New file for X session management.

1 files changed, 533 insertions, 0 deletions

diff --git a/src/xsmfns.c b/src/xsmfns.c
new file mode 100644
index 00000000000..fe0570b665a
--- /dev/null
+++ b/src/xsmfns.c
@@ -0,0 +1,533 @@
+/* Session management module for systems which understand the X Session
+   management protocol.
+   Copyright (C) 2002 Free Software Foundation, Inc.
+
+This file is part of GNU Emacs.
+
+GNU Emacs is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Emacs is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Emacs; see the file COPYING.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+#include <config.h>
+
+#ifdef HAVE_X_SM
+
+#include <X11/SM/SMlib.h>
+#ifdef HAVE_STRING_H
+#include <string.h>
+#else
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+#endif
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+
+#include <sys/param.h>
+
+#include "systime.h"
+#include "sysselect.h"
+#include "lisp.h"
+#include "termhooks.h"
+
+#ifndef MAXPATHLEN
+#define MAXPATHLEN 1024
+#endif /* not MAXPATHLEN */
+
+
+/* The user login name.  */
+
+extern Lisp_Object Vuser_login_name;
+
+/* This is the event used when save_session occurs */
+
+static struct input_event emacs_event;
+
+/* The descriptor that we use to check for data from the session manager. */
+
+static int ice_fd = -1;
+
+/* A flag that says if we are in shutdown interactions or not. */
+
+static int doing_interact = False;
+
+/* The session manager object for the session manager connection */
+
+static SmcConn smc_conn;
+
+/* The client session id for this session */
+static char *client_id;
+
+/* The full path name to the Emacs program */
+static char *emacs_program;
+
+/* The client session id for this session as a lisp object. */
+
+Lisp_Object Vx_session_id;
+
+/* The id we had the previous session.  This is only available if we
+   have been started by the session manager with SMID_OPT. */
+
+Lisp_Object Vx_session_previous_id;
+
+/* The option we tell the session manager to start Emacs with when
+   restarting Emacs.  The client_id is appended. */
+
+#define SMID_OPT "--smid="
+
+
+/* Handle any messages from the session manager.  If no connection is
+   open to a session manager, just return 0.
+   Otherwise returns the number of events stored in buffer BUFP,
+   which can hold up to *NUMCHARS characters.  At most one event is
+   stored, an save_session_event. */
+int
+x_session_check_input (bufp, numchars)
+     struct input_event *bufp;
+     int *numchars;
+{
+  SELECT_TYPE read_fds;
+  EMACS_TIME tmout;
+  
+  if (ice_fd == -1) return 0;
+  
+  FD_ZERO (&read_fds);
+  FD_SET (ice_fd, &read_fds);
+      
+  tmout.tv_sec = 0;
+  tmout.tv_usec = 0;
+  
+  /* Reset this so wo can check kind after callbacks have been called by
+     IceProcessMessages.  The smc_interact_CB sets the kind to
+     save_session_event, but we don't know beforehand if that callback
+     will be called. */
+  emacs_event.kind = no_event;
+
+  if (select (ice_fd+1, &read_fds,
+              (SELECT_TYPE *)0, (SELECT_TYPE *)0, &tmout) < 0)
+    {
+      ice_fd = -1;
+      return 0;
+    }
+  
+
+  if (FD_ISSET (ice_fd, &read_fds))
+    IceProcessMessages (SmcGetIceConnection (smc_conn),
+                        (IceReplyWaitInfo *)0, (Bool *)0);
+
+  
+  /* Check if smc_interact_CB was called and we shall generate a
+     save_session event. */
+  if (*numchars > 0 && emacs_event.kind != no_event)
+    {
+      bcopy (&emacs_event, bufp, sizeof (struct input_event));
+      bufp++;
+      (*numchars)--;
+
+      return 1;
+    }
+
+  return 0;
+}
+
+/* Return non-zero if we have a connection to a session manager.*/
+int
+x_session_have_connection ()
+{
+  return ice_fd != -1;
+}
+
+/* This is called when the session manager says it is OK to interact with the
+   user.  Here we set the kind to save_session so an event is generated.
+   Then lisp code can interact with the user. */
+static void
+smc_interact_CB (smcConn, clientData)
+     SmcConn smcConn;
+     SmPointer clientData;
+{
+  doing_interact = True;
+  emacs_event.kind = save_session_event;
+}
+
+/* This is called when the session manager tells us to save ourself.
+   We set the required properties so the session manager can restart us,
+   plus the current working directory property (not mandatory) so we
+   are started in the correct directory.
+
+   If this is a shutdown and we can request to interact with the user,
+   we do so, because we don't know what the lisp code might do. */
+static void
+smc_save_yourself_CB (smcConn,
+                      clientData,
+                      saveType,
+                      shutdown,
+                      interactStyle,
+                      fast)
+     SmcConn smcConn;
+     SmPointer clientData;
+     int saveType;
+     Bool shutdown;
+     int interactStyle;
+     Bool fast;
+{
+#define NR_PROPS 5
+  
+  SmProp *props[NR_PROPS];
+  SmProp prop_ptr[NR_PROPS];
+  
+  SmPropValue values[20];
+  int val_idx = 0;
+  int props_idx = 0;
+  
+  char cwd[MAXPATHLEN+1];
+  char *smid_opt;
+
+  /* How to start a new instance of Emacs */
+  props[props_idx] = &prop_ptr[props_idx];
+  props[props_idx]->name = SmCloneCommand;
+  props[props_idx]->type = SmLISTofARRAY8;
+  props[props_idx]->num_vals = 1;
+  props[props_idx]->vals = &values[val_idx++];
+  props[props_idx]->vals[0].length = strlen (emacs_program);
+  props[props_idx]->vals[0].value = emacs_program;
+  ++props_idx;
+
+  /* The name of the program */
+  props[props_idx] = &prop_ptr[props_idx];
+  props[props_idx]->name = SmProgram;
+  props[props_idx]->type = SmARRAY8;
+  props[props_idx]->num_vals = 1;
+  props[props_idx]->vals = &values[val_idx++];
+  props[props_idx]->vals[0].length = strlen (XSTRING (Vinvocation_name)->data);
+  props[props_idx]->vals[0].value = XSTRING (Vinvocation_name)->data;
+  ++props_idx;
+  
+  /* How to restart Emacs (i.e.: /path/to/emacs --smid=xxxx). */
+  props[props_idx] = &prop_ptr[props_idx];
+  props[props_idx]->name = SmRestartCommand;
+  props[props_idx]->type = SmLISTofARRAY8;
+  props[props_idx]->num_vals = 2; /* 2 values: /path/to/emacs, --smid=xxx */
+  props[props_idx]->vals = &values[val_idx];
+  props[props_idx]->vals[0].length = strlen (emacs_program);
+  props[props_idx]->vals[0].value = emacs_program;
+
+  smid_opt = xmalloc (strlen (SMID_OPT) + strlen (client_id) + 1);
+  strcpy (smid_opt, SMID_OPT);
+  strcat (smid_opt, client_id);
+  
+  props[props_idx]->vals[1].length = strlen (smid_opt);
+  props[props_idx]->vals[1].value = smid_opt;
+  val_idx += 2;
+  ++props_idx;
+
+  /* User id */
+  props[props_idx] = &prop_ptr[props_idx];
+  props[props_idx]->name = SmUserID;
+  props[props_idx]->type = SmARRAY8;
+  props[props_idx]->num_vals = 1;
+  props[props_idx]->vals = &values[val_idx++];
+  props[props_idx]->vals[0].length = strlen (XSTRING (Vuser_login_name)->data);
+  props[props_idx]->vals[0].value = XSTRING (Vuser_login_name)->data;
+  ++props_idx;
+
+  /* The current directory property, not mandatory */
+#ifdef HAVE_GETCWD
+  if (getcwd (cwd, MAXPATHLEN+1) != 0)
+#else
+  if (getwd (cwd) != 0)
+#endif
+    {
+      props[props_idx] = &prop_ptr[props_idx];
+      props[props_idx]->name = SmCurrentDirectory;
+      props[props_idx]->type = SmARRAY8;
+      props[props_idx]->num_vals = 1;
+      props[props_idx]->vals = &values[val_idx++];
+      props[props_idx]->vals[0].length = strlen (cwd);
+      props[props_idx]->vals[0].value = cwd;
+      ++props_idx;
+    }
+  
+  
+  SmcSetProperties (smcConn, props_idx, props);
+
+  xfree (smid_opt);
+
+  /* See if we maybe shall interact with the user. */
+  if (interactStyle != SmInteractStyleAny
+      || ! shutdown
+      || saveType == SmSaveLocal
+      || ! SmcInteractRequest (smcConn, SmDialogNormal, smc_interact_CB, 0))
+    {
+      /* No interaction, we are done saving ourself. */
+      SmcSaveYourselfDone (smcConn, True);
+    }
+}
+
+/* According to the SM specification, this shall close the connection */
+static void
+smc_die_CB (smcConn, clientData)
+     SmcConn smcConn;
+     SmPointer clientData;
+{
+  SmcCloseConnection (smcConn, 0, 0);
+  ice_fd = -1;
+}
+
+/* We don't use the next two but they are mandatory, leave them empty.
+   According to the SM specification, we should not interact with the
+   user between smc_save_yourself_CB is called and until smc_save_complete_CB
+   is called.  It seems like a lot of job to implement this and it doesn't
+   even seem necessary. */
+static void
+smc_save_complete_CB (smcConn, clientData)
+     SmcConn smcConn;
+     SmPointer clientData;
+{
+  /* Empty */
+}
+
+static void
+smc_shutdown_cancelled_CB (smcConn, clientData)
+     SmcConn smcConn;
+     SmPointer clientData;
+{
+  /* Empty */
+}
+
+/* Error handlers for SM and ICE.  We don't wan't to exit Emacs just
+   because there is some error in the session management. */
+static void
+smc_error_handler (smcConn,
+                   swap,
+                   offendingMinorOpcode,
+                   offendingSequence,
+                   errorClass,
+                   severity,
+                   values)
+     SmcConn smcConn;
+     Bool swap;
+     int offendingMinorOpcode;
+     unsigned long offendingSequence;
+     int errorClass;
+     int severity;
+     SmPointer values;
+{
+  /* Empty */
+}
+
+static void
+ice_error_handler (iceConn,
+                   swap,
+                   offendingMinorOpcode,
+                   offendingSequence,
+                   errorClass,
+                   severity,
+                   values)
+     IceConn iceConn;
+     Bool swap;
+     int offendingMinorOpcode;
+     unsigned long offendingSequence;
+     int errorClass;
+     int severity;
+     IcePointer values;
+{
+  /* Empty */
+}
+
+
+static void
+ice_io_error_handler (iceConn)
+     IceConn iceConn;
+{
+  /* Connection probably gone. */
+  ice_fd = -1;
+}
+
+/* This is called when the ICE connection is created or closed.  The SM library
+   uses ICE as it transport protocol. */
+static void
+ice_conn_watch_CB (iceConn, clientData, opening, watchData)
+     IceConn iceConn;
+     IcePointer clientData;
+     Bool opening;
+     IcePointer *watchData;
+{
+  if (! opening)
+    {
+      ice_fd = -1;
+      return;
+    }
+  
+  ice_fd = IceConnectionNumber (iceConn);
+#ifndef F_SETOWN_BUG
+#ifdef F_SETOWN
+#ifdef F_SETOWN_SOCK_NEG
+  /* stdin is a socket here */
+  fcntl (ice_fd, F_SETOWN, -getpid ());
+#else /* ! defined (F_SETOWN_SOCK_NEG) */
+  fcntl (ice_fd, F_SETOWN, getpid ());
+#endif /* ! defined (F_SETOWN_SOCK_NEG) */
+#endif /* ! defined (F_SETOWN) */
+#endif /* F_SETOWN_BUG */
+
+#ifdef SIGIO
+  if (interrupt_input)
+    init_sigio (ice_fd);
+#endif /* ! defined (SIGIO) */
+}
+
+/* Try to open a connection to the session manager. */
+void
+x_session_initialize ()
+{
+#define SM_ERRORSTRING_LEN 512
+  char errorstring[SM_ERRORSTRING_LEN];
+  char* previous_id = NULL;
+  SmcCallbacks callbacks;
+  int  name_len = 0;
+  
+  /* Check if we where started by the session manager.  If so, we will
+     have a previous id. */
+  if (! EQ (Vx_session_previous_id, Qnil) && STRINGP (Vx_session_previous_id))
+    previous_id = XSTRING (Vx_session_previous_id)->data;
+
+  /* Construct the path to the Emacs program. */
+  if (! EQ (Vinvocation_directory, Qnil))
+    name_len += strlen (XSTRING (Vinvocation_directory)->data);
+  name_len += strlen (XSTRING (Vinvocation_name)->data);
+
+  /* This malloc will not be freed, but it is only done once, and hopefully
+     not very large  */
+  emacs_program = xmalloc (name_len + 1);
+  emacs_program[0] = '\0';
+
+  if (! EQ (Vinvocation_directory, Qnil))
+    strcpy (emacs_program, XSTRING (Vinvocation_directory)->data);
+  strcat (emacs_program, XSTRING (Vinvocation_name)->data);
+  
+  /* The SM protocol says all callbacks are mandatory, so set up all
+     here and in the mask passed to SmcOpenConnection */
+  callbacks.save_yourself.callback = smc_save_yourself_CB;
+  callbacks.save_yourself.client_data = 0;
+  callbacks.die.callback = smc_die_CB;
+  callbacks.die.client_data = 0;
+  callbacks.save_complete.callback = smc_save_complete_CB;
+  callbacks.save_complete.client_data = 0;
+  callbacks.shutdown_cancelled.callback = smc_shutdown_cancelled_CB;
+  callbacks.shutdown_cancelled.client_data = 0;
+
+  /* Set error handlers. */
+  SmcSetErrorHandler (smc_error_handler);
+  IceSetErrorHandler (ice_error_handler);
+  IceSetIOErrorHandler (ice_io_error_handler);
+
+  /* Install callback for when connection status changes. */
+  IceAddConnectionWatch (ice_conn_watch_CB, 0);
+
+  /* Open the connection to the session manager.  A failure is not
+     critical, it usualy means that no session manager is running.
+     The errorstring is here for debugging. */
+  smc_conn = SmcOpenConnection (NULL, NULL, 1, 0,
+                                (SmcSaveYourselfProcMask|
+                                 SmcDieProcMask|
+                                 SmcSaveCompleteProcMask|
+                                 SmcShutdownCancelledProcMask),
+                                &callbacks,
+                                previous_id,
+                                &client_id,
+                                SM_ERRORSTRING_LEN,
+                                errorstring);
+
+  if (smc_conn != 0)
+    Vx_session_id = make_string (client_id, strlen (client_id));
+}
+
+
+DEFUN ("handle-save-session", Fhandle_save_session,
+       Shandle_save_session, 1, 1, "e",
+       doc: /* Handle the save_yourself event from a session manager.
+A session manager can tell Emacs that the window system is shutting down 
+by sending Emacs a save_yourself message.  Emacs executes this function when
+such an event occurs.  This function then executes `emacs-session-save'.
+After that, this function informs the session manager that it can continue
+or abort shutting down the window system depending on the return value
+from `emacs-session-save'  If the return value is non-nil the session manager
+is told to abort the window system shutdown.
+
+Do not call this function yourself. */)
+     (event)
+     Lisp_Object event;
+{
+  /* Check doing_interact so that we don't do anything if someone called
+     this at the wrong time. */
+  if (doing_interact)
+    {
+      Bool cancel_shutdown = False;
+
+      cancel_shutdown = ! EQ (call0 (intern ("emacs-session-save")), Qnil);
+
+      SmcInteractDone (smc_conn, cancel_shutdown);
+      SmcSaveYourselfDone (smc_conn, True);
+
+      doing_interact = False;
+    }
+}
+
+
+/***********************************************************************
+                            Initialization
+ ***********************************************************************/
+void
+syms_of_xsmfns ()
+{
+  DEFVAR_LISP ("x-session-id", &Vx_session_id,
+    doc: /* The session id Emacs got from the session manager for this session.
+Changing the value does not change the session id used by Emacs.
+The value is nil if no session manager is running.
+See also `x-session-previous-id', `emacs-save-session-functions',
+`emacs-session-save' and `emacs-session-restore'." */);
+  Vx_session_id = Qnil;
+
+  DEFVAR_LISP ("x-session-previous-id", &Vx_session_previous_id,
+    doc: /* The previous session id Emacs got from session manager.
+If Emacs is running on a window system that has a session manager, the 
+session manager gives Emacs a session id.  It is feasible for Emacs lisp 
+code to use the session id to save configuration in, for example, a file 
+with a file name based on the session id.  If Emacs is running when the 
+window system is shut down, the session manager remembers that Emacs was 
+running and saves the session id Emacs had.
+
+When the window system is started again, the session manager restarts 
+Emacs and hands Emacs the session id it had the last time it was 
+running.  This is now the previous session id and the value of this 
+variable.  If configuration was saved in a file as stated above, the 
+previous session id shall be used to reconstruct the file name.
+
+The session id Emacs has while it is running is in the variable 
+`x-session-id'.  The value of this variable and `x-session-id' may be the
+same, depending on how the session manager works.
+
+See also `emacs-save-session-functions', `emacs-session-save' and
+`emacs-session-restore'." */);
+  Vx_session_previous_id = Qnil;
+  
+  defsubr (&Shandle_save_session);
+}
+
+#endif /* HAVE_X_SM */