ssh: rewrite proxy management for multiprocessing usagev2.15

We changed sync to use multiprocessing for parallel work.  This broke
the ssh proxy code as it's all based on threads.  Rewrite the logic to
be multiprocessing safe.

Now instead of the module acting as a stateful object, callers have to
instantiate a new ProxyManager class that holds all the state, an pass
that down to any users.

Bug: https://crbug.com/gerrit/12389
Change-Id: I4b1af116f7306b91e825d3c56fb4274c9b033562
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/305486
Tested-by: Mike Frysinger <vapier@google.com>
Reviewed-by: Chris Mcdonald <cjmcdonald@google.com>

1 files changed, 26 insertions, 4 deletions

diff --git a/tests/test_ssh.py b/tests/test_ssh.py
index 5a4f27e4..ffb5cb94 100644
--- a/tests/test_ssh.py
+++ b/tests/test_ssh.py
@@ -14,6 +14,8 @@
 
 """Unittests for the ssh.py module."""
 
+import multiprocessing
+import subprocess
 import unittest
 from unittest import mock
 
@@ -39,14 +41,34 @@ class SshTests(unittest.TestCase):
     with mock.patch('ssh._run_ssh_version', return_value='OpenSSH_1.2\n'):
       self.assertEqual(ssh.version(), (1, 2))
 
+  def test_context_manager_empty(self):
+    """Verify context manager with no clients works correctly."""
+    with multiprocessing.Manager() as manager:
+      with ssh.ProxyManager(manager):
+        pass
+
+  def test_context_manager_child_cleanup(self):
+    """Verify orphaned clients & masters get cleaned up."""
+    with multiprocessing.Manager() as manager:
+      with ssh.ProxyManager(manager) as ssh_proxy:
+        client = subprocess.Popen(['sleep', '964853320'])
+        ssh_proxy.add_client(client)
+        master = subprocess.Popen(['sleep', '964853321'])
+        ssh_proxy.add_master(master)
+    # If the process still exists, these will throw timeout errors.
+    client.wait(0)
+    master.wait(0)
+
   def test_ssh_sock(self):
     """Check sock() function."""
+    manager = multiprocessing.Manager()
+    proxy = ssh.ProxyManager(manager)
     with mock.patch('tempfile.mkdtemp', return_value='/tmp/foo'):
       # old ssh version uses port
       with mock.patch('ssh.version', return_value=(6, 6)):
-        self.assertTrue(ssh.sock().endswith('%p'))
-      ssh._ssh_sock_path = None
+        self.assertTrue(proxy.sock().endswith('%p'))
+
+      proxy._sock_path = None
       # new ssh version uses hash
       with mock.patch('ssh.version', return_value=(6, 7)):
-        self.assertTrue(ssh.sock().endswith('%C'))
-      ssh._ssh_sock_path = None
+        self.assertTrue(proxy.sock().endswith('%C'))