-/* 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.
+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.
-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 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"
#include "syspwd.h"
#include "syssignal.h" /* for kill */
-#ifndef CLASH_DETECTION
-#error CLASH_DETECTION is not defined??
-#endif
-
-/* 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;
-
-#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
-
-/* The name of the superlock file. This is SUPERLOCK_NAME appended to
- Vlock_directory. */
-Lisp_Object Vsuperlock_file, Vconfigure_superlock_file;
-
Lisp_Object Qask_user_about_supersession_threat;
Lisp_Object Qask_user_about_lock;
-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;
+#ifdef CLASH_DETECTION
+
+/* The strategy: to lock a file FN, create a symlink .#FN in FN's
+ directory, with link data `user@host.pid'. 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@hq.ileaf.com. */
- MAKE_LOCK_NAME assumes you have already verified that Vlock_directory
- is a string. */
-
-#ifndef HAVE_LONG_FILE_NAMES
+\f
+/* Here is the structure that stores information about a lock. */
-#define MAKE_LOCK_NAME(lock, file) \
- (lock = (char *) alloca (14 + XSTRING_LENGTH (Vlock_directory) + 1), \
- fill_in_lock_short_file_name (lock, (file)))
+typedef struct
+{
+ char *user;
+ char *host;
+ unsigned long pid;
+} lock_info_type;
+
+/* 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)
+
+/* 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)
+fill_in_lock_file_name (lockfile, fn)
+ register char *lockfile;
+ register Lisp_Object fn;
{
- REGISTER union
- {
- unsigned int word [2];
- unsigned char byte [8];
- } crc;
- REGISTER unsigned char *p, new;
+ register char *p;
- CHECK_STRING (Vlock_directory);
+ strcpy (lockfile, XSTRING_DATA(fn));
- /* 7-bytes cyclic code for burst correction on byte-by-byte basis.
- the used polynomial is D^7 + D^6 + D^3 +1. pot@cnuce.cnr.it */
+ /* 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;
- crc.word[0] = crc.word[1] = 0;
-
- for (p = XSTRING_DATA (fn); new = *p++; )
- {
- 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;
- }
-
- {
- 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]);
- }
+ /* Insert the `.#'. */
+ p[1] = '.';
+ p[2] = '#';
}
-#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)))
+/* 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. */
-static void
-fill_in_lock_file_name (REGISTER char *lockfile, REGISTER Lisp_Object fn)
- /* fn must be a Lisp_String! */
+static int
+lock_file_1 (char *lfname,int force)
{
- REGISTER char *p;
-
- CHECK_STRING (Vlock_directory);
+ register int err;
+ char *user_name;
+ char *host_name;
+ char *lock_info_str;
- strcpy (lockfile, (char *) XSTRING_DATA (Vlock_directory));
+ 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);
- p = lockfile + strlen (lockfile);
+ sprintf (lock_info_str, "%s@%s.%lu", user_name, host_name,
+ (unsigned long) getpid ());
- if (p == lockfile /* lock-directory is empty?? */
- || *(p - 1) != '/') /* in case lock-directory doesn't end in / */
+ err = symlink (lock_info_str, lfname);
+ if (errno == EEXIST && force)
{
- *p = '/';
- p++;
+ unlink (lfname);
+ err = symlink (lock_info_str, lfname);
}
- strcpy (p, (char *) XSTRING_DATA (fn));
+ return err == 0;
+}
+\f
+/* 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. */
- for (; *p; p++)
+static int
+current_lock_owner (lock_info_type *owner, char *lfname)
+{
+#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
+ {
+ 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)
{
- if (*p == '/')
- *p = '!';
+ xfree (lfinfo);
+ return errno == ENOENT ? 0 : -1;
}
+
+ /* 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@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)
+ {
+ FREE_LOCK_INFO (*owner);
+ }
+ return ret;
}
-#endif /* !defined HAVE_LONG_FILE_NAMES */
+\f
+/* 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 Lisp_Object
-lock_file_owner_name (CONST char *lfname)
+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)
{
/* 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. */
+ /* Somebody updated the code in this function and removed the previous
+ comment. -slb */
- 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;
/* 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 */
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));
-}
-
-\f
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;
}
-
\f
-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;
}
return Qnil;
}
-\f
/* Unlock the file visited in buffer BUFFER. */
+
void
unlock_buffer (struct buffer *buffer)
{
}
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);
+
+ if (owner > 0)
+ FREE_LOCK_INFO (locker);
- return lock_file_owner_name (lfname);
+ return ret;
}
+\f
+/* Initialization functions. */
+
void
syms_of_filelock (void)
{
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-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 */
projects / chise / xemacs-chise.git.1 / blobdiff