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
   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 /* The option to make Emacs start in the given directory.  */
  94
  95 #define CHDIR_OPT "--chdir="
  96
  97 static void
  98 ice_connection_closed (void)
  99 {
 100   if (ice_fd >= 0)
 101     delete_keyboard_wait_descriptor (ice_fd);
 102   ice_fd = -1;
 103 }
 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 (struct input_event *bufp)
 112 {
 113   SELECT_TYPE read_fds;
 114   EMACS_TIME tmout;
 115   int ret;
 116
 117   if (ice_fd == -1) return 0;
 118   FD_ZERO (&read_fds);
 119   FD_SET (ice_fd, &read_fds);
 120
 121   tmout.tv_sec = 0;
 122   tmout.tv_usec = 0;
 123
 124   /* Reset this so wo can check kind after callbacks have been called by
 125      IceProcessMessages.  The smc_interact_CB sets the kind to
 126      SAVE_SESSION_EVENT, but we don't know beforehand if that callback
 127      will be called.  */
 128   emacs_event.kind = NO_EVENT;
 129
 130   ret = select (ice_fd+1, &read_fds,
 131                 (SELECT_TYPE *)0, (SELECT_TYPE *)0, &tmout);
 132
 133   if (ret < 0)
 134     {
 135       ice_connection_closed ();
 136     }
 137   else if (ret > 0 && FD_ISSET (ice_fd, &read_fds))
 138     {
 139       ret = IceProcessMessages (SmcGetIceConnection (smc_conn),
 140                                 (IceReplyWaitInfo *)0, (Bool *)0);
 141       if (ret != IceProcessMessagesSuccess)
 142         {
 143           /* Either IO error or Connection closed.  */
 144           if (ret == IceProcessMessagesIOError)
 145             IceCloseConnection (SmcGetIceConnection (smc_conn));
 146
 147           ice_connection_closed ();
 148         }
 149     }
 150
 151   /* Check if smc_interact_CB was called and we shall generate a
 152      SAVE_SESSION_EVENT.  */
 153   if (emacs_event.kind != NO_EVENT)
 154     bcopy (&emacs_event, bufp, sizeof (struct input_event));
 155
 156   return emacs_event.kind != NO_EVENT ? 1 : 0;
 157 }
 158
 159 /* Return non-zero if we have a connection to a session manager.  */
 160
 161 int
 162 x_session_have_connection (void)
 163 {
 164   return ice_fd != -1;
 165 }
 166
 167 /* This is called when the session manager says it is OK to interact with the
 168    user.  Here we set the kind to SAVE_SESSION_EVENT so an event is generated.
 169    Then lisp code can interact with the user.  */
 170
 171 static void
 172 smc_interact_CB (SmcConn smcConn, SmPointer clientData)
 173 {
 174   doing_interact = True;
 175   emacs_event.kind = SAVE_SESSION_EVENT;
 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, *chdir_opt = NULL;
 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.  */
 233   props[props_idx] = &prop_ptr[props_idx];
 234   props[props_idx]->name = SmRestartCommand;
 235   props[props_idx]->type = SmLISTofARRAY8;
 236   /* /path/to/emacs, --smid=xxx --no-splash --chdir=dir */
 237   props[props_idx]->num_vals = 4;
 238   props[props_idx]->vals = &values[val_idx];
 239   props[props_idx]->vals[0].length = strlen (emacs_program);
 240   props[props_idx]->vals[0].value = emacs_program;
 241
 242   smid_opt = xmalloc (strlen (SMID_OPT) + strlen (client_id) + 1);
 243   strcpy (smid_opt, SMID_OPT);
 244   strcat (smid_opt, client_id);
 245
 246   props[props_idx]->vals[1].length = strlen (smid_opt);
 247   props[props_idx]->vals[1].value = smid_opt;
 248
 249   props[props_idx]->vals[2].length = strlen (NOSPLASH_OPT);
 250   props[props_idx]->vals[2].value = NOSPLASH_OPT;
 251
 252   cwd = get_current_dir_name ();
 253   if (cwd)
 254     {
 255       chdir_opt = xmalloc (strlen (CHDIR_OPT) + strlen (cwd) + 1);
 256       strcpy (chdir_opt, CHDIR_OPT);
 257       strcat (chdir_opt, cwd);
 258
 259       props[props_idx]->vals[3].length = strlen (chdir_opt);
 260       props[props_idx]->vals[3].value = chdir_opt;
 261     }
 262
 263   val_idx += cwd ? 4 : 3;
 264   ++props_idx;
 265
 266   /* User id.  */
 267   props[props_idx] = &prop_ptr[props_idx];
 268   props[props_idx]->name = SmUserID;
 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 (SDATA (Vuser_login_name));
 273   props[props_idx]->vals[0].value = SDATA (Vuser_login_name);
 274   ++props_idx;
 275
 276
 277   if (cwd)
 278     {
 279       props[props_idx] = &prop_ptr[props_idx];
 280       props[props_idx]->name = SmCurrentDirectory;
 281       props[props_idx]->type = SmARRAY8;
 282       props[props_idx]->num_vals = 1;
 283       props[props_idx]->vals = &values[val_idx++];
 284       props[props_idx]->vals[0].length = strlen (cwd);
 285       props[props_idx]->vals[0].value = cwd;
 286       ++props_idx;
 287     }
 288
 289
 290   SmcSetProperties (smcConn, props_idx, props);
 291
 292   xfree (smid_opt);
 293   xfree (chdir_opt);
 294
 295   free (cwd);
 296
 297   /* See if we maybe shall interact with the user.  */
 298   if (interactStyle != SmInteractStyleAny
 299       || ! shutdown
 300       || saveType == SmSaveLocal
 301       || ! SmcInteractRequest (smcConn, SmDialogNormal, smc_interact_CB, 0))
 302     {
 303       /* No interaction, we are done saving ourself.  */
 304       SmcSaveYourselfDone (smcConn, True);
 305     }
 306 }
 307
 308 /* According to the SM specification, this shall close the connection.  */
 309
 310 static void
 311 smc_die_CB (SmcConn smcConn, SmPointer clientData)
 312 {
 313   SmcCloseConnection (smcConn, 0, 0);
 314   ice_connection_closed ();
 315 }
 316
 317 /* We don't use the next two but they are mandatory, leave them empty.
 318    According to the SM specification, we should not interact with the
 319    user between smc_save_yourself_CB is called and until smc_save_complete_CB
 320    is called.  It seems like a lot of job to implement this and it doesn't
 321    even seem necessary.  */
 322
 323 static void
 324 smc_save_complete_CB (SmcConn smcConn, SmPointer clientData)
 325 {
 326   /* Empty */
 327 }
 328
 329 static void
 330 smc_shutdown_cancelled_CB (SmcConn smcConn, SmPointer clientData)
 331 {
 332   /* Empty */
 333 }
 334
 335 /* Error handlers for SM and ICE.  We don't want to exit Emacs just
 336    because there is some error in the session management.  */
 337
 338 static void
 339 smc_error_handler (smcConn,
 340                    swap,
 341                    offendingMinorOpcode,
 342                    offendingSequence,
 343                    errorClass,
 344                    severity,
 345                    values)
 346      SmcConn smcConn;
 347      Bool swap;
 348      int offendingMinorOpcode;
 349      unsigned long offendingSequence;
 350      int errorClass;
 351      int severity;
 352      SmPointer values;
 353 {
 354   /* Empty  */
 355 }
 356
 357 static void
 358 ice_error_handler (iceConn,
 359                    swap,
 360                    offendingMinorOpcode,
 361                    offendingSequence,
 362                    errorClass,
 363                    severity,
 364                    values)
 365      IceConn iceConn;
 366      Bool swap;
 367      int offendingMinorOpcode;
 368      unsigned long offendingSequence;
 369      int errorClass;
 370      int severity;
 371      IcePointer values;
 372 {
 373   /* Empty  */
 374 }
 375
 376
 377 static void
 378 ice_io_error_handler (IceConn iceConn)
 379 {
 380   /* Connection probably gone.  */
 381   ice_connection_closed ();
 382 }
 383
 384 /* This is called when the ICE connection is created or closed.  The SM library
 385    uses ICE as it transport protocol.  */
 386
 387 static void
 388 ice_conn_watch_CB (IceConn iceConn, IcePointer clientData, int opening, IcePointer *watchData)
 389 {
 390   if (! opening)
 391     {
 392       ice_connection_closed ();
 393       return;
 394     }
 395
 396   ice_fd = IceConnectionNumber (iceConn);
 397 #ifdef F_SETOWN
 398   fcntl (ice_fd, F_SETOWN, getpid ());
 399 #endif /* ! defined (F_SETOWN) */
 400
 401 #ifdef SIGIO
 402   if (interrupt_input)
 403     init_sigio (ice_fd);
 404 #endif /* ! defined (SIGIO) */
 405
 406   add_keyboard_wait_descriptor (ice_fd);
 407 }
 408
 409 /* Create the client leader window.  */
 410
 411 static void
 412 create_client_leader_window (struct x_display_info *dpyinfo, 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 (struct x_display_info *dpyinfo)
 439 {
 440 #define SM_ERRORSTRING_LEN 512
 441   char errorstring[SM_ERRORSTRING_LEN];
 442   char* previous_id = NULL;
 443   SmcCallbacks callbacks;
 444   int  name_len = 0;
 445
 446   ice_fd = -1;
 447   doing_interact = False;
 448
 449   /* Check if we where started by the session manager.  If so, we will
 450      have a previous id.  */
 451   if (! EQ (Vx_session_previous_id, Qnil) && STRINGP (Vx_session_previous_id))
 452     previous_id = SDATA (Vx_session_previous_id);
 453
 454   /* Construct the path to the Emacs program.  */
 455   if (! EQ (Vinvocation_directory, Qnil))
 456     name_len += strlen (SDATA (Vinvocation_directory));
 457   name_len += strlen (SDATA (Vinvocation_name));
 458
 459   /* This malloc will not be freed, but it is only done once, and hopefully
 460      not very large   */
 461   emacs_program = xmalloc (name_len + 1);
 462   emacs_program[0] = '\0';
 463
 464   if (! EQ (Vinvocation_directory, Qnil))
 465     strcpy (emacs_program, SDATA (Vinvocation_directory));
 466   strcat (emacs_program, SDATA (Vinvocation_name));
 467
 468   /* The SM protocol says all callbacks are mandatory, so set up all
 469      here and in the mask passed to SmcOpenConnection.  */
 470   callbacks.save_yourself.callback = smc_save_yourself_CB;
 471   callbacks.save_yourself.client_data = 0;
 472   callbacks.die.callback = smc_die_CB;
 473   callbacks.die.client_data = 0;
 474   callbacks.save_complete.callback = smc_save_complete_CB;
 475   callbacks.save_complete.client_data = 0;
 476   callbacks.shutdown_cancelled.callback = smc_shutdown_cancelled_CB;
 477   callbacks.shutdown_cancelled.client_data = 0;
 478
 479   /* Set error handlers.  */
 480   SmcSetErrorHandler (smc_error_handler);
 481   IceSetErrorHandler (ice_error_handler);
 482   IceSetIOErrorHandler (ice_io_error_handler);
 483
 484   /* Install callback for when connection status changes.  */
 485   IceAddConnectionWatch (ice_conn_watch_CB, 0);
 486
 487   /* Open the connection to the session manager.  A failure is not
 488      critical, it usually means that no session manager is running.
 489      The errorstring is here for debugging.  */
 490   smc_conn = SmcOpenConnection (NULL, NULL, 1, 0,
 491                                 (SmcSaveYourselfProcMask|
 492                                  SmcDieProcMask|
 493                                  SmcSaveCompleteProcMask|
 494                                  SmcShutdownCancelledProcMask),
 495                                 &callbacks,
 496                                 previous_id,
 497                                 &client_id,
 498                                 SM_ERRORSTRING_LEN,
 499                                 errorstring);
 500
 501   if (smc_conn != 0)
 502     {
 503       Vx_session_id = make_string (client_id, strlen (client_id));
 504
 505 #ifdef USE_GTK
 506       /* GTK creats a leader window by itself, but we need to tell
 507          it about our client_id.  */
 508       gdk_set_sm_client_id (client_id);
 509 #else
 510       create_client_leader_window (dpyinfo, client_id);
 511 #endif
 512     }
 513 }
 514
 515 /* Ensure that the session manager is not contacted again. */
 516
 517 void
 518 x_session_close (void)
 519 {
 520   ice_connection_closed ();
 521 }
 522
 523
 524 DEFUN ("handle-save-session", Fhandle_save_session,
 525        Shandle_save_session, 1, 1, "e",
 526        doc: /* Handle the save_yourself event from a session manager.
 527 A session manager can tell Emacs that the window system is shutting down
 528 by sending Emacs a save_yourself message.  Emacs executes this function when
 529 such an event occurs.  This function then executes `emacs-session-save'.
 530 After that, this function informs the session manager that it can continue
 531 or abort shutting down the window system depending on the return value
 532 from `emacs-session-save'  If the return value is non-nil the session manager
 533 is told to abort the window system shutdown.
 534
 535 Do not call this function yourself. */)
 536      (event)
 537      Lisp_Object event;
 538 {
 539   /* Check doing_interact so that we don't do anything if someone called
 540      this at the wrong time. */
 541   if (doing_interact)
 542     {
 543       Bool cancel_shutdown = False;
 544
 545       cancel_shutdown = ! EQ (call0 (intern ("emacs-session-save")), Qnil);
 546
 547       SmcInteractDone (smc_conn, cancel_shutdown);
 548       SmcSaveYourselfDone (smc_conn, True);
 549
 550       doing_interact = False;
 551     }
 552
 553   return Qnil;
 554 }
 555
 556 \f
 557 /***********************************************************************
 558                             Initialization
 559  ***********************************************************************/
 560 void
 561 syms_of_xsmfns (void)
 562 {
 563   DEFVAR_LISP ("x-session-id", &Vx_session_id,
 564     doc: /* The session id Emacs got from the session manager for this session.
 565 Changing the value does not change the session id used by Emacs.
 566 The value is nil if no session manager is running.
 567 See also `x-session-previous-id', `emacs-save-session-functions',
 568 `emacs-session-save' and `emacs-session-restore'." */);
 569   Vx_session_id = Qnil;
 570
 571   DEFVAR_LISP ("x-session-previous-id", &Vx_session_previous_id,
 572     doc: /* The previous session id Emacs got from session manager.
 573 If Emacs is running on a window system that has a session manager, the
 574 session manager gives Emacs a session id.  It is feasible for Emacs Lisp
 575 code to use the session id to save configuration in, for example, a file
 576 with a file name based on the session id.  If Emacs is running when the
 577 window system is shut down, the session manager remembers that Emacs was
 578 running and saves the session id Emacs had.
 579
 580 When the window system is started again, the session manager restarts
 581 Emacs and hands Emacs the session id it had the last time it was
 582 running.  This is now the previous session id and the value of this
 583 variable.  If configuration was saved in a file as stated above, the
 584 previous session id shall be used to reconstruct the file name.
 585
 586 The session id Emacs has while it is running is in the variable
 587 `x-session-id'.  The value of this variable and `x-session-id' may be the
 588 same, depending on how the session manager works.
 589
 590 See also `emacs-save-session-functions', `emacs-session-save' and
 591 `emacs-session-restore'." */);
 592   Vx_session_previous_id = Qnil;
 593
 594   defsubr (&Shandle_save_session);
 595 }
 596
 597 #endif /* HAVE_X_SM */
 598
 599 /* arch-tag: 56a2c58c-adfa-430a-b772-130abd29fd2e
 600    (do not change this comment) */