mitogen: Report child Python version to parent during bootstrap

Author: moreati

mitogen/core.py

@@ -170,7 +170,7 @@ def set_blocking(fd, blocking):
 
 PY24 = sys.version_info < (2, 5)
 PY3 = sys.version_info > (3,)
-if PY3:
+if sys.version_info >= (3, 0):
     import pickle
     import _thread as thread
     from io import BytesIO
@@ -237,6 +237,13 @@ def set_blocking(fd, blocking):
 #: writing small trailer chunks.
 CHUNK_SIZE = 131072
 
+#: Markers sent by bootstrap stages when it's ready to receive the next stage,
+#: e.g. compressed :class:`mitogen.core`.
+EC0 = b('MITO000')
+EC1 = b('MITO001')
+EC2 = b('MITO002 %d %d' % sys.version_info[0:2])
+EC2_PATTERN = b(r'MITO002 (\d) (\d\d?)')
+
 _tls = threading.local()
 
 
@@ -4304,7 +4311,7 @@ def main(self):
                 _v and LOG.debug('Recovered sys.executable: %r', sys.executable)
 
                 if self.config.get('send_ec2', True):
-                    self.stream.transmit_side.write(b('MITO002\n'))
+                    self.stream.transmit_side.write(EC2 + b('\n'))
                 self.broker._py24_25_compat()
                 self.log_handler.uncork()
                 self.dispatcher.run()

mitogen/fork.py

@@ -213,7 +213,7 @@ def _child_main(self, childfp):
             self.options.on_fork()
         mitogen.core.set_blocking(childfp.fileno(), True)
 
-        childfp.send(b('MITO002\n'))
+        childfp.send(mitogen.core.EC2 + b('\n'))
 
         # Expected by the ExternalContext.main().
         os.dup2(childfp.fileno(), 1)

mitogen/parent.py

@@ -1186,18 +1186,8 @@ def on_unrecognized_partial_line_received(self, line):
 
 class BootstrapProtocol(RegexProtocol):
     """
-    Respond to stdout of a child during bootstrap. Wait for :attr:`EC0_MARKER`
-    to be written by the first stage to indicate it can receive the bootstrap,
-    then await :attr:`EC1_MARKER` to indicate success, and
-    :class:`MitogenProtocol` can be enabled.
-    """
-    #: Sentinel value emitted by the first stage to indicate it is ready to
-    #: receive the compressed bootstrap. For :mod:`mitogen.ssh` this must have
-    #: length of at least `max(len('password'), len('debug1:'))`
-    EC0_MARKER = b('MITO000')
-    EC1_MARKER = b('MITO001')
-    EC2_MARKER = b('MITO002')
-
+    Respond to readiness markers sent to parent by child doing bootstrap.
+    """
     def __init__(self, broker):
         super(BootstrapProtocol, self).__init__()
         self._writer = mitogen.core.BufferedWriter(broker, self)
@@ -1213,7 +1203,11 @@ def _on_ec1_received(self, line, match):
         LOG.debug('%r: first stage received mitogen.core source', self)
 
     def _on_ec2_received(self, line, match):
-        LOG.debug('%r: new child booted successfully', self)
+        py_major, py_minor = int(match.group(1)), int(match.group(2))
+        LOG.debug(
+            '%r: new child booted successfully on Python %d.%d',
+            self, py_major, py_minor,
+        )
         self.stream.conn._complete_connection()
         return False
 
@@ -1222,9 +1216,9 @@ def on_unrecognized_line_received(self, line):
             line.decode('utf-8', 'replace'))
 
     PATTERNS = [
-        (re.compile(EC0_MARKER), _on_ec0_received),
-        (re.compile(EC1_MARKER), _on_ec1_received),
-        (re.compile(EC2_MARKER), _on_ec2_received),
+        (re.compile(mitogen.core.EC0), _on_ec0_received),
+        (re.compile(mitogen.core.EC1), _on_ec1_received),
+        (re.compile(mitogen.core.EC2_PATTERN), _on_ec2_received),
     ]
 
 

tests/first_stage_test.py

@@ -312,7 +312,7 @@ def test_valid_syntax(self):
             stdout, stderr = proc.communicate()
             self.assertEqual(0, proc.returncode)
             self.assertEqual(stdout,
-                mitogen.parent.BootstrapProtocol.EC0_MARKER+b('\n'))
+                mitogen.core.EC0 + b('\n'))
             self.assertIn(
                 b("Error -3 while decompressing data"),  # Unknown compression method
                 stderr,
@@ -356,7 +356,7 @@ def test_premature_eof(self):
             self.assertEqual(0, returncode)
             self.assertEqual(
                 proc.stdout.read(),
-                mitogen.parent.BootstrapProtocol.EC0_MARKER + b("\n"),
+                mitogen.core.EC0 + b("\n"),
             )
             self.assertIn(
                 b("Error -5 while decompressing data"),