[Python-checkins] r42244 - in python/trunk: Doc/lib/libmmap.tex Lib/test/output/test_mmap Lib/test/test_mmap.py Misc/NEWS Modules/mmapmodule.c
neal.norwitz
python-checkins at python.org
Sun Feb 5 06:45:48 CET 2006
Author: neal.norwitz
Date: Sun Feb 5 06:45:43 2006
New Revision: 42244
Modified:
python/trunk/Doc/lib/libmmap.tex
python/trunk/Lib/test/output/test_mmap
python/trunk/Lib/test/test_mmap.py
python/trunk/Misc/NEWS
python/trunk/Modules/mmapmodule.c
Log:
Patch #1407135, bug #1424041, make mmap.mmap(-1, length) work the same
on both Unix (SVR4 and BSD) and Windows. Restores behaviour of passing -1
for anonymous memory on Unix. Use MAP_ANONYMOUS instead of _ANON since
the latter is deprecated according to Linux (gentoo) man pages.
Should we continue to allow mmap.mmap(0, length) to work on Windows?
0 is a valid fd.
Will backport bugfix portions.
Modified: python/trunk/Doc/lib/libmmap.tex
==============================================================================
--- python/trunk/Doc/lib/libmmap.tex (original)
+++ python/trunk/Doc/lib/libmmap.tex Sun Feb 5 06:45:43 2006
@@ -37,7 +37,8 @@
exception. Assignment to an \constant{ACCESS_WRITE} memory map
affects both memory and the underlying file. Assignment to an
\constant{ACCESS_COPY} memory map affects memory but does not update
-the underlying file.
+the underlying file. \versionchanged[To map anonymous memory,
+-1 should be passed as the fileno along with the length]{2.5}
\begin{funcdesc}{mmap}{fileno, length\optional{, tagname\optional{, access}}}
\strong{(Windows version)} Maps \var{length} bytes from the file
Modified: python/trunk/Lib/test/output/test_mmap
==============================================================================
--- python/trunk/Lib/test/output/test_mmap (original)
+++ python/trunk/Lib/test/output/test_mmap Sun Feb 5 06:45:43 2006
@@ -34,4 +34,5 @@
Try opening a bad file descriptor...
Ensuring that passing 0 as map length sets map size to current file size.
Ensuring that passing 0 as map length sets map size to current file size.
+ anonymous mmap.mmap(-1, PAGESIZE)...
Test passed
Modified: python/trunk/Lib/test/test_mmap.py
==============================================================================
--- python/trunk/Lib/test/test_mmap.py (original)
+++ python/trunk/Lib/test/test_mmap.py Sun Feb 5 06:45:43 2006
@@ -283,7 +283,7 @@
print ' Try opening a bad file descriptor...'
try:
- mmap.mmap(-1, 4096)
+ mmap.mmap(-2, 4096)
except mmap.error:
pass
else:
@@ -380,6 +380,16 @@
finally:
os.unlink(TESTFN)
- print ' Test passed'
+def test_anon():
+ print " anonymous mmap.mmap(-1, PAGESIZE)..."
+ m = mmap.mmap(-1, PAGESIZE)
+ for x in xrange(PAGESIZE):
+ verify(m[x] == '\0', "anonymously mmap'ed contents should be zero")
+
+ for x in xrange(PAGESIZE):
+ m[x] = ch = chr(x & 255)
+ vereq(m[x], ch)
test_both()
+test_anon()
+print ' Test passed'
Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS (original)
+++ python/trunk/Misc/NEWS Sun Feb 5 06:45:43 2006
@@ -216,6 +216,10 @@
Extension Modules
-----------------
+- Patch #1407135, bug #1424041: harmonize mmap behavior of anonymous memory.
+ mmap.mmap(-1, size) now returns anonymous memory in both Unix and Windows.
+ mmap.mmap(0, size) should not be used on Windows for anonymous memory.
+
- Patch #1422385: The nis module now supports access to domains other
than the system default domain.
Modified: python/trunk/Modules/mmapmodule.c
==============================================================================
--- python/trunk/Modules/mmapmodule.c (original)
+++ python/trunk/Modules/mmapmodule.c Sun Feb 5 06:45:43 2006
@@ -54,6 +54,11 @@
#include <string.h>
#include <sys/types.h>
+/* maybe define MAP_ANON in terms of MAP_ANONYMOUS */
+#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
+# define MAP_ANONYMOUS MAP_ANON
+#endif
+
static PyObject *mmap_module_error;
typedef enum
@@ -863,6 +868,7 @@
PyObject *map_size_obj = NULL;
int map_size;
int fd, flags = MAP_SHARED, prot = PROT_WRITE | PROT_READ;
+ int devzero = -1;
int access = (int)ACCESS_DEFAULT;
static const char *keywords[] = {"fileno", "length",
"flags", "prot",
@@ -921,15 +927,41 @@
m_obj->data = NULL;
m_obj->size = (size_t) map_size;
m_obj->pos = (size_t) 0;
- m_obj->fd = dup(fd);
- if (m_obj->fd == -1) {
- Py_DECREF(m_obj);
- PyErr_SetFromErrno(mmap_module_error);
- return NULL;
+ if (fd == -1) {
+ m_obj->fd = -1;
+ /* Assume the caller wants to map anonymous memory.
+ This is the same behaviour as Windows. mmap.mmap(-1, size)
+ on both Windows and Unix map anonymous memory.
+ */
+#ifdef MAP_ANONYMOUS
+ /* BSD way to map anonymous memory */
+ flags |= MAP_ANONYMOUS;
+#else
+ /* SVR4 method to map anonymous memory is to open /dev/zero */
+ fd = devzero = open("/dev/zero", O_RDWR);
+ if (devzero == -1) {
+ Py_DECREF(m_obj);
+ PyErr_SetFromErrno(mmap_module_error);
+ return NULL;
+ }
+#endif
+ } else {
+ m_obj->fd = dup(fd);
+ if (m_obj->fd == -1) {
+ Py_DECREF(m_obj);
+ PyErr_SetFromErrno(mmap_module_error);
+ return NULL;
+ }
}
+
m_obj->data = mmap(NULL, map_size,
prot, flags,
fd, 0);
+
+ if (devzero != -1) {
+ close(devzero);
+ }
+
if (m_obj->data == (char *)-1) {
m_obj->data = NULL;
Py_DECREF(m_obj);
@@ -986,8 +1018,15 @@
if (map_size < 0)
return NULL;
- /* if an actual filename has been specified */
- if (fileno != 0) {
+ /* assume -1 and 0 both mean invalid filedescriptor
+ to 'anonymously' map memory.
+ XXX: fileno == 0 is a valid fd, but was accepted prior to 2.5.
+ XXX: Should this code be added?
+ if (fileno == 0)
+ PyErr_Warn(PyExc_DeprecationWarning,
+ "don't use 0 for anonymous memory");
+ */
+ if (fileno != -1 && fileno != 0) {
fh = (HANDLE)_get_osfhandle(fileno);
if (fh==(HANDLE)-1) {
PyErr_SetFromErrno(mmap_module_error);
@@ -1123,10 +1162,10 @@
PyDict_SetItemString (dict, "MAP_EXECUTABLE",
PyInt_FromLong(MAP_EXECUTABLE) );
#endif
-#ifdef MAP_ANON
- PyDict_SetItemString (dict, "MAP_ANON", PyInt_FromLong(MAP_ANON) );
+#ifdef MAP_ANONYMOUS
+ PyDict_SetItemString (dict, "MAP_ANON", PyInt_FromLong(MAP_ANONYMOUS) );
PyDict_SetItemString (dict, "MAP_ANONYMOUS",
- PyInt_FromLong(MAP_ANON) );
+ PyInt_FromLong(MAP_ANONYMOUS) );
#endif
PyDict_SetItemString (dict, "PAGESIZE",
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