
 447   /* Construct the path to the Emacs program.  */
 448   if (! EQ (Vinvocation_directory, Qnil))
 449     name_len += strlen (SDATA (Vinvocation_directory));
 450   name_len += strlen (SDATA (Vinvocation_name));
 451
 452   /* This malloc will not be freed, but it is only done once, and hopefully
 453      not very large   */
 454   emacs_program = xmalloc (name_len + 1);
 455   emacs_program[0] = '\0';
 456
 457   if (! EQ (Vinvocation_directory, Qnil))
 458     strcpy (emacs_program, SDATA (Vinvocation_directory));
 459   strcat (emacs_program, SDATA (Vinvocation_name));
 460
 461   /* The SM protocol says all callbacks are mandatory, so set up all
 462      here and in the mask passed to SmcOpenConnection.  */
 463   callbacks.save_yourself.callback = smc_save_yourself_CB;
 464   callbacks.save_yourself.client_data = 0;
 465   callbacks.die.callback = smc_die_CB;
 466   callbacks.die.client_data = 0;
 467   callbacks.save_complete.callback = smc_save_complete_CB;
 468   callbacks.save_complete.client_data = 0;
 469   callbacks.shutdown_cancelled.callback = smc_shutdown_cancelled_CB;
 470   callbacks.shutdown_cancelled.client_data = 0;
 471
 472   /* Set error handlers.  */
 473   SmcSetErrorHandler (smc_error_handler);
 474   IceSetErrorHandler (ice_error_handler);
 475   IceSetIOErrorHandler (ice_io_error_handler);
 476
 477   /* Install callback for when connection status changes.  */
 478   IceAddConnectionWatch (ice_conn_watch_CB, 0);
 479
 480   /* Open the connection to the session manager.  A failure is not
 481      critical, it usually means that no session manager is running.
 482      The errorstring is here for debugging.  */
 483   smc_conn = SmcOpenConnection (NULL, NULL, 1, 0,
 484                                 (SmcSaveYourselfProcMask|
 485                                  SmcDieProcMask|
 486                                  SmcSaveCompleteProcMask|
 487                                  SmcShutdownCancelledProcMask),
 488                                 &callbacks,
 489                                 previous_id,
 490                                 &client_id,
 491                                 SM_ERRORSTRING_LEN,
 492                                 errorstring);
 493
 494   if (smc_conn != 0)
 495     {
 496       Vx_session_id = make_string (client_id, strlen (client_id));
 497
 498 #ifdef USE_GTK
 499       /* GTK creats a leader window by itself, but we need to tell
 500          it about our client_id.  */
 501       gdk_set_sm_client_id (client_id);
 502 #else
 503       create_client_leader_window (dpyinfo, client_id);
 504 #endif
 505     }
 506 }
 507
 508 /* Ensure that the session manager is not contacted again. */
 509
 510 void
 511 x_session_close ()
 512 {
 513   ice_fd = -1;
 514 }
 515
 516
 517 DEFUN ("handle-save-session", Fhandle_save_session,
 518        Shandle_save_session, 1, 1, "e",
 519        doc: /* Handle the save_yourself event from a session manager.
 520 A session manager can tell Emacs that the window system is shutting down
 521 by sending Emacs a save_yourself message.  Emacs executes this function when
 522 such an event occurs.  This function then executes `emacs-session-save'.
 523 After that, this function informs the session manager that it can continue
 524 or abort shutting down the window system depending on the return value
 525 from `emacs-session-save'  If the return value is non-nil the session manager
 526 is told to abort the window system shutdown.
 527
 528 Do not call this function yourself. */)
 529      (event)
 530      Lisp_Object event;
 531 {
 532   /* Check doing_interact so that we don't do anything if someone called
 533      this at the wrong time. */
 534   if (doing_interact)
 535     {
 536       Bool cancel_shutdown = False;
 537
 538       cancel_shutdown = ! EQ (call0 (intern ("emacs-session-save")), Qnil);
 539
 540       SmcInteractDone (smc_conn, cancel_shutdown);
 541       SmcSaveYourselfDone (smc_conn, True);
 542
 543       doing_interact = False;
 544     }
 545
 546   return Qnil;
 547 }
 548
 549 \f
 550 /***********************************************************************
 551                             Initialization
 552  ***********************************************************************/
 553 void
 554 syms_of_xsmfns ()
 555 {
 556   DEFVAR_LISP ("x-session-id", &Vx_session_id,
 557     doc: /* The session id Emacs got from the session manager for this session.
 558 Changing the value does not change the session id used by Emacs.
 559 The value is nil if no session manager is running.
 560 See also `x-session-previous-id', `emacs-save-session-functions',
 561 `emacs-session-save' and `emacs-session-restore'." */);
 562   Vx_session_id = Qnil;
 563
 564   DEFVAR_LISP ("x-session-previous-id", &Vx_session_previous_id,
 565     doc: /* The previous session id Emacs got from session manager.
 566 If Emacs is running on a window system that has a session manager, the
 567 session manager gives Emacs a session id.  It is feasible for Emacs Lisp
 568 code to use the session id to save configuration in, for example, a file
 569 with a file name based on the session id.  If Emacs is running when the
 570 window system is shut down, the session manager remembers that Emacs was
 571 running and saves the session id Emacs had.
 572
 573 When the window system is started again, the session manager restarts
 574 Emacs and hands Emacs the session id it had the last time it was
 575 running.  This is now the previous session id and the value of this
 576 variable.  If configuration was saved in a file as stated above, the
 577 previous session id shall be used to reconstruct the file name.
 578
 579 The session id Emacs has while it is running is in the variable
 580 `x-session-id'.  The value of this variable and `x-session-id' may be the
 581 same, depending on how the session manager works.
 582
 583 See also `emacs-save-session-functions', `emacs-session-save' and
 584 `emacs-session-restore'." */);
 585   Vx_session_previous_id = Qnil;
 586
 587   defsubr (&Shandle_save_session);
 588 }
 589
 590 #endif /* HAVE_X_SM */
 591
 592 /* arch-tag: 56a2c58c-adfa-430a-b772-130abd29fd2e
 593    (do not change this comment) */