isync

commit 85b5c5b8c9a24dddd6f050028ac62a6fed1f7333
parent dd1b19a99a98baea16795b35029a6f36263f5232
Author: Michael Elkins <me@mutt.org>
Date:   Thu, 20 Jun 2002 23:33:13 +0000

remove debian/files

move dotlocking code to dotlock.c.

dotlocking code fixed to ignore whether or not the lockfile exists on
open().  we only care about whether fcntl() was able to lock it.

Diffstat:
M
Makefile.am
 | 
2
+-
A
dotlock.c
 | 
89
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
dotlock.h
 | 
22
++++++++++++++++++++++
M
maildir.c
 | 
71
+++++++++--------------------------------------------------------------

4 files changed, 121 insertions(+), 63 deletions(-)
diff --git a/Makefile.am b/Makefile.am
@@ -1,7 +1,7 @@
 SUBDIRS=debian
 bin_PROGRAMS=isync
 isync_SOURCES=main.c imap.c sync.c maildir.c isync.h list.c cram.c config.c \
-	      debug.h
+	      debug.h dotlock.c dotlock.h
 isync_LDADD=@DEBUGOBJ@
 isync_DEPENDENCIES=@DEBUGOBJ@
 EXTRA_isync_SOURCES=debug.c
diff --git a/dotlock.c b/dotlock.c
@@ -0,0 +1,89 @@
+/* $Id$
+ *
+ * isync - IMAP4 to maildir mailbox synchronizer
+ * Copyright (C) 2002 Michael R. Elkins <me@mutt.org>
+ *
+ *  This program 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 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ * this file contains routines to establish a mutex using a `dotlock' file
+ */
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#if TESTING
+#include <stdio.h>
+#endif
+#include "dotlock.h"
+
+static struct flock lck = { 0, SEEK_SET, 0, 0, 0 };
+
+static void make_lock (int type)
+{
+  lck.l_type = type;
+  lck.l_pid = getpid ();
+}
+
+int dotlock_lock (const char *path, int *fd)
+{
+  *fd = open (path, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
+  if (*fd == -1)
+    return -1;
+  make_lock (F_WRLCK);
+  if (fcntl (*fd, F_SETLKW, &lck))
+  {
+    close (*fd);
+    *fd = -1;
+    return -1;
+  }
+  return 0;
+}
+
+int dotlock_unlock (int *fd)
+{
+  int r = 0;
+
+  if (*fd != -1)
+  {
+    make_lock (F_UNLCK);
+    if (fcntl (*fd, F_SETLKW, &lck))
+      r = -1;
+    close (*fd);
+    *fd = -1;
+  }
+  return r;
+}
+
+#if TESTING
+int main (void)
+{
+  int fd;
+
+  if (dotlock_lock ("./lock", &fd))
+  {
+    perror ("dotlock_lock");
+    goto done;
+  }
+  puts("sleeping for 5 seconds");
+  sleep(5);
+  if (dotlock_unlock (&fd))
+  {
+    perror ("dotlock_lock");
+  }
+done:
+  exit (0);
+}
+#endif
diff --git a/dotlock.h b/dotlock.h
@@ -0,0 +1,22 @@
+/* $Id$
+ *
+ * isync - IMAP4 to maildir mailbox synchronizer
+ * Copyright (C) 2002 Michael R. Elkins <me@mutt.org>
+ *
+ *  This program 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 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+int dotlock_lock (const char *, int *);
+int dotlock_unlock (int *);
diff --git a/maildir.c b/maildir.c
@@ -29,26 +29,7 @@
 #include <errno.h>
 #include <time.h>
 #include "isync.h"
-
-static int
-do_lock (int fd, int flag)
-{
-    struct flock lck;
-
-    memset (&lck, 0, sizeof (lck));
-    lck.l_type = flag;
-    lck.l_whence = SEEK_SET;
-    lck.l_start = 0;
-    lck.l_len = 0;
-
-    if (fcntl (fd, F_SETLK, &lck))
-    {
-	perror ("fcntl");
-	return -1;
-    }
-
-    return 0;
-}
+#include "dotlock.h"
 
 /* 2,<flags> */
 static void
@@ -117,44 +98,8 @@ read_uid (const char *path, const char *file, unsigned int *uid /* out */)
     return ret;
 }
 
-/* NOTE: this is NOT NFS safe */
-static int
-maildir_lock (mailbox_t * m)
-{
-    char path[_POSIX_PATH_MAX];
-
-    snprintf (path, sizeof (path), "%s/isynclock", m->path);
-    m->lockfd = open (path, O_WRONLY | O_CREAT | O_EXCL, S_IWUSR | S_IRUSR);
-    if (m->lockfd == -1)
-    {
-	perror (path);
-	return -1;
-    }
-    if (do_lock (m->lockfd, F_WRLCK))
-    {
-	close (m->lockfd);
-	m->lockfd = -1;
-	return -1;
-    }
-    return 0;
-}
-
-static void
-maildir_unlock (mailbox_t * m)
-{
-  char path[_POSIX_PATH_MAX];
-
-  if (m->lockfd != -1)
-  {
-    snprintf (path, sizeof (path), "%s/isynclock", m->path);
-    unlink (path);
-    do_lock (m->lockfd, F_UNLCK);
-    close (m->lockfd);
-    m->lockfd = -1;
-  }
-}
-
-/* open a maildir mailbox.
+/*
+ * open a maildir mailbox.
  * if OPEN_FAST is set, we just check to make
  * sure its a valid mailbox and don't actually parse it.  any IMAP messages
  * with the \Recent flag set are guaranteed not to be in the mailbox yet,
@@ -231,10 +176,12 @@ maildir_open (const char *path, int flags)
 	}
     }
 
-    /* we need a mutex on the maildir because of the state files that isync
+    /*
+     * we need a mutex on the maildir because of the state files that isync
      * uses.
      */
-    if (maildir_lock (m))
+    snprintf (buf, sizeof (buf), "%s/isynclock", m->path);
+    if (dotlock_lock (buf, &m->lockfd))
 	goto err;
 
     /* check for the uidvalidity value */
@@ -311,7 +258,7 @@ maildir_open (const char *path, int flags)
   err:
     if (m->db)
 	dbm_close (m->db);
-    maildir_unlock (m);
+    dotlock_unlock (&m->lockfd);
     free (m->path);
     free (m);
     return NULL;
@@ -436,7 +383,7 @@ maildir_close (mailbox_t * mbox)
 	dbm_close (mbox->db);
 
     /* release the mutex on the mailbox */
-    maildir_unlock (mbox);
+    dotlock_unlock (&mbox->lockfd);
 
     /* per the maildir(5) specification, delivery agents are supposed to
      * set a 24-hour timer on items placed in the `tmp' directory.