merge changes from trunk

git-svn-id: http://arthurdejong.org/svn/nss-pam-ldapd/nss-pam-ldapd-solaris@1349 ef36b2f9-881f-0410-afb5-c4e39611909c

1 files changed, 70 insertions, 0 deletions

diff --git a/pynslcd/mypidfile.py b/pynslcd/mypidfile.py
new file mode 100644
index 0000000..4781089
--- /dev/null
+++ b/pynslcd/mypidfile.py
@@ -0,0 +1,70 @@
+
+# mypidfile.py - functions for properly locking a PIDFile
+#
+# Copyright (C) 2010 Arthur de Jong
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301 USA
+
+import fcntl
+import errno
+import os
+
+
+class MyPIDLockFile(object):
+    """Implementation of a PIDFile fit for use with the daemon module
+    that locks the PIDFile with fcntl.lockf()."""
+
+    def __init__(self, path):
+        self.path = path
+
+    def __enter__(self):
+        """Lock the PID file and write the process ID to the file."""
+        fd = os.open(self.path, os.O_RDWR | os.O_CREAT, 0644)
+        try:
+            fcntl.lockf(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
+            pidfile = os.fdopen(fd, 'w')
+        except:
+            os.close(fd)
+            raise
+        pidfile.write('%d\n' % os.getpid())
+        pidfile.flush()
+        self.pidfile = pidfile
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        """Release the lock (close the lockfile)."""
+        fcntl.lockf(self.pidfile.fileno(), fcntl.LOCK_UN)
+        self.pidfile.close()
+        del self.pidfile
+
+    def is_locked(self):
+        """Check whether the file is already present and locked."""
+        try:
+            fd = os.open(self.path, os.O_RDWR, 0644)
+            # Python doesn't seem to have F_TEST so we'll just try to lock
+            fcntl.lockf(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
+            # if we're here we must have aquired the lock
+            fcntl.lockf(fd, fcntl.LOCK_UN)
+            return False
+        except (IOError, OSError), e:
+            if e.errno == errno.ENOENT:
+                return False
+            if e.errno in (errno.EACCES, errno.EAGAIN):
+                return True
+            raise
+        finally:
+            if 'fd' in locals():
+                os.close(fd)