From 9689c11b3624a7f6e235d411953e5a4b7bc0c454 Mon Sep 17 00:00:00 2001
From: Quantum <quantum2048@gmail.com>
Date: Sun, 19 Nov 2017 02:17:31 -0500
Subject: [PATCH] Implement flock locking.

---
 _2048/lock.py    | 49 +++++++++++++++++++++++++++++-------------------
 _2048/manager.py |  2 --
 2 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/_2048/lock.py b/_2048/lock.py
index b51e64f..865d502 100644
--- a/_2048/lock.py
+++ b/_2048/lock.py
@@ -1,28 +1,39 @@
-"""An implementation of a file locker."""
+class FileLockBase(object):
+    def __init__(self, fd):
+        if hasattr(fd, 'fileno') and callable(fd.fileno):
+            self.fd = fd.fileno()
+        else:
+            self.fd = fd
+
+    def acquire(self, blocking=True):
+        raise NotImplementedError()
+
+    def release(self):
+        raise NotImplementedError()
+
+    def __enter__(self):
+        self.acquire()
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.release()
+
 
-# Import msvcrt if possible.
 try:
     import msvcrt
 except ImportError:
-    # Currently no linux solution with fcntl.
-    raise RuntimeError('Linux locker not written yet.')
-else:
-    class FileLock(object):
-        def __init__(self, fd, size=65536):
-            if hasattr(fd, 'fileno') and callable(fd.fileno):
-                self.fd = fd.fileno()
-            else:
-                self.fd = fd
-            self.size = size
+    import fcntl
+    import os
 
+    class FileLock(FileLockBase):
         def acquire(self, blocking=True):
-            msvcrt.locking(self.fd, (msvcrt.LK_NBLCK, msvcrt.LK_LOCK)[blocking], self.size)
+            fcntl.flock(self.fd, fcntl.LOCK_EX | (0 if blocking else fcntl.LOCK_NB))
 
         def release(self):
-            msvcrt.locking(self.fd, msvcrt.LK_UNLCK, self.size)
+            fcntl.flock(self.fd, fcntl.LOCK_UN)
+else:
+    class FileLock(FileLockBase):
+        def acquire(self, blocking=True):
+            msvcrt.locking(self.fd, (msvcrt.LK_NBLCK, msvcrt.LK_LOCK)[blocking], -1)
 
-        def __enter__(self):
-            self.acquire()
-
-        def __exit__(self, exc_type, exc_val, exc_tb):
-            self.release()
+        def release(self):
+            msvcrt.locking(self.fd, msvcrt.LK_UNLCK, -1)
diff --git a/_2048/manager.py b/_2048/manager.py
index 4462297..e4982d5 100644
--- a/_2048/manager.py
+++ b/_2048/manager.py
@@ -1,5 +1,3 @@
-"""Defines the Game manager."""
-
 import os
 import errno
 import itertools