[Python-checkins] closes bpo-31903: Release the GIL when calling into SystemConfiguration (GH-4178)

[Miss Islington (bot)]

https://github.com/python/cpython/commit/aa12534acff4868f6dce9e2364a66fbb0ebcb3ca
commit: aa12534acff4868f6dce9e2364a66fbb0ebcb3ca
branch: 3.6
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: GitHub <noreply at github.com>
date: 2018-09-12T08:38:36-07:00
summary:

closes bpo-31903: Release the GIL when calling into SystemConfiguration (GH-4178)

(cherry picked from commit 4859ba0d2ce4506fddc3f55f90f8dce031b3804f)

Co-authored-by: Max Bélanger <aeromax at gmail.com>

files:
A Misc/NEWS.d/next/macOS/2017-11-01-16-53-12.bpo-31903.K6jCVG.rst
M Modules/_scproxy.c

diff --git a/Misc/NEWS.d/next/macOS/2017-11-01-16-53-12.bpo-31903.K6jCVG.rst b/Misc/NEWS.d/next/macOS/2017-11-01-16-53-12.bpo-31903.K6jCVG.rst
new file mode 100644
index 000000000000..3788112cd730
--- /dev/null
+++ b/Misc/NEWS.d/next/macOS/2017-11-01-16-53-12.bpo-31903.K6jCVG.rst
@@ -0,0 +1,2 @@
+In :mod:`_scproxy`, drop the GIL when calling into ``SystemConfiguration`` to avoid
+deadlocks.
diff --git a/Modules/_scproxy.c b/Modules/_scproxy.c
index 1ce4b776f3e2..e37515ee6552 100644
--- a/Modules/_scproxy.c
+++ b/Modules/_scproxy.c
@@ -62,7 +62,10 @@ get_proxy_settings(PyObject* mod __attribute__((__unused__)))
     PyObject* v;
     int r;
 
+    Py_BEGIN_ALLOW_THREADS
     proxyDict = SCDynamicStoreCopyProxies(NULL);
+    Py_END_ALLOW_THREADS
+
     if (!proxyDict) {
         Py_INCREF(Py_None);
         return Py_None;
@@ -173,7 +176,10 @@ get_proxies(PyObject* mod __attribute__((__unused__)))
     int r;
     CFDictionaryRef proxyDict = NULL;
 
+    Py_BEGIN_ALLOW_THREADS
     proxyDict = SCDynamicStoreCopyProxies(NULL);
+    Py_END_ALLOW_THREADS
+
     if (proxyDict == NULL) {
         return PyDict_New();
     }