diff --git a/gunicorn/arbiter.py b/gunicorn/arbiter.py
index 23e895d6..ef9c2d5a 100644
--- a/gunicorn/arbiter.py
+++ b/gunicorn/arbiter.py
@@ -15,7 +15,7 @@ import sys
 import time
 import traceback
 
-from gunicorn.pidfile import set_pidfile, unlink_pidfile
+from gunicorn.pidfile import Pidfile
 from gunicorn.sock import create_socket
 from gunicorn.workers.sync import SyncWorker
 from gunicorn import util
@@ -92,7 +92,8 @@ class Arbiter(object):
         self.pid = os.getpid()
         self.init_signals()
         self.LISTENER = create_socket(self.cfg)
-        self.pidfile = set_pidfile(self.pid, self.cfg.pidfile, self.pidfile)
+        self.pidfile = Pidfile(self.cfg.pidfile)
+        self.pidfile.create(self.pid)
         self.log.info("Arbiter booted")
         self.log.info("Listening at: %s" % self.LISTENER)
         
@@ -152,14 +153,14 @@ class Arbiter(object):
                 self.log.info("Unhandled exception in main loop:\n%s" %  
                             traceback.format_exc())
                 self.stop(False)
-                if self.pidfile:
-                    unlink_pidfile(self.pid, self.pidfile)
+                if self.pidfile is not None:
+                    self.pidfile.unlink()
                 sys.exit(-1)
 
         self.stop()
         self.log.info("Shutting down: %s" % self.master_name)
-        if self.pidfile:
-            unlink_pidfile(self.pid, self.pidfile)
+        if self.pidfile is not None:
+            self.pidfile.unlink()
         sys.exit(0)
         
     def handle_chld(self, sig, frame):
@@ -285,9 +286,8 @@ class Arbiter(object):
         """\
         Relaunch the master and workers.
         """
-        if self.pidfile:
-            old_pidfile = "%s.oldbin" % self.pidfile
-            self.pidfile = set_pidfile(self.pid, old_pidfile)            
+        if self.pidfile is not None:
+            self.pidfile.rename("%s.oldbin" % self.pidfile.path)         
         
         self.reexec_pid = os.fork()
         if self.reexec_pid != 0:
diff --git a/gunicorn/pidfile.py b/gunicorn/pidfile.py
index bdcac048..10756999 100644
--- a/gunicorn/pidfile.py
+++ b/gunicorn/pidfile.py
@@ -10,52 +10,60 @@ import os
 import tempfile
 
 
-def set_pidfile(pid, path, oldpath=None):
-    oldpid = valid_pidfile(path)
-    if oldpid:
-        if oldpath is not None and path == oldpath and \
-                oldpid == os.getpid():
-            return path
-        raise RuntimeError("Already running on PID %s " \
-                    "(or pid file '%s' is stale)" % (os.getpid(), path))
-                    
-    if oldpath:    
-        unlink_pidfile(pid, path)
-
-    # write pidfile
-    fd, fname = tempfile.mkstemp(dir=os.path.dirname(path))
-    os.write(fd, "%s\n" % pid)
-    os.rename(fname, path)
-    os.close(fd)
-    return path
+class Pidfile(object):
     
-def unlink_pidfile(pid, path):
-    """ delete pidfile"""
-    try:
-        with open(path, "r") as f:
-            pid1 =  int(f.read() or 0)
-            
-        if pid1 == pid:
-            os.unlink(path)
-    except:
-        pass
-    
-def valid_pidfile(path):
-    """ Validate pidfile and make it stale if needed"""
-    try:
-        with open(path, "r") as f:
-            wpid = int(f.read() or 0)
+    def __init__(self, path):
+        self.path = path
+        self.pid = None
+        
+    def create(self, pid):
+        oldpid = self.validate()
+        if oldpid:
+            if oldpid == os.getpid():
+                return
+            raise RuntimeError("Already running on PID %s " \
+                "(or pid file '%s' is stale)" % (os.getpid(), self.path))
 
-            if wpid <= 0: return None
- 
-            try:
-                os.kill(wpid, 0)
-                return wpid
-            except OSError, e:
-                if e[0] == errno.ESRCH:
-                    return
-                raise
-    except IOError, e:
-        if e[0] == errno.ENOENT:
-            return
-        raise
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+        self.pid = pid
+        
+        # write pidfile
+        fd, fname = tempfile.mkstemp(dir=os.path.dirname(self.path))
+        os.write(fd, "%s\n" % self.pid)
+        os.rename(fname, self.path)
+        os.close(fd)
+        
+    def rename(self, path):
+        self.unlink()
+        self.path = path
+        self.create(self.pid)
+        
+    def unlink(self):
+        """ delete pidfile"""
+        try:
+            with open(self.path, "r") as f:
+                pid1 =  int(f.read() or 0)
+
+            if pid1 == self.pid:
+                os.unlink(self.path)
+        except:
+            pass
+       
+    def validate(self):
+        """ Validate pidfile and make it stale if needed"""
+        try:
+            with open(self.path, "r") as f:
+                wpid = int(f.read() or 0)
+
+                if wpid <= 0: return None
+
+                try:
+                    os.kill(wpid, 0)
+                    return wpid
+                except OSError, e:
+                    if e[0] == errno.ESRCH:
+                        return
+                    raise
+        except IOError, e:
+            if e[0] == errno.ENOENT:
+                return
+            raise
\ No newline at end of file