--- a/mercurial/lock.py	Sun Oct 04 19:28:43 2015 -0700
+++ b/mercurial/lock.py	Sun Oct 04 20:02:50 2015 -0700
@@ -7,6 +7,7 @@
 
 from __future__ import absolute_import
 
+import contextlib
 import errno
 import os
 import socket
@@ -171,19 +172,20 @@
         locker = self._readlock()
         return self._testlock(locker)
 
-    def prepinherit(self):
-        """prepare for the lock to be inherited by a Mercurial subprocess
+    @contextlib.contextmanager
+    def inherit(self):
+        """context for the lock to be inherited by a Mercurial subprocess.
 
-        Returns a string that will be recognized by the lock in the
-        subprocess. Communicating this string to the subprocess needs to be done
-        separately -- typically by an environment variable.
+        Yields a string that will be recognized by the lock in the subprocess.
+        Communicating this string to the subprocess needs to be done separately
+        -- typically by an environment variable.
         """
         if not self.held:
             raise error.LockInheritanceContractViolation(
-                'prepinherit can only be called while lock is held')
+                'inherit can only be called while lock is held')
         if self._inherited:
             raise error.LockInheritanceContractViolation(
-                'prepinherit cannot be called while lock is already inherited')
+                'inherit cannot be called while lock is already inherited')
         if self.releasefn:
             self.releasefn()
         if self._parentheld:
@@ -191,15 +193,12 @@
         else:
             lockname = '%s:%s' % (lock._host, self.pid)
         self._inherited = True
-        return lockname
-
-    def reacquire(self):
-        if not self._inherited:
-            raise error.LockInheritanceContractViolation(
-                'reacquire can only be called after prepinherit')
-        if self.acquirefn:
-            self.acquirefn()
-        self._inherited = False
+        try:
+            yield lockname
+        finally:
+            if self.acquirefn:
+                self.acquirefn()
+            self._inherited = False
 
     def release(self):
         """release the lock and execute callback function if any