python-3.6.zip added from Github

README.cosmo contains the necessary links.

third_party/python/Lib/test/fork_wait.py

@@ -0,0 +1,91 @@
+"""This test case provides support for checking forking and wait behavior.
+
+To test different wait behavior, override the wait_impl method.
+
+We want fork1() semantics -- only the forking thread survives in the
+child after a fork().
+
+On some systems (e.g. Solaris without posix threads) we find that all
+active threads survive in the child after a fork(); this is an error.
+"""
+
+import os, sys, time, unittest
+import test.support as support
+
+threading = support.import_module('threading')
+
+LONGSLEEP = 2
+SHORTSLEEP = 0.5
+NUM_THREADS = 4
+
+class ForkWait(unittest.TestCase):
+
+    def setUp(self):
+        self._threading_key = support.threading_setup()
+        self.alive = {}
+        self.stop = 0
+        self.threads = []
+
+    def tearDown(self):
+        # Stop threads
+        self.stop = 1
+        for thread in self.threads:
+            thread.join()
+        thread = None
+        self.threads.clear()
+        support.threading_cleanup(*self._threading_key)
+
+    def f(self, id):
+        while not self.stop:
+            self.alive[id] = os.getpid()
+            try:
+                time.sleep(SHORTSLEEP)
+            except OSError:
+                pass
+
+    def wait_impl(self, cpid):
+        for i in range(10):
+            # waitpid() shouldn't hang, but some of the buildbots seem to hang
+            # in the forking tests.  This is an attempt to fix the problem.
+            spid, status = os.waitpid(cpid, os.WNOHANG)
+            if spid == cpid:
+                break
+            time.sleep(2 * SHORTSLEEP)
+
+        self.assertEqual(spid, cpid)
+        self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8))
+
+    def test_wait(self):
+        for i in range(NUM_THREADS):
+            thread = threading.Thread(target=self.f, args=(i,))
+            thread.start()
+            self.threads.append(thread)
+
+        # busy-loop to wait for threads
+        deadline = time.monotonic() + 10.0
+        while len(self.alive) < NUM_THREADS:
+            time.sleep(0.1)
+            if deadline < time.monotonic():
+                break
+
+        a = sorted(self.alive.keys())
+        self.assertEqual(a, list(range(NUM_THREADS)))
+
+        prefork_lives = self.alive.copy()
+
+        if sys.platform in ['unixware7']:
+            cpid = os.fork1()
+        else:
+            cpid = os.fork()
+
+        if cpid == 0:
+            # Child
+            time.sleep(LONGSLEEP)
+            n = 0
+            for key in self.alive:
+                if self.alive[key] != prefork_lives[key]:
+                    n += 1
+            os._exit(n)
+        else:
+            # Parent
+            self.wait_impl(cpid)