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 #define 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
 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 = SmCloneCommand;
 208   props[props_idx]->type = 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 = SmProgram;
 218   props[props_idx]->type = 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 = SmRestartCommand;
 228   props[props_idx]->type = 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 = SmUserID;
 262   props[props_idx]->type = 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 = SmCurrentDirectory;
 274       props[props_idx]->type = 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
 290   /* See if we maybe shall interact with the user.  */
 291   if (interactStyle != SmInteractStyleAny
 292       || ! shutdown
 293       || saveType == SmSaveLocal
 294       || ! SmcInteractRequest (smcConn, SmDialogNormal, smc_interact_CB, 0))
 295     {
 296       /* No interaction, we are done saving ourself.  */
 297       SmcSaveYourselfDone (smcConn, True);
 298     }
 299 }
 300
 301 /* According to the SM specification, this shall close the connection.  */
 302
 303 static void
 304 smc_die_CB (SmcConn smcConn, SmPointer clientData)
 305 {
 306   SmcCloseConnection (smcConn, 0, 0);
 307   ice_connection_closed ();
 308 }
 309
 310 /* We don't use the next two but they are mandatory, leave them empty.
 311    According to the SM specification, we should not interact with the
 312    user between smc_save_yourself_CB is called and until smc_save_complete_CB
 313    is called.  It seems like a lot of job to implement this and it doesn't
 314    even seem necessary.  */
 315
 316 static void
 317 smc_save_complete_CB (SmcConn smcConn, SmPointer clientData)
 318 {
 319   /* Empty */
 320 }
 321
 322 static void
 323 smc_shutdown_cancelled_CB (SmcConn smcConn, SmPointer clientData)
 324 {
 325   /* Empty */
 326 }
 327
 328 /* Error handlers for SM and ICE.  We don't want to exit Emacs just
 329    because there is some error in the session management.  */
 330
 331 static void
 332 smc_error_handler (SmcConn smcConn,
 333                    Bool swap,
 334                    int offendingMinorOpcode,
 335                    unsigned long offendingSequence,
 336                    int errorClass,
 337                    int severity,
 338                    SmPointer values)
 339 {
 340   /* Empty  */
 341 }
 342
 343 static void
 344 ice_error_handler (IceConn iceConn,
 345                    Bool swap,
 346                    int offendingMinorOpcode,
 347                    unsigned long offendingSequence,
 348                    int errorClass,
 349                    int severity,
 350                    IcePointer values)
 351 {
 352   /* Empty  */
 353 }
 354
 355
 356 static void
 357 ice_io_error_handler (IceConn iceConn)
 358 {
 359   /* Connection probably gone.  */
 360   ice_connection_closed ();
 361 }
 362
 363 /* This is called when the ICE connection is created or closed.  The SM library
 364    uses ICE as it transport protocol.  */
 365
 366 static void
 367 ice_conn_watch_CB (IceConn iceConn, IcePointer clientData, int opening, IcePointer *watchData)
 368 {
 369   if (! opening)
 370     {
 371       ice_connection_closed ();
 372       return;
 373     }
 374
 375   ice_fd = IceConnectionNumber (iceConn);
 376 #ifdef F_SETOWN
 377   fcntl (ice_fd, F_SETOWN, getpid ());
 378 #endif /* ! defined (F_SETOWN) */
 379
 380 #ifdef SIGIO
 381   if (interrupt_input)
 382     init_sigio (ice_fd);
 383 #endif /* ! defined (SIGIO) */
 384
 385   add_keyboard_wait_descriptor (ice_fd);
 386 }
 387
 388 /* Create the client leader window.  */
 389
 390 #ifndef USE_GTK
 391 static void
 392 create_client_leader_window (struct x_display_info *dpyinfo, char *client_id)
 393 {
 394   Window w;
 395   XClassHint class_hints;
 396   Atom sm_id;
 397
 398   w = XCreateSimpleWindow (dpyinfo->display,
 399                            dpyinfo->root_window,
 400                            -1, -1, 1, 1,
 401                            CopyFromParent, CopyFromParent, CopyFromParent);
 402
 403   class_hints.res_name = (char *) SDATA (Vx_resource_name);
 404   class_hints.res_class = (char *) SDATA (Vx_resource_class);
 405   XSetClassHint (dpyinfo->display, w, &class_hints);
 406   XStoreName (dpyinfo->display, w, class_hints.res_name);
 407
 408   sm_id = XInternAtom (dpyinfo->display, "SM_CLIENT_ID", False);
 409   XChangeProperty (dpyinfo->display, w, sm_id, XA_STRING, 8, PropModeReplace,
 410                    (unsigned char *)client_id, strlen (client_id));
 411
 412   dpyinfo->client_leader_window = w;
 413 }
 414 #endif /* ! USE_GTK */
 415
 416
 417 /* Try to open a connection to the session manager.  */
 418
 419 void
 420 x_session_initialize (struct x_display_info *dpyinfo)
 421 {
 422 #define SM_ERRORSTRING_LEN 512
 423   char errorstring[SM_ERRORSTRING_LEN];
 424   char* previous_id = NULL;
 425   SmcCallbacks callbacks;
 426   int  name_len = 0;
 427
 428   ice_fd = -1;
 429   doing_interact = False;
 430
 431   /* Check if we where started by the session manager.  If so, we will
 432      have a previous id.  */
 433   if (! EQ (Vx_session_previous_id, Qnil) && STRINGP (Vx_session_previous_id))
 434     previous_id = SSDATA (Vx_session_previous_id);
 435
 436   /* Construct the path to the Emacs program.  */
 437   if (! EQ (Vinvocation_directory, Qnil))
 438     name_len += strlen (SSDATA (Vinvocation_directory));
 439   name_len += strlen (SSDATA (Vinvocation_name));
 440
 441   /* This malloc will not be freed, but it is only done once, and hopefully
 442      not very large   */
 443   emacs_program = xmalloc (name_len + 1);
 444   emacs_program[0] = '\0';
 445
 446   if (! EQ (Vinvocation_directory, Qnil))
 447     strcpy (emacs_program, SSDATA (Vinvocation_directory));
 448   strcat (emacs_program, SSDATA (Vinvocation_name));
 449
 450   /* The SM protocol says all callbacks are mandatory, so set up all
 451      here and in the mask passed to SmcOpenConnection.  */
 452   callbacks.save_yourself.callback = smc_save_yourself_CB;
 453   callbacks.save_yourself.client_data = 0;
 454   callbacks.die.callback = smc_die_CB;
 455   callbacks.die.client_data = 0;
 456   callbacks.save_complete.callback = smc_save_complete_CB;
 457   callbacks.save_complete.client_data = 0;
 458   callbacks.shutdown_cancelled.callback = smc_shutdown_cancelled_CB;
 459   callbacks.shutdown_cancelled.client_data = 0;
 460
 461   /* Set error handlers.  */
 462   SmcSetErrorHandler (smc_error_handler);
 463   IceSetErrorHandler (ice_error_handler);
 464   IceSetIOErrorHandler (ice_io_error_handler);
 465
 466   /* Install callback for when connection status changes.  */
 467   IceAddConnectionWatch (ice_conn_watch_CB, 0);
 468
 469   /* Open the connection to the session manager.  A failure is not
 470      critical, it usually means that no session manager is running.
 471      The errorstring is here for debugging.  */
 472   smc_conn = SmcOpenConnection (NULL, NULL, 1, 0,
 473                                 (SmcSaveYourselfProcMask|
 474                                  SmcDieProcMask|
 475                                  SmcSaveCompleteProcMask|
 476                                  SmcShutdownCancelledProcMask),
 477                                 &callbacks,
 478                                 previous_id,
 479                                 &client_id,
 480                                 SM_ERRORSTRING_LEN,
 481                                 errorstring);
 482
 483   if (smc_conn != 0)
 484     {
 485       Vx_session_id = make_string (client_id, strlen (client_id));
 486
 487 #ifdef USE_GTK
 488       /* GTK creats a leader window by itself, but we need to tell
 489          it about our client_id.  */
 490       gdk_set_sm_client_id (client_id);
 491 #else
 492       create_client_leader_window (dpyinfo, client_id);
 493 #endif
 494     }
 495 }
 496
 497 /* Ensure that the session manager is not contacted again. */
 498
 499 void
 500 x_session_close (void)
 501 {
 502   ice_connection_closed ();
 503 }
 504
 505
 506 DEFUN ("handle-save-session", Fhandle_save_session,
 507        Shandle_save_session, 1, 1, "e",
 508        doc: /* Handle the save_yourself event from a session manager.
 509 A session manager can tell Emacs that the window system is shutting down
 510 by sending Emacs a save_yourself message.  Emacs executes this function when
 511 such an event occurs.  This function then executes `emacs-session-save'.
 512 After that, this function informs the session manager that it can continue
 513 or abort shutting down the window system depending on the return value
 514 from `emacs-session-save'  If the return value is non-nil the session manager
 515 is told to abort the window system shutdown.
 516
 517 Do not call this function yourself. */)
 518   (Lisp_Object event)
 519 {
 520   /* Check doing_interact so that we don't do anything if someone called
 521      this at the wrong time. */
 522   if (doing_interact)
 523     {
 524       Bool cancel_shutdown = False;
 525
 526       cancel_shutdown = ! EQ (call0 (intern ("emacs-session-save")), Qnil);
 527
 528       SmcInteractDone (smc_conn, cancel_shutdown);
 529       SmcSaveYourselfDone (smc_conn, True);
 530
 531       doing_interact = False;
 532     }
 533
 534   return Qnil;
 535 }
 536
 537 \f
 538 /***********************************************************************
 539                             Initialization
 540  ***********************************************************************/
 541 void
 542 syms_of_xsmfns (void)
 543 {
 544   DEFVAR_LISP ("x-session-id", &Vx_session_id,
 545     doc: /* The session id Emacs got from the session manager for this session.
 546 Changing the value does not change the session id used by Emacs.
 547 The value is nil if no session manager is running.
 548 See also `x-session-previous-id', `emacs-save-session-functions',
 549 `emacs-session-save' and `emacs-session-restore'." */);
 550   Vx_session_id = Qnil;
 551
 552   DEFVAR_LISP ("x-session-previous-id", &Vx_session_previous_id,
 553     doc: /* The previous session id Emacs got from session manager.
 554 If Emacs is running on a window system that has a session manager, the
 555 session manager gives Emacs a session id.  It is feasible for Emacs Lisp
 556 code to use the session id to save configuration in, for example, a file
 557 with a file name based on the session id.  If Emacs is running when the
 558 window system is shut down, the session manager remembers that Emacs was
 559 running and saves the session id Emacs had.
 560
 561 When the window system is started again, the session manager restarts
 562 Emacs and hands Emacs the session id it had the last time it was
 563 running.  This is now the previous session id and the value of this
 564 variable.  If configuration was saved in a file as stated above, the
 565 previous session id shall be used to reconstruct the file name.
 566
 567 The session id Emacs has while it is running is in the variable
 568 `x-session-id'.  The value of this variable and `x-session-id' may be the
 569 same, depending on how the session manager works.
 570
 571 See also `emacs-save-session-functions', `emacs-session-save' and
 572 `emacs-session-restore'." */);
 573   Vx_session_previous_id = Qnil;
 574
 575   defsubr (&Shandle_save_session);
 576 }
 577
 578 #endif /* HAVE_X_SM */
 579
 580 /* arch-tag: 56a2c58c-adfa-430a-b772-130abd29fd2e
 581    (do not change this comment) */