qemurunner: configurable timeout for run_serial()

Some commands might need to run longer than the default timeout of
five seconds. If that occurred, run_serial() returned with a status
code of zero (sic!) and no other indication of what went wrong.

Now the timeout is configurable (with five still the default) and
an explicit warning ("<<< run_serial(): command timed out after 5 seconds without output >>>")
gets appended at the end of the data returned to the caller.

While at it, the logic for checking for the timeout was updated a bit
because both implementations could overshoot the timeout when entering
select() right before the final deadline.

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 5 insertions, 3 deletions

diff --git a/meta/lib/oeqa/utils/qemutinyrunner.py b/meta/lib/oeqa/utils/qemutinyrunner.py
index ec52473834..b1009a0a37 100644
--- a/meta/lib/oeqa/utils/qemutinyrunner.py
+++ b/meta/lib/oeqa/utils/qemutinyrunner.py
@@ -107,14 +107,14 @@ class QemuTinyRunner(QemuRunner):
 
         return self.is_alive()
 
-    def run_serial(self, command):
+    def run_serial(self, command, timeout=5):
         self.server_socket.sendall(command+'\n')
         data = ''
         status = 0
         stopread = False
-        endtime = time.time()+5
+        endtime = time.time()+timeout
         while time.time()<endtime and not stopread:
-                sread, _, _ = select.select([self.server_socket],[],[],5)
+                sread, _, _ = select.select([self.server_socket],[],[],1)
                 for sock in sread:
                         answer = sock.recv(1024)
                         if answer:
@@ -124,6 +124,8 @@ class QemuTinyRunner(QemuRunner):
                                 stopread = True
         if not data:
             status = 1
+        if not stopread:
+            data += "<<< run_serial(): command timed out after %d seconds without output >>>\r\n\r\n" % timeout
         return (status, str(data))
 
     def find_child(self,parent_pid):