bitbake: bb/main.py: avoid starting server when not needed

Fixed 1:
$ . ../poky/oe-init-build-env-memres .
$ bitbake -m
$ bitbake -m # shutdown it again
$ bitbake -m
Starting bitbake server...
Terminated bitbake server.

It starts the server and kill it which is redundant.

$ bitbake -m
$ bitbake --status-only
Starting bitbake server...

It starts the server which is not what we need.

(Bitbake rev: 335fd0106359dddfe1eeb0c7d0bc03f8454b895c)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/main.py

@@ -368,8 +368,10 @@ def bitbake_main(configParams, configuration):
                           configuration.debug_domains)
 
     server_connection, ui_module = setup_bitbake(configParams, configuration)
-    if server_connection is None and configParams.kill_server:
-        return 0
+    # No server connection
+    if server_connection is None:
+        if configParams.status_only or configParams.kill_server:
+            return 1
 
     if not configParams.server_only:
         if configParams.status_only:
@@ -426,6 +428,10 @@ def setup_bitbake(configParams, configuration, extrafeatures=None, setup_logging
                 topdir, lock = lockBitbake()
                 sockname = topdir + "/bitbake.sock"
                 if lock:
+                    if configParams.status_only or configParams.kill_server:
+                        logger.info("bitbake server is not running.")
+                        lock.close()
+                        return None, None
                     # we start a server with a given configuration
                     logger.info("Starting bitbake server...")
                     server = bb.server.process.BitBakeServer(lock, sockname, configuration, featureset)