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