[True patch] FSF 20.x style clash detection.

XEmacs hacking is too addictive. I came back after training and finished it. This is now tested. It still needs looking over by somebody with more XEmacs C experience. It still won't work on 'msw. I have also have mode one inspection round through the code and it seems all OK to me now. I have brought over our GCPROing of some variables since that seems needed and it is always good to be on the safe side. Likewise the code now uses callx_in_buffer like our old code did. Jan P.S. Should I replace GNU Emacs by XEmacs in the copyright statements? 1998-05-14 Jan Vroonhof <vroonhof(a)math.ethz.ch&gt; * emacs.c (main_1): Removed references to *vars_of_filelock. * lisp.h: Added Fsystem_name. * filelock.c: Replaced by version from FSF 20.2. Now implements locking by using symlinks which is NFS safe. However keep the GCPRO's in lock_file and the calls to callx_in_buffer like our old version (and of course use ansi C, acessor macros, etc). Index: src/emacs.c =================================================================== RCS file: /usr/CVSroot/XEmacs/xemacs-20/src/emacs.c,v retrieving revision 1.77 diff -u -r1.77 emacs.c --- emacs.c 1998/05/14 04:46:24 1.77 +++ emacs.c 1998/05/15 03:42:38 ＠＠ -1269,9 +1269,6 ＠＠ vars_of_extents (); vars_of_faces (); vars_of_fileio (); -#ifdef CLASH_DETECTION - vars_of_filelock (); -#endif vars_of_floatfns (); vars_of_font_lock (); vars_of_frame (); ＠＠ -1522,10 +1519,6 ＠＠ /* These two might call Ffile_name_as_directory(), which might depend on all sorts of things; I'm not sure. */ complex_vars_of_emacs (); - -#ifdef CLASH_DETECTION - complex_vars_of_filelock (); -#endif /* CLASH_DETECTION */ /* This creates a couple of basic keymaps and depends on Lisp hashtables and Ffset() (both of which depend on some variables Index: src/filelock.c =================================================================== RCS file: /usr/CVSroot/XEmacs/xemacs-20/src/filelock.c,v retrieving revision 1.9 diff -u -r1.9 filelock.c --- filelock.c 1998/03/31 20:11:41 1.9 +++ filelock.c 1998/05/15 03:42:39 ＠＠ -1,24 +1,23 ＠＠ -/* Copyright (C) 1985, 1986, 1987, 1992, 1993, 1994 - Free Software Foundation, Inc. +/* Copyright (C) 1985, 86, 87, 93, 94, 96 Free Software Foundation, Inc. -This file is part of XEmacs. +This file is part of GNU Emacs. -XEmacs 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. - -XEmacs 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. +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 XEmacs; see the file COPYING. If not, write to +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. */ -/* Synched up with: FSF 19.30. */ +/* Synced with FSF 20.2 */ #include <config.h> #include "lisp.h" ＠＠ -31,186 +30,284 ＠＠ #include "syspwd.h" #include "syssignal.h" /* for kill */ -#ifndef CLASH_DETECTION -#error CLASH_DETECTION is not defined?? -#endif +Lisp_Object Qask_user_about_supersession_threat; +Lisp_Object Qask_user_about_lock; -/* FSFmacs uses char *lock_dir and char *superlock_file instead of - the Lisp variables we use. */ -/* The name of the directory in which we keep lock files, with a '/' - appended. */ -Lisp_Object Vlock_directory, Vconfigure_lock_directory; - -#if 0 /* FSFmacs */ -/* Look in startup.el */ -/* The name of the file in the lock directory which is used to - arbitrate access to the entire directory. */ -#define SUPERLOCK_NAME "!!!SuperLock!!!" -#endif +#ifdef CLASH_DETECTION + +/* The strategy: to lock a file FN, create a symlink .#FN in FN's + directory, with link data `user(a)host.pid&#39;. This avoids a single + mount (== failure) point for lock files. + + When the host in the lock data is the current host, we can check if + the pid is valid with kill. + + Otherwise, we could look at a separate file that maps hostnames to + reboot times to see if the remote pid can possibly be valid, since we + don't want Emacs to have to communicate via pipes or sockets or + whatever to other processes, either locally or remotely; rms says + that's too unreliable. Hence the separate file, which could + theoretically be updated by daemons running separately -- but this + whole idea is unimplemented; in practice, at least in our + environment, it seems such stale locks arise fairly infrequently, and + Emacs' standard methods of dealing with clashes suffice. + + We use symlinks instead of normal files because (1) they can be + stored more efficiently on the filesystem, since the kernel knows + they will be small, and (2) all the info about the lock can be read + in a single system call (readlink). Although we could use regular + files to be useful on old systems lacking symlinks, nowadays + virtually all such systems are probably single-user anyway, so it + didn't seem worth the complication. + + Similarly, we don't worry about a possible 14-character limit on + file names, because those are all the same systems that don't have + symlinks. + + This is compatible with the locking scheme used by Interleaf (which + has contributed this implementation for Emacs), and was designed by + Ethan Jacobson, Kimbo Mundy, and others. + + --karl＠cs.umb.edu/karl(a)hq.ileaf.com. */ + + +/* Here is the structure that stores information about a lock. */ -/* The name of the superlock file. This is SUPERLOCK_NAME appended to - Vlock_directory. */ -Lisp_Object Vsuperlock_file, Vconfigure_superlock_file; +typedef struct +{ + char *user; + char *host; + unsigned long pid; +} lock_info_type; -Lisp_Object Qask_user_about_supersession_threat; -Lisp_Object Qask_user_about_lock; +/* When we read the info back, we might need this much more, + enough for decimal representation plus null. */ +#define LOCK_PID_MAX (4 * sizeof (unsigned long)) + +/* Free the two dynamically-allocated pieces in PTR. */ +#define FREE_LOCK_INFO(i) do { xfree ((i).user); xfree ((i).host); } while (0) -static void lock_superlock (CONST char *lfname); -static int lock_file_1 (CONST char *lfname, int mode); -static int lock_if_free (CONST char *lfname); -static int current_lock_owner (CONST char *); -static int current_lock_owner_1 (CONST char *); - -/* Set LOCK to the name of the lock file for the filename FILE. - char *LOCK; Lisp_Object FILE; - - MAKE_LOCK_NAME assumes you have already verified that Vlock_directory - is a string. */ - -#ifndef HAVE_LONG_FILE_NAMES - -#define MAKE_LOCK_NAME(lock, file) \ - (lock = (char *) alloca (14 + XSTRING_LENGTH (Vlock_directory) + 1), \ - fill_in_lock_short_file_name (lock, (file))) + +/* Write the name of the lock file for FN into LFNAME. Length will be + that of FN plus two more for the leading `.#' plus one for the null. */ +#define MAKE_LOCK_NAME(lock, file) \ + (lock = (char *) alloca (XSTRING_LENGTH(file) + 2 + 1), \ + fill_in_lock_file_name (lock, (file))) static void -fill_in_lock_short_file_name (REGISTER char *lockfile, REGISTER Lisp_Object fn) -{ - REGISTER union - { - unsigned int word [2]; - unsigned char byte [8]; - } crc; - REGISTER unsigned char *p, new; +fill_in_lock_file_name (lockfile, fn) + register char *lockfile; + register Lisp_Object fn; +{ + register char *p; + + strcpy (lockfile, XSTRING_DATA(fn)); + + /* Shift the nondirectory part of the file name (including the null) + right two characters. Here is one of the places where we'd have to + do something to support 14-character-max file names. */ + for (p = lockfile + strlen (lockfile); p != lockfile && *p != '/'; p--) + p[2] = *p; + + /* Insert the `.#'. */ + p[1] = '.'; + p[2] = '#'; +} - CHECK_STRING (Vlock_directory); +/* Lock the lock file named LFNAME. + If FORCE is nonzero, we do so even if it is already locked. + Return 1 if successful, 0 if not. */ - /* 7-bytes cyclic code for burst correction on byte-by-byte basis. - the used polynomial is D^7 + D^6 + D^3 +1. pot(a)cnuce.cnr.it */ +static int +lock_file_1 (char *lfname,int force) +{ + register int err; + char *user_name; + char *host_name; + char *lock_info_str; - crc.word[0] = crc.word[1] = 0; + if (STRINGP (Fuser_login_name (Qnil))) + user_name = (char *)XSTRING_DATA((Fuser_login_name (Qnil))); + else + user_name = ""; + if (STRINGP (Fsystem_name ())) + host_name = (char *)XSTRING_DATA((Fsystem_name ())); + else + host_name = ""; + lock_info_str = (char *)alloca (strlen (user_name) + strlen (host_name) + + LOCK_PID_MAX + 5); + + sprintf (lock_info_str, &quot;%s(a)%s.%lu&quot;, user_name, host_name, + (unsigned long) getpid ()); - for (p = XSTRING_DATA (fn); new = *p++; ) + err = symlink (lock_info_str, lfname); + if (errno == EEXIST && force) { - new += crc.byte[6]; - crc.byte[6] = crc.byte[5] + new; - crc.byte[5] = crc.byte[4]; - crc.byte[4] = crc.byte[3]; - crc.byte[3] = crc.byte[2] + new; - crc.byte[2] = crc.byte[1]; - crc.byte[1] = crc.byte[0]; - crc.byte[0] = new; + unlink (lfname); + err = symlink (lock_info_str, lfname); } - { - int need_slash = 0; - - /* in case lock-directory doesn't end in / */ - if (XSTRING_BYTE (Vlock_directory, - XSTRING_LENGTH (Vlock_directory) - 1) != '/') - need_slash = 1; - - sprintf (lockfile, "%s%s%.2x%.2x%.2x%.2x%.2x%.2x%.2x", - (char *) XSTRING_DATA (Vlock_directory), - need_slash ? "/" : "", - crc.byte[0], crc.byte[1], crc.byte[2], crc.byte[3], - crc.byte[4], crc.byte[5], crc.byte[6]); - } + return err == 0; } -#else /* defined HAVE_LONG_FILE_NAMES */ -/* +2 for terminating null and possible extra slash */ -#define MAKE_LOCK_NAME(lock, file) \ - (lock = (char *) alloca (XSTRING_LENGTH (file) + \ - XSTRING_LENGTH (Vlock_directory) + 2), \ - fill_in_lock_file_name (lock, (file))) + +/* Return 0 if nobody owns the lock file LFNAME or the lock is obsolete, + 1 if another process owns it (and set OWNER (if non-null) to info), + 2 if the current process owns it, + or -1 if something is wrong with the locking mechanism. */ -static void -fill_in_lock_file_name (REGISTER char *lockfile, REGISTER Lisp_Object fn) - /* fn must be a Lisp_String! */ +static int +current_lock_owner (lock_info_type *owner, char *lfname) { - REGISTER char *p; - - CHECK_STRING (Vlock_directory); - - strcpy (lockfile, (char *) XSTRING_DATA (Vlock_directory)); - - p = lockfile + strlen (lockfile); - - if (p == lockfile /* lock-directory is empty?? */ - || *(p - 1) != '/') /* in case lock-directory doesn't end in / */ +#ifndef index + extern char *rindex (), *index (); +#endif + int o, p, len, ret; + int local_owner = 0; + char *at, *dot; + char *lfinfo = 0; + int bufsize = 50; + /* Read arbitrarily-long contents of symlink. Similar code in + file-symlink-p in fileio.c. */ + do { - *p = '/'; - p++; + bufsize *= 2; + lfinfo = (char *) xrealloc (lfinfo, bufsize); + len = readlink (lfname, lfinfo, bufsize); + } + while (len >= bufsize); + + /* If nonexistent lock file, all is well; otherwise, got strange error. */ + if (len == -1) + { + xfree (lfinfo); + return errno == ENOENT ? 0 : -1; } - strcpy (p, (char *) XSTRING_DATA (fn)); - - for (; *p; p++) + /* Link info exists, so `len' is its length. Null terminate. */ + lfinfo[len] = 0; + + /* Even if the caller doesn't want the owner info, we still have to + read it to determine return value, so allocate it. */ + if (!owner) + { + owner = (lock_info_type *) alloca (sizeof (lock_info_type)); + local_owner = 1; + } + + /* Parse USER(a)HOST.PID. If can't parse, return -1. */ + /* The USER is everything before the first ＠. */ + at = index (lfinfo, '＠'); + dot = rindex (lfinfo, '.'); + if (!at || !dot) { + xfree (lfinfo); + return -1; + } + len = at - lfinfo; + owner->user = (char *) xmalloc (len + 1); + strncpy (owner->user, lfinfo, len); + owner->user[len] = 0; + + /* The PID is everything after the last `.'. */ + owner->pid = atoi (dot + 1); + + /* The host is everything in between. */ + len = dot - at - 1; + owner->host = (char *) xmalloc (len + 1); + strncpy (owner->host, at + 1, len); + owner->host[len] = 0; + + /* We're done looking at the link info. */ + xfree (lfinfo); + + /* On current host? */ + if (STRINGP (Fsystem_name ()) + && strcmp (owner->host, XSTRING_DATA(Fsystem_name ())) == 0) + { + if (owner->pid == getpid ()) + ret = 2; /* We own it. */ + else if (owner->pid > 0 + && (kill (owner->pid, 0) >= 0 || errno == EPERM)) + ret = 1; /* An existing process on this machine owns it. */ + /* The owner process is dead or has a strange pid (<=0), so try to + zap the lockfile. */ + else if (unlink (lfname) < 0) + ret = -1; + else + ret = 0; + } + else + { /* If we wanted to support the check for stale locks on remote machines, + here's where we'd do it. */ + ret = 1; + } + + /* Avoid garbage. */ + if (local_owner || ret <= 0) { - if (*p == '/') - *p = '!'; + FREE_LOCK_INFO (*owner); } + return ret; } -#endif /* !defined HAVE_LONG_FILE_NAMES */ -static Lisp_Object -lock_file_owner_name (CONST char *lfname) + +/* Lock the lock named LFNAME if possible. + Return 0 in that case. + Return positive if some other process owns the lock, and info about + that process in CLASHER. + Return -1 if cannot lock for any other reason. */ + +static int +lock_if_free (lock_info_type *clasher, char *lfname) { - struct stat s; - struct passwd *the_pw = 0; + if (lock_file_1 (lfname, 0) == 0) + { + int locker; - if (lstat (lfname, &s) == 0) - the_pw = getpwuid (s.st_uid); - return (the_pw == 0 ? Qnil : build_string (the_pw->pw_name)); -} + if (errno != EEXIST) + return -1; + + locker = current_lock_owner (clasher, lfname); + if (locker == 2) + { + FREE_LOCK_INFO (*clasher); + return 0; /* We ourselves locked it. */ + } + else if (locker == 1) + return 1; /* Someone else has it. */ + return -1; /* Something's wrong. */ + } + return 0; +} -/* lock_file locks file fn, +/* lock_file locks file FN, meaning it serves notice on the world that you intend to edit that file. This should be done only when about to modify a file-visiting buffer previously unmodified. - Do not (normally) call lock_buffer for a buffer already modified, + Do not (normally) call this for a buffer already modified, as either the file is already locked, or the user has already decided to go ahead without locking. - When lock_buffer returns, either the lock is locked for us, + When this returns, either the lock is locked for us, or the user has said to go ahead without locking. - If the file is locked by someone else, lock_buffer calls + If the file is locked by someone else, this calls ask-user-about-lock (a Lisp function) with two arguments, - the file name and the name of the user who did the locking. + the file name and info about the user who did the locking. This function can signal an error, or return t meaning take away the lock, or return nil meaning ignore the lock. */ -/* The lock file name is the file name with "/" replaced by "!" - and put in the Emacs lock directory. */ -/* (ie., /ka/king/junk.tex -> /!/!ka!king!junk.tex). */ - -/* If HAVE_LONG_FILE_NAMES is not defined, the lock file name is the hex - representation of a 14-bytes CRC generated from the file name - and put in the Emacs lock directory (not very nice, but it works). - (ie., /ka/king/junk.tex -> /!/12a82c62f1c6da). */ - void lock_file (Lisp_Object fn) { - /* This function can GC. */ - /* dmoore - and can destroy current_buffer and all sorts of other - mean nasty things with pointy teeth. If you call this make sure - you protect things right. */ - - REGISTER Lisp_Object attack, orig_fn; - REGISTER char *lfname; - struct gcpro gcpro1, gcpro2; - Lisp_Object subject_buf = Qnil; - - if (NILP (Vlock_directory) || NILP (Vsuperlock_file)) - return; - CHECK_STRING (fn); - CHECK_STRING (Vlock_directory); + register Lisp_Object attack, orig_fn; + register char *lfname, *locker; + lock_info_type lock_info; + struct gcpro gcpro1,gcpro2; + Lisp_Object subject_buf; GCPRO2 (fn, subject_buf); orig_fn = fn; ＠＠ -221,29 +318,34 ＠＠ /* See if this file is visited and has changed on disk since it was visited. */ - subject_buf = Fget_file_buffer (fn); - if (!NILP (subject_buf) - && NILP (Fverify_visited_file_modtime (subject_buf)) - && !NILP (Ffile_exists_p (fn))) - call1_in_buffer (XBUFFER (subject_buf), - Qask_user_about_supersession_threat, fn); + { + subject_buf = get_truename_buffer (orig_fn); + if (!NILP (subject_buf) + && NILP (Fverify_visited_file_modtime (subject_buf)) + && !NILP (Ffile_exists_p (fn))) + call1_in_buffer (XBUFFER(subject_buf), + Qask_user_about_supersession_threat, fn); + } /* Try to lock the lock. */ - if (lock_if_free (lfname) <= 0) - /* Return now if we have locked it, or if lock dir does not exist */ + if (lock_if_free (&lock_info, lfname) <= 0) + /* Return now if we have locked it, or if lock creation failed */ goto done; /* Else consider breaking the lock */ + locker = (char *) alloca (strlen (lock_info.user) + strlen (lock_info.host) + + LOCK_PID_MAX + 9); + sprintf (locker, "%s＠%s (pid %lu)", lock_info.user, lock_info.host, + lock_info.pid); + FREE_LOCK_INFO (lock_info); + attack = call2_in_buffer (BUFFERP (subject_buf) ? XBUFFER (subject_buf) : - current_buffer, Qask_user_about_lock, fn, - lock_file_owner_name (lfname)); + current_buffer, Qask_user_about_lock , fn, + build_string (locker)); if (!NILP (attack)) /* User says take the lock */ { - CHECK_STRING (Vsuperlock_file); - lock_superlock (lfname); - lock_file_1 (lfname, O_WRONLY); - unlink ((char *) XSTRING_DATA (Vsuperlock_file)); + lock_file_1 (lfname, 1); goto done; } /* User says ignore the lock */ ＠＠ -251,197 +353,46 ＠＠ UNGCPRO; } - -/* Lock the lock file named LFNAME. - If MODE is O_WRONLY, we do so even if it is already locked. - If MODE is O_WRONLY | O_EXCL | O_CREAT, we do so only if it is free. - Return 1 if successful, 0 if not. */ - -static int -lock_file_1 (CONST char *lfname, int mode) -{ - REGISTER int fd; - char buf[20]; - - if ((fd = open (lfname, mode, 0666)) >= 0) - { -#if defined(WINDOWSNT) - chmod(lfname, _S_IREAD|_S_IWRITE); -#elif defined(USG) - chmod (lfname, 0666); -#else - fchmod (fd, 0666); -#endif - sprintf (buf, "%ld ", (long) getpid ()); - write (fd, buf, strlen (buf)); - close (fd); - return 1; - } - else - return 0; -} - -/* Lock the lock named LFNAME if possible. - Return 0 in that case. - Return positive if lock is really locked by someone else. - Return -1 if cannot lock for any other reason. */ - -static int -lock_if_free (CONST char *lfname) -{ - REGISTER int clasher; - - while (lock_file_1 (lfname, O_WRONLY | O_EXCL | O_CREAT) == 0) - { - if (errno != EEXIST) - return -1; - clasher = current_lock_owner (lfname); - if (clasher != 0) - if (clasher != getpid ()) - return (clasher); - else return (0); - /* Try again to lock it */ - } - return 0; -} - -/* Return the pid of the process that claims to own the lock file LFNAME, - or 0 if nobody does or the lock is obsolete, - or -1 if something is wrong with the locking mechanism. */ - -static int -current_lock_owner (CONST char *lfname) -{ - int owner = current_lock_owner_1 (lfname); - if (owner == 0 && errno == ENOENT) - return (0); - /* Is it locked by a process that exists? */ - if (owner != 0 && (kill (owner, 0) >= 0 || errno == EPERM)) - return (owner); - if (unlink (lfname) < 0) - return (-1); - return (0); -} - -static int -current_lock_owner_1 (CONST char *lfname) -{ - REGISTER int fd; - char buf[20]; - int tem; - - fd = open (lfname, O_RDONLY, 0666); - if (fd < 0) - return 0; - tem = read (fd, buf, sizeof buf); - close (fd); - return (tem <= 0 ? 0 : atoi (buf)); -} - - void unlock_file (Lisp_Object fn) { - /* This function can GC. */ - /* dmoore - and can destroy current_buffer and all sorts of other - mean nasty things with pointy teeth. If you call this make sure - you protect things right. */ - - REGISTER char *lfname; - if (NILP (Vlock_directory) || NILP (Vsuperlock_file)) return; - CHECK_STRING (fn); - CHECK_STRING (Vlock_directory); - CHECK_STRING (Vsuperlock_file); + register char *lfname; fn = Fexpand_file_name (fn, Qnil); MAKE_LOCK_NAME (lfname, fn); - lock_superlock (lfname); - - if (current_lock_owner_1 (lfname) == getpid ()) + if (current_lock_owner (0, lfname) == 2) unlink (lfname); - - unlink ((char *) XSTRING_DATA (Vsuperlock_file)); -} - -static void -lock_superlock (CONST char *lfname) -{ - REGISTER int i, fd; - DIR *lockdir; - - for (i = -20; i < 0 && - (fd = open ((char *) XSTRING_DATA (Vsuperlock_file), - O_WRONLY | O_EXCL | O_CREAT, 0666)) < 0; - i++) - { - if (errno != EEXIST) - return; - - /* This seems to be necessary to prevent Emacs from hanging when the - competing process has already deleted the superlock, but it's still - in the NFS cache. So we force NFS to synchronize the cache. */ - lockdir = opendir ((char *) XSTRING_DATA (Vlock_directory)); - if (lockdir) - closedir (lockdir); - - emacs_sleep (1); - } - if (fd >= 0) - { -#if defined(WINDOWSNT) - chmod(lfname, _S_IREAD|_S_IWRITE); -#elif defined(USG) - chmod ((char *) XSTRING_DATA (Vsuperlock_file), 0666); -#else - fchmod (fd, 0666); -#endif - write (fd, lfname, strlen (lfname)); - close (fd); - } } void -unlock_all_files (void) +unlock_all_files () { - /* This function can GC. */ - - Lisp_Object tail; - REGISTER struct buffer *b; - struct gcpro gcpro1; + register Lisp_Object tail; + register struct buffer *b; - GCPRO1 (tail); - for (tail = Vbuffer_alist; GC_CONSP (tail); - tail = XCDR (tail)) + for (tail = Vbuffer_alist; GC_CONSP (tail); tail = XCDR (tail)) { b = XBUFFER (XCDR (XCAR (tail))); - if (STRINGP (b->file_truename) && - BUF_SAVE_MODIFF (b) < BUF_MODIFF (b)) + if (STRINGP (b->file_truename) && BUF_SAVE_MODIFF (b) < BUF_MODIFF (b)) unlock_file (b->file_truename); } - UNGCPRO; } -  -DEFUN ("lock-buffer", Flock_buffer, 0, 1, 0, /* -Lock FILE, if current buffer is modified. -FILE defaults to current buffer's visited file, +DEFUN ("lock-buffer", Flock_buffer, 0, 1, 0, /* + Lock FILE, if current buffer is modified.\n\ +FILE defaults to current buffer's visited file,\n\ or else nothing is done if current buffer isn't visiting a file. */ - (fn)) + (file)) { - /* This function can GC */ - /* dmoore - and can destroy current_buffer and all sorts of other - mean nasty things with pointy teeth. If you call this make sure - you protect things right. */ - - if (NILP (fn)) - fn = current_buffer->file_truename; - CHECK_STRING (fn); + if (NILP (file)) + file = current_buffer->file_truename; + CHECK_STRING (file); if (BUF_SAVE_MODIFF (current_buffer) < BUF_MODIFF (current_buffer) - && !NILP (fn)) - lock_file (fn); + && !NILP (file)) + lock_file (file); return Qnil; } ＠＠ -462,9 +413,9 ＠＠ return Qnil; } - /* Unlock the file visited in buffer BUFFER. */ + void unlock_buffer (struct buffer *buffer) { ＠＠ -478,32 +429,37 ＠＠ } DEFUN ("file-locked-p", Ffile_locked_p, 0, 1, 0, /* -Return nil if the FILENAME is not locked, + Return nil if the FILENAME is not locked,\n\ t if it is locked by you, else a string of the name of the locker. */ - (fn)) + (filename)) { - /* This function can GC */ - REGISTER char *lfname; + Lisp_Object ret; + register char *lfname; int owner; + lock_info_type locker; - if (NILP (Vlock_directory) || NILP (Vsuperlock_file)) - return Qnil; - CHECK_STRING (Vlock_directory); + filename = Fexpand_file_name (filename, Qnil); - fn = Fexpand_file_name (fn, Qnil); + MAKE_LOCK_NAME (lfname, filename); - MAKE_LOCK_NAME (lfname, fn); - - owner = current_lock_owner (lfname); + owner = current_lock_owner (&locker, lfname); if (owner <= 0) - return Qnil; - else if (owner == getpid ()) - return Qt; + ret = Qnil; + else if (owner == 2) + ret = Qt; + else + ret = build_string (locker.user); - return lock_file_owner_name (lfname); + if (owner > 0) + FREE_LOCK_INFO (locker); + + return ret; } + +/* Initialization functions. */ + void syms_of_filelock (void) { ＠＠ -517,40 +473,5 ＠＠ defsymbol (&Qask_user_about_lock, "ask-user-about-lock"); } -void -vars_of_filelock (void) -{ - DEFVAR_LISP ("lock-directory", &Vlock_directory /* -Don't change this -*/ ); - Vlock_directory = Qnil; - DEFVAR_LISP ("superlock-file", &Vsuperlock_file /* -Don't change this -*/ ); - Vsuperlock_file = Qnil; -} -void -complex_vars_of_filelock (void) -{ - DEFVAR_LISP ("configure-lock-directory", &Vconfigure_lock_directory /* -For internal use by the build procedure only. -configure's idea of what LOCK-DIRECTORY will be. -*/ ); -#ifdef PATH_LOCK - Vconfigure_lock_directory = - Ffile_name_as_directory (build_string (PATH_LOCK)); -#else - Vconfigure_lock_directory = Qnil; -#endif - DEFVAR_LISP ("configure-superlock-file", &Vconfigure_superlock_file /* -For internal use by the build procedure only. -configure's idea of what SUPERLOCK-FILE will be. -*/ ); -#ifdef PATH_SUPERLOCK - Vconfigure_superlock_file = build_string (PATH_SUPERLOCK); -#else - Vconfigure_superlock_file = Qnil; -#endif - /* All the rest done dynamically by startup.el */ -} +#endif /* CLASH_DETECTION */ Index: src/lisp.h =================================================================== RCS file: /usr/CVSroot/XEmacs/xemacs-20/src/lisp.h,v retrieving revision 1.32 diff -u -r1.32 lisp.h --- lisp.h 1998/05/12 01:06:47 1.32 +++ lisp.h 1998/05/15 03:42:41 ＠＠ -2684,6 +2684,7 ＠＠ EXFUN (Fsymbol_name, 1); EXFUN (Fsymbol_plist, 1); EXFUN (Fsymbol_value, 1); +EXFUN (Fsystem_name, 0); EXFUN (Fthrow, 2); EXFUN (Ftimes, MANY); EXFUN (Ftruncate, 1);