Reland r210268: "Improve forwarder2 setup/tear down in telemetry."

build/android/pylib/forwarder.py

Index: build/android/pylib/forwarder.py
diff --git a/build/android/pylib/forwarder.py b/build/android/pylib/forwarder.py
index 1666004091b69f244f9a26e5b360fb23761cbb65..5bdb1cd4ce92b2598e9cff38295f19fd3950c572 100644
--- a/build/android/pylib/forwarder.py
+++ b/build/android/pylib/forwarder.py
@@ -40,6 +40,7 @@ class Forwarder(object):
     """
     assert build_type in ('Release', 'Debug')
     self._adb = adb
+    self._device_to_host_port_map = dict()
     self._host_to_device_port_map = dict()
     self._device_initialized = False
     self._host_adb_control_port = 0
@@ -89,6 +90,7 @@ class Forwarder(object):
                           'expected "device_port:host_port"') % output)
         device_port = int(tokens[0])
         host_port = int(tokens[1])
+        self._device_to_host_port_map[device_port] = host_port
         self._host_to_device_port_map[host_port] = device_port
         logging.info('Forwarding device port: %d to host port: %d.',
                      device_port, host_port)
@@ -115,24 +117,35 @@ class Forwarder(object):
       device_port: A previously forwarded port (through Run()).
     """
     with self._lock:
-      redirection_command = [
-          '--serial-id=' + self._adb.Adb().GetSerialNumber(), '--unmap',
-          str(device_port)]
-      (exit_code, output) = cmd_helper.GetCmdStatusAndOutput(
-          [self._host_forwarder_path] + redirection_command)
-      if exit_code != 0:
-        logging.error('%s exited with %d:\n%s' % (
-            self._host_forwarder_path, exit_code, '\n'.join(output)))
+      self._UnmapDevicePortInternalLocked(device_port)
+
+  def _UnmapDevicePortInternalLocked(self, device_port):
+    if not device_port in self._device_to_host_port_map:
+      return
+    redirection_command = [
+        '--serial-id=' + self._adb.Adb().GetSerialNumber(), '--unmap',
+        str(device_port)]
+    (exit_code, output) = cmd_helper.GetCmdStatusAndOutput(
+        [self._host_forwarder_path] + redirection_command)
+    if exit_code != 0:
+      logging.error('%s exited with %d:\n%s' % (
+          self._host_forwarder_path, exit_code, '\n'.join(output)))
+    host_port = self._device_to_host_port_map[device_port]
+    del self._device_to_host_port_map[device_port]
+    del self._host_to_device_port_map[host_port]
 
   @staticmethod
-  def KillHost(build_type):
+  def KillHost(build_type='Debug'):
     """Kills the forwarder process running on the host.
 
     Args:
-      build_type: 'Release' or 'Debug'
+      build_type: 'Release' or 'Debug' (default='Debug')
     """
     logging.info('Killing host_forwarder.')
     host_forwarder_path = _MakeBinaryPath(build_type, 'host_forwarder')
+    if not os.path.exists(host_forwarder_path):
+      host_forwarder_path = _MakeBinaryPath(
+          'Release' if build_type == 'Debug' else 'Debug', 'host_forwarder')
     assert os.path.exists(host_forwarder_path), 'Please build forwarder2'
     (exit_code, output) = cmd_helper.GetCmdStatusAndOutput(
         [host_forwarder_path, '--kill-server'])
@@ -173,8 +186,8 @@ class Forwarder(object):
     with self._lock:
       return self._host_to_device_port_map.get(host_port)
 
-  # Deprecated.
   def Close(self):
-    """Terminates the forwarder process."""
-    # TODO(pliard): Remove references in client code.
-    pass
+    """Releases the previously forwarded ports."""
+    with self._lock:
+      for device_port in self._device_to_host_port_map.copy():
+        self._UnmapDevicePortInternalLocked(device_port)