code.delx.au - gnu-emacs/blob - src/xsmfns.c

   1 /* Session management module for systems which understand the X Session
   2    management protocol.
   3    Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs; see the file COPYING.  If not, write to
  19 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22 #include <config.h>
  23
  24 #ifdef HAVE_X_SM
  25
  26 #include <X11/SM/SMlib.h>
  27 #include <X11/Xlib.h>
  28 #include <X11/Xutil.h>
  29
  30 #ifdef HAVE_STRING_H
  31 #include <string.h>
  32 #else
  33 #ifdef HAVE_STRINGS_H
  34 #include <strings.h>
  35 #endif
  36 #endif
  37
  38 #ifdef HAVE_UNISTD_H
  39 #include <unistd.h>
  40 #endif
  41 #ifdef HAVE_STDLIB_H
  42 #include <stdlib.h>
  43 #endif
  44
  45 #include <sys/param.h>
  46 #include <stdio.h>
  47
  48 #include "systime.h"
  49 #include "sysselect.h"
  50 #include "lisp.h"
  51 #include "frame.h"
  52 #include "termhooks.h"
  53 #include "termopts.h"
  54 #include "xterm.h"
  55
  56 #ifndef MAXPATHLEN
  57 #define MAXPATHLEN 1024
  58 #endif /* not MAXPATHLEN */
  59
  60
  61 /* The user login name.  */
  62
  63 extern Lisp_Object Vuser_login_name;
  64
  65 /* This is the event used when SAVE_SESSION_EVENT occurs.  */
  66
  67 static struct input_event emacs_event;
  68
  69 /* The descriptor that we use to check for data from the session manager.  */
  70
  71 static int ice_fd = -1;
  72
  73 /* A flag that says if we are in shutdown interactions or not.  */
  74
  75 static int doing_interact = False;
  76
  77 /* The session manager object for the session manager connection.  */
  78
  79 static SmcConn smc_conn;
  80
  81 /* The client session id for this session.  */
  82
  83 static char *client_id;
  84
  85 /* The full path name to the Emacs program.  */
  86
  87 static char *emacs_program;
  88
  89 /* The client session id for this session as a lisp object.  */
  90
  91 Lisp_Object Vx_session_id;
  92
  93 /* The id we had the previous session.  This is only available if we
  94    have been started by the session manager with SMID_OPT.  */
  95
  96 Lisp_Object Vx_session_previous_id;
  97
  98 /* The option we tell the session manager to start Emacs with when
  99    restarting Emacs.  The client_id is appended.  */
 100
 101 #define SMID_OPT "--smid="
 102
 103
 104 /* The option to start Emacs without the splash screen when
 105    restarting Emacs.  */
 106
 107 #define NOSPLASH_OPT "--no-splash"
 108
 109
 110 /* Handle any messages from the session manager.  If no connection is
 111    open to a session manager, just return 0.
 112    Otherwise returns 1 if SAVE_SESSION_EVENT is stored in buffer BUFP.  */
 113
 114 int
 115 x_session_check_input (bufp)
 116      struct input_event *bufp;
 117 {
 118   SELECT_TYPE read_fds;
 119   EMACS_TIME tmout;
 120
 121   if (ice_fd == -1) return 0;
 122
 123   FD_ZERO (&read_fds);
 124   FD_SET (ice_fd, &read_fds);
 125
 126   tmout.tv_sec = 0;
 127   tmout.tv_usec = 0;
 128
 129   /* Reset this so wo can check kind after callbacks have been called by
 130      IceProcessMessages.  The smc_interact_CB sets the kind to
 131      SAVE_SESSION_EVENT, but we don't know beforehand if that callback
 132      will be called.  */
 133   emacs_event.kind = NO_EVENT;
 134
 135   if (select (ice_fd+1, &read_fds,
 136               (SELECT_TYPE *)0, (SELECT_TYPE *)0, &tmout) < 0)
 137     {
 138       ice_fd = -1;
 139       return 0;
 140     }
 141
 142
 143   if (FD_ISSET (ice_fd, &read_fds))
 144     IceProcessMessages (SmcGetIceConnection (smc_conn),
 145                         (IceReplyWaitInfo *)0, (Bool *)0);
 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     return 0;
 152
 153   bcopy (&emacs_event, bufp, sizeof (struct input_event));
 154   return 1;
 155 }
 156
 157 /* Return non-zero if we have a connection to a session manager.  */
 158
 159 int
 160 x_session_have_connection ()
 161 {
 162   return ice_fd != -1;
 163 }
 164
 165 /* This is called when the session manager says it is OK to interact with the
 166    user.  Here we set the kind to SAVE_SESSION_EVENT so an event is generated.
 167    Then lisp code can interact with the user.  */
 168
 169 static void
 170 smc_interact_CB (smcConn, clientData)
 171      SmcConn smcConn;
 172      SmPointer clientData;
 173 {
 174   doing_interact = True;
 175   emacs_event.kind = SAVE_SESSION_EVENT;
 176 }
 177
 178 /* This is called when the session manager tells us to save ourselves.
 179    We set the required properties so the session manager can restart us,
 180    plus the current working directory property (not mandatory) so we
 181    are started in the correct directory.
 182
 183    If this is a shutdown and we can request to interact with the user,
 184    we do so, because we don't know what the lisp code might do.  */
 185
 186 static void
 187 smc_save_yourself_CB (smcConn,
 188                       clientData,
 189                       saveType,
 190                       shutdown,
 191                       interactStyle,
 192                       fast)
 193      SmcConn smcConn;
 194      SmPointer clientData;
 195      int saveType;
 196      Bool shutdown;
 197      int interactStyle;
 198      Bool fast;
 199 {
 200 #define NR_PROPS 5
 201
 202   SmProp *props[NR_PROPS];
 203   SmProp prop_ptr[NR_PROPS];
 204
 205   SmPropValue values[20];
 206   int val_idx = 0;
 207   int props_idx = 0;
 208
 209   char cwd[MAXPATHLEN+1];
 210   char *smid_opt;
 211
 212   /* How to start a new instance of Emacs.  */
 213   props[props_idx] = &prop_ptr[props_idx];
 214   props[props_idx]->name = SmCloneCommand;
 215   props[props_idx]->type = SmLISTofARRAY8;
 216   props[props_idx]->num_vals = 1;
 217   props[props_idx]->vals = &values[val_idx++];
 218   props[props_idx]->vals[0].length = strlen (emacs_program);
 219   props[props_idx]->vals[0].value = emacs_program;
 220   ++props_idx;
 221
 222   /* The name of the program.  */
 223   props[props_idx] = &prop_ptr[props_idx];
 224   props[props_idx]->name = SmProgram;
 225   props[props_idx]->type = SmARRAY8;
 226   props[props_idx]->num_vals = 1;
 227   props[props_idx]->vals = &values[val_idx++];
 228   props[props_idx]->vals[0].length = strlen (SDATA (Vinvocation_name));
 229   props[props_idx]->vals[0].value = SDATA (Vinvocation_name);
 230   ++props_idx;
 231
 232   /* How to restart Emacs (i.e.: /path/to/emacs --smid=xxxx --no-splash).  */
 233   props[props_idx] = &prop_ptr[props_idx];
 234   props[props_idx]->name = SmRestartCommand;
 235   props[props_idx]->type = SmLISTofARRAY8;
 236   props[props_idx]->num_vals = 3; /* /path/to/emacs, --smid=xxx --no-splash  */
 237   props[props_idx]->vals = &values[val_idx];
 238   props[props_idx]->vals[0].length = strlen (emacs_program);
 239   props[props_idx]->vals[0].value = emacs_program;
 240
 241   smid_opt = xmalloc (strlen (SMID_OPT) + strlen (client_id) + 1);
 242   strcpy (smid_opt, SMID_OPT);
 243   strcat (smid_opt, client_id);
 244
 245   props[props_idx]->vals[1].length = strlen (smid_opt);
 246   props[props_idx]->vals[1].value = smid_opt;
 247
 248   props[props_idx]->vals[2].length = strlen (NOSPLASH_OPT);
 249   props[props_idx]->vals[2].value = NOSPLASH_OPT;
 250   val_idx += 3;
 251   ++props_idx;
 252
 253   /* User id.  */
 254   props[props_idx] = &prop_ptr[props_idx];
 255   props[props_idx]->name = SmUserID;
 256   props[props_idx]->type = SmARRAY8;
 257   props[props_idx]->num_vals = 1;
 258   props[props_idx]->vals = &values[val_idx++];
 259   props[props_idx]->vals[0].length = strlen (SDATA (Vuser_login_name));
 260   props[props_idx]->vals[0].value = SDATA (Vuser_login_name);
 261   ++props_idx;
 262
 263   /* The current directory property, not mandatory.  */
 264 #ifdef HAVE_GETCWD
 265   if (getcwd (cwd, MAXPATHLEN+1) != 0)
 266 #else
 267   if (getwd (cwd) != 0)
 268 #endif
 269     {
 270       props[props_idx] = &prop_ptr[props_idx];
 271       props[props_idx]->name = SmCurrentDirectory;
 272       props[props_idx]->type = SmARRAY8;
 273       props[props_idx]->num_vals = 1;
 274       props[props_idx]->vals = &values[val_idx++];
 275       props[props_idx]->vals[0].length = strlen (cwd);
 276       props[props_idx]->vals[0].value = cwd;
 277       ++props_idx;
 278     }
 279
 280
 281   SmcSetProperties (smcConn, props_idx, props);
 282
 283   xfree (smid_opt);
 284
 285   /* See if we maybe shall interact with the user.  */
 286   if (interactStyle != SmInteractStyleAny
 287       || ! shutdown
 288       || saveType == SmSaveLocal
 289       || ! SmcInteractRequest (smcConn, SmDialogNormal, smc_interact_CB, 0))
 290     {
 291       /* No interaction, we are done saving ourself.  */
 292       SmcSaveYourselfDone (smcConn, True);
 293     }
 294 }
 295
 296 /* According to the SM specification, this shall close the connection.  */
 297
 298 static void
 299 smc_die_CB (smcConn, clientData)
 300      SmcConn smcConn;
 301      SmPointer clientData;
 302 {
 303   SmcCloseConnection (smcConn, 0, 0);
 304   ice_fd = -1;
 305 }
 306
 307 /* We don't use the next two but they are mandatory, leave them empty.
 308    According to the SM specification, we should not interact with the
 309    user between smc_save_yourself_CB is called and until smc_save_complete_CB
 310    is called.  It seems like a lot of job to implement this and it doesn't
 311    even seem necessary.  */
 312
 313 static void
 314 smc_save_complete_CB (smcConn, clientData)
 315      SmcConn smcConn;
 316      SmPointer clientData;
 317 {
 318   /* Empty */
 319 }
 320
 321 static void
 322 smc_shutdown_cancelled_CB (smcConn, clientData)
 323      SmcConn smcConn;
 324      SmPointer clientData;
 325 {
 326   /* Empty */
 327 }
 328
 329 /* Error handlers for SM and ICE.  We don't want to exit Emacs just
 330    because there is some error in the session management.  */
 331
 332 static void
 333 smc_error_handler (smcConn,
 334                    swap,
 335                    offendingMinorOpcode,
 336                    offendingSequence,
 337                    errorClass,
 338                    severity,
 339                    values)
 340      SmcConn smcConn;
 341      Bool swap;
 342      int offendingMinorOpcode;
 343      unsigned long offendingSequence;
 344      int errorClass;
 345      int severity;
 346      SmPointer values;
 347 {
 348   /* Empty  */
 349 }
 350
 351 static void
 352 ice_error_handler (iceConn,
 353                    swap,
 354                    offendingMinorOpcode,
 355                    offendingSequence,
 356                    errorClass,
 357                    severity,
 358                    values)
 359      IceConn iceConn;
 360      Bool swap;
 361      int offendingMinorOpcode;
 362      unsigned long offendingSequence;
 363      int errorClass;
 364      int severity;
 365      IcePointer values;
 366 {
 367   /* Empty  */
 368 }
 369
 370
 371 static void
 372 ice_io_error_handler (iceConn)
 373      IceConn iceConn;
 374 {
 375   /* Connection probably gone.  */
 376   ice_fd = -1;
 377 }
 378
 379 /* This is called when the ICE connection is created or closed.  The SM library
 380    uses ICE as it transport protocol.  */
 381
 382 static void
 383 ice_conn_watch_CB (iceConn, clientData, opening, watchData)
 384      IceConn iceConn;
 385      IcePointer clientData;
 386      Bool opening;
 387      IcePointer *watchData;
 388 {
 389   if (! opening)
 390     {
 391       ice_fd = -1;
 392       return;
 393     }
 394
 395   ice_fd = IceConnectionNumber (iceConn);
 396 #ifndef F_SETOWN_BUG
 397 #ifdef F_SETOWN
 398 #ifdef F_SETOWN_SOCK_NEG
 399   /* stdin is a socket here */
 400   fcntl (ice_fd, F_SETOWN, -getpid ());
 401 #else /* ! defined (F_SETOWN_SOCK_NEG) */
 402   fcntl (ice_fd, F_SETOWN, getpid ());
 403 #endif /* ! defined (F_SETOWN_SOCK_NEG) */
 404 #endif /* ! defined (F_SETOWN) */
 405 #endif /* F_SETOWN_BUG */
 406
 407 #ifdef SIGIO
 408   if (interrupt_input)
 409     init_sigio (ice_fd);
 410 #endif /* ! defined (SIGIO) */
 411 }
 412
 413 /* Create the client leader window.  */
 414
 415 static void
 416 create_client_leader_window (dpyinfo, client_id)
 417      struct x_display_info *dpyinfo;
 418      char *client_id;
 419 {
 420   Window w;
 421   XClassHint class_hints;
 422   Atom sm_id;
 423
 424   w = XCreateSimpleWindow (dpyinfo->display,
 425                            dpyinfo->root_window,
 426                            -1, -1, 1, 1,
 427                            CopyFromParent, CopyFromParent, CopyFromParent);
 428
 429   class_hints.res_name = (char *) SDATA (Vx_resource_name);
 430   class_hints.res_class = (char *) SDATA (Vx_resource_class);
 431   XSetClassHint (dpyinfo->display, w, &class_hints);
 432   XStoreName (dpyinfo->display, w, class_hints.res_name);
 433
 434   sm_id = XInternAtom (dpyinfo->display, "SM_CLIENT_ID", False);
 435   XChangeProperty (dpyinfo->display, w, sm_id, XA_STRING, 8, PropModeReplace,
 436                    client_id, strlen (client_id));
 437
 438   dpyinfo->client_leader_window = w;
 439 }
 440
 441 /* Try to open a connection to the session manager.  */
 442
 443 void
 444 x_session_initialize (dpyinfo)
 445      struct x_display_info *dpyinfo;
 446 {
 447 #define SM_ERRORSTRING_LEN 512
 448   char errorstring[SM_ERRORSTRING_LEN];
 449   char* previous_id = NULL;
 450   SmcCallbacks callbacks;
 451   int  name_len = 0;
 452
 453   /* Check if we where started by the session manager.  If so, we will
 454      have a previous id.  */
 455   if (! EQ (Vx_session_previous_id, Qnil) && STRINGP (Vx_session_previous_id))
 456     previous_id = SDATA (Vx_session_previous_id);
 457
 458   /* Construct the path to the Emacs program.  */
 459   if (! EQ (Vinvocation_directory, Qnil))
 460     name_len += strlen (SDATA (Vinvocation_directory));
 461   name_len += strlen (SDATA (Vinvocation_name));
 462
 463   /* This malloc will not be freed, but it is only done once, and hopefully
 464      not very large   */
 465   emacs_program = xmalloc (name_len + 1);
 466   emacs_program[0] = '\0';
 467
 468   if (! EQ (Vinvocation_directory, Qnil))
 469     strcpy (emacs_program, SDATA (Vinvocation_directory));
 470   strcat (emacs_program, SDATA (Vinvocation_name));
 471
 472   /* The SM protocol says all callbacks are mandatory, so set up all
 473      here and in the mask passed to SmcOpenConnection.  */
 474   callbacks.save_yourself.callback = smc_save_yourself_CB;
 475   callbacks.save_yourself.client_data = 0;
 476   callbacks.die.callback = smc_die_CB;
 477   callbacks.die.client_data = 0;
 478   callbacks.save_complete.callback = smc_save_complete_CB;
 479   callbacks.save_complete.client_data = 0;
 480   callbacks.shutdown_cancelled.callback = smc_shutdown_cancelled_CB;
 481   callbacks.shutdown_cancelled.client_data = 0;
 482
 483   /* Set error handlers.  */
 484   SmcSetErrorHandler (smc_error_handler);
 485   IceSetErrorHandler (ice_error_handler);
 486   IceSetIOErrorHandler (ice_io_error_handler);
 487
 488   /* Install callback for when connection status changes.  */
 489   IceAddConnectionWatch (ice_conn_watch_CB, 0);
 490
 491   /* Open the connection to the session manager.  A failure is not
 492      critical, it usually means that no session manager is running.
 493      The errorstring is here for debugging.  */
 494   smc_conn = SmcOpenConnection (NULL, NULL, 1, 0,
 495                                 (SmcSaveYourselfProcMask|
 496                                  SmcDieProcMask|
 497                                  SmcSaveCompleteProcMask|
 498                                  SmcShutdownCancelledProcMask),
 499                                 &callbacks,
 500                                 previous_id,
 501                                 &client_id,
 502                                 SM_ERRORSTRING_LEN,
 503                                 errorstring);
 504
 505   if (smc_conn != 0)
 506     {
 507       Vx_session_id = make_string (client_id, strlen (client_id));
 508
 509 #ifdef USE_GTK
 510       /* GTK creats a leader window by itself, but we need to tell
 511          it about our client_id.  */
 512       gdk_set_sm_client_id (client_id);
 513 #else
 514       create_client_leader_window (dpyinfo, client_id);
 515 #endif
 516     }
 517 }
 518
 519
 520 DEFUN ("handle-save-session", Fhandle_save_session,
 521        Shandle_save_session, 1, 1, "e",
 522        doc: /* Handle the save_yourself event from a session manager.
 523 A session manager can tell Emacs that the window system is shutting down
 524 by sending Emacs a save_yourself message.  Emacs executes this function when
 525 such an event occurs.  This function then executes `emacs-session-save'.
 526 After that, this function informs the session manager that it can continue
 527 or abort shutting down the window system depending on the return value
 528 from `emacs-session-save'  If the return value is non-nil the session manager
 529 is told to abort the window system shutdown.
 530
 531 Do not call this function yourself. */)
 532      (event)
 533      Lisp_Object event;
 534 {
 535   /* Check doing_interact so that we don't do anything if someone called
 536      this at the wrong time. */
 537   if (doing_interact)
 538     {
 539       Bool cancel_shutdown = False;
 540
 541       cancel_shutdown = ! EQ (call0 (intern ("emacs-session-save")), Qnil);
 542
 543       SmcInteractDone (smc_conn, cancel_shutdown);
 544       SmcSaveYourselfDone (smc_conn, True);
 545
 546       doing_interact = False;
 547     }
 548
 549   return Qnil;
 550 }
 551
 552 \f
 553 /***********************************************************************
 554                             Initialization
 555  ***********************************************************************/
 556 void
 557 syms_of_xsmfns ()
 558 {
 559   DEFVAR_LISP ("x-session-id", &Vx_session_id,
 560     doc: /* The session id Emacs got from the session manager for this session.
 561 Changing the value does not change the session id used by Emacs.
 562 The value is nil if no session manager is running.
 563 See also `x-session-previous-id', `emacs-save-session-functions',
 564 `emacs-session-save' and `emacs-session-restore'." */);
 565   Vx_session_id = Qnil;
 566
 567   DEFVAR_LISP ("x-session-previous-id", &Vx_session_previous_id,
 568     doc: /* The previous session id Emacs got from session manager.
 569 If Emacs is running on a window system that has a session manager, the
 570 session manager gives Emacs a session id.  It is feasible for Emacs lisp
 571 code to use the session id to save configuration in, for example, a file
 572 with a file name based on the session id.  If Emacs is running when the
 573 window system is shut down, the session manager remembers that Emacs was
 574 running and saves the session id Emacs had.
 575
 576 When the window system is started again, the session manager restarts
 577 Emacs and hands Emacs the session id it had the last time it was
 578 running.  This is now the previous session id and the value of this
 579 variable.  If configuration was saved in a file as stated above, the
 580 previous session id shall be used to reconstruct the file name.
 581
 582 The session id Emacs has while it is running is in the variable
 583 `x-session-id'.  The value of this variable and `x-session-id' may be the
 584 same, depending on how the session manager works.
 585
 586 See also `emacs-save-session-functions', `emacs-session-save' and
 587 `emacs-session-restore'." */);
 588   Vx_session_previous_id = Qnil;
 589
 590   defsubr (&Shandle_save_session);
 591 }
 592
 593 #endif /* HAVE_X_SM */
 594
 595 /* arch-tag: 56a2c58c-adfa-430a-b772-130abd29fd2e
 596    (do not change this comment) */