bitbake: bitbake: Always use separate process for PR Service

Using the threading module interacts badly with multiprocessing used elsewhere
in bitbake under certain machine loads. This was leading to bitbake hanging on
Ctrl+C when the PR Server was being used.

This patch converts it to always use the daemonize code which
then means the threading code isn't required.

[YOCTO #3742]

(Bitbake rev: 2d0bbd9398ab839bd2d1e29e50b25d52efb1ce2a)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/server/process.py

@@ -266,5 +266,5 @@ class BitBakeServer(object):
         return self.connection
 
     def launchUI(self, uifunc, *args):
-        return bb.cooker.server_main(self.cooker, uifunc, *args)
+        return uifunc(*args)
 

bitbake/lib/prserv/serv.py

@@ -97,16 +97,7 @@ class PRServer(SimpleXMLRPCServer):
         return
 
     def start(self):
-        if self.daemon is True:
-            logger.info("PRServer: try to start daemon...")
-            self.daemonize()
-        else:
-            atexit.register(self.delpid)
-            pid = str(os.getpid()) 
-            pf = file(self.pidfile, 'w+')
-            pf.write("%s\n" % pid)
-            pf.close()
-            self.work_forever()
+        self.daemonize()
 
     def delpid(self):
         os.remove(self.pidfile)
@@ -118,6 +109,7 @@ class PRServer(SimpleXMLRPCServer):
         try:
             pid = os.fork()
             if pid > 0:
+                os.waitpid(pid, 0)
                 #parent return instead of exit to give control 
                 return
         except OSError as e:
@@ -131,7 +123,7 @@ class PRServer(SimpleXMLRPCServer):
         try:
             pid = os.fork()
             if pid > 0: #parent
-                sys.exit(0)
+                os._exit(0)
         except OSError as e:
             raise Exception("%s [%d]" % (e.strerror, e.errno))
 
@@ -155,7 +147,7 @@ class PRServer(SimpleXMLRPCServer):
         pf.close()
 
         self.work_forever()
-        sys.exit(0)
+        os._exit(0)
 
 class PRServSingleton():
     def __init__(self, dbfile, logfile, interface):
@@ -164,21 +156,14 @@ class PRServSingleton():
         self.interface = interface
         self.host = None
         self.port = None
-        self.event = threading.Event()
-
-    def _work(self):
-        self.prserv = PRServer(self.dbfile, self.logfile, self.interface, False)
-        self.host, self.port = self.prserv.getinfo()
-        self.event.set()
-        self.prserv.work_forever()
-        del self.prserv.db
 
     def start(self):
-        self.working_thread = threading.Thread(target=self._work)
-        self.working_thread.start()
+        self.prserv = PRServer(self.dbfile, self.logfile, self.interface)
+        self.prserv.start()
+        self.host, self.port = self.prserv.getinfo()
+        del self.prserv.db
 
     def getinfo(self):
-        self.event.wait()
         return (self.host, self.port)
 
 class PRServerConnection():