/* Lock files for editing.
- Copyright (C) 1985, 86, 87, 93, 94, 96, 98, 1999 Free Software Foundation, Inc.
+ Copyright (C) 1985, 86, 87, 93, 94, 96, 98, 1999, 2000, 2001
+ Free Software Foundation, Inc.
This file is part of GNU Emacs.
Boston, MA 02111-1307, USA. */
+#include <config.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <signal.h>
-#include <config.h>
+#include <stdio.h>
#ifdef VMS
#include "vms-pwd.h"
#endif /* not VMS */
#include <sys/file.h>
-#ifdef USG
+#ifdef HAVE_FCNTL_H
#include <fcntl.h>
+#endif
+#ifdef HAVE_STRING_H
#include <string.h>
-#endif /* USG */
+#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef __FreeBSD__
-#include <sys/time.h>
-#include <sys/types.h>
#include <sys/sysctl.h>
#endif /* __FreeBSD__ */
+#include <errno.h>
+#ifndef errno
+extern int errno;
+#endif
+
#include "lisp.h"
#include "buffer.h"
#include "charset.h"
#include "coding.h"
#include "systime.h"
-#include <time.h>
-#include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
+/* The directory for writing temporary files. */
+
+Lisp_Object Vtemporary_file_directory;
#ifdef CLASH_DETECTION
#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
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 ()
{
- struct utmp ut, *utp;
- int fd;
- EMACS_TIME time_before, after;
+#if defined (BOOT_TIME) && ! defined (NO_WTMP_FILE)
int counter;
+#endif
if (boot_time_initialized)
return boot_time;
boot_time_initialized = 1;
- EMACS_GET_TIME (time_before);
-
- /* Try calculating the last boot time
- from the uptime as obtained from /proc/uptime.
-
- This has a disadvantage in that if the system time has been
- changed (say to correct the clock),
- then current_time - uptime != wtmp_boot_time.
- However, the speedup from doing this can be so great
- that I think it is worth that problem occasionally. */
-
- while ((fd = open ("/proc/uptime", O_RDONLY)) >= 0)
- {
- char buf[100];
- int res;
- double upsecs;
- time_t uptime;
-
- read (fd, buf, sizeof buf);
- close (fd);
-
- res = sscanf (buf, "%lf", &upsecs);
-
- /* If the current time did not tick while we were getting the
- uptime, we have a valid result. */
- EMACS_GET_TIME (after);
- if (res == 1 && EMACS_SECS (after) == EMACS_SECS (time_before))
- {
- boot_time = EMACS_SECS (time_before) - (time_t) upsecs;
- return boot_time;
- }
-
- /* Otherwise, try again to read the uptime. */
- time_before = after;
- }
#if defined (CTL_KERN) && defined (KERN_BOOTTIME)
{
int mib[2];
}
#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.
if (! NILP (Ffile_exists_p (tempname)))
{
Lisp_Object args[6];
- tempname = Fmake_temp_name (build_string ("wtmp"));
+
+ /* 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;
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;
{
/* On some versions of IRIX, opening a nonexistent file name
is likely to crash in the utmp routines. */
- desc = open (filename, O_RDONLY);
+ desc = emacs_open (filename, O_RDONLY, 0);
if (desc < 0)
return;
- close (desc);
+ emacs_close (desc);
utmpname (filename);
}
/* 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. */
+ 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 (STRING_BYTES (XSTRING (file)) + 2 + 1), \
+ (lock = (char *) alloca (STRING_BYTES (XSTRING (file)) + 2 + 1 + 1 + 1), \
fill_in_lock_file_name (lock, (file)))
static void
register Lisp_Object fn;
{
register char *p;
+ struct stat st;
+ int count = 0;
strcpy (lockfile, XSTRING (fn)->data);
/* Insert the `.#'. */
p[1] = '.';
p[2] = '#';
+
+ p = p + strlen (p);
+
+ while (lstat (lockfile, &st) == 0 && !S_ISLNK (st.st_mode))
+ {
+ if (count > 9)
+ {
+ *p = '\0';
+ return;
+ }
+ sprintf (p, ".%d", count++);
+ }
}
/* Lock the lock file named LFNAME.
#ifndef index
extern char *rindex (), *index ();
#endif
- int o, p, len, ret;
+ int len, ret;
int local_owner = 0;
char *at, *dot, *colon;
char *lfinfo = 0;
{
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);
lock_info_type *clasher;
register char *lfname;
{
- if (lock_file_1 (lfname, 0) == 0)
+ while (lock_file_1 (lfname, 0) == 0)
{
int locker;
}
else if (locker == 1)
return 1; /* Someone else has it. */
+ else if (locker == -1)
+ return -1; /* current_lock_owner returned strange error. */
- return -1; /* Something's wrong. */
+ /* We deleted a stale lock; try again to lock the file. */
}
return 0;
}
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);
visited. */
{
register Lisp_Object subject_buf;
- struct gcpro gcpro1;
subject_buf = get_truename_buffer (orig_fn);
- GCPRO1 (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;
}
+ UNGCPRO;
/* Try to lock the lock. */
if (lock_if_free (&lock_info, lfname) <= 0)
register Lisp_Object tail;
register struct buffer *b;
- for (tail = Vbuffer_alist; GC_CONSP (tail); tail = XCONS (tail)->cdr)
+ for (tail = Vbuffer_alist; GC_CONSP (tail); tail = XCDR (tail))
{
- b = XBUFFER (XCONS (XCONS (tail)->car)->cdr);
+ b = XBUFFER (XCDR (XCAR (tail)));
if (STRINGP (b->file_truename) && BUF_SAVE_MODIFF (b) < BUF_MODIFF (b))
{
- register char *lfname;
-
- MAKE_LOCK_NAME (lfname, b->file_truename);
-
- if (current_lock_owner (0, lfname) == 2)
- unlink (lfname);
+ 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.")
- (file)
+ 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 (file))
file = current_buffer->file_truename;
else
- CHECK_STRING (file, 0);
+ CHECK_STRING (file);
if (SAVE_MODIFF < MODIFF
&& !NILP (file))
lock_file (file);
}
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 (SAVE_MODIFF < MODIFF
&& STRINGP (current_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.")
- (filename)
- Lisp_Object filename;
+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;
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);