bpo-32941: Add madvise() for mmap objects (GH-6172)
Allow mmap objects to access the madvise() system call.
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index fdd60bb..36cbaf9 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -708,11 +708,54 @@
}
#endif
+#ifdef HAVE_MADVISE
+static PyObject *
+mmap_madvise_method(mmap_object *self, PyObject *args)
+{
+ int option;
+ Py_ssize_t start = 0, length;
+
+ CHECK_VALID(NULL);
+ length = self->size;
+
+ if (!PyArg_ParseTuple(args, "i|nn:madvise", &option, &start, &length)) {
+ return NULL;
+ }
+
+ if (start < 0 || start >= self->size) {
+ PyErr_SetString(PyExc_ValueError, "madvise start out of bounds");
+ return NULL;
+ }
+ if (length < 0) {
+ PyErr_SetString(PyExc_ValueError, "madvise length invalid");
+ return NULL;
+ }
+ if (PY_SSIZE_T_MAX - start < length) {
+ PyErr_SetString(PyExc_OverflowError, "madvise length too large");
+ return NULL;
+ }
+
+ if (start + length > self->size) {
+ length = self->size - start;
+ }
+
+ if (madvise(self->data + start, length, option) != 0) {
+ PyErr_SetFromErrno(PyExc_OSError);
+ return NULL;
+ }
+
+ Py_RETURN_NONE;
+}
+#endif // HAVE_MADVISE
+
static struct PyMethodDef mmap_object_methods[] = {
{"close", (PyCFunction) mmap_close_method, METH_NOARGS},
{"find", (PyCFunction) mmap_find_method, METH_VARARGS},
{"rfind", (PyCFunction) mmap_rfind_method, METH_VARARGS},
{"flush", (PyCFunction) mmap_flush_method, METH_VARARGS},
+#ifdef HAVE_MADVISE
+ {"madvise", (PyCFunction) mmap_madvise_method, METH_VARARGS},
+#endif
{"move", (PyCFunction) mmap_move_method, METH_VARARGS},
{"read", (PyCFunction) mmap_read_method, METH_VARARGS},
{"read_byte", (PyCFunction) mmap_read_byte_method, METH_NOARGS},
@@ -1494,5 +1537,80 @@
setint(dict, "ACCESS_READ", ACCESS_READ);
setint(dict, "ACCESS_WRITE", ACCESS_WRITE);
setint(dict, "ACCESS_COPY", ACCESS_COPY);
+
+#ifdef HAVE_MADVISE
+ // Conventional advice values
+#ifdef MADV_NORMAL
+ setint(dict, "MADV_NORMAL", MADV_NORMAL);
+#endif
+#ifdef MADV_RANDOM
+ setint(dict, "MADV_RANDOM", MADV_RANDOM);
+#endif
+#ifdef MADV_SEQUENTIAL
+ setint(dict, "MADV_SEQUENTIAL", MADV_SEQUENTIAL);
+#endif
+#ifdef MADV_WILLNEED
+ setint(dict, "MADV_WILLNEED", MADV_WILLNEED);
+#endif
+#ifdef MADV_DONTNEED
+ setint(dict, "MADV_DONTNEED", MADV_DONTNEED);
+#endif
+
+ // Linux-specific advice values
+#ifdef MADV_REMOVE
+ setint(dict, "MADV_REMOVE", MADV_REMOVE);
+#endif
+#ifdef MADV_DONTFORK
+ setint(dict, "MADV_DONTFORK", MADV_DONTFORK);
+#endif
+#ifdef MADV_DOFORK
+ setint(dict, "MADV_DOFORK", MADV_DOFORK);
+#endif
+#ifdef MADV_HWPOISON
+ setint(dict, "MADV_HWPOISON", MADV_HWPOISON);
+#endif
+#ifdef MADV_MERGEABLE
+ setint(dict, "MADV_MERGEABLE", MADV_MERGEABLE);
+#endif
+#ifdef MADV_UNMERGEABLE
+ setint(dict, "MADV_UNMERGEABLE", MADV_UNMERGEABLE);
+#endif
+#ifdef MADV_SOFT_OFFLINE
+ setint(dict, "MADV_SOFT_OFFLINE", MADV_SOFT_OFFLINE);
+#endif
+#ifdef MADV_HUGEPAGE
+ setint(dict, "MADV_HUGEPAGE", MADV_HUGEPAGE);
+#endif
+#ifdef MADV_NOHUGEPAGE
+ setint(dict, "MADV_NOHUGEPAGE", MADV_NOHUGEPAGE);
+#endif
+#ifdef MADV_DONTDUMP
+ setint(dict, "MADV_DONTDUMP", MADV_DONTDUMP);
+#endif
+#ifdef MADV_DODUMP
+ setint(dict, "MADV_DODUMP", MADV_DODUMP);
+#endif
+#ifdef MADV_FREE // (Also present on FreeBSD and macOS.)
+ setint(dict, "MADV_FREE", MADV_FREE);
+#endif
+
+ // FreeBSD-specific
+#ifdef MADV_NOSYNC
+ setint(dict, "MADV_NOSYNC", MADV_NOSYNC);
+#endif
+#ifdef MADV_AUTOSYNC
+ setint(dict, "MADV_AUTOSYNC", MADV_AUTOSYNC);
+#endif
+#ifdef MADV_NOCORE
+ setint(dict, "MADV_NOCORE", MADV_NOCORE);
+#endif
+#ifdef MADV_CORE
+ setint(dict, "MADV_CORE", MADV_CORE);
+#endif
+#ifdef MADV_PROTECT
+ setint(dict, "MADV_PROTECT", MADV_PROTECT);
+#endif
+#endif // HAVE_MADVISE
+
return module;
}