-/* Copyright (C) 1985, 1986, 1987, 1992 Free Software Foundation, Inc.
+/* Lock files for editing.
+ Copyright (C) 1985, 1986, 1987, 1993, 1994, 1996, 1998, 1999, 2000, 2001,
+ 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
This file is part of GNU Emacs.
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, 675 Mass Ave, Cambridge, MA 02139, USA. */
+the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA. */
+#include <config.h>
#include <sys/types.h>
#include <sys/stat.h>
-#include "config.h"
+#include <signal.h>
+#include <stdio.h>
-#ifdef VMS
-#include "vms-pwd.h"
-#else
+#ifdef HAVE_PWD_H
#include <pwd.h>
#endif
-#include <errno.h>
#include <sys/file.h>
-#ifdef USG
+#ifdef HAVE_FCNTL_H
#include <fcntl.h>
-#endif /* USG */
+#endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#ifdef __FreeBSD__
+#include <sys/sysctl.h>
+#endif /* __FreeBSD__ */
+
+#include <errno.h>
+#ifndef errno
+extern int errno;
+#endif
#include "lisp.h"
-#include "paths.h"
#include "buffer.h"
+#include "charset.h"
+#include "coding.h"
+#include "systime.h"
-extern int errno;
+/* The directory for writing temporary files. */
-extern char *egetenv ();
+Lisp_Object Vtemporary_file_directory;
#ifdef CLASH_DETECTION
-
-/* If system does not have symbolic links, it does not have lstat.
- In that case, use ordinary stat instead. */
-#ifndef S_IFLNK
-#define lstat stat
+#include <utmp.h>
+
+#if !defined (S_ISLNK) && defined (S_IFLNK)
+#define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
#endif
+/* A file whose last-modified time is just after the most recent boot.
+ Define this to be NULL to disable checking for this file. */
+#ifndef BOOT_TIME_FILE
+#define BOOT_TIME_FILE "/var/run/random-seed"
+#endif
+
+#ifndef WTMP_FILE
+#define WTMP_FILE "/var/log/wtmp"
+#endif
+
+/* 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. */
+
+\f
+/* Return the time of the last system boot. */
+
+static time_t boot_time;
+static int boot_time_initialized;
+
+extern Lisp_Object Vshell_file_name;
+
+#ifdef BOOT_TIME
+static void get_boot_time_1 P_ ((char *, int));
+#endif
+
+static time_t
+get_boot_time ()
+{
+#if defined (BOOT_TIME) && ! defined (NO_WTMP_FILE)
+ int counter;
+#endif
-/* The name of the directory in which we keep lock files, with a '/'
- appended. */
-char *lock_path;
+ if (boot_time_initialized)
+ return boot_time;
+ boot_time_initialized = 1;
+
+#if defined (CTL_KERN) && defined (KERN_BOOTTIME)
+ {
+ int mib[2];
+ size_t size;
+ struct timeval boottime_val;
+
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_BOOTTIME;
+ size = sizeof (boottime_val);
+
+ if (sysctl (mib, 2, &boottime_val, &size, NULL, 0) >= 0)
+ {
+ boot_time = boottime_val.tv_sec;
+ return boot_time;
+ }
+ }
+#endif /* defined (CTL_KERN) && defined (KERN_BOOTTIME) */
+
+ if (BOOT_TIME_FILE)
+ {
+ struct stat st;
+ if (stat (BOOT_TIME_FILE, &st) == 0)
+ {
+ boot_time = st.st_mtime;
+ return boot_time;
+ }
+ }
+
+#if defined (BOOT_TIME) && ! defined (NO_WTMP_FILE)
+#ifndef CANNOT_DUMP
+ /* The utmp routines maintain static state.
+ Don't touch that state unless we are initialized,
+ since it might not survive dumping. */
+ if (! initialized)
+ return boot_time;
+#endif /* not CANNOT_DUMP */
+
+ /* Try to get boot time from utmp before wtmp,
+ since utmp is typically much smaller than wtmp.
+ Passing a null pointer causes get_boot_time_1
+ to inspect the default file, namely utmp. */
+ get_boot_time_1 ((char *) 0, 0);
+ if (boot_time)
+ return boot_time;
+
+ /* Try to get boot time from the current wtmp file. */
+ get_boot_time_1 (WTMP_FILE, 1);
+
+ /* If we did not find a boot time in wtmp, look at wtmp, and so on. */
+ for (counter = 0; counter < 20 && ! boot_time; counter++)
+ {
+ char cmd_string[100];
+ Lisp_Object tempname, filename;
+ int delete_flag = 0;
+
+ filename = Qnil;
+
+ sprintf (cmd_string, "%s.%d", WTMP_FILE, counter);
+ tempname = build_string (cmd_string);
+ if (! NILP (Ffile_exists_p (tempname)))
+ filename = tempname;
+ else
+ {
+ sprintf (cmd_string, "%s.%d.gz", WTMP_FILE, counter);
+ tempname = build_string (cmd_string);
+ if (! NILP (Ffile_exists_p (tempname)))
+ {
+ Lisp_Object args[6];
+
+ /* The utmp functions on mescaline.gnu.org accept only
+ file names up to 8 characters long. Choose a 2
+ character long prefix, and call make_temp_file with
+ second arg non-zero, so that it will add not more
+ than 6 characters to the prefix. */
+ tempname = Fexpand_file_name (build_string ("wt"),
+ Vtemporary_file_directory);
+ tempname = make_temp_name (tempname, 1);
+ args[0] = Vshell_file_name;
+ args[1] = Qnil;
+ args[2] = Qnil;
+ args[3] = Qnil;
+ args[4] = build_string ("-c");
+ sprintf (cmd_string, "gunzip < %s.%d.gz > %s",
+ WTMP_FILE, counter, SDATA (tempname));
+ args[5] = build_string (cmd_string);
+ Fcall_process (6, args);
+ filename = tempname;
+ delete_flag = 1;
+ }
+ }
+
+ if (! NILP (filename))
+ {
+ get_boot_time_1 (SDATA (filename), 1);
+ if (delete_flag)
+ unlink (SDATA (filename));
+ }
+ }
+
+ return boot_time;
+#else
+ return 0;
+#endif
+}
+
+#ifdef BOOT_TIME
+/* Try to get the boot time from wtmp file FILENAME.
+ This succeeds if that file contains a reboot record.
+
+ If FILENAME is zero, use the same file as before;
+ if no FILENAME has ever been specified, this is the utmp file.
+ Use the newest reboot record if NEWEST is nonzero,
+ the first reboot record otherwise.
+ Ignore all reboot records on or before BOOT_TIME.
+ Success is indicated by setting BOOT_TIME to a larger value. */
+
+void
+get_boot_time_1 (filename, newest)
+ char *filename;
+ int newest;
+{
+ struct utmp ut, *utp;
+ int desc;
+
+ if (filename)
+ {
+ /* On some versions of IRIX, opening a nonexistent file name
+ is likely to crash in the utmp routines. */
+ desc = emacs_open (filename, O_RDONLY, 0);
+ if (desc < 0)
+ return;
+
+ emacs_close (desc);
+
+ utmpname (filename);
+ }
-/* The name of the file in the lock directory which is used to
- arbitrate access to the entire directory. */
-#define SUPERLOCK_NAME "!!!SuperLock!!!"
+ setutent ();
-/* The path to the superlock file. This is SUPERLOCK_NAME appended to
- lock_path. */
-char *superlock_path;
+ while (1)
+ {
+ /* Find the next reboot record. */
+ ut.ut_type = BOOT_TIME;
+ utp = getutid (&ut);
+ if (! utp)
+ break;
+ /* Compare reboot times and use the newest one. */
+ if (utp->ut_time > boot_time)
+ {
+ boot_time = utp->ut_time;
+ if (! newest)
+ break;
+ }
+ /* Advance on element in the file
+ so that getutid won't repeat the same one. */
+ utp = getutent ();
+ if (! utp)
+ break;
+ }
+ endutent ();
+}
+#endif /* BOOT_TIME */
+\f
+/* Here is the structure that stores information about a lock. */
-/* Set LOCK to the name of the lock file for the filename FILE.
- char *LOCK; Lisp_Object FILE; */
-#define MAKE_LOCK_PATH(lock, file) \
- (lock = (char *) alloca (XSTRING (file)->size + strlen (lock_path) + 1), \
+typedef struct
+{
+ char *user;
+ char *host;
+ unsigned long pid;
+ time_t boot_time;
+} 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 1 for the
+ trailing period plus one for the digit after it plus one for the
+ null. */
+#define MAKE_LOCK_NAME(lock, file) \
+ (lock = (char *) alloca (SBYTES (file) + 2 + 1 + 1 + 1), \
fill_in_lock_file_name (lock, (file)))
+static void
fill_in_lock_file_name (lockfile, fn)
register char *lockfile;
register Lisp_Object fn;
{
register char *p;
+ struct stat st;
+ int count = 0;
+
+ strcpy (lockfile, SDATA (fn));
- strcpy (lockfile, lock_path);
+ /* 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;
- p = lockfile + strlen (lockfile);
+ /* Insert the `.#'. */
+ p[1] = '.';
+ p[2] = '#';
- strcpy (p, XSTRING (fn)->data);
+ p = p + strlen (p);
- for (; *p; p++)
+ while (lstat (lockfile, &st) == 0 && !S_ISLNK (st.st_mode))
{
- if (*p == '/')
- *p = '!';
+ if (count > 9)
+ {
+ *p = '\0';
+ return;
+ }
+ sprintf (p, ".%d", count++);
}
}
-static Lisp_Object
-lock_file_owner_name (lfname)
+/* 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 int
+lock_file_1 (lfname, force)
char *lfname;
+ int force;
{
- struct stat s;
- struct passwd *the_pw;
- extern struct passwd *getpwuid ();
+ register int err;
+ time_t boot_time;
+ char *user_name;
+ char *host_name;
+ char *lock_info_str;
+
+ /* Call this first because it can GC. */
+ boot_time = get_boot_time ();
+
+ if (STRINGP (Fuser_login_name (Qnil)))
+ user_name = (char *)SDATA (Fuser_login_name (Qnil));
+ else
+ user_name = "";
+ if (STRINGP (Fsystem_name ()))
+ host_name = (char *)SDATA (Fsystem_name ());
+ else
+ host_name = "";
+ lock_info_str = (char *)alloca (strlen (user_name) + strlen (host_name)
+ + LOCK_PID_MAX + 30);
- if (lstat (lfname, &s) == 0)
- the_pw = getpwuid (s.st_uid);
- return (the_pw == 0 ? Qnil : build_string (the_pw->pw_name));
+ if (boot_time)
+ sprintf (lock_info_str, "%s@%s.%lu:%lu", user_name, host_name,
+ (unsigned long) getpid (), (unsigned long) boot_time);
+ else
+ sprintf (lock_info_str, "%s@%s.%lu", user_name, host_name,
+ (unsigned long) getpid ());
+
+ err = symlink (lock_info_str, lfname);
+ if (errno == EEXIST && force)
+ {
+ unlink (lfname);
+ err = symlink (lock_info_str, lfname);
+ }
+
+ return err == 0;
}
+/* Return 1 if times A and B are no more than one second apart. */
-/* lock_file locks file fn,
+int
+within_one_second (a, b)
+ time_t a, b;
+{
+ return (a - b >= -1 && a - b <= 1);
+}
+\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. */
+
+static int
+current_lock_owner (owner, lfname)
+ lock_info_type *owner;
+ char *lfname;
+{
+#ifndef index
+ extern char *rindex (), *index ();
+#endif
+ int len, ret;
+ int local_owner = 0;
+ char *at, *dot, *colon;
+ 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);
+ errno = 0;
+ len = readlink (lfname, lfinfo, bufsize);
+#ifdef ERANGE
+ /* HP-UX reports ERANGE if the buffer is too small. */
+ if (len == -1 && errno == ERANGE)
+ len = bufsize;
+#endif
+ }
+ while (len >= bufsize);
+
+ /* If nonexistent lock file, all is well; otherwise, got strange error. */
+ if (len == -1)
+ {
+ 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:BOOT_TIME. 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 from the last `.' to the `:'. */
+ owner->pid = atoi (dot + 1);
+ colon = dot;
+ while (*colon && *colon != ':')
+ colon++;
+ /* After the `:', if there is one, comes the boot time. */
+ if (*colon == ':')
+ owner->boot_time = atoi (colon + 1);
+ else
+ owner->boot_time = 0;
+
+ /* 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, SDATA (Fsystem_name ())) == 0)
+ {
+ if (owner->pid == getpid ())
+ ret = 2; /* We own it. */
+ else if (owner->pid > 0
+ && (kill (owner->pid, 0) >= 0 || errno == EPERM)
+ && (owner->boot_time == 0
+ || within_one_second (owner->boot_time, get_boot_time ())))
+ 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;
+}
+
+\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 int
+lock_if_free (clasher, lfname)
+ lock_info_type *clasher;
+ register char *lfname;
+{
+ while (lock_file_1 (lfname, 0) == 0)
+ {
+ int locker;
+
+ 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. */
+ else if (locker == -1)
+ return -1; /* current_lock_owner returned strange error. */
+
+ /* We deleted a stale lock; try again to lock the file. */
+ }
+ return 0;
+}
+
+/* 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). */
-
void
lock_file (fn)
- register Lisp_Object fn;
+ Lisp_Object fn;
{
- register Lisp_Object attack;
- register char *lfname;
+ register Lisp_Object attack, orig_fn, encoded_fn;
+ register char *lfname, *locker;
+ lock_info_type lock_info;
+ struct gcpro gcpro1;
+
+ /* Don't do locking while dumping Emacs.
+ Uncompressing wtmp files uses call-process, which does not work
+ in an uninitialized Emacs. */
+ if (! NILP (Vpurify_flag))
+ return;
+
+ orig_fn = fn;
+ GCPRO1 (fn);
+ fn = Fexpand_file_name (fn, Qnil);
+ encoded_fn = ENCODE_FILE (fn);
- MAKE_LOCK_PATH (lfname, fn);
+ /* Create the name of the lock-file for file fn */
+ MAKE_LOCK_NAME (lfname, encoded_fn);
/* See if this file is visited and has changed on disk since it was
visited. */
{
- register Lisp_Object subject_buf = Fget_file_buffer (fn);
+ register Lisp_Object subject_buf;
+
+ subject_buf = get_truename_buffer (orig_fn);
+
if (!NILP (subject_buf)
&& NILP (Fverify_visited_file_modtime (subject_buf))
&& !NILP (Ffile_exists_p (fn)))
call1 (intern ("ask-user-about-supersession-threat"), fn);
+
}
+ UNGCPRO;
/* 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 */
return;
/* Else consider breaking the lock */
- attack = call2 (intern ("ask-user-about-lock"), fn,
- lock_file_owner_name (lfname));
+ 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 (intern ("ask-user-about-lock"), fn, build_string (locker));
if (!NILP (attack))
/* User says take the lock */
{
- lock_superlock (lfname);
- lock_file_1 (lfname, O_WRONLY) ;
- unlink (superlock_path);
+ lock_file_1 (lfname, 1);
return;
}
/* User says ignore the lock */
}
-/* 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. */
-
-int
-lock_file_1 (lfname, mode)
- int mode; char *lfname;
-{
- register int fd;
- char buf[20];
-
- if ((fd = open (lfname, mode, 0666)) >= 0)
- {
-#ifdef USG
- chmod (lfname, 0666);
-#else
- fchmod (fd, 0666);
-#endif
- sprintf (buf, "%d ", 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. */
-
-int
-lock_if_free (lfname)
- register 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. */
-
-int
-current_lock_owner (lfname)
- 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);
-}
-
-int
-current_lock_owner_1 (lfname)
- 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 (fn)
register Lisp_Object fn;
{
register char *lfname;
- MAKE_LOCK_PATH (lfname, fn);
+ fn = Fexpand_file_name (fn, Qnil);
+ fn = ENCODE_FILE (fn);
- lock_superlock (lfname);
+ MAKE_LOCK_NAME (lfname, fn);
- if (current_lock_owner_1 (lfname) == getpid ())
+ if (current_lock_owner (0, lfname) == 2)
unlink (lfname);
-
- unlink (superlock_path);
-}
-
-lock_superlock (lfname)
- char *lfname;
-{
- register int i, fd;
-
- for (i = -20; i < 0 && (fd = open (superlock_path,
- O_WRONLY | O_EXCL | O_CREAT, 0666)) < 0;
- i++)
- {
- if (errno != EEXIST)
- return;
- sleep (1);
- }
- if (fd >= 0)
- {
-#ifdef USG
- chmod (superlock_path, 0666);
-#else
- fchmod (fd, 0666);
-#endif
- write (fd, lfname, strlen (lfname));
- close (fd);
- }
}
void
register Lisp_Object tail;
register struct buffer *b;
- for (tail = Vbuffer_alist; XGCTYPE (tail) == Lisp_Cons;
- tail = XCONS (tail)->cdr)
+ for (tail = Vbuffer_alist; GC_CONSP (tail); tail = XCDR (tail))
{
- b = XBUFFER (XCONS (XCONS (tail)->car)->cdr);
- if (XTYPE (b->filename) == Lisp_String &&
- b->save_modified < BUF_MODIFF (b))
- unlock_file (b->filename);
+ b = XBUFFER (XCDR (XCAR (tail)));
+ if (STRINGP (b->file_truename) && BUF_SAVE_MODIFF (b) < BUF_MODIFF (b))
+ {
+ unlock_file(b->file_truename);
+ }
}
}
-
\f
DEFUN ("lock-buffer", Flock_buffer, Slock_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)
- Lisp_Object fn;
+ 0, 1, 0,
+ doc: /* Lock FILE, if current buffer is modified.
+FILE defaults to current buffer's visited file,
+or else nothing is done if current buffer isn't visiting a file. */)
+ (file)
+ Lisp_Object file;
{
- if (NILP (fn))
- fn = current_buffer->filename;
+ if (NILP (file))
+ file = current_buffer->file_truename;
else
- CHECK_STRING (fn, 0);
- if (current_buffer->save_modified < MODIFF
- && !NILP (fn))
- lock_file (fn);
- return Qnil;
+ CHECK_STRING (file);
+ if (SAVE_MODIFF < MODIFF
+ && !NILP (file))
+ lock_file (file);
+ return Qnil;
}
DEFUN ("unlock-buffer", Funlock_buffer, Sunlock_buffer,
- 0, 0, 0,
- "Unlock the file visited in the current buffer,\n\
-if it should normally be locked.")
- ()
+ 0, 0, 0,
+ doc: /* Unlock the file visited in the current buffer.
+If the buffer is not modified, this does nothing because the file
+should not be locked in that case. */)
+ ()
{
- if (current_buffer->save_modified < MODIFF &&
- XTYPE (current_buffer->filename) == Lisp_String)
- unlock_file (current_buffer->filename);
+ if (SAVE_MODIFF < MODIFF
+ && STRINGP (current_buffer->file_truename))
+ unlock_file (current_buffer->file_truename);
return Qnil;
}
-\f
/* Unlock the file visited in buffer BUFFER. */
+void
unlock_buffer (buffer)
struct buffer *buffer;
{
- if (buffer->save_modified < BUF_MODIFF (buffer) &&
- XTYPE (buffer->filename) == Lisp_String)
- unlock_file (buffer->filename);
+ if (BUF_SAVE_MODIFF (buffer) < BUF_MODIFF (buffer)
+ && STRINGP (buffer->file_truename))
+ unlock_file (buffer->file_truename);
}
-DEFUN ("file-locked-p", Ffile_locked_p, Sfile_locked_p, 0, 1, 0,
- "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)
- Lisp_Object fn;
+DEFUN ("file-locked-p", Ffile_locked_p, Sfile_locked_p, 1, 1, 0,
+ doc: /* Return a value indicating whether FILENAME is locked.
+The value is nil if the FILENAME is not locked,
+t if it is locked by you, else a string saying which user has locked it. */)
+ (filename)
+ Lisp_Object filename;
{
+ Lisp_Object ret;
register char *lfname;
int owner;
+ lock_info_type locker;
- fn = Fexpand_file_name (fn, Qnil);
+ filename = Fexpand_file_name (filename, Qnil);
- MAKE_LOCK_PATH (lfname, fn);
+ MAKE_LOCK_NAME (lfname, filename);
- owner = current_lock_owner (lfname);
+ owner = current_lock_owner (&locker, lfname);
if (owner <= 0)
- return (Qnil);
- else if (owner == getpid ())
- return (Qt);
-
- return (lock_file_owner_name (lfname));
-}
+ ret = Qnil;
+ else if (owner == 2)
+ ret = Qt;
+ else
+ ret = build_string (locker.user);
+
+ if (owner > 0)
+ FREE_LOCK_INFO (locker);
+ return ret;
+}
\f
/* Initialization functions. */
+void
init_filelock ()
{
- lock_path = egetenv ("EMACSLOCKDIR");
- if (! lock_path)
- lock_path = PATH_LOCK;
-
- /* Make sure it ends with a slash. */
- if (lock_path[strlen (lock_path) - 1] != '/')
- {
- lock_path = strcpy ((char *) xmalloc (strlen (lock_path) + 2),
- lock_path);
- strcat (lock_path, "/");
- }
-
- superlock_path = (char *) xmalloc ((strlen (lock_path)
- + sizeof (SUPERLOCK_NAME)));
- strcpy (superlock_path, lock_path);
- strcat (superlock_path, SUPERLOCK_NAME);
+ boot_time = 0;
+ boot_time_initialized = 0;
}
+void
syms_of_filelock ()
{
+ DEFVAR_LISP ("temporary-file-directory", &Vtemporary_file_directory,
+ doc: /* The directory for writing temporary files. */);
+ Vtemporary_file_directory = Qnil;
+
defsubr (&Sunlock_buffer);
defsubr (&Slock_buffer);
defsubr (&Sfile_locked_p);
}
#endif /* CLASH_DETECTION */
+
+/* arch-tag: e062676d-50b2-4be0-ab96-197c81b181a1
+ (do not change this comment) */