[Python-checkins] r76007 - python/trunk/Modules/_io/bufferedio.c

[antoine.pitrou]

Author: antoine.pitrou
Date: Sun Nov  1 12:58:22 2009
New Revision: 76007

Log:
Buffered I/O: optimize lock taking in the common non-contended case.



Modified:
   python/trunk/Modules/_io/bufferedio.c

Modified: python/trunk/Modules/_io/bufferedio.c
==============================================================================
--- python/trunk/Modules/_io/bufferedio.c	(original)
+++ python/trunk/Modules/_io/bufferedio.c	Sun Nov  1 12:58:22 2009
@@ -260,9 +260,11 @@
 
 #ifdef WITH_THREAD
 #define ENTER_BUFFERED(self) \
-    Py_BEGIN_ALLOW_THREADS \
-    PyThread_acquire_lock(self->lock, 1); \
-    Py_END_ALLOW_THREADS
+    if (!PyThread_acquire_lock(self->lock, 0)) { \
+        Py_BEGIN_ALLOW_THREADS \
+        PyThread_acquire_lock(self->lock, 1); \
+        Py_END_ALLOW_THREADS \
+    }
 
 #define LEAVE_BUFFERED(self) \
     PyThread_release_lock(self->lock);