From 3900088cb6d70769c7905ea0afa8b6f161186fde Mon Sep 17 00:00:00 2001
From: "Travis E. Oliphant" <oliphant@enthought.com>
Date: Fri, 6 Jun 2008 20:52:38 +0000
Subject: [PATCH] Remove locking from buffer protocol as-per discussion.

---
 Include/object.h          | 11 -----------
 Modules/_bsddb.c          |  6 ------
 Modules/_ctypes/_ctypes.c |  5 -----
 Modules/arraymodule.c     |  5 -----
 Objects/abstract.c        |  6 ------
 Objects/memoryobject.c    |  3 ---
 6 files changed, 36 deletions(-)

diff --git a/Include/object.h b/Include/object.h
index 62c4961380a..e924131b61f 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -163,7 +163,6 @@ typedef void (*releasebufferproc)(PyObject *, Py_buffer *);
 #define PyBUF_WRITABLE 0x0001
 /*  we used to include an E, backwards compatible alias  */
 #define PyBUF_WRITEABLE PyBUF_WRITABLE
-#define PyBUF_LOCK 0x0002
 #define PyBUF_FORMAT 0x0004
 #define PyBUF_ND 0x0008
 #define PyBUF_STRIDES (0x0010 | PyBUF_ND)
@@ -174,25 +173,15 @@ typedef void (*releasebufferproc)(PyObject *, Py_buffer *);
 
 #define PyBUF_CONTIG (PyBUF_ND | PyBUF_WRITABLE)
 #define PyBUF_CONTIG_RO (PyBUF_ND)
-#define PyBUF_CONTIG_LCK (PyBUF_ND | PyBUF_LOCK)
-#define PyBUF_CONTIG_XLCK (PyBUF_ND | PyBUF_LOCK | PyBUF_WRITABLE)
 
 #define PyBUF_STRIDED (PyBUF_STRIDES | PyBUF_WRITABLE)
 #define PyBUF_STRIDED_RO (PyBUF_STRIDES)
-#define PyBUF_STRIDED_LCK (PyBUF_STRIDES | PyBUF_LOCK)
-#define PyBUF_STRIDED_XLCK (PyBUF_STRIDES | PyBUF_LOCK | PyBUF_WRITABLE)
 
 #define PyBUF_RECORDS (PyBUF_STRIDES | PyBUF_WRITABLE | PyBUF_FORMAT)
 #define PyBUF_RECORDS_RO (PyBUF_STRIDES | PyBUF_FORMAT)
-#define PyBUF_RECORDS_LCK (PyBUF_STRIDES | PyBUF_LOCK | PyBUF_FORMAT)
-#define PyBUF_RECORDS_XLCK (PyBUF_STRIDES | PyBUF_LOCK | PyBUF_WRITABLE \
-			    | PyBUF_FORMAT)
 
 #define PyBUF_FULL (PyBUF_INDIRECT | PyBUF_WRITABLE | PyBUF_FORMAT)
 #define PyBUF_FULL_RO (PyBUF_INDIRECT | PyBUF_FORMAT)
-#define PyBUF_FULL_LCK (PyBUF_INDIRECT | PyBUF_LOCK | PyBUF_FORMAT)
-#define PyBUF_FULL_XLCK (PyBUF_INDIRECT | PyBUF_LOCK | PyBUF_WRITABLE \
-			 | PyBUF_FORMAT)
 
 
 #define PyBUF_READ  0x100
diff --git a/Modules/_bsddb.c b/Modules/_bsddb.c
index 04c38356643..3a67a1e600a 100644
--- a/Modules/_bsddb.c
+++ b/Modules/_bsddb.c
@@ -312,12 +312,6 @@ static Py_buffer * _malloc_view(PyObject *obj)
                         "Py_buffer malloc failed");
         return NULL;
     }
-    /* We use PyBUF_LOCK to prevent other threads from trashing the data
-       buffer while we release the GIL.  http://bugs.python.org/issue1035 */
-    if (PyObject_GetBuffer(obj, view, PyBUF_LOCK) == -1) {
-        PyMem_Free(view);
-        return NULL;
-    }
     if (view->ndim > 1) {
         PyErr_SetString(PyExc_BufferError,
                         "buffers must be single dimension");
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index fe598d770fe..c840757add8 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -2449,11 +2449,6 @@ static int CData_GetBuffer(PyObject *_self, Py_buffer *view, int flags)
 	Py_ssize_t i;
 
 	if (view == NULL) return 0;
-	if (((flags & PyBUF_LOCK) == PyBUF_LOCK)) {
-		PyErr_SetString(PyExc_BufferError,
-				"Cannot lock this object.");
-		return -1;
-	}
 
 	view->buf = self->b_ptr;
 	view->len = self->b_size;
diff --git a/Modules/arraymodule.c b/Modules/arraymodule.c
index a84126d12b3..ea59a426abf 100644
--- a/Modules/arraymodule.c
+++ b/Modules/arraymodule.c
@@ -1779,11 +1779,6 @@ static const void *emptybuf = "";
 static int
 array_buffer_getbuf(arrayobject *self, Py_buffer *view, int flags)
 {
-        if ((flags & PyBUF_LOCK)) {
-                PyErr_SetString(PyExc_BufferError,
-                                "Cannot lock data");
-                return -1;
-        }
         if (view==NULL) goto finish;
 
         view->buf = (void *)self->ob_item;
diff --git a/Objects/abstract.c b/Objects/abstract.c
index 11adc772ad8..60a5e849cfd 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -672,12 +672,6 @@ PyBuffer_FillInfo(Py_buffer *view, void *buf, Py_ssize_t len,
 	      int readonly, int flags)
 {
 	if (view == NULL) return 0;
-	if (((flags & PyBUF_LOCK) == PyBUF_LOCK) &&
-	    readonly != 0) {
-		PyErr_SetString(PyExc_BufferError,
-				"Cannot lock this object.");
-		return -1;
-	}
 	if (((flags & PyBUF_WRITABLE) == PyBUF_WRITABLE) &&
 	    (readonly == 1)) {
 		PyErr_SetString(PyExc_BufferError,
diff --git a/Objects/memoryobject.c b/Objects/memoryobject.c
index 27ceb7a2e52..9bb16971d6a 100644
--- a/Objects/memoryobject.c
+++ b/Objects/memoryobject.c
@@ -230,9 +230,6 @@ PyMemoryView_GetContiguous(PyObject *obj, int buffertype, char fort)
         case PyBUF_WRITE:
                 flags = PyBUF_FULL;
                 break;
-        case PyBUF_SHADOW:
-                flags = PyBUF_FULL_XLCK;
-                break;
         }
 
         if (PyObject_GetBuffer(obj, view, flags) != 0) {