src/xsmfns.c

   1 /* Session management module for systems which understand the X Session
   2    management protocol.
   3
   4 Copyright (C) 2002-2011  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 #ifndef 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 = strlen (SSDATA (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 = strlen (SSDATA (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   i = 3 + initial_argc;
 227   props[props_idx]->num_vals = i;
 228   vp = (SmPropValue *) xmalloc (i * sizeof(*vp));
 229   props[props_idx]->vals = vp;
 230   props[props_idx]->vals[vp_idx].length = strlen (emacs_program);
 231   props[props_idx]->vals[vp_idx++].value = emacs_program;
 232
 233   smid_opt = xmalloc (strlen (SMID_OPT) + strlen (client_id) + 1);
 234   strcpy (smid_opt, SMID_OPT);
 235   strcat (smid_opt, client_id);
 236
 237   props[props_idx]->vals[vp_idx].length = strlen (smid_opt);
 238   props[props_idx]->vals[vp_idx++].value = smid_opt;
 239
 240   props[props_idx]->vals[vp_idx].length = strlen (NOSPLASH_OPT);
 241   props[props_idx]->vals[vp_idx++].value = NOSPLASH_OPT;
 242
 243   if (cwd)
 244     {
 245       chdir_opt = xmalloc (strlen (CHDIR_OPT) + strlen (cwd) + 1);
 246       strcpy (chdir_opt, CHDIR_OPT);
 247       strcat (chdir_opt, cwd);
 248
 249       props[props_idx]->vals[vp_idx].length = strlen (chdir_opt);
 250       props[props_idx]->vals[vp_idx++].value = chdir_opt;
 251     }
 252
 253   for (i = 1; i < initial_argc; ++i)
 254     {
 255       props[props_idx]->vals[vp_idx].length = strlen (initial_argv[i]);
 256       props[props_idx]->vals[vp_idx++].value = initial_argv[i];
 257     }
 258
 259   ++props_idx;
 260
 261   SmcSetProperties (smcConn, props_idx, props);
 262
 263   xfree (smid_opt);
 264   xfree (chdir_opt);
 265   xfree (cwd);
 266   xfree (vp);
 267
 268   for (i = 0; i < props_idx; ++i)
 269     {
 270       xfree (props[i]->type);
 271       xfree (props[i]->name);
 272     }
 273
 274   /* See if we maybe shall interact with the user.  */
 275   if (interactStyle != SmInteractStyleAny
 276       || ! shutdown
 277       || saveType == SmSaveLocal
 278       || ! SmcInteractRequest (smcConn, SmDialogNormal, smc_interact_CB, 0))
 279     {
 280       /* No interaction, we are done saving ourself.  */
 281       SmcSaveYourselfDone (smcConn, True);
 282     }
 283 }
 284
 285 /* According to the SM specification, this shall close the connection.  */
 286
 287 static void
 288 smc_die_CB (SmcConn smcConn, SmPointer clientData)
 289 {
 290   emacs_event.kind = SAVE_SESSION_EVENT;
 291   emacs_event.arg = Qt;
 292 }
 293
 294 /* We don't use the next two but they are mandatory, leave them empty.
 295    According to the SM specification, we should not interact with the
 296    user between smc_save_yourself_CB is called and until smc_save_complete_CB
 297    is called.  It seems like a lot of job to implement this and it doesn't
 298    even seem necessary.  */
 299
 300 static void
 301 smc_save_complete_CB (SmcConn smcConn, SmPointer clientData)
 302 {
 303   /* Empty */
 304 }
 305
 306 static void
 307 smc_shutdown_cancelled_CB (SmcConn smcConn, SmPointer clientData)
 308 {
 309   /* Empty */
 310 }
 311
 312 /* Error handlers for SM and ICE.  We don't want to exit Emacs just
 313    because there is some error in the session management.  */
 314
 315 static void
 316 smc_error_handler (SmcConn smcConn,
 317                    Bool swap,
 318                    int offendingMinorOpcode,
 319                    unsigned long offendingSequence,
 320                    int errorClass,
 321                    int severity,
 322                    SmPointer values)
 323 {
 324   /* Empty  */
 325 }
 326
 327 static void
 328 ice_error_handler (IceConn iceConn,
 329                    Bool swap,
 330                    int offendingMinorOpcode,
 331                    unsigned long offendingSequence,
 332                    int errorClass,
 333                    int severity,
 334                    IcePointer values)
 335 {
 336   /* Empty  */
 337 }
 338
 339
 340 static void
 341 ice_io_error_handler (IceConn iceConn)
 342 {
 343   /* Connection probably gone.  */
 344   ice_connection_closed ();
 345 }
 346
 347 /* This is called when the ICE connection is created or closed.  The SM library
 348    uses ICE as it transport protocol.  */
 349
 350 static void
 351 ice_conn_watch_CB (IceConn iceConn, IcePointer clientData,
 352                    int opening, IcePointer *watchData)
 353 {
 354   if (! opening)
 355     {
 356       ice_connection_closed ();
 357       return;
 358     }
 359
 360   ice_fd = IceConnectionNumber (iceConn);
 361   add_read_fd (ice_fd, x_session_check_input, NULL);
 362 }
 363
 364 /* Create the client leader window.  */
 365
 366 #ifndef USE_GTK
 367 static void
 368 create_client_leader_window (struct x_display_info *dpyinfo, char *client_id)
 369 {
 370   Window w;
 371   XClassHint class_hints;
 372   Atom sm_id;
 373
 374   w = XCreateSimpleWindow (dpyinfo->display,
 375                            dpyinfo->root_window,
 376                            -1, -1, 1, 1,
 377                            CopyFromParent, CopyFromParent, CopyFromParent);
 378
 379   class_hints.res_name = SSDATA (Vx_resource_name);
 380   class_hints.res_class = SSDATA (Vx_resource_class);
 381   XSetClassHint (dpyinfo->display, w, &class_hints);
 382   XStoreName (dpyinfo->display, w, class_hints.res_name);
 383
 384   XChangeProperty (dpyinfo->display, w, dpyinfo->Xatom_SM_CLIENT_ID,
 385                    XA_STRING, 8, PropModeReplace,
 386                    (unsigned char *)client_id, strlen (client_id));
 387
 388   dpyinfo->client_leader_window = w;
 389 }
 390 #endif /* ! USE_GTK */
 391
 392
 393 /* Try to open a connection to the session manager.  */
 394
 395 void
 396 x_session_initialize (struct x_display_info *dpyinfo)
 397 {
 398 #define SM_ERRORSTRING_LEN 512
 399   char errorstring[SM_ERRORSTRING_LEN];
 400   char* previous_id = NULL;
 401   SmcCallbacks callbacks;
 402   int  name_len = 0;
 403
 404   ice_fd = -1;
 405   doing_interact = False;
 406
 407   /* Check if we where started by the session manager.  If so, we will
 408      have a previous id.  */
 409   if (! EQ (Vx_session_previous_id, Qnil) && STRINGP (Vx_session_previous_id))
 410     previous_id = SSDATA (Vx_session_previous_id);
 411
 412   /* Construct the path to the Emacs program.  */
 413   if (! EQ (Vinvocation_directory, Qnil))
 414     name_len += strlen (SSDATA (Vinvocation_directory));
 415   name_len += strlen (SSDATA (Vinvocation_name));
 416
 417   /* This malloc will not be freed, but it is only done once, and hopefully
 418      not very large   */
 419   emacs_program = xmalloc (name_len + 1);
 420   emacs_program[0] = '\0';
 421
 422   if (! EQ (Vinvocation_directory, Qnil))
 423     strcpy (emacs_program, SSDATA (Vinvocation_directory));
 424   strcat (emacs_program, SSDATA (Vinvocation_name));
 425
 426   /* The SM protocol says all callbacks are mandatory, so set up all
 427      here and in the mask passed to SmcOpenConnection.  */
 428   callbacks.save_yourself.callback = smc_save_yourself_CB;
 429   callbacks.save_yourself.client_data = 0;
 430   callbacks.die.callback = smc_die_CB;
 431   callbacks.die.client_data = 0;
 432   callbacks.save_complete.callback = smc_save_complete_CB;
 433   callbacks.save_complete.client_data = 0;
 434   callbacks.shutdown_cancelled.callback = smc_shutdown_cancelled_CB;
 435   callbacks.shutdown_cancelled.client_data = 0;
 436
 437   /* Set error handlers.  */
 438   SmcSetErrorHandler (smc_error_handler);
 439   IceSetErrorHandler (ice_error_handler);
 440   IceSetIOErrorHandler (ice_io_error_handler);
 441
 442   /* Install callback for when connection status changes.  */
 443   IceAddConnectionWatch (ice_conn_watch_CB, 0);
 444
 445   /* Open the connection to the session manager.  A failure is not
 446      critical, it usually means that no session manager is running.
 447      The errorstring is here for debugging.  */
 448   smc_conn = SmcOpenConnection (NULL, NULL, 1, 0,
 449                                 (SmcSaveYourselfProcMask|
 450                                  SmcDieProcMask|
 451                                  SmcSaveCompleteProcMask|
 452                                  SmcShutdownCancelledProcMask),
 453                                 &callbacks,
 454                                 previous_id,
 455                                 &client_id,
 456                                 SM_ERRORSTRING_LEN,
 457                                 errorstring);
 458
 459   if (smc_conn != 0)
 460     {
 461       Vx_session_id = make_string (client_id, strlen (client_id));
 462
 463 #ifdef USE_GTK
 464       /* GTK creats a leader window by itself, but we need to tell
 465          it about our client_id.  */
 466       gdk_x11_set_sm_client_id (client_id);
 467 #else
 468       create_client_leader_window (dpyinfo, client_id);
 469 #endif
 470     }
 471 }
 472
 473 /* Ensure that the session manager is not contacted again. */
 474
 475 void
 476 x_session_close (void)
 477 {
 478   ice_connection_closed ();
 479 }
 480
 481
 482 DEFUN ("handle-save-session", Fhandle_save_session,
 483        Shandle_save_session, 1, 1, "e",
 484        doc: /* Handle the save_yourself event from a session manager.
 485 A session manager can tell Emacs that the window system is shutting down
 486 by sending Emacs a save_yourself message.  Emacs executes this function when
 487 such an event occurs.  This function then executes `emacs-session-save'.
 488 After that, this function informs the session manager that it can continue
 489 or abort shutting down the window system depending on the return value
 490 from `emacs-session-save'  If the return value is non-nil the session manager
 491 is told to abort the window system shutdown.
 492
 493 Do not call this function yourself. */)
 494   (Lisp_Object event)
 495 {
 496   int kill_emacs = CONSP (event) && CONSP (XCDR (event))
 497     && EQ (Qt, XCAR (XCDR (event)));
 498
 499   /* Check doing_interact so that we don't do anything if someone called
 500      this at the wrong time. */
 501   if (doing_interact && ! kill_emacs)
 502     {
 503       Bool cancel_shutdown = False;
 504
 505       cancel_shutdown = ! EQ (call0 (intern ("emacs-session-save")), Qnil);
 506
 507       SmcInteractDone (smc_conn, cancel_shutdown);
 508       SmcSaveYourselfDone (smc_conn, True);
 509
 510       doing_interact = False;
 511     }
 512   else if (kill_emacs)
 513     {
 514       /* We should not do user interaction here, but it is not easy to
 515          prevent.  Fix this in next version.  */
 516       Fkill_emacs (Qnil);
 517
 518       /* This will not be reached, but we want kill-emacs-hook to be run.  */
 519       SmcCloseConnection (smc_conn, 0, 0);
 520       ice_connection_closed ();
 521     }
 522
 523   return Qnil;
 524 }
 525
 526
 527 \f
 528 /***********************************************************************
 529                             Initialization
 530  ***********************************************************************/
 531 void
 532 syms_of_xsmfns (void)
 533 {
 534   DEFVAR_LISP ("x-session-id", Vx_session_id,
 535     doc: /* The session id Emacs got from the session manager for this session.
 536 Changing the value does not change the session id used by Emacs.
 537 The value is nil if no session manager is running.
 538 See also `x-session-previous-id', `emacs-save-session-functions',
 539 `emacs-session-save' and `emacs-session-restore'." */);
 540   Vx_session_id = Qnil;
 541
 542   DEFVAR_LISP ("x-session-previous-id", Vx_session_previous_id,
 543     doc: /* The previous session id Emacs got from session manager.
 544 If Emacs is running on a window system that has a session manager, the
 545 session manager gives Emacs a session id.  It is feasible for Emacs Lisp
 546 code to use the session id to save configuration in, for example, a file
 547 with a file name based on the session id.  If Emacs is running when the
 548 window system is shut down, the session manager remembers that Emacs was
 549 running and saves the session id Emacs had.
 550
 551 When the window system is started again, the session manager restarts
 552 Emacs and hands Emacs the session id it had the last time it was
 553 running.  This is now the previous session id and the value of this
 554 variable.  If configuration was saved in a file as stated above, the
 555 previous session id shall be used to reconstruct the file name.
 556
 557 The session id Emacs has while it is running is in the variable
 558 `x-session-id'.  The value of this variable and `x-session-id' may be the
 559 same, depending on how the session manager works.
 560
 561 See also `emacs-save-session-functions', `emacs-session-save' and
 562 `emacs-session-restore'." */);
 563   Vx_session_previous_id = Qnil;
 564
 565   defsubr (&Shandle_save_session);
 566 }
 567
 568 #endif /* HAVE_X_SM */