Bug 1438679 - [mozrunner] DeviceRunner has to override returncode and wait() to check for remote process status. r=gbrown

Without returncode and wait() being overridden the default
implementation of the Runner class takes precedence and will
run the check for the adb command but not the remote process.
This always returns 0 because adb runs or forks itself as daemon.

Instead the remote process has to be checked for existence.

MozReview-Commit-ID: GvuAaMSxBT2

--HG--
extra : rebase_source : 9dc790a343d8f53bf00589c68f16e51a17d1b057

testing/mozbase/mozrunner/mozrunner/base/device.py

@@ -82,11 +82,9 @@ class DeviceRunner(BaseRunner):
         pid = BaseRunner.start(self, *args, **kwargs)
 
         timeout = 10  # seconds
-        starttime = datetime.datetime.now()
-        while datetime.datetime.now() - starttime < datetime.timedelta(seconds=timeout):
-            if self.is_running():
-                break
-            time.sleep(1)
+        end_time = datetime.datetime.now() + datetime.timedelta(seconds=timeout)
+        while not self.is_running() and datetime.datetime.now() < end_time:
+            time.sleep(.1)
         else:
             print("timed out waiting for '%s' process to start" % self.app_ctx.remote_process)
 
@@ -95,34 +93,52 @@ class DeviceRunner(BaseRunner):
         return pid
 
     def stop(self, sig=None):
-        def _wait_for_shutdown(pid, timeout=10):
-            start_time = datetime.datetime.now()
-            end_time = datetime.timedelta(seconds=timeout)
-            while datetime.datetime.now() - start_time < end_time:
-                if self.is_running() != pid:
-                    return True
-                time.sleep(1)
-            return False
+        if self.is_running():
+            timeout = 10
 
-        remote_pid = self.is_running()
-        if remote_pid:
-            self.app_ctx.dm.killProcess(
-                self.app_ctx.remote_process, sig=sig)
-            if not _wait_for_shutdown(remote_pid) and sig is not None:
+            self.app_ctx.dm.killProcess(self.app_ctx.remote_process, sig=sig)
+            if self.wait(timeout) is None and sig is not None:
                 print("timed out waiting for '%s' process to exit, trying "
                       "without signal {}".format(
                           self.app_ctx.remote_process, sig))
 
             # need to call adb stop otherwise the system will attempt to
             # restart the process
-            remote_pid = self.is_running() or remote_pid
             self.app_ctx.stop_application()
-            if not _wait_for_shutdown(remote_pid):
+            if self.wait(timeout) is None:
                 print("timed out waiting for '%s' process to exit".format(
                     self.app_ctx.remote_process))
 
-    def is_running(self):
-        return self.app_ctx.dm.processExist(self.app_ctx.remote_process)
+    @property
+    def returncode(self):
+        """The returncode of the remote process.
+
+        A value of None indicates the process is still running. Otherwise 0 is
+        returned, because there is no known way yet to retrieve the real exit code.
+        """
+        if self.app_ctx.dm.processExist(self.app_ctx.remote_process):
+            return None
+
+        return 0
+
+    def wait(self, timeout=None):
+        """Wait for the remote process to exit.
+
+        :param timeout: if not None, will return after timeout seconds.
+
+        :returns: the process return code or None if timeout was reached
+                  and the process is still running.
+        """
+        end_time = None
+        if timeout is not None:
+            end_time = datetime.datetime.now() + datetime.timedelta(seconds=timeout)
+
+        while self.is_running():
+            if end_time is not None and datetime.datetime.now() > end_time:
+                break
+            time.sleep(.1)
+
+        return self.returncode
 
     def on_output(self, line):
         match = re.findall(r"TEST-START \| ([^\s]*)", line)