src/xsmfns.c

   1 /* Session management module for systems which understand the X Session
   2    management protocol.
   3
   4 Copyright (C) 2002-2012  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 #include <unistd.h>
  30 #include <sys/param.h>
  31 #include <stdio.h>
  32 #include <setjmp.h>
  33
  34 #include "lisp.h"
  35 #include "systime.h"
  36 #include "sysselect.h"
  37 #include "frame.h"
  38 #include "termhooks.h"
  39 #include "termopts.h"
  40 #include "xterm.h"
  41 #include "process.h"
  42 #include "keyboard.h"
  43
  44 #if defined USE_GTK && !defined HAVE_GTK3
  45 #define gdk_x11_set_sm_client_id(w) gdk_set_sm_client_id (w)
  46 #endif
  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 option we tell the session manager to start Emacs with when
  73    restarting Emacs.  The client_id is appended.  */
  74
  75 #define SMID_OPT "--smid="
  76
  77
  78 /* The option to start Emacs without the splash screen when
  79    restarting Emacs.  */
  80
  81 static char NOSPLASH_OPT[] = "--no-splash";
  82
  83 /* The option to make Emacs start in the given directory.  */
  84
  85 #define CHDIR_OPT "--chdir="
  86
  87 static void
  88 ice_connection_closed (void)
  89 {
  90   if (ice_fd >= 0)
  91     delete_read_fd (ice_fd);
  92   ice_fd = -1;
  93 }
  94
  95
  96 /* Handle any messages from the session manager.  If no connection is
  97    open to a session manager, just return.  */
  98
  99 static void
 100 x_session_check_input (int fd, void *data, int for_read)
 101 {
 102   int ret;
 103
 104   if (ice_fd == -1) return;
 105
 106   /* Reset this so wo can check kind after callbacks have been called by
 107      IceProcessMessages.  The smc_interact_CB sets the kind to
 108      SAVE_SESSION_EVENT, but we don't know beforehand if that callback
 109      will be called.  */
 110   emacs_event.kind = NO_EVENT;
 111
 112   ret = IceProcessMessages (SmcGetIceConnection (smc_conn),
 113                             (IceReplyWaitInfo *)0, (Bool *)0);
 114   if (ret != IceProcessMessagesSuccess)
 115     {
 116       /* Either IO error or Connection closed.  */
 117       if (ret == IceProcessMessagesIOError)
 118         IceCloseConnection (SmcGetIceConnection (smc_conn));
 119
 120       ice_connection_closed ();
 121     }
 122
 123   /* Check if smc_interact_CB was called and we shall generate a
 124      SAVE_SESSION_EVENT.  */
 125   if (emacs_event.kind != NO_EVENT)
 126     kbd_buffer_store_event (&emacs_event);
 127 }
 128
 129 /* Return non-zero if we have a connection to a session manager.  */
 130
 131 int
 132 x_session_have_connection (void)
 133 {
 134   return ice_fd != -1;
 135 }
 136
 137 /* This is called when the session manager says it is OK to interact with the
 138    user.  Here we set the kind to SAVE_SESSION_EVENT so an event is generated.
 139    Then lisp code can interact with the user.  */
 140
 141 static void
 142 smc_interact_CB (SmcConn smcConn, SmPointer clientData)
 143 {
 144   doing_interact = True;
 145   emacs_event.kind = SAVE_SESSION_EVENT;
 146   emacs_event.arg = Qnil;
 147 }
 148
 149 /* This is called when the session manager tells us to save ourselves.
 150    We set the required properties so the session manager can restart us,
 151    plus the current working directory property (not mandatory) so we
 152    are started in the correct directory.
 153
 154    If this is a shutdown and we can request to interact with the user,
 155    we do so, because we don't know what the lisp code might do.  */
 156
 157 static void
 158 smc_save_yourself_CB (SmcConn smcConn,
 159                       SmPointer clientData,
 160                       int saveType,
 161                       Bool shutdown,
 162                       int interactStyle,
 163                       Bool fast)
 164 {
 165 #define NR_PROPS 5
 166
 167   SmProp *props[NR_PROPS];
 168   SmProp prop_ptr[NR_PROPS];
 169
 170   SmPropValue values[20], *vp;
 171   int val_idx = 0, vp_idx = 0;
 172   int props_idx = 0;
 173   int i;
 174   char *cwd = get_current_dir_name ();
 175   char *smid_opt, *chdir_opt = NULL;
 176
 177   /* How to start a new instance of Emacs.  */
 178   props[props_idx] = &prop_ptr[props_idx];
 179   props[props_idx]->name = xstrdup (SmCloneCommand);
 180   props[props_idx]->type = xstrdup (SmLISTofARRAY8);
 181   props[props_idx]->num_vals = 1;
 182   props[props_idx]->vals = &values[val_idx++];
 183   props[props_idx]->vals[0].length = strlen (emacs_program);
 184   props[props_idx]->vals[0].value = emacs_program;
 185   ++props_idx;
 186
 187   /* The name of the program.  */
 188   props[props_idx] = &prop_ptr[props_idx];
 189   props[props_idx]->name = xstrdup (SmProgram);
 190   props[props_idx]->type = xstrdup (SmARRAY8);
 191   props[props_idx]->num_vals = 1;
 192   props[props_idx]->vals = &values[val_idx++];
 193   props[props_idx]->vals[0].length = SBYTES (Vinvocation_name);
 194   props[props_idx]->vals[0].value = SDATA (Vinvocation_name);
 195   ++props_idx;
 196
 197   /* User id.  */
 198   props[props_idx] = &prop_ptr[props_idx];
 199   props[props_idx]->name = xstrdup (SmUserID);
 200   props[props_idx]->type = xstrdup (SmARRAY8);
 201   props[props_idx]->num_vals = 1;
 202   props[props_idx]->vals = &values[val_idx++];
 203   props[props_idx]->vals[0].length = SBYTES (Vuser_login_name);
 204   props[props_idx]->vals[0].value = SDATA (Vuser_login_name);
 205   ++props_idx;
 206
 207
 208   if (cwd)
 209     {
 210       props[props_idx] = &prop_ptr[props_idx];
 211       props[props_idx]->name = xstrdup (SmCurrentDirectory);
 212       props[props_idx]->type = xstrdup (SmARRAY8);
 213       props[props_idx]->num_vals = 1;
 214       props[props_idx]->vals = &values[val_idx++];
 215       props[props_idx]->vals[0].length = strlen (cwd);
 216       props[props_idx]->vals[0].value = cwd;
 217       ++props_idx;
 218     }
 219
 220
 221   /* How to restart Emacs.  */
 222   props[props_idx] = &prop_ptr[props_idx];
 223   props[props_idx]->name = xstrdup (SmRestartCommand);
 224   props[props_idx]->type = xstrdup (SmLISTofARRAY8);
 225   /* /path/to/emacs, --smid=xxx --no-splash --chdir=dir ... */
 226   if (INT_MAX - 3 < initial_argc)
 227     memory_full (SIZE_MAX);
 228   i = 3 + initial_argc;
 229   props[props_idx]->num_vals = i;
 230   vp = xnmalloc (i, sizeof *vp);
 231   props[props_idx]->vals = vp;
 232   props[props_idx]->vals[vp_idx].length = strlen (emacs_program);
 233   props[props_idx]->vals[vp_idx++].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[vp_idx].length = strlen (smid_opt);
 240   props[props_idx]->vals[vp_idx++].value = smid_opt;
 241
 242   props[props_idx]->vals[vp_idx].length = strlen (NOSPLASH_OPT);
 243   props[props_idx]->vals[vp_idx++].value = NOSPLASH_OPT;
 244
 245   if (cwd)
 246     {
 247       chdir_opt = xmalloc (strlen (CHDIR_OPT) + strlen (cwd) + 1);
 248       strcpy (chdir_opt, CHDIR_OPT);
 249       strcat (chdir_opt, cwd);
 250
 251       props[props_idx]->vals[vp_idx].length = strlen (chdir_opt);
 252       props[props_idx]->vals[vp_idx++].value = chdir_opt;
 253     }
 254
 255   for (i = 1; i < initial_argc; ++i)
 256     {
 257       props[props_idx]->vals[vp_idx].length = strlen (initial_argv[i]);
 258       props[props_idx]->vals[vp_idx++].value = initial_argv[i];
 259     }
 260
 261   ++props_idx;
 262
 263   SmcSetProperties (smcConn, props_idx, props);
 264
 265   xfree (smid_opt);
 266   xfree (chdir_opt);
 267   xfree (cwd);
 268   xfree (vp);
 269
 270   for (i = 0; i < props_idx; ++i)
 271     {
 272       xfree (props[i]->type);
 273       xfree (props[i]->name);
 274     }
 275
 276   /* See if we maybe shall interact with the user.  */
 277   if (interactStyle != SmInteractStyleAny
 278       || ! shutdown
 279       || saveType == SmSaveLocal
 280       || ! SmcInteractRequest (smcConn, SmDialogNormal, smc_interact_CB, 0))
 281     {
 282       /* No interaction, we are done saving ourself.  */
 283       SmcSaveYourselfDone (smcConn, True);
 284     }
 285 }
 286
 287 /* According to the SM specification, this shall close the connection.  */
 288
 289 static void
 290 smc_die_CB (SmcConn smcConn, SmPointer clientData)
 291 {
 292   emacs_event.kind = SAVE_SESSION_EVENT;
 293   emacs_event.arg = Qt;
 294 }
 295
 296 /* We don't use the next two but they are mandatory, leave them empty.
 297    According to the SM specification, we should not interact with the
 298    user between smc_save_yourself_CB is called and until smc_save_complete_CB
 299    is called.  It seems like a lot of job to implement this and it doesn't
 300    even seem necessary.  */
 301
 302 static void
 303 smc_save_complete_CB (SmcConn smcConn, SmPointer clientData)
 304 {
 305   /* Empty */
 306 }
 307
 308 static void
 309 smc_shutdown_cancelled_CB (SmcConn smcConn, SmPointer clientData)
 310 {
 311   /* Empty */
 312 }
 313
 314 /* Error handlers for SM and ICE.  We don't want to exit Emacs just
 315    because there is some error in the session management.  */
 316
 317 static void
 318 smc_error_handler (SmcConn smcConn,
 319                    Bool swap,
 320                    int offendingMinorOpcode,
 321                    unsigned long offendingSequence,
 322                    int errorClass,
 323                    int severity,
 324                    SmPointer values)
 325 {
 326   /* Empty  */
 327 }
 328
 329 static void
 330 ice_error_handler (IceConn iceConn,
 331                    Bool swap,
 332                    int offendingMinorOpcode,
 333                    unsigned long offendingSequence,
 334                    int errorClass,
 335                    int severity,
 336                    IcePointer values)
 337 {
 338   /* Empty  */
 339 }
 340
 341
 342 static void
 343 ice_io_error_handler (IceConn iceConn)
 344 {
 345   /* Connection probably gone.  */
 346   ice_connection_closed ();
 347 }
 348
 349 /* This is called when the ICE connection is created or closed.  The SM library
 350    uses ICE as it transport protocol.  */
 351
 352 static void
 353 ice_conn_watch_CB (IceConn iceConn, IcePointer clientData,
 354                    int opening, IcePointer *watchData)
 355 {
 356   if (! opening)
 357     {
 358       ice_connection_closed ();
 359       return;
 360     }
 361
 362   ice_fd = IceConnectionNumber (iceConn);
 363   add_read_fd (ice_fd, x_session_check_input, NULL);
 364 }
 365
 366 /* Create the client leader window.  */
 367
 368 #ifndef USE_GTK
 369 static void
 370 create_client_leader_window (struct x_display_info *dpyinfo, char *client_ID)
 371 {
 372   Window w;
 373   XClassHint class_hints;
 374
 375   w = XCreateSimpleWindow (dpyinfo->display,
 376                            dpyinfo->root_window,
 377                            -1, -1, 1, 1,
 378                            CopyFromParent, CopyFromParent, CopyFromParent);
 379
 380   class_hints.res_name = SSDATA (Vx_resource_name);
 381   class_hints.res_class = SSDATA (Vx_resource_class);
 382   XSetClassHint (dpyinfo->display, w, &class_hints);
 383   XStoreName (dpyinfo->display, w, class_hints.res_name);
 384
 385   XChangeProperty (dpyinfo->display, w, dpyinfo->Xatom_SM_CLIENT_ID,
 386                    XA_STRING, 8, PropModeReplace,
 387                    (unsigned char *) client_ID, strlen (client_ID));
 388
 389   dpyinfo->client_leader_window = w;
 390 }
 391 #endif /* ! USE_GTK */
 392
 393
 394 /* Try to open a connection to the session manager.  */
 395
 396 void
 397 x_session_initialize (struct x_display_info *dpyinfo)
 398 {
 399 #define SM_ERRORSTRING_LEN 512
 400   char errorstring[SM_ERRORSTRING_LEN];
 401   char* previous_id = NULL;
 402   SmcCallbacks callbacks;
 403   ptrdiff_t name_len = 0;
 404
 405   ice_fd = -1;
 406   doing_interact = False;
 407
 408   /* Check if we where started by the session manager.  If so, we will
 409      have a previous id.  */
 410   if (! EQ (Vx_session_previous_id, Qnil) && STRINGP (Vx_session_previous_id))
 411     previous_id = SSDATA (Vx_session_previous_id);
 412
 413   /* Construct the path to the Emacs program.  */
 414   if (! EQ (Vinvocation_directory, Qnil))
 415     name_len += SBYTES (Vinvocation_directory);
 416   name_len += SBYTES (Vinvocation_name);
 417
 418   /* This malloc will not be freed, but it is only done once, and hopefully
 419      not very large   */
 420   emacs_program = xmalloc (name_len + 1);
 421   emacs_program[0] = '\0';
 422
 423   if (! EQ (Vinvocation_directory, Qnil))
 424     strcpy (emacs_program, SSDATA (Vinvocation_directory));
 425   strcat (emacs_program, SSDATA (Vinvocation_name));
 426
 427   /* The SM protocol says all callbacks are mandatory, so set up all
 428      here and in the mask passed to SmcOpenConnection.  */
 429   callbacks.save_yourself.callback = smc_save_yourself_CB;
 430   callbacks.save_yourself.client_data = 0;
 431   callbacks.die.callback = smc_die_CB;
 432   callbacks.die.client_data = 0;
 433   callbacks.save_complete.callback = smc_save_complete_CB;
 434   callbacks.save_complete.client_data = 0;
 435   callbacks.shutdown_cancelled.callback = smc_shutdown_cancelled_CB;
 436   callbacks.shutdown_cancelled.client_data = 0;
 437
 438   /* Set error handlers.  */
 439   SmcSetErrorHandler (smc_error_handler);
 440   IceSetErrorHandler (ice_error_handler);
 441   IceSetIOErrorHandler (ice_io_error_handler);
 442
 443   /* Install callback for when connection status changes.  */
 444   IceAddConnectionWatch (ice_conn_watch_CB, 0);
 445
 446   /* Open the connection to the session manager.  A failure is not
 447      critical, it usually means that no session manager is running.
 448      The errorstring is here for debugging.  */
 449   smc_conn = SmcOpenConnection (NULL, NULL, 1, 0,
 450                                 (SmcSaveYourselfProcMask|
 451                                  SmcDieProcMask|
 452                                  SmcSaveCompleteProcMask|
 453                                  SmcShutdownCancelledProcMask),
 454                                 &callbacks,
 455                                 previous_id,
 456                                 &client_id,
 457                                 SM_ERRORSTRING_LEN,
 458                                 errorstring);
 459
 460   if (smc_conn != 0)
 461     {
 462       Vx_session_id = build_string (client_id);
 463
 464 #ifdef USE_GTK
 465       /* GTK creates a leader window by itself, but we need to tell
 466          it about our client_id.  */
 467       gdk_x11_set_sm_client_id (client_id);
 468 #else
 469       create_client_leader_window (dpyinfo, client_id);
 470 #endif
 471     }
 472 }
 473
 474 /* Ensure that the session manager is not contacted again. */
 475
 476 void
 477 x_session_close (void)
 478 {
 479   ice_connection_closed ();
 480 }
 481
 482
 483 DEFUN ("handle-save-session", Fhandle_save_session,
 484        Shandle_save_session, 1, 1, "e",
 485        doc: /* Handle the save_yourself event from a session manager.
 486 A session manager can tell Emacs that the window system is shutting down
 487 by sending Emacs a save_yourself message.  Emacs executes this function when
 488 such an event occurs.  This function then executes `emacs-session-save'.
 489 After that, this function informs the session manager that it can continue
 490 or abort shutting down the window system depending on the return value
 491 from `emacs-session-save'  If the return value is non-nil the session manager
 492 is told to abort the window system shutdown.
 493
 494 Do not call this function yourself. */)
 495   (Lisp_Object event)
 496 {
 497   int kill_emacs = CONSP (event) && CONSP (XCDR (event))
 498     && EQ (Qt, XCAR (XCDR (event)));
 499
 500   /* Check doing_interact so that we don't do anything if someone called
 501      this at the wrong time. */
 502   if (doing_interact && ! kill_emacs)
 503     {
 504       Bool cancel_shutdown = False;
 505
 506       cancel_shutdown = ! EQ (call0 (intern ("emacs-session-save")), Qnil);
 507
 508       SmcInteractDone (smc_conn, cancel_shutdown);
 509       SmcSaveYourselfDone (smc_conn, True);
 510
 511       doing_interact = False;
 512     }
 513   else if (kill_emacs)
 514     {
 515       /* We should not do user interaction here, but it is not easy to
 516          prevent.  Fix this in next version.  */
 517       Fkill_emacs (Qnil);
 518
 519       /* This will not be reached, but we want kill-emacs-hook to be run.  */
 520       SmcCloseConnection (smc_conn, 0, 0);
 521       ice_connection_closed ();
 522     }
 523
 524   return Qnil;
 525 }
 526
 527
 528 \f
 529 /***********************************************************************
 530                             Initialization
 531  ***********************************************************************/
 532 void
 533 syms_of_xsmfns (void)
 534 {
 535   DEFVAR_LISP ("x-session-id", Vx_session_id,
 536     doc: /* The session id Emacs got from the session manager for this session.
 537 Changing the value does not change the session id used by Emacs.
 538 The value is nil if no session manager is running.
 539 See also `x-session-previous-id', `emacs-save-session-functions',
 540 `emacs-session-save' and `emacs-session-restore'." */);
 541   Vx_session_id = Qnil;
 542
 543   DEFVAR_LISP ("x-session-previous-id", Vx_session_previous_id,
 544     doc: /* The previous session id Emacs got from session manager.
 545 If Emacs is running on a window system that has a session manager, the
 546 session manager gives Emacs a session id.  It is feasible for Emacs Lisp
 547 code to use the session id to save configuration in, for example, a file
 548 with a file name based on the session id.  If Emacs is running when the
 549 window system is shut down, the session manager remembers that Emacs was
 550 running and saves the session id Emacs had.
 551
 552 When the window system is started again, the session manager restarts
 553 Emacs and hands Emacs the session id it had the last time it was
 554 running.  This is now the previous session id and the value of this
 555 variable.  If configuration was saved in a file as stated above, the
 556 previous session id shall be used to reconstruct the file name.
 557
 558 The session id Emacs has while it is running is in the variable
 559 `x-session-id'.  The value of this variable and `x-session-id' may be the
 560 same, depending on how the session manager works.
 561
 562 See also `emacs-save-session-functions', `emacs-session-save' and
 563 `emacs-session-restore'." */);
 564   Vx_session_previous_id = Qnil;
 565
 566   defsubr (&Shandle_save_session);
 567 }
 568
 569 #endif /* HAVE_X_SM */