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 impl_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 impl_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 impl_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 }
 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,
 187                       clientData,
 188                       saveType,
 189                       shutdown,
 190                       interactStyle,
 191                       fast)
 192      SmcConn smcConn;
 193      SmPointer clientData;
 194      int saveType;
 195      Bool shutdown;
 196      int interactStyle;
 197      Bool fast;
 198 {
 199 #define NR_PROPS 5
 200
 201   SmProp *props[NR_PROPS];
 202   SmProp prop_ptr[NR_PROPS];
 203
 204   SmPropValue values[20];
 205   int val_idx = 0;
 206   int props_idx = 0;
 207
 208   char *cwd = NULL;
 209   char *smid_opt;
 210
 211   /* How to start a new instance of Emacs.  */
 212   props[props_idx] = &prop_ptr[props_idx];
 213   props[props_idx]->name = SmCloneCommand;
 214   props[props_idx]->type = SmLISTofARRAY8;
 215   props[props_idx]->num_vals = 1;
 216   props[props_idx]->vals = &values[val_idx++];
 217   props[props_idx]->vals[0].length = strlen (emacs_program);
 218   props[props_idx]->vals[0].value = emacs_program;
 219   ++props_idx;
 220
 221   /* The name of the program.  */
 222   props[props_idx] = &prop_ptr[props_idx];
 223   props[props_idx]->name = SmProgram;
 224   props[props_idx]->type = SmARRAY8;
 225   props[props_idx]->num_vals = 1;
 226   props[props_idx]->vals = &values[val_idx++];
 227   props[props_idx]->vals[0].length = strlen (SDATA (Vinvocation_name));
 228   props[props_idx]->vals[0].value = SDATA (Vinvocation_name);
 229   ++props_idx;
 230
 231   /* How to restart Emacs (i.e.: /path/to/emacs --smid=xxxx --no-splash).  */
 232   props[props_idx] = &prop_ptr[props_idx];
 233   props[props_idx]->name = SmRestartCommand;
 234   props[props_idx]->type = SmLISTofARRAY8;
 235   props[props_idx]->num_vals = 3; /* /path/to/emacs, --smid=xxx --no-splash  */
 236   props[props_idx]->vals = &values[val_idx];
 237   props[props_idx]->vals[0].length = strlen (emacs_program);
 238   props[props_idx]->vals[0].value = emacs_program;
 239
 240   smid_opt = xmalloc (strlen (SMID_OPT) + strlen (client_id) + 1);
 241   strcpy (smid_opt, SMID_OPT);
 242   strcat (smid_opt, client_id);
 243
 244   props[props_idx]->vals[1].length = strlen (smid_opt);
 245   props[props_idx]->vals[1].value = smid_opt;
 246
 247   props[props_idx]->vals[2].length = strlen (NOSPLASH_OPT);
 248   props[props_idx]->vals[2].value = NOSPLASH_OPT;
 249   val_idx += 3;
 250   ++props_idx;
 251
 252   /* User id.  */
 253   props[props_idx] = &prop_ptr[props_idx];
 254   props[props_idx]->name = SmUserID;
 255   props[props_idx]->type = SmARRAY8;
 256   props[props_idx]->num_vals = 1;
 257   props[props_idx]->vals = &values[val_idx++];
 258   props[props_idx]->vals[0].length = strlen (SDATA (Vuser_login_name));
 259   props[props_idx]->vals[0].value = SDATA (Vuser_login_name);
 260   ++props_idx;
 261
 262   cwd = get_current_dir_name ();
 263
 264   if (cwd)
 265     {
 266       props[props_idx] = &prop_ptr[props_idx];
 267       props[props_idx]->name = SmCurrentDirectory;
 268       props[props_idx]->type = SmARRAY8;
 269       props[props_idx]->num_vals = 1;
 270       props[props_idx]->vals = &values[val_idx++];
 271       props[props_idx]->vals[0].length = strlen (cwd);
 272       props[props_idx]->vals[0].value = cwd;
 273       ++props_idx;
 274     }
 275
 276
 277   SmcSetProperties (smcConn, props_idx, props);
 278
 279   xfree (smid_opt);
 280
 281   free (cwd);
 282
 283   /* See if we maybe shall interact with the user.  */
 284   if (interactStyle != SmInteractStyleAny
 285       || ! shutdown
 286       || saveType == SmSaveLocal
 287       || ! SmcInteractRequest (smcConn, SmDialogNormal, smc_interact_CB, 0))
 288     {
 289       /* No interaction, we are done saving ourself.  */
 290       SmcSaveYourselfDone (smcConn, True);
 291     }
 292 }
 293
 294 /* According to the SM specification, this shall close the connection.  */
 295
 296 static void
 297 smc_die_CB (smcConn, clientData)
 298      SmcConn smcConn;
 299      SmPointer clientData;
 300 {
 301   SmcCloseConnection (smcConn, 0, 0);
 302   ice_connection_closed ();
 303 }
 304
 305 /* We don't use the next two but they are mandatory, leave them empty.
 306    According to the SM specification, we should not interact with the
 307    user between smc_save_yourself_CB is called and until smc_save_complete_CB
 308    is called.  It seems like a lot of job to implement this and it doesn't
 309    even seem necessary.  */
 310
 311 static void
 312 smc_save_complete_CB (smcConn, clientData)
 313      SmcConn smcConn;
 314      SmPointer clientData;
 315 {
 316   /* Empty */
 317 }
 318
 319 static void
 320 smc_shutdown_cancelled_CB (smcConn, clientData)
 321      SmcConn smcConn;
 322      SmPointer clientData;
 323 {
 324   /* Empty */
 325 }
 326
 327 /* Error handlers for SM and ICE.  We don't want to exit Emacs just
 328    because there is some error in the session management.  */
 329
 330 static void
 331 smc_error_handler (smcConn,
 332                    swap,
 333                    offendingMinorOpcode,
 334                    offendingSequence,
 335                    errorClass,
 336                    severity,
 337                    values)
 338      SmcConn smcConn;
 339      Bool swap;
 340      int offendingMinorOpcode;
 341      unsigned long offendingSequence;
 342      int errorClass;
 343      int severity;
 344      SmPointer values;
 345 {
 346   /* Empty  */
 347 }
 348
 349 static void
 350 ice_error_handler (iceConn,
 351                    swap,
 352                    offendingMinorOpcode,
 353                    offendingSequence,
 354                    errorClass,
 355                    severity,
 356                    values)
 357      IceConn iceConn;
 358      Bool swap;
 359      int offendingMinorOpcode;
 360      unsigned long offendingSequence;
 361      int errorClass;
 362      int severity;
 363      IcePointer values;
 364 {
 365   /* Empty  */
 366 }
 367
 368
 369 static void
 370 ice_io_error_handler (iceConn)
 371      IceConn iceConn;
 372 {
 373   /* Connection probably gone.  */
 374   ice_connection_closed ();
 375 }
 376
 377 /* This is called when the ICE connection is created or closed.  The SM library
 378    uses ICE as it transport protocol.  */
 379
 380 static void
 381 ice_conn_watch_CB (iceConn, clientData, opening, watchData)
 382      IceConn iceConn;
 383      IcePointer clientData;
 384      Bool opening;
 385      IcePointer *watchData;
 386 {
 387   if (! opening)
 388     {
 389       ice_connection_closed ();
 390       return;
 391     }
 392
 393   ice_fd = IceConnectionNumber (iceConn);
 394 #ifdef F_SETOWN
 395   fcntl (ice_fd, F_SETOWN, getpid ());
 396 #endif /* ! defined (F_SETOWN) */
 397
 398 #ifdef SIGIO
 399   if (interrupt_input)
 400     init_sigio (ice_fd);
 401 #endif /* ! defined (SIGIO) */
 402
 403   add_keyboard_wait_descriptor (ice_fd);
 404 }
 405
 406 /* Create the client leader window.  */
 407
 408 static void
 409 create_client_leader_window (dpyinfo, client_id)
 410      struct x_display_info *dpyinfo;
 411      char *client_id;
 412 {
 413   Window w;
 414   XClassHint class_hints;
 415   Atom sm_id;
 416
 417   w = XCreateSimpleWindow (dpyinfo->display,
 418                            dpyinfo->root_window,
 419                            -1, -1, 1, 1,
 420                            CopyFromParent, CopyFromParent, CopyFromParent);
 421
 422   class_hints.res_name = (char *) SDATA (Vx_resource_name);
 423   class_hints.res_class = (char *) SDATA (Vx_resource_class);
 424   XSetClassHint (dpyinfo->display, w, &class_hints);
 425   XStoreName (dpyinfo->display, w, class_hints.res_name);
 426
 427   sm_id = XInternAtom (dpyinfo->display, "SM_CLIENT_ID", False);
 428   XChangeProperty (dpyinfo->display, w, sm_id, XA_STRING, 8, PropModeReplace,
 429                    client_id, strlen (client_id));
 430
 431   dpyinfo->client_leader_window = w;
 432 }
 433
 434 /* Try to open a connection to the session manager.  */
 435
 436 void
 437 x_session_initialize (dpyinfo)
 438      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 ()
 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 ()
 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) */