bpo-33021: Release the GIL during fstat() calls (GH-6019) · python/cpython@4484f9d (original) (raw)

3 files changed

lines changed

Original file line number	Diff line number	Diff line change
@@ -0,0 +1,2 @@
	1	+Release the GIL during fstat() calls, avoiding hang of all threads when
	2	+calling mmap.mmap(), os.urandom(), and random.seed(). Patch by Nir Soffer.

Original file line number	Diff line number	Diff line change
@@ -1050,6 +1050,7 @@ static PyObject *
1050	1050	new_mmap_object(PyTypeObject type, PyObject args, PyObject *kwdict)
1051	1051	{
1052	1052	struct _Py_stat_struct status;
	1053	+int fstat_result;
1053	1054	mmap_object *m_obj;
1054	1055	Py_ssize_t map_size;
1055	1056	off_t offset = 0;
@@ -1115,8 +1116,14 @@ new_mmap_object(PyTypeObject type, PyObject args, PyObject *kwdict)
1115	1116	if (fd != -1)
1116	1117	(void)fcntl(fd, F_FULLFSYNC);
1117	1118	#endif
1118		-if (fd != -1 && _Py_fstat_noraise(fd, &status) == 0
1119		-&& S_ISREG(status.st_mode)) {
	1119	+
	1120	+if (fd != -1) {
	1121	+Py_BEGIN_ALLOW_THREADS
	1122	+fstat_result = _Py_fstat_noraise(fd, &status);
	1123	+Py_END_ALLOW_THREADS
	1124	+ }
	1125	+
	1126	+if (fd != -1 && fstat_result == 0 && S_ISREG(status.st_mode)) {
1120	1127	if (map_size == 0) {
1121	1128	if (status.st_size == 0) {
1122	1129	PyErr_SetString(PyExc_ValueError,

Original file line number	Diff line number	Diff line change
@@ -301,10 +301,15 @@ dev_urandom(char *buffer, Py_ssize_t size, int raise)
301	301
302	302	if (raise) {
303	303	struct _Py_stat_struct st;
	304	+int fstat_result;
304	305
305	306	if (urandom_cache.fd >= 0) {
	307	+Py_BEGIN_ALLOW_THREADS
	308	+fstat_result = _Py_fstat_noraise(urandom_cache.fd, &st);
	309	+Py_END_ALLOW_THREADS
	310	+
306	311	/* Does the fd point to the same thing as before? (issue #21207) */
307		-if (_Py_fstat_noraise(urandom_cache.fd, &st)
	312	+if (fstat_result
308	313	\|
309	314	\|
310	315	/* Something changed: forget the cached fd (but don't close it,