terminal.py: avoid 100% cpu while waiting for phonehome pid file

Some of the less common terminal types haven't been tested with the
recent phonehome pid file changes and there may be error cases where
the pid file is never created.

(From OE-Core rev: 6b0cf568e9fbe28fb6e7b17f4ad92348d33e2bf4)

Signed-off-by: Andre McCurdy <armccurdy@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oe/terminal.py

@@ -221,6 +221,7 @@ def spawn(name, sh_cmd, title=None, env=None, d=None):
     # to a file using a "phonehome" wrapper script, then monitor the pid
     # until it exits.
     import tempfile
+    import time
     pidfile = tempfile.NamedTemporaryFile(delete = False).name
     try:
         sh_cmd = "oe-gnome-terminal-phonehome " + pidfile + " " + sh_cmd
@@ -232,13 +233,13 @@ def spawn(name, sh_cmd, title=None, env=None, d=None):
             raise ExecutionError(sh_cmd, pipe.returncode, output)
 
         while os.stat(pidfile).st_size <= 0:
+            time.sleep(0.01)
             continue
         with open(pidfile, "r") as f:
             pid = int(f.readline())
     finally:
         os.unlink(pidfile)
 
-    import time
     while True:
         try:
             os.kill(pid, 0)