diff options
Diffstat (limited to 'src/filelock.c')
| -rw-r--r-- | src/filelock.c | 36 |
1 files changed, 18 insertions, 18 deletions
diff --git a/src/filelock.c b/src/filelock.c index 33de9a4e7db..bcad75199cd 100644 --- a/src/filelock.c +++ b/src/filelock.c @@ -80,14 +80,14 @@ Lisp_Object Vtemporary_file_directory; #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 @@ -105,15 +105,15 @@ Lisp_Object Vtemporary_file_directory; 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. */ @@ -344,7 +344,7 @@ fill_in_lock_file_name (lockfile, fn) 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] = '#'; @@ -368,7 +368,7 @@ fill_in_lock_file_name (lockfile, fn) static int lock_file_1 (lfname, force) - char *lfname; + char *lfname; int force; { register int err; @@ -394,7 +394,7 @@ lock_file_1 (lfname, force) (unsigned long) getpid (), (unsigned long) boot_time); else sprintf (lock_info_str, "%s@%s.%lu", user_name, host_name, - (unsigned long) getpid ()); + (unsigned long) getpid ()); err = symlink (lock_info_str, lfname); if (errno == EEXIST && force) @@ -448,7 +448,7 @@ current_lock_owner (owner, lfname) #endif } while (len >= bufsize); - + /* If nonexistent lock file, all is well; otherwise, got strange error. */ if (len == -1) { @@ -458,7 +458,7 @@ current_lock_owner (owner, lfname) /* 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) @@ -466,7 +466,7 @@ current_lock_owner (owner, lfname) 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, '@'); @@ -480,7 +480,7 @@ current_lock_owner (owner, lfname) 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; @@ -500,7 +500,7 @@ current_lock_owner (owner, lfname) /* We're done looking at the link info. */ xfree (lfinfo); - + /* On current host? */ if (STRINGP (Fsystem_name ()) && strcmp (owner->host, SDATA (Fsystem_name ())) == 0) @@ -524,7 +524,7 @@ current_lock_owner (owner, lfname) here's where we'd do it. */ ret = 1; } - + /* Avoid garbage. */ if (local_owner || ret <= 0) { @@ -543,7 +543,7 @@ current_lock_owner (owner, lfname) static int lock_if_free (clasher, lfname) lock_info_type *clasher; - register char *lfname; + register char *lfname; { while (lock_file_1 (lfname, 0) == 0) { @@ -551,7 +551,7 @@ lock_if_free (clasher, lfname) if (errno != EEXIST) return -1; - + locker = current_lock_owner (clasher, lfname); if (locker == 2) { @@ -634,7 +634,7 @@ lock_file (fn) 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 */ @@ -691,7 +691,7 @@ or else nothing is done if current buffer isn't visiting a file. */) if (SAVE_MODIFF < MODIFF && !NILP (file)) lock_file (file); - return Qnil; + return Qnil; } DEFUN ("unlock-buffer", Funlock_buffer, Sunlock_buffer, |