diff -r 849826a900d2 Lib/test/support/__init__.py
--- a/Lib/test/support/__init__.py	Tue Oct 25 21:49:19 2016 -0500
+++ b/Lib/test/support/__init__.py	Fri Oct 28 09:11:27 2016 +0200
@@ -93,6 +93,7 @@
     "check__all__",
     # sys
     "is_jython", "is_android", "check_impl_detail", "unix_shell",
+    "setswitchinterval",
     # network
     "HOST", "IPV6_ENABLED", "find_unused_port", "bind_port", "open_urlresource",
     # processes
@@ -2467,3 +2468,18 @@
     # The sequence should be deallocated just after the end of iterating
     gc_collect()
     test.assertTrue(done)
+
+
+_is_android_emulator = None
+def setswitchinterval(interval):
+    # Setting a very low gil interval on the Android emulator causes python
+    # to hang (issue #26939).
+    minimum_interval = 1e-5
+    if is_android and interval < minimum_interval:
+        global _is_android_emulator
+        if _is_android_emulator is None:
+            _is_android_emulator = (subprocess.check_output(
+                               ['getprop', 'ro.kernel.qemu']).strip() == b'1')
+        if _is_android_emulator:
+            interval = minimum_interval
+    return sys.setswitchinterval(interval)
diff -r 849826a900d2 Lib/test/test_functools.py
--- a/Lib/test/test_functools.py	Tue Oct 25 21:49:19 2016 -0500
+++ b/Lib/test/test_functools.py	Fri Oct 28 09:11:27 2016 +0200
@@ -1303,7 +1303,7 @@
                 f.cache_clear()
 
         orig_si = sys.getswitchinterval()
-        sys.setswitchinterval(1e-6)
+        support.setswitchinterval(1e-6)
         try:
             # create n threads in order to fill cache
             threads = [threading.Thread(target=full, args=[k])